Note: Descriptions are shown in the official language in which they were submitted.
WO 96/01731 2 1 9 4 ~ 5 ~ .'OlS78
Title: Packaging material, packaging pad and machine for l ,."r n ;"c
packaging material
Descriytion of Invention
This invention is concerned with hlll,l u . _IllcllL~ relating to packaging
material, such as is used to protect fragile articles during tl~u~ ulL~Liun
A packaging material known from US-A-2294478 and US-A-4105724
comprises a sheet of planar material (such as paper) provided with a plurality of
transverse rows of 1~ ; n ~(1;, l ,lly-spaced slits~ with the slits of one row being offset
from the slits of the adjacent row whereby when the sheet is subjected to
Irmgit~ ir~l tension, the sheet stretches as the slits open, producing "lands" which
extend out of the plane of the sheet increasing its thickness and enabling the
material to be used for cushioning purposes. Such a material is hereinafter
referred to as being . .~ hlc material of the kind specified.
A sheet of such material may be used in a number of different ways,
but because of the resilience, when tension on the sheet is relaxed the slits tend
to close and the sheet adopts more or less its planar form. Thus it is in general
necessary for the sheet of material to be wrapped around an article to be
protected and retained thereon under tension. Difficulty is also encountered in
utilising sheet material of the kind specified as a packaging means which can beused as an infill, or which can be placed under or on or around articles to be
protected.
It is also known from US-A-3306513 to spray the expanded sheet with
a suitable liquid, which may ~,UII. Il.~,.lLIy be fire retardant, which when dried
retains the sheet expanded and allows it to be used as a ~ "~h ~"",~, material even
when laid flat. However such spraying renders the sheet stiff, and reduces the
adv~lk.gcs of a "soft" cushioning material, in addition to hllludu~ g into the
packaging material possibly undesired chemical additives.
According to this invention there is provided a packaging material
Culll,uli~illg a base sheet of "". ~ hlP ~material and a second sheet of
/ material, the second sheet being provided with a plurality of rows of
WO 96/01731 2 ~ 9 4 0 5 1 r ~ 578 ~
lnnf~it~ in~Ally-5paced slits, with the slits of one row being offset from the slits of
an adjacent row, the second sheet being secured to the base sheet whilst in
expanded condition.
By the term '.. ~ as used herein we mean u.. -~ Ahlr in
the context of use, and not in any absolute sense. In particular we mean
~jgrlifir~ntly less .oYpz~n~ than the ~ r material which is used, to
achieve the purpose for which it is used.
In its simplest form the invention may be put into practice by
procuring a sheet of . -I.A~..l-l,l~ material of the kind specified, e.g. Kraft paper
having any ~II./,U~ weight, typically of between 45 and 150gms per square
metre, provided with parallel rows of slits extending L. ~ of the sheet, the
slits in one row being offset from the slits in an adjacent row, tensioning the
paper in the lnnejtll-iin~l direction to open the slits, and securing the tensioned
paper whilst in the said condition to a sheet of Illl -lJAll ~ Kraft paper,
typically having a similar density.
The second sheet may be secured to the base sheet by any aAu~lu~liA le
means, such as by adhesive, but preferably the sheets are secured together by a
physical method which does not utilise additional ~ such as by
crimping or pressure welding.
A two-ply sheet in accordance with this invention may thus have a
thickness of about ten times the thickness of a single sheet, and stay in its
expanded state indefinitely. It may thus be used as a packing material without
special steps being taken to retain the ~Yp~n~l~bl-o material in its eAvpanded form,
and for example one or more pieces of such material may be laid down and
fragile ~w-.uu--.,,.~ be laid thereon.
Preferably the sheet material in accu.dA-I~e with the invention
comprises a plurality of plies of ~ ~I,A, l -h lr material, e.g. two, preferably three or
more plies also secured to the base sheet whilst in expanded condition. In this
malmer a significant thickness increase and impact absorption capability may be
obtained relatively ineAIJ..~:~.ly. Preferably one of the sheets of . .I.A~ hl~
W096/01731 r~l,...,; . 1~78
21 9405t
material is in a reverse . ..; .1,.1;~ ~ . In this way the raised areas in one sheet tend
to interlock within the apertures of an adjacent sheet to improve the stability of
the packaging material.
