Note: Descriptions are shown in the official language in which they were submitted.
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The present invention is directed to an air conveyor
for gathering waste film and conveying the film ln web form to a
convenient disposal unit such as a scrap g:rinding unitO A prin-
cipal function of the air conveyor is to gather the film in man-
- 5 ageable form for delivery to the scrap grinder.
In a typical manufacturing operation for fabricating
heavy plastic film such as 7 to 15 mil Mylar (a trademark), the
plastic is extruded and drawn in web form through the fabricating
equipment to windup rolls~ During the course of manufacture,
large quantities of scrap are generated which must be disposed
of. In start-up operations, substandard film is usually formed
as the forming equipment is brought to normal operating condi-
tion. In addition, during periods of normal manufacturing opera-
tion, the film web may break occasionally causing a massivepileup of waste film on the plant floor.
There are existing air conveyors for disposing of rela-
tively thin gauge film which accumulates during a manufacturing
mishap. In such air conveyors, the film is moved and conveyed
through the action of the conveyor air ~ets. However, stiffer or
heavier film material of from 7 to 15 mils cannot be gathered or
converged into convenlent form for introductlon into a scrap
grinder. Heavy film behaves as does she~t metal, plywoPd, or 25 cardboard in that they fold only in one dimension at a time and
are not susceptible to forming compound bends without crinkling
or creasing. Because heavy film creases or crinkles, it cannot
be handled by an air conveyor of the type used for disposing of
thin gauge film.
: At present therefore, thick scrap film is handled manu-
~ ally. Substandard waste film generated during startup operations
:~ is pulled aside and accumulated until normal film forming machine
: operation is achieved. Then the waste film is disposed of manu-
ally. Should the film web rupture during machine opsration, the
film formlng e~uipment must be shut down while the scrap film is
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gathered and remov~d.
The present invention is directed to an air conveyor
for removing waste or scrap heavy fllm material such as Mylar
between approximately 7 to 1~ mils. An air conveyor according to
the present inventlon takes waste f~lm in web form and reduces
its effective width by a factor of up to 7 to 1 by forming a
transverse generally uniform sinusoidal corrugation or pleat in
$he film. In this pleated form the waste film may be introduced
into any suitabl~ scrap disposal unik such as a scrap grinder or
chipper for reprocessing.
In a preferred form, an alr conveyor according to the
invention includes an entrance section and a corrugating or
pleating for conveying and pleating waste film. The entrance
section of the conveyor comprises an air conveyor of known con-
struction including a plenum chamber and a deck plats incised
with slots arranged to issue ~ets of conveying air in the direc-
tion of conveyance. The conveyor is at least as wide as the web
of waste film in order to obtain initial control of the film.
; The corrugating or pleating section of the conveyor cooperates
with the entrance section to define a continuous conveying path
for the film. The conveyor corrugating section comprises con-
- fronting n~sted conveyor surfaces which cooperate to impart a
transverse generally sinusoidal curvature to the moving web.
That is to say, the web enters the pleating section with its
- leading edge belng in a generally straight line confiyuration and
leaves with the leading edge in a generally slnusoidal curve. ~s
a result of this transition in shape, the waste film web is
reduced in width and is in a more convenient form for introduc-
tion into a film disposal unit.
The conveyor pleating saction preferably comprises
- upper and lower portions with their conveying surfaces being in
confronting relatlon to each other and being spaced apart a gap
sufficient to acco~modate the travelling web. One of the con-
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veyor portions has a surface which develops 1nto t~o or more
troughs each increasing in depth in the direction of conveyance
as the conveyor converges toward its exit end. One or more
ridges separate ad~acent troughs so that a transverse cross-sec-
tion of the exit end of the pleater is generally sinusoidal inform.
The other portion of the conveyor pleatlng section is
similarly formed o~ troughs and ridges to give a generally sinu-
soidal transverse curve at the pleater exit end. The upper andlower portions are nested with each ridge of one lying along a
trough of the other portion of the pleating section.
