Note: Claims are shown in the official language in which they were submitted.
-26-
CLAIMS:
1. A machine for providing a draw tape in a plastic web, the plastic
web having top and bottom layers, the top layer having a first main body
portion, a first top layer edge portion, and first top layer free edge, the
bottom layer having a second main body portion, second bottom layer edge
portion, and second bottom layer free edge; the first and second edge
portions of the top and bottom layers respectively being folded onto
respective first and second main body portions of the top and bottom layers,
to form respective first top layer and second bottom layer hems, with
respective first top layer and second bottom layer draw tapes being
incorporated into the hems, the first and second edge portions being sealed
to the respective main body portions to form first top layer and second
bottom layer sealed hems, with the first top layer and second bottom layer
draw tapes in the respective sealed hems, said machine comprising:
(a) hole forming apparatus forming holes, at spaced locations in the
web, in the edge portions adjacent respective first and second free
edges of the web;
(b) tape unwind apparatus following the hole forming apparatus for
feeding first and second draw tapes into proximity with, and
aligned with, the first and second edge portions;
(c) hem forming apparatus adjacent the tape unwind apparatus for
separating first and second edge regions of the top and bottom
layers from each other, for traverse along parallel but spaced first
and second paths while holding the main body portions of the top
- 27 -
and bottom layers in surface-to-surface contact with each other,
the first and second edge regions including the respective first and
second edge portions and the respective first and second free
edges, said hem forming apparatus for receiving the first and
second draw tapes, and for forming the first and second hems and
incorporating the draw tapes therein; and
(d) hem sealing apparatus downstream from the hem forming
apparatus for sealing the first and second edge portions to the
respective first and second main body portions of the respective
layers, thus sealing the hems and securing the respective draw
tapes therein.
2. The machine as in claim 1, said hem forming apparatus including
first and second hem folding plows having hem folding edges, and a
separating plow adjacent said first hem folding plow, said separating plow
separating the second edge region of the bottom layer from the
corresponding first edge region of the top layer, the separated first and
second edge regions, at corresponding points along the first and second
paths, lying in surfaces intersecting each other along an imaginary line
having a component extending in the direction of travel of the web.
3. The machine as in claim 2, including a separating notch formed by
cooperating elements of said first hem folding plow and said separating
plow, automatically initiating separation of the edge region of the bottom
layer from the edge region of the top layer when the first and second edge
regions traverse transversely across said separating notch.
- 28 -
4. The machine as in claim 2, said hem folding plows having hem
folding edges extending at transverse angles to the direction of travel of the
web.
5. The machine as in claim 4, said hem forming apparatus including
first and second hem forming plows receiving folded edge portions of the
web from said hem folding edges, and folding the folded edge portions back
onto the respective main body portions forming the respective hems.
6. The machine as in claim 1, said hem forming apparatus being
disposed downstream in the processing sequence from said hole forming
apparatus, whereby the edge regions are separated after leaving said hole
forming apparatus.
7. The machine as in claim 1, said hem forming apparatus forming the
first and second hems about the first and second draw tapes.
8. The machine as in claim 1, said hem forming apparatus including
first and second hem folding plows having first and second hem folding
edges extending at first and second transverse angles to the direction of
travel of the web and folding the first and second edge portions of the web,
and first and second hem forming plows having first and second hem
forming edges extending at third and fourth transverse angles to the
direction of travel of the web and receiving the first and second folded edge
portions from said hem folding edges, and folding the folded edge portions
back onto the main body portions, thus forming the first and second hems.
9. The machine as in claim 8, each said hem folding plow having an
aperture therein, the respective draw tape advancing through the respective
- 29 -
aperture in said hem folding plow for forming of the respective hem about
the tape.
10. The machine as in claim 9, the respective draw tapes advancing
between each said hem folding plow and the respective layers.
11. The machine as in claim 8, said first and second hem folding
edges comprising trailing edges of said hem folding plows, said first and
second hem forming edges comprising leading edges of said hem forming
plows.
12. The machine as in claim 8, and wherein each said draw tape
advances over the respective said hem folding plow in contact with the
respective layer of web material in parallel with the folding of the edge
portion of the respective layer by the respective said hem folding plow.
13. The machine as in claim 1, said hem forming apparatus including a
separating plow separating the second edge region of the bottom layer from
the corresponding first edge region of the top layer.
14. The machine as in claim 1, including at least one turning member
downstream of said hem forming apparatus, assisting in returning the edge
regions into face-to-face relationship with each other.
15. The machine as in claim 14, said at least one turning member
comprising an upstanding turning cone.
16. The machine as in claim 1, including a turning member
downstream of said hem forming apparatus, turning portions of the top and
- 30 -
bottom layers, and air lubrication between said turning member and the
bottom layer.
17. A machine for providing a draw tape in a plastic web, the plastic
web having top and bottom layers, the top layer having a first main body
portion, a first top layer edge portion, and first top layer free edge, the
bottom layer having a second main body portion, second bottom layer edge
portion, and second bottom layer free edge; the first top and second bottom
edge portions of the top and bottom layers respectively being folded onto
respective first and second main body portions of the top and bottom layers,
to form respective first top layer and second bottom layer hems, with
respective first top layer and second bottom layer draw tapes being
incorporated into the hems, the first and second edge portions being sealed
to the respective main body portions to form first top layer and second
bottom layer sealed hems, with the first top layer and second bottom layer
draw tapes in the respective sealed hems, said machine comprising:
(a) hole forming apparatus for folding the first and second edge
portions nested together back onto one of the top and bottom main
body portions and forming holes therein, at spaced locations
adjacent respective first and second free edges of the web, then
unfolding the first and second edge portions;
(b) tape unwind apparatus following the hole forming apparatus for
feeding draw tape material into proximity with, and aligned with,
the first and second edge portions;
(c) hem forming apparatus following the tape unwind apparatus for
receiving the draw tape material as first and second draw tapes,
- 31 -
and for receiving the unfolded edge portions of the web, with holes
therein, re-folding the first top and second bottom edge portions,
toward each other and onto first and second ones of the main body
portions of the respective layers, and incorporating the draw tapes
into the hems, thus forming the first and second hems and
incorporating the draw tapes inside; and
(d) hem sealing apparatus downstream from the hem forming
apparatus for sealing the first and second edge portions to the
respective first and second main body portions, thus sealing the
hems and securing the respective draw tapes therein.
18. The machine as in claim 17, said hole forming apparatus receiving
the web with the top layer in overlying contact with the bottom layer, and
folding the first and second edge portions with the first edge portion of the
top layer nested inside the second edge portion of the bottom layer.
19. The machine as in claim 17, said hem forming apparatus forming
the first and second hems about the first and second draw tapes.
20. The machine as in claim 17, said hem forming apparatus including
first and second hem folding plows having first and second hem folding
edges extending at first and second transverse angles to the direction of
travel of the web and folding the first and second edge portions of the web,
and first and second hem forming plows having first and second hem
forming edges extending at third and fourth transverse angles to the
direction of travel of the web and receiving the first and second folded edge
portions from said hem folding edges, and folding the folded edge portions
- 32 -
back onto the respective first and second main body portions, thus forming
the first and second hems.