If desired a further sheet of u~ l"hl~ material may be utilised
with the rYr~n~l~hl.o material thus ~ .ed between the two sheets of
...,..1.~...l~.l~ material.
Cul~ lk,llLl~y the outer surface or surfaces of the ImrYrl~n~lqh
material may be printed so as to carry the name of the contents, mqm~fzlrtllrer~frih~tr,r, or warnings or the like.
Packaging material in acculdall~ with this invention may be wound
on a roll, from which d~lu~liàl~ lengths may be cut as desired, or may be
delivered in pre-set lengths.
According to this invention there is also provided a method of
.,.~.,.,r-. 1,.. ;.,g a packaging material involving
a) procuring a first length of sheet material;
b) procuring a second length of sheet material;
c) applying to said second length generally Llal~ .ly to tbe length
thereof a plurality of short slits, adjacent slits in the Irngit~ ir ql direction being
offset in the lateral direction, whereby when the sheet is subjected to a
Ir...~,;l".l;..,.l tension,theslitsopenaslandsbetweenadjacentslitsbecomeinclinedto the plane of the sheet; and
d) securing the second length whilst under tension to the first length.
According to this invention there is provided a machine for use in the
mqmlfq~lre of packaging material ~ c
a) first supply means to supply a first".., .1.~ sheet material;
b) second supply means to supply a second material of the kind
g a plurality of lrmgitll~lin~lly-5paced slits with the slits of one row being
off-set from the slits of the adjacent row;
c) means to bring the first and second sheets into crnti~loll~ ;.",
whilst they are being drawn from their respective supply means; and
wo 96/01731 2 1 9 4 0 5 I PcT/Gsss/ols7s
d) securing means to secure the two sheets together with the first sheet
m its expanded condition.
CUI1._IP~ LI~Y the supply means comprises mounting means for
respective rolls of r ~ and .. . 1'~ 1 1 3r materials. I~owever if desiredmounting means may be provided for rolls of ~ r material, the machine
comprises slitting means to apply slits to the sheet drawn from one of the rolls to
provide for the supply of the oY~ n~lq~l~ sheet material.
Preferably the machine comprises first wiLhJ-~ means to draw the
first material from its roll, and second wiLLdl~l hl~ means to draw the second
material from its roll, said first wiLhJ~....h~g means operating at a linear rate
which is faster than that of the second wiLlld,....;l,~, means.
Preferably the second wiLhJ~....;-~g means comprises spaced rollers,
adv ~ g~ ;ulll~l iahlg a surface which is, to some extent at least, resiliently
.1~ f"".. 1~,1,
Preferably the machine comprises an expanding means operative to
apply tension to the second material .~ to leaving the wiLhdl~. hlg
means.
Preferably the expanding means comprises spaced rollers operative to
grip the second sheet and to expand it whilst drawing it from its wiLhdl,. hlg
means. If desired, the rollers may comprise a plurality of Ir,~d;r~, e,~t~ liug
~uJe~Liu~ to enter into the slits. Such projections may be in the form of bristles
provided on the exterior of the roller. Preferably however the rollers of the
expanding means is toothed, the teeth thereof passing through the openings
provided in the material by virtue of it having been expanded, and pulling the
material away from the wiLhdl~wi-lg means at a rate faster than the wiLhdl~;llg
means is operative to pull said second material from the second supply means.
Preferably the teeth are triangular in It)ngit~lriin:~l cross-section,
preferably being prismatic in form. Preferably each ~ ul~C~,.clllial row of teeth
is spaced, and preferably the rollers are so offset that the teeth of one roller are
WO 96/01731 PCTIGB95/01578
21 940~
located in the axial direction directly opposite to a space existing between twoadjacent ~;h~u.llf~ lLial rows of teeth of the other roller.
Preferably the spacing of the rollers is such that there is little or no
diametral gap between the crowns of the teeth of the two rollers.
Preferably one roller is provided with power drive means, the other
roller being free, and being rotated by f ~f;~ l of the teeth thereof in the slits
of the ~.I.,..,.I,~hlr sheet material as the sbeet material is drawn through theexpanding means by the driven roller.