The over result then is a conveyor pleater section
which receives a generally flat waste film web and reforms the
web to have a generally sinusoidal transverse curve so that as
the web moves it is reduced in overall width.
It is to be understood that the deck plate surfaces of
the trough and rldge portlons of the pleating seckion are incised
with slots for issulng conveying air ~ets for moving the film
material.
The conveyor may be provided with one or more exlt con-
veyor sections for preserving the sinusoldal form of the film asit moves to the waste disposal unit. The exlt conveyor sections
serve also to continue converging the pleated film after it
leaves the film pleating section. Preferably the exit conveyor
has confronting air conveyor sections positioned along opposite
sides of the pleated web and in converging relation to each other
~; along the path of conveyance.
After leaving the exi~ conveyor sectlon, the film is
~;~ introduced into a scrap grinder or other disposal unit.
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According to one aspect thereof the present invention
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thus provides an air conveyor for conveying plastic film web of
predetermined width and indetermlnate length comprising an
entrance section having a width at least as wide as the film
being conveyPd, said entrance section comprislng a deck plate
having slots oriented to issue air ~ets for conveylng the film
along the entrance section, a pleater section located downstream
of said entrance section, said pleater section comprising air
conveyor sections positioned over and under said film web, said
over and under sections each having W-shaped deck surfaces in
nested confronting relationship to define a gap therebetween hav-
ing a generally sinusoidal profile ext~nding transversely of the
film, each of said W-shaped deck surfaces having slots therein
for issuing conveying air ~ets ln the direction of conveyance,
means for supplying air under pressure to both the entrance and
pleater sections of the air conveyor whereby the air conveyor
reduces the width of the film by imparting a generally slnusoldal
shape thereto.
According to another aspect thereof the present inven-
tion provides an air conveyor for conveying plastic scrap filmcompr~sing an entrance section at least as wide as the film being
conv~yed, said entrance section havlng a perforated deck plate
and a plenum chamber cooperating to generate air ~ets for moving
the film along the perforated deck, means for supplying pressur-
ized air to said plenum chamber, a pleater section comprisiny
confronking air conveyor sections having deck plate surfaces
defining a generally sinusoidal gap therebetween positioned over
and under said film web for conveying and reducing the width of
- the film as it is conveyed, the deck plate surfaces being nested
W-shaped surfaces, and means for grinding the film.
Thus, the present invention provides a conveyor capable
of use in controlling and conveying waste film to a disposal
unit~
The present invention also provides an air conveyor as
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part of a film-forming installation to enable removal of waste
film generated during film forming operations.
The present invention again provides an air conveyor
for removal of heavy gauge film such as Mylar~
The present invention further provides an air conv~yor
which transforms generally flat heavy fllm into a convenient form
for disposal by imposing a generally sinusoidal transverse curva-
ture to the film as it is conveyed to a disposal unit.
A preferred embodiment of the invention has been chosenfor purposes of illustrating and describing the principles o~ the
invPntion and is shown in the accompanying drawing, in which:-
Figure 1 is a schematic side elevational view, partlyin section, showing an overall factory layout of an air conveyor
for heavy film according to the invention;
Figure 2 is a plan view of the air conveyor portion of
Figure 1 with the top pleater unit removed;
Figure 3 is a fragmentary perspective view of an air
slot incised into the air conveyor deck plate surface for issuing
conveying air ~ets;
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: Figure 4 is a sectional view taken along line 4-4 of
Figure 2 showing the incline nf a trough portion of the lower
pleater unit of the air conveyor;
Figures 5 through 8 are sectional vlews taken along
lines 5-5 through 8-8 of Figure 2, respectlvely, illustrating the
surface contour o~ the lower plea~er unit of the air conveyor;
: 35 Figure 9 is a plan view of the deck plate surface o~
the top pleater unit;
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Figures 10 through 13 are sectional views taken along
lines 10-10 through 13-13 of Figure g to illustrate the surface
contour of the top pleater unit deck surface;
Figure 14 is a sectional view taken along line 14-14 of
Figure 2 to illustrate the generally sinusoidal shape imparted
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_J heavy ~ilm by the air conveyor.