21. The machine as in claim 20, each said hem folding plow having an
aperture therein, the respective draw tape advancing through the respective
aperture in said hem folding plow for forming of the respective hem about
the tape.
22. The machine as in claim 21, the respective draw tapes advancing
between each said hem folding plow and the respective layers.
23. The machine as in claim 20, said first and second hem folding
edges comprising trailing edges of said hem folding plows, said first and
second hem forming edges comprising leading edges of said hem forming
plows.
24. The machine as in claim 20 wherein each said draw tape
advances over the respective said hem folding plow in contact with the
respective layer of web material in parallel with the folding of the edge
portion of the respective layer by the respective said hem folding plow.
25. The machine as in claim 17, said top and bottom layers
comprising first and second edge regions respectively, said hem forming
apparatus including a separating plow separating the second edge region of
the bottom layer from the corresponding first edge region of the top layer.
26. The machine as in claim 17, including at least one turning member
downstream of said hem forming apparatus, assisting in returning the edge
regions into face-to-face relationship with each other.
- 33 -
27. A machine for providing a draw tape in a plastic web, the plastic
web having top and bottom layers, the top layer having a first main body
portion, a first top layer edge portion, and first top layer free edge, the
bottom layer having a second main body portion, second bottom layer edge
portion, and second bottom layer free edge; the first and second edge
portions of the top and bottom layers respectively being folded onto
respective first and second main body portions of the top and bottom layers,
to form respective first top layer and second bottom layer hems, with
respective first top layer and second bottom layer draw tapes being
incorporated into the hems, the first and second edge portions being sealed
to the respective main body portions to form first top layer and second
bottom layer sealed hems, with the first and second draw tapes in the
respective sealed hems, said machine comprising:
(a) hole forming apparatus for forming holes, at spaced locations in the
first and second edge portions adjacent respective first and second
free edges of the web;
(b) tape unwind apparatus adjacent the hole forming apparatus for
feeding draw tape material into proximity with the first and second
edge portions; and
(c) hem forming and sealing apparatus following the tape unwind
apparatus for receiving the draw tape material as first and second
draw tapes, and for forming the first and second hems,
incorporating the draw tapes into the hems, and sealing the first
and second edge portions to the respective first and second main
body portions of the respective layers using respective first and
- 34 -
second hem sealing elements, thus sealing the hems and securing
the respective draw tapes therein, said hem forming and sealing
apparatus including first and second stretching rollers applying
transverse stretching forces to the respective layers at the first and
second hems, with the draw tapes therein, upstream of the
respective first and second hem sealing elements, while holding the
main body portions of the top and bottom layers in surface-to-
surface contact with each other.
28. The machine as in claim 27, said hem forming and sealing
apparatus being disposed downstream in the processing sequence from said
hole forming apparatus.
29. The machine as in claim 27, said hem forming apparatus forming
the first and second hems about the first and second draw tapes.
30. The machine as in claim 27, said hem forming and sealing
apparatus including first and second hem folding plows having first and
second hem folding edges extending at first and second transverse angles to
the direction of travel of the web and folding the first and second edge
portions of the web, and first and second hem forming plows having first
and second hem forming edges extending at third and fourth transverse
angles to the direction of travel of the web and receiving the first and
second
folded edge portions from said hem folding edges, and folding the folded
edge portions back onto the respective first and second main body portions,
thus forming the first and second hems.
31. The machine as in claim 30, each said hem folding plow having an
aperture therein, the respective draw tape advancing through the respective
- 35 -
aperture in said hem folding plow for forming of the respective hem about
the tape.
32. The machine as in claim 27, and wherein each said draw tape
advances over the respective said hem folding plow in contact with the
respective layer of web material in parallel with the folding of the edge
portion of the respective layer by the respective said hem folding plow.
33. The machine as in claim 27, said hem forming and sealing
apparatus including a separating plow separating the second edge region of
the bottom layer from the corresponding first edge region of the top layer.
34. A machine for providing a draw tape in a plastic web, the plastic
web having top and bottom layers, the top layer having a first main body
portion, a first top layer edge portion, and first top layer free edge, the
second bottom layer having a second main body portion, second bottom
layer edge portion, and second bottom layer free edge; the first and second
edge portions of the top and bottom layers respectively being folded onto
respective first and second main body portions of the top and bottom layers,
to form respective first top layer and second bottom layer hems, with
respective first top layer and second bottom layer draw tapes being
incorporated into the hems, the first and second edge portions being sealed
to the respective main body portions to form first top layer and second
bottom layer sealed hems, with the first and second draw tapes in the
respective sealed hems, said machine comprising:
(a) hole forming apparatus for forming holes, at spaced locations in the
edge portions adjacent respective first and second free edges of
the web;
- 36 -
(b) tape unwind apparatus downstream from the hole forming
apparatus for feeding draw tape material into proximity with the
first and second edge portions;
(c) hem forming and sealing apparatus, adjacent the hole forming
apparatus for separating one of first and second edge regions of
the top and bottom layers from the other of the first and second
edge regions, turning the plane of the second edge region through
a dihedral angle of at least 30 degrees with respect to the plane of
the first edge region while holding the main body portions of the
top and bottom layers in surface-to-surface contact with each
other, receiving the draw tape material as first and second draw
tapes at the respective edge regions, forming the first and second
hems and incorporating the draw tape material into the hems, said
hem sealing apparatus sealing the first and second edge portions to
the respective first and second main body portions of the
respective layers, thus sealing the hems and securing the draw
tapes in the respective sealed hems while the first and second edge
regions are separated; and
(d) a turning member comprising an upstanding turning cone disposed
downstream of said hem forming and sealing apparatus, for
assisting in returning the separated one of the edge regions into
face-to-face relationship with the other of the edge regions.
35. The machine as in claim 34, separating the first and second edge
regions at an angle of from 30 degrees to about 160 degrees.
- 37 -
36. The machine as in claim 34, including a second turning member
downstream of said turning cone, the returning of the separated one of the
edge regions into face-to-face relationship with the other of the edge regions
being effected first by said turning cone.
37. The machine as in claim 34, said hem forming and sealing
apparatus maintaining the other of the first and second edge regions as a
generally straight line extension of the main body portion of the respective
layer.
38. A machine for providing a draw tape in a plastic web, the plastic
web having top and bottom layers, the top layer having a first main body
portion, a first top layer edge portion, and first top layer free edge, the
bottom layer having a second main body portion, second bottom layer edge
portion, and second bottom layer free edge; the first and second edge
portions of the top and bottom layers respectively being folded onto
respective first and second main body portions of the top and bottom layers,
to form respective first top layer and second bottom layer hems, with
respective first top layer and second bottom layer draw tapes being
incorporated into the hems, the first and second edge portions being sealed
to the respective main body portions to form first top layer and second
bottom layer sealed hems, with the first and second draw tapes in the
respective sealed hems, said machine comprising:
(a) hole forming apparatus forming holes, at spaced locations in the
edge portions adjacent respective first and second free edges of
the web;
- 38 -
(b) a plow downstream from the hole forming apparatus for separating
the first and second edge portions and turning the plane of the
bottom edge portion through a dihedral angle with respect to the
plane of the top edge portion,
(c) tape unwind apparatus following the separating plow for feeding
first and second draw tapes into proximity with the first and
second separated edge portions; and
(d) hem forming and sealing apparatus following the tape unwind
apparatus for receiving the draw tapes, forming the first and
second hems, incorporating the draw tapes in the hems, and
sealing the first and second separated edge portions to the
respective first and second main body portions of the respective
layers using respective first and second hem sealing elements, thus
sealing the first and second hems and securing the respective draw
tapes therein, said hem forming and sealing apparatus including an
electrostatic pinning device pinning a formed hem, with draw tape
therein, to an underlying support, and thereby controlling
transverse positioning of the formed hem with respect to said
machine as the hem traverses from the hem forming to the hem
sealing apparatus.