In this manner, problems of ~u~lllulli~aliOIl of the two toothed rollers
may be minimic,~,i
Thus, preferably, the expanding means is operative to feed sheet
material ILcl~,llllu~ at a rate cllbst~ntialiy similar to the rate at which the first
wilhJI~w;llg means is operative to feed the 1Ill .p~ hlr sheet material from thesupply thereof.
The two sheets may be brought into face to face contiguous
",~1,;l, j"...,~ t~ 1~ prior to entry into the nip of the expanding means, or
rly after exit of the ~ ".l hlC material from the expanding means.
Preferably the securing means is loc. ted duwl~LI~ull of the nip of the
expanding means. Preferably the securing means is operative to secure the sheetstogether along 1. . Uf ~ 1;- ~ '1 lines at least two of which are located adjacent to tbe
edge margins of the sheets.
AJv;~ gf u~ , the securing means comprises knurling means.
Preferably support means is provided to support the sheets between
the expanding means and the securing means, / . _IL~lllly afforded by su~uO~
bands of rubber or the like cl ~ material.
A lv~ er u~ , the machine comprises further supply means for the
supply of further ~ lr sheet material, and preferably further supply means
for the supply of further ~ hk sheet material, the ~,ol~LIu~,~iull and
~ .,...g~ ~ .,1 being such that the sheets of ~p~ material are fed through
the cxpanding means together, ~UIIv~ lltly in Çf~ntif~lo~ with at
_ _ _ _ , . . . ... . . _ .. . .. . .
wo96/01731 2 1 9405 1 ~ 578
Ieast one of the sheets of ,." .l.~,..1.hlr sheet material. Thus, if desired, the
sheets of ~ hlr material may be fed through the expanding means together,
with the sheets of ,~ P material being ~ d~.;.,L~d between sheets of
l.k material as they pass through the expanding rollers, but preferably
one of the sheets of, ,..~ hl~ sheet material is brought into conti~ uc
relqtionchir with the plurality of sheets of ~ l,lP material ~ h ~ to
passage thereof through the expanding means, but prior tc passage thereof
through the securing means (knurling rollers).
There will now be given a detailed description, to be read with
reference to the q ~.."l.~ hlg drawings, of a packaging material which is a
preferred ~mho-1im-~nt of this invention, having been selected for the purposes of
illustrating the invention by way of example, the method by which the packaging
material is made, and the machine upon which it is made, also being illustrativeof the invention in certain of its aspects.
In the a.,.,vl--~dllyhlg drawings:
Fgure 1 is a schematic view of the packaging material which is the
preferred ~_1ll1; odhl-e.ll of the invention, part thereof having been torn away to
expose inner layers, for the purposes of clarity;
Figure 2 is a schematic view showing a machine for use in the
mqm-fP~hlrc of the said material;
Figure 3 is a view showing the pattern of slits applied to the sheet
material as it passes between a pair of slitting rolls;
Figure 4 is a view, taken on the line 4-4 of Figure 2, showing a pair of
crimping rollers utilised in the m~n~lf~rhlre of the preferred ~, ,ho~
Figure 5 is a schematic side elevation of the machine which is the
preferred elllbodi~ ll of the invention;
Figure 6 is an enlarged view showing expanding means and securing
means of the machine;
Figure 7 is an elevation taken in the direction of the arrow A of Figure
5, showing front views of the two rollers of the expanding means; and
WO 96/01731 1-~ 01578
21 940~1
Figure 8 is an enlarged view showing the sheets of material passing
through the expanding means.
The packaging material which is a preferred ~ ~1.9~ 1 of t}us
invention comprises three plies, 4, 6 and 8 of Kraft paper, being stored on
respective supplies thereof in the form of rolls 5, 7 and 9 (Figure 2). The sheets
6 and 8 are each fed through a pair of slitting rolls 10, 12 by which a plurality of
slits 13 are applied to each sheet, the slitting rolls also ~. ,, wiLl~v~ ;ng
means for wilhdl.. hl~ the sheet materials from the supply means 7 and 9.
The slits 13 are applied to the sheets 6 and 8 generally in the pattern
illustrated in Figure 3, that is consisting of a plurality of rows of slits, the slits in
each row (X) being co-linear and being parallel to the slits of an adjacent row
(Y), each slit extending lldll~ CI,~ to the length of the sheet and each slit being
offset in the lateral direction from an adjacent slit m the L,.,~,;l...l:..~l direction.