Figures 15 and 16 are perspcctive views of tlle lowexand upper portions respectively o~ t:hc pleatcr section of
the air conveyor.
Figure 17 is a section view ~aken alon~ line 17-17
of Fiyure 1 to ~how tlle generally sinusoidal contour
assumed by heavy film as it enters the film chipper.
Referring now to the drawing and in particular -to Figure
1, a heavy film air conveyor 10 of the invention is intended
primarily for use in a factory for producing heavy film 12
such as Mylar of between 7 and 15 mils ~:n thickness which
is formed and drawn over a support roll 14 to a windup
roll 16. ~ noted above, large amounts of w~ste film are
generated durincJ startup operàtions, and occasionally
during a production run when ~he Eilm web ruptures. In
practice, air conveyor 10 is posi~ioned below a suitable
opening 18 in the factory 100r 20 in order to capture
and convey waste film to a film chipper or grinder 22. `~ -
~he air conveyor may be oriented horizontally as shown, or
if deslred it may be orier,ted vertically or at an incline.
The air conveyor includes an entrance SectlQn 24
preferab1y at leask as wide as the film being conveyed. The
entrance sectlon captures the leading edge portion of the
film, carries i~ through a pleater section 26, tllrough
converging side panels ~8, 30, and into the film chipper 22.
ns the ~ilm is moved it changes shape from a flat sheet to
the generally sinusoidal transverse form shown in Figure ~7.
The conveyor entrance sec~ion comprises an air conveyor
having a per~orated deck plate 32, a plenum chamber 34 r and
and air fan or b]ower 36 for ~upplying pressurized air
throu~h a transition duct 38 to the plenum chamber. The
plenum chamber is fully enclosed and defined by side ~0, ~ottom
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92, and end walls ~, and deck pla~e 32. Tllc dccl~ platc
de~incs tllc convcy:ing sur~ace o~ tlle conveyor and is
perfora~ed with air slots ~G whicll emit jets of conveying
air indica~ed by arrows. I~acll air jet l~as a major conveying
componen~ along -the surace of the declc plate. The air
slots 46 are incised into the deck plate as shown in Figure
3 by cutting the deck plate 32 and depressing the down-
stream portion 4B of the deck plate ~o define air ~et slot 46.
~ t the outset it should be understood that the deck
plate surfaces of the entrance section 24, the pleater
section 26, and the side panels 28, 30 all have surEaces
perfoxated with a~ir slots o~ the configuration shown in
~igure 3,
Waste film 12 generated durincJ fi.lm forming operal:ions
moves through floor open.lng 1~ and i5 cap tured by the
entrance sec-tion 24 o~ the air conveyor. ~ccording to the
invention, -the film is converged throuyh the pleater
section 26 and side panels 28, 30 of the conveyor and is
reduced in width for feeding into the film chipper 22.
The pleated section 26 of the air conveyor prefera~ly
comprises upper SO and lower 52 portions which cooperate
to transform the film from a relatively flat condition
in which the leading edge approximates a strai~ht line
~in edge view) to a generally sinusoidal condi~ion in
which the film leading edge talces on the wave form sho~in
in Figure 17. This change ln form reduccs the film width
~nd facilitates int.roduction of the fi].m into the filn~
chipper 22.
The lower unit 52 of the pleater has a generally
"W"-shaped cross-section wit~l ~he "W"-shape developing
in depth and convergance in tlle conveyin~.direction in
manner illus~ratcd in rigures s-n. Tllat is to say, the
~ower pl~atcr unit 52 includes m~rgin~l ridges 54 following
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th~ allgle o~ convercJoncc o tlle plcated section and a ccntral ridgc
5G convcrging in the direction oE conveyancc. ~acll o tlle mar~inal
and central ridges arc coplanar wi~ll the declc p]a~c surface o~ tlle
entrance section o~ the convey~r. Tlle marginal and c~ntral ridges
are separatcd by intervening trouglls 58 which,also convcrge in the
conveying direction. In addition, eacll trough is inclincd in the
conveying dir~ction as shown in Fiyure 4.