39. The machine as in claim 38, said top and bottom layers
comprising first and second edge regions respectively, said hem forming and
sealing apparatus including a separating plow separating the second edge
region of the bottom layer from the corresponding first edge region of the
top layer.
- 39 -
40. A machine for providing a draw tape in a plastic web, the plastic
web having top and bottom layers, the top layer having a first main body
portion, and a first top layer edge portion, the bottom layer having a second
main body portion, and second bottom layer edge portion; the first top layer
and second bottom layer edge portions of the top and bottom layers
respectively being folded onto respective first and second main body
portions of the top and bottom layers, to form respective first and second
hems, with respective first top layer and second bottom layer draw tapes
being incorporated into the hems, the first and second edge portions being
sealed to the respective main body portions to form first and second sealed
hems, with the first top layer and second bottom layer draw tapes in the
respective sealed hems, said machine comprising:
(a) tape unwind apparatus for feeding draw tape material into
proximity with the first and second edge portions;
(b) hem forming apparatus following the tape unwind apparatus for
receiving the draw tape material as first top and second bottom
draw tapes, and for forming the first top layer and second bottom
layer hems and incorporating the draw tape material into the hems;
(c) hem sealing apparatus for sealing the first top layer and second
bottom layer edge portions to the respective first and second main
body portions of the respective layers, thus sealing the hems and
securing the respective draw tapes therein; and
(d) hole forming apparatus disposed up-stream in said machine from
said hem forming apparatus, said hole forming apparatus
comprising:
- 40 -
(i) in-turn and back-fold plows for receiving the first top and
second bottom edge portions of the web in a flat disposition
and folding the first top layer and second bottom layer edge
portions nested together back onto one of the first and
second main body portions of the web, and
(ii) a cutter for forming holes, at spaced locations in the nested
top and bottom layer edge portions adjacent respective first
top and second bottom free edges of the web before said
hem forming apparatus forms the first and second hems.
41. The machine as in claim 40, said hem forming apparatus forming
the first and second hems about the first and second draw tapes.
42. The machine as in claim 40, said hem forming apparatus including
first and second hem folding plows having first and second hem folding
edges extending at first and second transverse angles to the direction of
travel of the web and folding the first and second edge portions of the web,
and first and second hem forming plows having first and second hem
forming edges extending at third and fourth transverse angles to the
direction of travel of the web and receiving the first and second folded edge
portions from said hem folding edges, and folding the folded edge portions
back onto the respective first and second main body portions, thus forming
the first and second hems.
43. The machine as in claim 42, each said hem folding plow having an
aperture therein, the respective draw tape advancing through the respective
- 41 -
aperture in said hem folding plow for forming of the respective hem about
the tape.
44. The machine as in claim 43, the respective draw tapes advancing
between each said hem folding plow and the respective layers.
45. The machine as in claim 42, said first and second hem folding
edges comprising trailing edges of said hem folding plows, said first and
second hem forming edges comprising leading edges of said hem forming
plows.
46. The machine as in claim 42, and wherein each said draw tape
advances aver the respective said hem folding plow in contact with the
respective layer of web material in parallel with the folding of the edge
portion of the respective layer by the respective said hem folding plow.
47. A machine for providing a draw tape in a plastic web, the plastic
web having top and bottom layers, the top layer having a first main body
portion, and a first top layer edge portion, the bottom layer having a second
main body portion, and second bottom layer edge portion; the first and
second edge portions of the top and bottom layers respectively being folded
onto respective first and second main body portions of the top and bottom
layers, to form respective first top layer and second bottom layer hems, with
respective first top layer and second bottom layer draw tapes being
incorporated into the hems, the first and second edge portions being sealed
to the respective main body portions to form first and second sealed hems,
with the first and second draw tapes in the respective sealed hems, said
machine comprising:
- 42 -
(a) hole forming apparatus, comprising:
(i) plows for receiving the first and second edge portions of the
web in a flat disposition and folding the first and second
edge portions nested together back onto one of the first and
second main body portions of the web,
(ii) a cutter for forming holes, at spaced locations in the nested
top and bottom layer edge portions adjacent respective first
and second free edges of the web; and
(iii) a plow for returning said nested first and second edge
portions to the flat disposition;
(b) tape unwind apparatus downstream from the hole forming
apparatus for feeding first and second draw tapes into proximity
with, and aligned with, the first and second edge portions;
(c) hem forming apparatus adjacent the tape unwind apparatus for
receiving the first and second draw tapes and folding the first and
second edge portions about respective ones of the first and second
draw tapes and onto respective first and second main body
portions of the respective layers, thus forming the first and second
hems about the draw tapes, with the draw tapes inside; and
(d) hem sealing apparatus following the hem forming apparatus for
sealing the first and second edge portions to the respective first
and second main body portions, thus sealing the hems and
securing the respective draw tapes therein.
- 43 -
48. The machine as in claim 47, said hem forming apparatus including
first and second hem folding plows having first and second hem folding
edges extending at first and second transverse angles to the direction of
travel of the web and folding the first and second edge portions of the web,
and first and second hem forming plows having first and second hem
forming edges extending at third and fourth transverse angles to the
direction of travel of the web and receiving the first and second folded edge
portions from said hem folding edges, and folding the folded edge portions
back onto the respective first and second main body portions, thus forming
the first and second hems.
49. The machine as in claim 48, each said hem folding plow having an
aperture therein, the respective draw tape advancing through the respective
aperture in said hem folding plow for forming of the respective hem about
the tape.
50. The machine as in claim 49, the respective draw tapes advancing
between each said hem folding plow and the respective layers.
51. The machine as in claim 48, said first and second hem folding
edges comprising trailing edges of said hem folding plows, said first and
second hem forming edges comprising leading edges of said hem forming
plows.
52. The machine as in claim 48, each said draw tape advances over
the respective said hem folding plow in contact with the respective layer of
web material in parallel with the folding of the edge portion of the
respective
layer by the respective said hem folding plow.
-44-
53. The machine as in claim 47, said top and bottom layers
comprising first and second edge regions respectively, said hem forming
apparatus including a separating plow separating the second edge region of
the bottom layer from the corresponding first edge region of the top layer.
54. The machine as in claim 47, said hem forming apparatus being
disposed downstream in the processing sequence from said hole forming
apparatus.