Such sheet material, as is known in the art, when subjected to a Ir~ngit~ iT.ql
tension (in the direction A Figure 3) causes the slits to open, and the material to
expand in thickness, "lands" of the material becoming inclined to the plane of the
sheet, permitting the material to be used as a cushioning material.
On subjection to the material 6 and 8 to the slitting rolls 10, 12, the
two sheets are brought together and passed between a further pair of rollers 14,16, ~ , expanding means of the machine, which are caused to rotate
faster than the rolls 10, 12 so as to "stretch" the sheets 4 and 6, opening up the
slits as h~"t;h~L~vlc~ described. Tmm~ iqfely ~"b ~ the sheets 4 and 6 are
combined with a sheet of unslitted (i.e. .- A~ r) Kraft paper, and passed
through a pair of knurling or crimping rollers 18, 20 by which the sheets 4 and 6
are crimped along the edge regions (19~ l9k) to the sheet 8, whereby the sheet
8 retains the sheets 4 and 6 under tension, and hence in their expanded states.
C~ -lly the crimping rollers 18 and 20 constitute Willldl~..;llg
means for w;il..l..~ g sheet material from the supply S thereof.
As is shown in Figure 2, the paper is drawn from the rolls 7 and 9 in
opposite directions - that is, with the "top" face of the paper facing in opposite
. _ . . . . _ _ _ . .
WO 96/01731 PCT/GB95/01!578
2 1 9405 1
directions. In this nriPr~t~lti,-n it has been found that, on stretching of the paper,
the "lands" which are produced are inclined in opposite directions, and whilst they
tend to interlock do not tend to nest to the same extent as when the paper is fed
through in the same ,, i ~
Thus where two or more iayers are used as; .. 1: -Ir cushioning
sheets, the sheet are oriented with their top face alternately in different
directions.
The packaging material thus provided may be wound onto a roll, from
which lengths of the material may ~...I..r.~ y be cut as desired for use. Where
the packaging material is cut to length, ~,u~ this is effected by an
operation which combines ~ tinine with a transverse pressure weld, such that
the ends of the pad are sealed in the same marmer as the side edges. This
prevents a reduction in the efficacy of the pad by a relaxation of the stretching of
the inner layers, at the end regions.
It would be possible to provide a further lru ~L;~ pressure weld or
welds between the edge regions of the sheet, if desired, and for example two
relatively closely spaced such welds could be provided midway between the edges
with the sheet 5llhc~qu~nrly being cut, e.g. by a slitting knife, between such two
welds to provide two half-width sheets.
Whilst the packaging material which is the preferred ~ -l-o~l; . .1 of
this invention comprises two sheets of expansible material and one sheet of
..l-l)le material, if desired three or more sheets of ~Yp~nrl5lhl~ material
may be utilised, and if desired the ~ ",I l,lr material may be ~ld~;~hcd
between two sheets of " ~ l.lP material. Collv~ y in such
~h~ the crimping rollers 18 and ~0 provide wiLlnll,,~ ; means for both
sheets of u - .I.,...l~hl.o sheet material.
The .... -l,~ hle material, may be plain, or printed with an
,ulu~u~ e message, warning, logo, trade mark, name or the like.
The machine which is the preferred ~ l-o.li..~ .1 of this invention
comprises a housing 106 ~u, ~ at a base part thereof, mûunting means 108
WO ~6/01731 F~ .,, f/01578
~ 2 l 9405 1
including mounting members 108a, 108b, 108c and axles 109 on which rolls 110a,
110b, llOc ~ L.~ of paper-like material may be moumted.
In the use of the machine which is the preferred ~ l,o~ of this
invention, in the ~",-""r ~. c of packaging material of the kind specified, the
material mounted on the mounting members 108a, 108b and 108c is pre-slitted
material of the kind specified. Lengths 112a, 112b, 112c of the sheet material are
brought into face to face .. l~ l,;p by wilhdl~lw;llg means 116 in the form of
a pair of driven rollers 118a, 118b, the rollers having rubberised surfaces and
being operative to feed the 3-ply materiai indicated by the numeral 120 in Figure
1 towards the expanding means 122.
As will be seen in Figure 5, the sheet materials 112~, 112kand 112c
are withdrawn from the rollers llOa and 110c in the same ~lri~n~:lti~m, whilst the
sheet is withdrawn from the roller 110b in the opposite r,, ;, ..li,l ;....