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~ djacent ridges 54, 56 and trouyhs 58 are soparated by wedge-
shaped gusse~s ~0 which become wider in the direction of conveyance
,so as to connect contiguous ridge and trougll surfaces.
The surfaces of ridge, gusset and trough define an activo
conveying surface 51 per~orated with air slots,46 for issuing air
jets in tlle direction o~ conveyance. If desired the marginal
ridges may have air jets oriented to issue air jets in khe di:c~ction
eonvergence. The overall effect o~ air jets in the pleater section
is to move the film in the conveying direction so that it assumes
a "W"-shape or generally sinusoidal transverse shape for convenient
entry into the ilm chipper. , - ,~
~ s best shown ln Figures 1 and 9 through 16, the pleater
section includes an upper unit 50 having an active air conveyor sur- -
face 53 formed wlth ridges 62 and trough 64 arranged to nest with
the active surface of the lower pleater unit in fo~mlng a "W" shaped
gap 66 (Figure 14) for pleating -the film 12. The upper unit includes
a plenum chamber 55 supplied with pressurized air in tho same manner
as the lower unit 52. ~s sl-own in Figures 9-13, tl~e upper active
surface inc]udes marginal ridges 61, converging rid~es 62 and
~rough 64 whicll converge in the manner illustrated in Figurcs 10-13
and 16. Gussets 68 join adjacent ridge and trough surfaces of ~he
upper active surface 53. The entire active surface 53 ls incised
with a,ir slots ~G substantially in tht~ same manner as the active sur-
face o the lower unit.
The upper 50 and lower 52 units o~ e pleatcr are shown in
Figllres 15 and 16. I~ will appear that tlle plcator UllitS S0 n1ltl 52
converge in the direction of convoyance and llave active ridge
and trough surEnccs or uleating ~ilm. Tho uppcr and lower pleater
uni~s nest to dc~ine~ a cJencral]y uniEorm (J;l~ or crr~atinCl
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tne fi.lm. The entirc dock plate surfaces of the upper and
lower pleatcr units are pcrforated with air slots 46~or
issuing air jets to convey and converge the film ;.n a
~: ~onerally sinusoidal curve.
As is preerred, a pair of side panels 28,30 lie
ln confronting converging relation along the li.ne of
conveyance between tllc pleater 26 and the chippcr 22 to
further squeeze the ilm 12. ~ach side panel inclades
a plenum chan~er 70 and a perforated dec]c plate 72. Each
. plenum chamber is supplied with pressurized air by means
of an air blower 7~ through a tr~nsition cluct 76. L~ach
deck p].ate is incised with air slots 4G as shown in
Figure 3 Eor issuing air jets alon~ the cleclc pl.a~e surface.
The side panels continue squeeziny or convergincJ the sin-
usoidal sh~pe film after it emerges from khe pleater section
and as it approaches the chipper.
It is to be understood that the heavy film air conveyor
;~ of the invention may be oriented horizontally, vertically or
~ at any intermediate incline. The air conveyor may be used
; with or witllout the upper pleater unit.
In one use of the invention, 14 mil film was conver~ed
by a ratlo of approxima-~ely 5 to 1 omi-tting the upper pleater
unit ~nd with 2" ~1.G. air pressure in the entrance and pleater
sections and with 3 W.G. in the side panels.
In another use including the upper pleater unit with
. a gap o~ 6 inches bet~een pleater units, a convcrgence x~tio
. of 7 to 1 was obtained for 14 mil film using the same plenum
air pressures as the earlier example.
In ~ach case the air velocity issuing from the air jets
is much l~igher tllan film spe~ed so tha~ ~he air conve~or exerts
sufficient pull on tlle Eilm to avoid film jamming tlle conveyor
d~lring us~.
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