55. A machine for providing a draw tape in a plastic web, the plastic
web having top and bottom layers, the top layer having a first top layer main
body portion, a first top layer edge portion and a first top layer free edge,
the
bottom layer having a second bottom layer main body portion, a second
bottom layer edge portion, and second bottom layer free edge; the first top
and second bottom edge portions respectively of the top and bottom layers
respectively being folded onto respective first top and second bottom main
body portions of the top and bottom layers, to form respective first top layer
and second bottom layer hems, with respective first top layer and second
bottom layer draw tapes being incorporated into the hems, the first and
second edge portions being sealed to the respective main body portions to
form first top layer and second bottom layer sealed hems, with the first and
second draw tapes in the respective seated hems, the machine comprising:
(a) hole forming apparatus for forming holes at spaced locations in the
web, in the edge portions adjacent respective first top and second
bottom free edges of the web, said hole forming apparatus
including:
-45-
(i) an in-turn plow for receiving the first and second edge
portions of the web in a flat disposition and turning the first
and second edge portions nested inwardly toward the main
body portions of the web,
(ii) a back-fold plow following the in-turn plow for receiving the
in-turned edge portions of the web and folding the nested
edge portions back onto one of the first and second main
body portions of the web, the back-fold plow having a
notch,
(iii) a hole cutter located adjacent the notch in said back-fold
plow for cutting holes in the web as the web traverses the
notch, and
(iv) an out-turning plow following the hole cutter for receiving
the first and second edge portions from the back-fold plow
and restoring the first and second edge portions to a flat
condition;
(b) tape unwind apparatus adjacent the hole forming apparatus for
feeding draw tape material into proximity with the first and second
edges;
(c) hem forming apparatus disposed downstream in the processing
sequence from the hole forming apparatus for receiving the draw
tape material as first and second draw tapes, and forming the first
and second hems; and
-46-
(d) hem sealing apparatus adjacent the hem forming apparatus for
sealing the first and second edge portions to the respective web
layers, thus sealing the hems and securing the respective draw
tapes therein.
56. The machine as in claim 55, said in-turn plow receiving the web
with the top layer in overlying contact with the bottom layer, and folding the
first and second edge portions with the first edge portion of the top layer
nested inside the second edge portion of the bottom layer.
57. The machine as in claim 55, said hem forming apparatus forming
the first and second hems about the first and second draw tapes.
58. The machine as in claim 55, said hem forming apparatus including
first and second hem folding plows having first and second hem folding
edges extending at first and second transverse angles to the direction of
travel of the web and folding the first and second edge portions of the web,
and first and second hem forming plows having first and second hem
forming edges extending at third and fourth transverse angles to the
direction of travel of the web and receiving the first and second folded edge
portions from said hem folding edges, and folding the folded edge portions
back onto the respective first and second main body portions, thus forming
the first and second hems.
59. The machine as in claim 58, each said hem folding plow having an
aperture therein, the respective draw tape advancing through the respective
aperture in said hem folding plow for forming of the respective hem about
the tape.
-47-
60. The machine as in claim 59, the respective draw tapes advancing
between each said hem folding plow and the respective layers.
61. The machine as in claim 58, said first and second hem folding
edges comprising trailing edges of said hem folding plows, said first and
second hem forming edges comprising leading edges of said hem forming
plows.
62. The machine as in claim 61 wherein said hem folding plows and
said hem forming plows each have web contact surfaces for contacting
respective edge regions of the respective top and bottom layers of said web,
said web contact surfaces on said first hem forming plow and said first hem
folding plow being disposed at an obtuse dihedral angle with respect to each
other, and said web contact surfaces on said second hem forming plow and
said second hem folding plow being disposed at an obtuse dihedral angle
with respect to each other.
63. The machine as in claim 58 wherein each said draw tape
advances over the respective said hem folding plow in contact with the
respective layer of web material in parallel with the folding of the edge
portion of the respective layer by the respective said hem folding plow.
64. The machine as in claim 55, said in-turn plow having an outer
edge disposed at an angle with respect to a free edge of the web, extending
inwardly across the web along the direction of travel of the web, and aligned
with a first inner edge of said back-fold plow, said first inner edge of said
back-fold plow being disposed at an angle with respect to an edge of the
web approximately equal to the angle formed by the outer edge of the in-
turn plow with respect to an edge of the web, said back-fold plow having a
-48-
second inner edge, intersecting said first inner edge and being disposed at an
angle with respect to a free edge of the web, approximately equal to the
angle formed by the outer edge of the in-turn plow with respect to a free
edge of the web, but advancing outwardly across the web along the
direction of advance of the web, said out-turning plow having an outer edge
aligned with said second inner edge of said back-fold plow, respective loci on
said outer edges on said in-turn plow and said out-turning plow being aligned
with each other along a transverse dimension of the web.
65. The machine as in claim 64, said back-fold plow having an outer
edge extending in the direction of travel of said web, having a notch in said
outer edge, and a hole cutter adjacent the notch in said outer edge of the
back-fold plow for cutting spaced holes in the folded edge portions of the
top and bottom layers of the web as the folded edge portions traverse the
notch.
66. The machine as in claim 55, said in-turn plow, said back-fold
plow, and said out-turning plow having respective first, second, and third
web guiding surfaces guiding the web adjacent said edge portions, said first
and third web guiding surfaces being disposed at obtuse angles with respect
to said second web guiding surface.
67. The machine as in claim 66, said first and third web guiding
surfaces defining substantially equal and opposite angles from said second
web guiding surface.
68. The machine as in claim 55, said top and bottom layers
comprising first and second edge regions respectively, said hem forming
-49-
apparatus including a separating plow separating the second edge region of
the bottom layer from the corresponding first edge region of the top layer.
69. The machine as in claim 55, including at least one turning member
downstream of said hem forming apparatus, assisting in returning the edge
regions into face-to-face relationship with each other.
70. The machine as in claim 69, said at least one turning member
comprising an upstanding turning cone.
71. The machine as in claim 70, including a second turning member
downstream of said turning cone, returning the separated one of the edge
regions into face-to-face relationship with the other of the edge regions
being
effected by said turning cone.
72. A method of providing a draw tape in a plastic web, the plastic
web being folded longitudinally along the length thereof to form top and
bottom layers of the plastic web, first and second edge portions of the top
and bottom layers respectively being folded onto respective first and second
main body portions of the top and bottom layers, to form respective first and
second hems, with respective first and second draw tapes in the hems, the
first and second edge portions being sealed to the respective main body
portions to form first and second sealed hems with the first and second draw
tapes therein, the method comprising the steps of:
(a) forming holes at spaced locations in the edge portions adjacent
first and second free edges of the web by (i) receiving the first and
second edge portions of the web in a flat disposition and turning
the first and second edge portions inwardly toward the main body
-50-
portions of the web, with one of the first and second edge portions
nested in the other of the first and second edge portions, (ii)
folding the edge portions back onto the main body portion of the
nested one of the first and second edge portions, and (iii) forming
holes in the first and second edge portions at loci adjacent but
spaced from free edges of the respective layers;
(b) feeding draw tape material into proximity with the first and second
edge portions;
(c) receiving the draw tape material as first and second draw tapes
and forming the first and second hems and incorporating the first
and second draw tapes into the hems; and
(d) seating the first and second edge portions to the respective first
and second main body portions of the respective layers to form the
first and second sealed hems, and thus sealing the hems and
securing the respective draw tapes therein.