The machine comprises expanding means 1~ provided by upper and
lower rollers 124a, 124b, each roller ~....l..;~".g ~h~ullLL,l~,llLi~ll rows of teeth
which are triangular in axial cross-section (as shown in Figure 6) but which arerectangular in l--n~itnriir~ql cross-section, as can be seen in Figure 7.
The c;.cu--lf~,lcuLi~l rows 126a - 126z of teeth on the upper roller 124a
are spaced apart, and the rows of teeth 127a - 127z of the lower roller 124b areoffset laterally, as seen in Figure 7, so that each row 127a is located opposite to
a gap between an adjacent pair of rows (e.g.) 126a, 126b, and vice versa.
However, the diametral distance between the crowns of the teeth of
the roller 124a and those of the roller 124b is zero, or close to zero.
The rollers of the expanding means 1~ operate at a linear rate higher
than that of the wi~ ....h-g rollers 118a, 118b so that as the three sheets of
. .l.~".l~l,lf material pass from the wiLlldlawillg rollers 118 into the expanding
rollers, the material is stretched l~mgitllriil~qliy, and the slits thereof open up to
~ produce inclined "lands" as is known in the art. The teeth 125 of the lower roller
enter into the openings produced in the lower sheets, drawing the material
through the stretching means. ~ fou~ the teeth 127 of the upper roller
, . . . .. .. . . .. .. .. .. . . . . . . . . . .
WO 96/01731 2 1 9 4 0 5 1 P~T/GB95/01578
enter into the openings produced in the upper sheets, causing the three sheets to
partially nest, as is illustrated in Figure 8. This is an effect of the reversal of the
1;,- of the ~ - ' sheet 112b. Fl~K. ~ ' of the teeth 126 within
the openings of the upper sheets causes the roller 124a to rotate, and in this way
problems of ;.rll.hlolu;.~liol. are avoided. However if desired the upper roller124_ may be driven in ~y--~h~uLu~lll with the lower roller 124b.
Alternative to the rollers being provided with teeth, the rollers may be
provided with bristles, disposed around the ~ u,,,r~ e thcreof, the ~ ntls~hl.o
material being fed between the bristles, the bristles readily passing through the
slits and through the openings provided as the lands are stretched out of the plane
of the surface of the material, the bristles having a flexibility selected such that
they will be deformed, rather than to cause the sheet material to tear. In such
cir~nnC~n~c preferably the bristles are provided on the ~;h~;ulllre.~ l surface
of the or each rûller at a relatively high density, so as to ensure that a plurality
of bristles at each time pass into the openings of the sheet material, to spread the
stretching load applied to the sheet material, to reduce tendency of the paper to
tear.
Preferably the bristles are arranged on the ci.~ul~ n~e of the or
each roller on a strip of carrier material of relatively narrow width, applied to the
~h~ullLr~ ial surface of the roller in a helical array. By spacing the two rollers
a short distance apart such that the bristles intermesh, adequate pcl.~,l.,lliu.l of
the bristles into the openings of the sheet material is ensured.
By ensuring an d~lJlu~lidle flexibility of the bristles, those bristles
which are not required to penetrate into a slit of material will be deflected into
a non-operative positiou on ,~, L.. ,.~ l with the sheet material as it passes
between the two rollers.
Thus, the bristles may be of natural bristle, such as is used in brushes,
but may of course be of a synthetic material, such as plastic or rubber.
Wound around the rollers 124a and 124b, and further rollers 130a,
13Ob le~pc~ ly, are supporting means in the form of rubber bands 132a, 132b
WO96/01731 I~ /al578
21 94051
11
which support the expanded sheet material as it passes from the expanding means,exerting some l-~ 5;m~ I constraint to prevent tbe material from ~ I ;' k to
any significant degree.
The machine which is the preferred c ho~ of this invention
comprises further mounting means 140, Culllul i~hlg supports 142_ 142b for rollers
on which respective rolls l46a, 146b of ~ p- ~ f sheet material, such as Kraft
or E~raft paper, may be mounted. Closely du...l~Ll~ u of the exit of the
~ ~l, "~ r material from the expanding means 122 is provided securing means
150, in the form of a pair of hlt~ llillg knurling rollers 152_ 1521- adapted to
crimp together side edge margins of the composite sheet material.