73. A method as in claim 72, including unfolding the edge portions
with the holes therein and restoring the first and second edge portions to a
flat condition.
74. A method as in claim 73, including re-folding the first and second
edge portions at respective first and second hem folding plows and
advancing the respective draw tapes over the respective hem folding plows
in contact with the respective layers of web material in parallel with the
folding of the respective edge portions by the respective hem folding plows.
-51-
75. A method as in claim 74, each hem folding plow having an
aperture therein, the method including advancing the draw tapes through the
apertures in the respective hem folding plows.
76. A method as in claim 74, each hem folding plow having an
aperture therein, the method including advancing the draw tapes through the
apertures in the respective hem folding plows and into contact with the
respective top and bottom layers, with the draw tapes disposed between the
hem folding plows and the respective layers of the web.
77. A method as in claim 76, including advancing the respective layer
and draw tape together across a leading edge of a hem forming plow and
thus folding a free edge of the respective layer under the respective draw
tape to form the respective hem, with the draw tape contained therein.
78. A method as in claim 73, forming of the first and second hems
including folding the unfolded first and second edge portions onto respective
first and second ones of the main body portions of the respective layers.
79. A method as in claim 73, including re-folding the first and second
edge portions onto the first and second ones of the main body portions of
the respective layers, and forming the first and second hems, wit h the first
and second draw tapes therein, and sealing the first and second free edges
of the respective edge portions to the main bodies of the top and bottom
layers respectively, with the draw tapes therein.
80. A method as in claim 79, the re-folding comprising folding
respective edge portions about the respective first and second draw tapes.
-52-
81. A method as in claim 81, including, prior to re-folding the first and
second edge portions, separating first and second edge regions, including the
respective first and second edge portions, of the top and bottom layers from
each other, white holding the remainders of the top and bottom layers in
surface-to-surface contact with each other.
82. A method as in claim 81, including returning the separated one of
the edge regions into face-to-face relationship with the other of the edge
regions after seating the first and second hems.
83. A method as in claim 81, including returning the separated one of
the edge regions into face-to-face relationship with the other of the edge
regions, over an upstanding turning cone, after sealing the first and second
hems.
84. A method as in claim 79, the re-folding comprising folding each
respective edge portion about a trailing edge of a hem folding plow and
receiving the folded edge portion and forming the hem therefrom by passing
the folded edge over a leading edge of a hem forming plow.
85. A method as in claim 72, including forming the first and second
hems downstream of forming the holes in the edge portions.
86. A method as in claim 72, including re-folding the first and second
edge portions about first and second hem folding plows and separating first
and second edge regions of the top and bottom layers, including the
respective edge portions, at a separating plow for traverse along parallel but
spaced first and second paths, the first hem folding plow and the separating
plow, in combination, comprising a separating notch formed by cooperating
-53-
elements thereof, the method including traversing the second edge portion of
the bottom layer transversely across the separating notch and thereby
initiating separation of the second edge regions from the first edge region.
87. A method as in claim 86, including traversing the second edge
portion across the separating notch while the bottom layer is under tension.
88. A method as in claim 86, including traversing the second edge
portion transversely across the separating notch while the first edge portion
extends across the notch and thereby initiating separation of the first and
second edge regions.
89. A method as in claim 84, including returning the separated one of
the edge regions into face-to-face relationship with the other of the edge
regions, over an upstanding turning cone, after sealing the first and second
hems.
90. A method as in claim 72, including controlling the temperature of
the web at the formed hems before sealing the edge portions to the
respective main body portions in forming the hem seals.
91. A method of providing a draw tape in a plastic web, the plastic
web being folded longitudinally along the length thereof to form top and
bottom layers of the plastic web, first and second edge portions of the top
and bottom layers respectively being folded onto respective first and second
main body portions of the top and bottom layers, to form respective first and
second hems, with respective first and second draw tapes in the hems, the
first and second edge portions being sealed to the respective main body
-54-
portions to form first and second sealed hems with the first and second draw
tapes therein, the method comprising the steps of:
(a) feeding draw tape material into proximity with the first and second
edge portions;
(b) receiving the draw tape material as first and second draw tapes
and forming the first and second hems and incorporating the first
and second draw tapes into the hems;
(c) sealing the first and second edge portions to the respective first
and second main body portions of the respective layers, thus
sealing the hems and securing the respective draw tapes therein;
and
(d) prior to forming the hems and receiving the draw tapes, the step of
forming holes at spaced locations in the edge portions adjacent
first and second free edges of the web.
92. A method as in claim 91, the step of forming holes including
receiving the first and second edge portions of the web in a flat disposition
and turning the first and second edge portions toward the main body
portions of the web, (ii) folding the edge portions back onto at least one of
the main body portions, (iii) forming holes in the first and second edge
portions at loci adjacent but spaced from the free edges thereof, and (iv)
unfolding the edge portions with the holes therein and restoring the first and
second edge portions to flat disposition.
-55-
93. A method as in claim 91, the method including forming the first
and second hems about the first and second draw tapes.
94. A method as in claim 91, the step of forming the holes including
folding the first and second edge portions back onto at least one main body
portion and, after forming the holes, unfolding the first and second edge
portions prior to forming the hems.
95. A method as in claim 94, including re-folding the first and second
edge portions onto the first and second ones of the main body portions of
the respective layers, and forming the first and second hems, with first and
second draw tapes therein, and sealing the first and second free edges of the
respective edge portions to the main bodies of the top and bottom layers
respectively, with the draw tapes therein.
96. A method as in claim 95, including, prior to re-folding the first and
second edge portions, separating first and second edge regions, including the
respective first and second edge portions, of the top and bottom layers from
each other, while holding the remainders of the widths of the top and
bottom layers in surface-to-surface contact with each other.
97. A method as in claim 96, including returning the separated one of
the edge regions into face-to-face relationship with the other of the edge
regions, after sealing the first and second hems.
98. A method as in claim 95, the re-folding comprising folding each
respective edge portion about a trailing edge of a hem folding plow and
receiving the folded edge portion and forming the hem therefrom by passing
the folded edge over a leading edge of a hem forming plow.
-56-
99. A method as in claim 94, the re-folding comprising folding
respective edge portions about the respective first and second draw tapes.
100. A method as in claim 94, including refolding the first and second
edge portions at respective first and second hem folding plows and
advancing the respective draw tapes over the respective said hem folding
plows in contact with the respective layers of web material in parallel with
the folding of the respective edge portions by the respective hem folding
plows.
101. A method as in claim 100, each hem folding plow having an
aperture therein, the method including advancing the draw tapes through the
apertures in the respective hem folding plows.
102. A method as in claim 100, each hem folding plow having an
aperture therein, the method including advancing the draw tapes through the
apertures in the respective hem folding plows and into contact with the
respective top and bottom layers, with the draw tapes disposed between the
hem folding plows and the respective layers of the web.
103. A method as in claim 102, including advancing the respective
layer and draw tape together across a leading edge of a hem forming plow
and thus folding a free edge of the respective layer under the respective
draw tape to form the respective hem, with the draw tape contained therein.
104. A method as in claim 94, including re-folding the first and second
edge portions about first and second hem folding plows and separating first
and second edge regions of the top and bottom layers, including the
-57-
respective edge portions, at a separating plow for traverse along parallel but
spaced first and second paths, the first hem folding plow and the separating
plow, in combination, comprising a separating notch formed by cooperating
elements thereof, the method including traversing the second edge portion of
the bottom layer transversely across the separating notch and thereby
initiating separation of the second edge region from the first edge region.
105. A method as in claim 104, including traversing the second edge
portion transversely across the separating notch while the first edge portion
extends across the notch and thereby initiating separation of the first and
second edge regions.
106. A method as in claim 104, including returning the separated one
of the edge regions into face-to-face relationship with the other of the edge
regions, over an upstanding turning cone, after sealing the first and second
hems.
107. A method as in claim 91, forming of the first and second hems
including folding the unfolded first and second edge portions onto respective
first and second ones of the main body portions of the respective layers.
108. A method as in claim 91, including controlling the temperature of
the web at the formed hems before sealing the edge portions to the
respective main body portions in forming the hem seals.
109. A method of providing a draw tape in a plastic web, the plastic
web being folded longitudinally along the length thereof to form top and
bottom layers of the plastic web, first and second edge portions of the top
and bottom layers respectively being folded onto respective first and second
-58-
main body portions of the top and bottom layers, to form respective first and
second hems, with respective first and second draw tapes in the hems, the
first and second edge portions being sealed to the respective main body
portions to form first and second sealed hems with the first and second draw
tapes therein, the method comprising the steps of:
(a) forming holes, at spaced locations in the web, in the edge portions
adjacent respective first and second free edges of the web;
(b) feeding first and second draw tapes into proximity with, and
aligned with, the first and second edge portions;
(c) receiving the draw tapes and folding the first and second edge
portions about respective ones of the first and second draw tapes
and onto respective first and second ones of the main body
portions of the respective layers thus forming the first and second
hems about the draw tapes, with the draw tapes inside; and
(d) sealing the first and second edge portions to the respective first
and second main body portions of the respective layers to form the
first and second sealed hems, and thus sealing the hems and
securing the respective draw tapes therein.
110. A method as in claim 109, forming of the first and second hems
including folding the unfolded first and second edge portions onto respective
first and second ones of the main body portions of the respective layers.
111. A method as in claim 109, including, prior to folding the first and
second edge portions, separating first and second edge regions, including the
-59-
respective first and second edge portions, of the top and bottom layers from
each other, while holding the remainders of the widths of the top and
bottom layers in surface-to-surface contact with each other.
112. A method as in claim 111, including returning the separated one
of the edge regions into face-to-face relationship with the other of the edge
regions after sealing the first and second hems.
113. A method as in claim 109, including forming the first and second
hems downstream of forming the holes in the edge portions.
114. A method as in claim 109, the folding comprising folding each
respective edge portion about a trailing edge of a hem folding plow and
receiving the folded edge portion and forming the hem therefrom by passing
the folded edge over a leading edge of a hem forming plow.
115. A method as in claim 109, including folding the first and second
edge portions at respective first and second hem folding plows and
advancing the respective draw tapes over the respective said hem folding
plows in contact with the respective layers of web material in parallel with
the folding of the respective edge portions by the respective hem folding
plows.
116. A method as in claim 109, each hem folding plow having an
aperture therein, the method including advancing the draw tapes through the
apertures in the respective hem folding plows.
117. A method as in claim 109, each hem folding plow having an
aperture therein, the method including advancing the draw tapes through the
-60-
apertures in the respective hem folding plows and into contact with the
respective top and bottom layers, with the draw tapes disposed between the
hem folding plows and the respective layers of the web material.
118. A method as in claim 109, including advancing the respective
layer and draw tape together across a leading edge of a hem forming plow
and thus folding a free edge of the respective layer under the respective
draw tape to form the respective hem, with the draw tape contained therein.
119. A method as in claim 109, including re-folding the first and
second edge portions about first and second hem folding plows and
separating first and second edge regions of the top and bottom layers,
including the respective edge portions, at a separating plow for traverse
along parallel but spaced first and second paths, the first hem folding plow
and the separating plow, in combination, comprising a separating notch
formed by cooperating elements thereof, the method including traversing the
second edge portion of the bottom layer transversely across the separating
notch and thereby initiating separation of the second edge region from the
first edge region.
120. A method as in claim 119, including returning the separated one
of the edge regions into face-to-face relationship with the other of the edge
regions, over an upstanding turning cone, after sealing the first and second
hems.
121. A method as in claim 109, including traversing the second edge
portion across the separating notch while the bottom layer is under tension.
-61-
122. A method as in claim 109, including traversing the second edge
portion transversely across the separating notch white the first edge portion
extends across the notch and thereby initiating separation of the first and
second edge regions.
123. A method of providing a draw tape in a plastic web, the plastic
web being folded longitudinally along the length thereof to form top and
bottom layers of the plastic web, first and second edge portions of the top
and bottom layers respectively being folded onto respective first and second
main body portions of the top and bottom layers, to form respective first and
second hems, with respective first and second draw tapes in the hems, the
first and second edge portions being sealed to the respective main body
portions to form first and second sealed hems with the first and second draw
tapes therein, the method comprising the steps of:
(a) forming holes, at spaced locations in the edge portions adjacent
respective first and second free edges of the web, including folding
the edge portions back onto the main body portion of at least one
of the layers, forming the holes while the edge portions are folded,
and subsequently unfolding the edge portions;
(b) feeding first and second draw tapes into proximity with, and
aligned with, the first and second edge portions;
(c) receiving the draw tapes and the unfolded edge portions of the
web with holes therein, at a hem forming station, re-folding the
first and second edge portions, toward each other and onto first
and second ones of the main body portions of the respective
layers, and incorporating the draw tapes into the hems, thus
-62-
forming the first and second hems and incorporating the draw
tapes inside; and
(d) sealing the first and second edge portions to the respective first
and second main body portions, thus sealing the hems and
securing the respective draw tapes therein.
124. A method as in claim 123, the re-folding comprising folding
respective edge portions about the respective first and second draw tapes.
125. A method as in claim 123, including, prior to re-folding the first
and second edge portions, separating first and second edge regions,
including the respective first and second edge portions, of the to p and
bottom layers from each other, while holding the remainders of the widths of
the top and bottom layers in surface-to-surface contact with each other.
126. A method as in claim 125, including returning the separated one
of the edge regions into face-to-face relationship with the other of the edge
regions after sealing the first and second hems.
127. A method as in claim 123, the re-folding comprising folding each
respective edge portion about a trailing edge of a hem folding plow and
receiving the folded edge portion and forming the hem therefrom by passing
the folded edge over a leading edge of a hem forming plow.
128. A method as in claim 123, including re-folding the first and
second edge portions at respective first and second hem folding plows and
advancing the respective draw tapes over the respective said hem folding
plows in contact with the respective layers of web material in parallel with
-63-
the folding of the respective edge portions by the respective hem folding
plows.
129. A method as in claim 128, each hem folding plow having an
aperture therein, the method including advancing the draw tapes through the
apertures in the respective hem folding plows.