Lengths 148a, 148b of the "" .~,~".l~hl~ sheet material are fed
respectivelyintocf~ntif~f~llclc' ' . aboveandbelowthecompositeexpanded
material as it leaves the supporting rollers 130, and together the five sheets are
fed through the securing means 150, which operates at least at one, preferably
both edge margins of the composite sheet. Such Se~.UIC-I.~,IIL of the expanded
material to the ~ud~ llillg sheets of u ~ hlf sheet material prevents any
ngihlf~;n~l movement of the ~ material as would take place if t_e
hl~ material were to contract towards its u~- ~L - .f~f~d form. The existence
of the two sheets of ~ _hlf~ sheet material thus retains the core of
,lr material stretched, and allow it to retain its capability of effecting a
chif,..inpf functionf in its use as a cushioning material.
If desired however some retention against rontr~f~1irn may be effected
by the use of a single sheet of ~--lf ~p ~ l_hlr material alone, i.e. one of the two
rollers 142 or 144 may be omitted.
Particularly in such ~h~ f ~ the securing means 150 may be
operative ~ lI;" r~ to secure the composite sheets together at an
;1.~. " n~ l, If spaced but l,~nf~;l"~l;,l~lly eAtelldillg line.
As with the embodiment shown in Figure 2, in the preferred
e.lll,odil..~.lL the securing means constitutes means for wiLIl-ll flWillg sheet material
WO96/01731 2 1 9 40~ ~ P~ tlS78
from the rolls 146~, 136, However if desired separate wiLhdla~ t means may
be provided for one or both sheets.
Whilst in the preferred f~mho~lim~nt the supply means is provided by
mounting means for respective sheets of Fyp~ hhF (slitted) material and for
~.l.~,..l,l.lF (unslitted) material, if desired the machine may be provided withmounting rolls for the supply of ~ l 1r (unslitted) material, such as in the
form of five rolls of Kraft paper, the second supply means ~ g in addition
to the mounting means for three of the rolls, slitting means for three of the
sheets, whereby the sheets are subjected to the all~ululJlir~ slitting operation~. h ~ to be drawn from the rolls thereof, and prior to being fed through the
expanding means 122.
Whilst in the preferred ~ .3.o l; ,I both sheets 148a and 148b of
..,.. l~ ~.l~hl, material are brought into contiguous ,~ -h;l, with the
c l.~" l~hlF sheet or sheets ~..l,:.~.l . ..l to said sheets passing through theexpanding means, if desired one of said sheets may be brought into such
contiguous ,~ l, before the ~ l3r material passes through the
expanding means. In such ~ i. . l . "~ the teeth of the adjacent roller will tend
to cause the ,~ d material to become corrugated, as the material is
deformed by ~ r, c, ~-- ~l with the teeth, as the teeth pass into the openings
provided in the expanded material. Preferably however no more than one such
sheet is so brought into contiguous .~ '; ' . upstream of the expanding means
It is to be ~ c;aL~d that whilst the invention has been described
above in the context of utilising sheet material provided with slits in the form of
a regular pattern of parallel slits, uniformly offset laterally in the 1....~,;1.,.l...~l
direction, if desired other slit ~ may be utilised, including a more
randomly arranged set of slits, or slits which enable the material to be expanded
other than by the ,~ of tension solely in the l...",,jl -l;l ~l direction. For
example an array of slits may be provided which extend at an angle to the
l.,l.~jl"~l;"~l axis, allowing the slit material to be expanded by tension laterally
thereof.
WO 96/01731 P.~ .~','01578
~ 2~9~051
Additionally whilst the invention has been described in relation to the
use of a Kraft material for both ~ P and ~ hl~ sheet materials,
if desired other materials may be utilised, including ,j~,...h;.._l;n--- of differerlt
types of material.
The features disclosed in the foregoing ~ or the
a~v...,u~ drawings, expressed in their specific forms or in terms of a means
for p ~... ,. :..g the disclosed function, or a method or process for attaining the
disclosed result, or a class or group of cllh$f~nr~ or romrnC;tinn~ as ~ U~)Iidt~,
may, separately or in any romhin~ti~m of such features, be utilised for realising
the invention in diverse forms thereof.