130. A method as in claim 128, each hem folding plow having an
aperture therein, the method including advancing the draw tapes through the
apertures in the respective hem folding plows and into contact with the
respective top and bottom layers, with the draw tapes disposed between the
hem folding plows and the respective layers of the web.
131. A method as in claim 130, including advancing the respective
layer and draw tape together across a leading edge of a hem forming plow
and thus folding a free edge of the respective layer under the respective
draw tape to form the respective hem, with the draw tape contained therein.
132. A method as in claim 123, including re-folding the first and
second edge portions about first and second hem folding plows and
separating first and second edge regions of the top and bottom layers,
including the respective edge portions, at a separating plow for traverse
along parallel but spaced first and second paths, the first hem folding plow
and the separating plow, in combination, comprising a separating notch
formed by cooperating elements thereof, the method including traversing the
second edge portion of the bottom layer transversely across the separating
notch and thereby initiating separation of the second edge region from the
first edge region.
-64-
133. A method as in claim 132, including traversing the second edge
portion transversely across the separating notch while the first edge portion
extends across the notch and thereby initiating separation of the first and
second edge regions.
134. A method as in claim 123, including controlling the temperature
of the web at the formed hems before sealing the edge portions to the
respective main body portions in forming the hem seals.
135. A method of providing a draw tape in a plastic web, the plastic
web being folded longitudinally along the length thereof to form top and
bottom layers of the plastic web, first and second edge portions of the top
and bottom layers respectively being folded onto respective first and second
main body portions of the top and bottom layers, to form respective first and
second hems, with respective first and second draw tapes in the hems, the
first and second edge portions being sealed to the respective main body
portions to form first and second sealed hems with the first and second draw
tapes therein, the method comprising the steps of;
(a) forming holes, at spaced locations in the edge portions adjacent
respective first and second free edges of the web;
(b) feeding draw tape material into proximity with the first and second
edge portions;
(c) receiving the draw tape material as first and second draw tapes
and forming the first and second hems and incorporating the draw
tape material into the hems; and
-65-
(d) sealing the first and second edge portions to the respective first
and second main body portions of the respective layers by applying
seal-forming heat from heat seal apparatus to the web, thus sealing
the hems and securing the respective draw tapes therein, and
cooling the temperature of the web at the formed hems to a
predictable controlled temperature before applying the seal-forming
heat to the web, thus to present the formed hems, at the
controlled temperature, to the heat seal apparatus.
136. A method as in claim 135, including controlling the temperature
of the web downstream of, and adjacent, the sealing of the first and second
edge portions to the main body portions of the respective layers.
137. A method of providing a draw tape in a plastic web, the plastic
web being folded longitudinally along the length thereof to form top and
bottom layers of the plastic web, first and second edge portions of the top
and bottom layers respectively being folded onto respective first and second
main body portions of the top and bottom layers, to form respective first and
second hems, with respective first and second draw tapes in the hems, the
first and second edge portions being sealed to the respective main body
portions to form first and second sealed hems with the first and second draw
tapes therein, the method comprising the steps of:
(a) forming holes, at spaced locations in the web, in the edge portions
adjacent respective first and second free edges of the web;
(b) feeding first and second draw tapes into proximity with, and
aligned with, the first and second edge portions;
-66-
(c) separating first and second edge regions of the top and bottom
layers from each other for traverse along parallel but spaced first
and second paths while holding the remainders of the widths of the
top and bottom layers in surface-to-surface contact with each
other, the first and second edge regions including the respective
first and second edge portions and the respective first and second
free edges, the hem forming apparatus receiving the first and
second draw tapes;
(d) folding the first and second edge portions onto respective first and
second ones of the main body portions in the edge regions of the
respective layers and, thus forming the first and second hems and
incorporating the draw tapes into the hems; and
(e) sealing the first and second edge portions to the respective first
and second main body portions of the respective layers, thus
sealing the hems and securing the respective draw tapes therein.
138. A method as in claim 137, including forming the holes upstream
in the method from the separating of the edge regions.
139. A method as in claim 137, the folding comprising folding each
respective edge portion about a trailing edge of a hem folding plow and
receiving the folded edge portion and forming the hem therefrom by passing
the folded edge over a leading edge of a hem forming plow.
140. A method as in claim 137, including folding the first and second
edge portions at respective first and second hem folding plows and
advancing the respective draw tapes over the respective said hem folding
-67-
plows in contact with the respective layers of web material in parallel with
the folding of the respective edge portions by the respective hem folding
plows.
141. A method as in claim 140, each hem folding plow having an
aperture therein, the method including advancing the draw tapes through the
apertures in the respective hem folding plows.
142. A method as in claim 140, each hem folding plow having an
aperture therein, the method including advancing the draw tapes through the
apertures in the respective hem folding prows and into contact with the
respective top and bottom layers, with the draw tapes disposed between the
hem folding plows and the respective layers of the web.
143. A method as in claim 142, including advancing the respective
layer and draw tape together across a leading edge of a hem forming plow
and thus folding a free edge of the respective layer under the respective
draw tape to form the respective hem, with the draw tape contained therein.
144. A method as in claim 137, including re-folding the first and
second edge portions about first and second hem folding plows and
separating first and second edge regions of the top and bottom layers,
including the respective edge portions, at a separating plow for traverse
along parallel but spaced first and second paths, the first hem folding plow
and the separating plow, in combination, comprising a separating notch
formed by cooperating elements thereof the method including traversing the
second edge portion of the bottom layer transversely across the separating
notch and thereby initiating separation of the second edge region from the
first edge region.
-68-
145. A method as in claim 144, including traversing the second edge
portion across the separating notch while the bottom layer is under tension.
146. A method as in claim 144, including traversing the second edge
portion transversely across the separating notch while the second edge
portion extend across the notch and thereby initiating separation of the first
and second edge regions.
147. A method as in claim 137, including returning the separated one
of the edge regions into face-to-face relationship with the other of the edge
regions after sealing the first and second hems.
148. A method as in claim 137, including returning the separated one
of the edge regions into face-to-face relationship with the other of the edge
regions, over an upstanding turning cone, after sealing the first and second
hems.
149. A method as in claim 137, including turning portions of the top
and bottom layers about a turning member downstream of the hem forming
apparatus, including air lubrication between the turning member and the
respective portion of the bottom layer.
150. Method as in claim 137, the separating of the first and second
edge regions comprising separating one of first and second edge regions
from the other of the first and second edge regions at an angle of about 30
degrees to about 160 degrees.
-69-
151. A method of providing a draw tape in a plastic web, the plastic
web being folded longitudinally along the length thereof to form top and
bottom layers of the plastic web, first and second edge portions of the top
and bottom layers respectively being folded onto respective first and second
main body portions of the top and bottom layers, to form respective first and
second hems, with respective first and second draw tapes in the hems, the
first and second edge portions being sealed to the respective main body
portions to form first and second sealed hems with the first and second draw
tapes therein, the method comprising the steps of:
(a) forming holes, at spaced locations in the web, in the edge portions
adjacent respective first and second free edges of the web;
(b) feeding draw tape material into proximity with the first and second
edge portions; and
(c) forming and sealing hems in the web by receiving the draw tape
material as first and second draw tapes, folding the first and
second edge portions onto respective first and second ones of the
main body portions of the respective layers, thus forming the first
and second hems with the draw tapes in the hems, and sealing the
first and second edge portions to the respective first and second
main body portions of the respective layers using respective first
and second hem sealing elements, thus sealing the hems and
securing the respective draw tapes therein, and
applying transverse stretching forces to the web at the first and second
hems, with the draw tapes therein, upstream of the respective first and
second sealing elements.
-70-
152. A method as in claim 151, the folding comprising folding
respective edge portions about the respective first and second draw tapes.
153. A method as in claim 151, including, prior to folding the first and
second edge portions, separating first and second edge regions, including the
respective first and second edge portions, of the top and bottom layers from
each other, while holding the remainders of the widths of the top and
bottom layers in surface-to-surface contact with each other.
154. A method as in claim 151, including forming the first and second
hems downstream of forming the holes in the edge portions.
155. A method as in claim 151, including electrostatic pinning the first
and second formed hems to respective first and second underlying supports,
and thereby controlling transverse positioning of the respective layers to the
equipment downstream of the electrostatic pinning step and upstream and
adjacent the hem sealing step.
156. A method as in claim 151, the first and second underlying
supports extending under the respective hem sealing element, and
supporting the hems while the hems are being sealed.
157. A method as in claim 151, including applying force on the web
directed against an underlying support having a surface generally parallel to
the surface of the web.
158. A method of providing a draw tape in a plastic web, the plastic
web being folded longitudinally along the length thereof to form top and
bottom layers of the plastic web, first and second edge portions of the top
-71-
and bottom layers respectively being folded onto respective first and second
main body portions of the top and bottom layers, to form respective first and
second hems, with respective first and second draw tapes in the hems, the
first and second edge portions being sealed to the respective main body
portions to form first and second sealed hems with the first and second draw
tapes therein, the method comprising the steps of:
(a) forming holes, at spaced locations in the web, in the edge portions
adjacent respective first and second free edges of the web;
(b) feeding first and second draw tapes into proximity with the first
and second edge portions; and
(c) forming and sealing hems in the web by receiving the draw tapes,
folding the first and second edge portions onto respective first and
second ones of the main body portions of the respective layers,
thus forming the first and second hems, and incorporating the draw
tapes in the hems, and sealing the first and second edge portions
to the respective first and second main body portions of the
respective layers using respective first and second hem sealing
elements, thus sealing the first and second hems and securing the
respective draw tapes therein,
including electrostatic pinning of the formed hems, with draw tapes therein,
to underlying supports, and thereby controlling transverse positioning of the
hems with respect to said equipment while the hem seals are being formed.
159. A method as in claim 158, the folding comprising folding
respective edge portions about the respective first and second draw tapes.
-72-
160. A method as in claim 158, including, prior to folding the first and
second edge portions, separating first and second edge regions, including the
respective first and second edge portions, of the top and bottom layers from
each other, while holding the remainders of the widths of the top and
bottom layers in surface-to-surface contact with each other.
161 . A method as in claim 158, including folding the first and second
edge portions at respective first and second hem folding plows and
advancing the respective draw tapes over the respective said hem folding
plows in contact with the respective layers of web material in parallel with
the folding of the respective edge portions by the respective hem folding
plows.
162. A method as in claim 158, including applying transverse
stretching forces to the layers with stretching devices at the first and
second
hems, with the draw tapes therein, prior to forming the hem seals, the
underlying supports extending from the respective stretching devices to the
respective hem sealing elements, thereby supporting the hems from the time
the layers are stretched until the hems are sealed.
163. A method as in claim 162, including supporting the hems with
supports at the seal loci while the hems are being sealed.
164. A method as in claim 158, the underlying support comprising a
support bar, and a driven belt between the support bar and the respective
hem, supporting the respective hem, and moving with the hem thereon, from
the electrostatic pinning device to the respective hem sealing element.
-73-
165. A method of providing a draw tape in a plastic web, the plastic
web being folded longitudinally along the length thereof to form top and
bottom layers of the plastic web, first and second edge portions of the top
and bottom layers respectively being folded onto respective first and second
main body portions of the top and bottom layers, to form respective first and
second hems, with respective first and second draw tapes in the hems, the
first and second edge portions being sealed to the respective main body
portions to form first and second sealed hems with the first and second draw
tapes therein, the method comprising the steps of:
(a) forming holes, at spaced locations in the web, in the edge portions
adjacent respective first and second free edges of the web;
(b) separating one of first and second edge regions of the top and
bottom layers from the other of the first and second edge regions
at an angle of at least 30 degrees while holding the remainders of
the widths of the top and bottom layers in surface-to-surface
contact with each other and maintaining the other of the first and
second edge regions as a generally straight line extension of the
remainder of the width of the respective layer;
(c) feeding draw tape material into proximity with the first and second
edge portions;
(d) forming and sealing hems in the web at the separated first and
second edge regions, by receiving the draw tape material at the
respective edge portions, folding the first and second edge portions
onto respective first and second ones of the main body portions of
the respective layers, thus forming the first and second hems, and
-74-
incorporating the draw tape material in the hems, and sealing the
first and second edge portions to the respective first and second
main body portions of the respective layers, thus sealing the hems
and securing the respective draw tapes in the respective sealed
hems while the first and second edge regions are so separated; and
(e) returning the separated one of the edge regions into face-to-face
relationship with the other of the edge regions over an upstanding
turning cone disposed downstream of the hem sealing step.
166. A method as in claim 165, including separating the first and
second edge regions at an angle of from 30 degrees to about 160 degrees.
167. A method as in claim 165, the method including returning the
separated one of the edge regions into face-to-face relationship with the
other of the edge regions over an upstanding turning cone and under a
second turning member, downstream of the turning cone.
168. A method as in claim 165, the method including maintaining the
other of the first and second edge regions as a generally straight line
extension of the remainder of the width of the respective layer.
169. A method of providing a draw tape in a plastic web, the plastic
web being folded longitudinally along the length thereof to form top and
bottom layers of the plastic web, first and second edge portions of the top
and bottom layers respectively being folded onto respective first and second
main body portions of the top and bottom layers, to form respective first and
second hems, with respective first and second draw tapes in the hems, the
first and second edge portions being sealed to the respective main body
-75-
portions to form first and second sealed hems with the first and second draw
tapes therein, the method comprising the steps of:
(a) forming holes, at spaced locations in the edge portions adjacent
respective first and second free edges of the web;
(b) feeding draw tape material into proximity with the first and second
edge portions;
(c) receiving the draw tape material as first and second draw tapes
and forming the first and second hems and incorporating the draw
tape material into the hems; and
(d) sealing the first and second edge portions to the respective first
and second main body portions of the respective layers by applying
seal-forming heat from heat seal apparatus to the web, thus sealing
the hems and securing the respective draw tapes therein, and
projecting liquid onto the web such that the web has a predictable
controlled temperature before applying the seal-forming heat to the
web, thus to present the formed hems, at the controlled
temperature, to the heat seal apparatus.
170. A method as in claim 169 wherein the projecting liquid
comprises water.
171. A method as in claim 169 wherein the projected liquid cools the
web.