Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TEAR RESISTANT DISPOSABLE BIB
FIELD OF THE INVENTION
0The present invention is related to disposable bibs, and more particularly, to a bib
that resists tearing.
BACKGROUND OF THE INVENTION
Disposable bibs are well known in the art. Such bibs can be provided for use on,for P~r~mrlto., babies being fed. Disposable bibs can have a l~min~te construction
con,p,;~;ng ml-hirle layers. For h.slal1ce, disposable bibs can include an abso.l,~".l
paper topsheet for receiving spilled food material and a plastic film barl~chP,et for
preventing penetration of spilled liquids through the bib and onto the baby's clothing.
The art also discloses bibs having three layers, such as a layer of thermoplastic
material between two layers of paper. Other bib designs shown in the art include bibs
having a multi-layer construction, inc~ linE a gauze decorative layer, as well as bibs
having a front panel formed from plastic film to have grooves and apertures for
cal~ and holding food. The art also teaches that it is known to cover a paper bib
with an open net or retirlll~ted material so that the paper is held together.
The following ~ercir~nces illustrate various bib constructions: U.S. Patent
3,286,279 issued Apr~ 1, 1964 to Brown; U.S. Patent 3,329,969 issued July 15, 196
to Farber et al.; U.S. Patent 3,608,092 issued S~lelllbel 28, 1971 to Taranto; U.S.
Patent 3,979,776 issued Sepl~ln~er 14, 1976 to G~uenwald; U.S. Patent 4,416,025
issued November 22, 1983 to Moret et al.; U.S. Patent 4,441,212 issued to Ahr; U.S.
Patent 4,445,231 issued May 1, 1984 to Noel; and U.S. Patent 4,884,299 issued
D~c~...h~r~,1989 to Rose.
One ploblell. with known disposable bibs having a paper and plastic layer
construction is that babies can tear off pieces of the bib. Tearing of the bib is
ul~de~il b'e bec~ ce it reduces effective coverage ofthe baby's clothes, and also creates
3s added pieces of waste requiring disposal.
Allc.n~ling to prevent tearing of the bib by design of the plastic film forming the
waLel~roof ba~ h~et alone, is generally not saticf~ctQry. Such plastic films generally
have an i"helenl tradeoff of ~l~englh and flc,~il)ilily. For PYamrle, s~ nger polymers
tend to be less flexible while sllellglh gained by increased llficL ~eCc also cGr.-y.o,.lises
40 flexibility.
Alternatively, adding a protective layer to the bacLj ~a~ lll facing surface of the
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bib does not provide the desired support to the paper topsheet. Adding a protective
layer on the outer front surface of the bib does not provide support to the plastic
b~c~hPet can affect the aesthetics of the outer front surface of the bib, and also can
hllel~èle with absorption of liquid spills on the outer front surface of the bib.
Accordingly, it is an object of the present invention to provide a disposable bib
0 which resists tearing without detrimPnt~liy i,l.pai~ing either absorption, aesthetics, or
flexibility of the bib.
Another object of the present invention is to provide a disposable bib having a
multi-layer construction.
Yet another object of the present invention is to provide a disposable bib having a
lS polymeric net layer disposed between and joined to a paper topsheet layer and a plastic
film b~.chP~et layer.
Yet another object of the present invention is to provide a disposable bib having a
rei~rcing network having openings sized to prevent tearing of the bib while
l)ellllilling abso.l"ion of liquid spills on an outer layer ofthe bib.
Yet another object of the present invention is to provide a disposabie bib having
an abso-l,èlll paper top~l.eel, a plastic film b~cl~chPet and a leh~rc;n~ middle layer
com~.is;,lg a polymeric net, ~L~;ICIQ the le;l~l~ing layer has a greater tensile strength
than at least one of the topsl.eet or the b~cl~chPet layers to carry pulling loads exerted
by the wearer, and whel e;n the opelull~s in the net are sized to prevent the wearer from
2s tearing off discrete pieces of the topsheet.
SUMMARY OF THE INVENTION
The present invention provides a flicpo~hle bib having a co.--posile
consl~,~.;lion. In one lelllbo~lhn~ n~ the bib can have a abso,l~nt, liquid ~. ,..t~hle
30 outer ~opsl.~l; a g~..-ent facing b~cL-cheet layer, the b~f~hP~t layer being liquid
i,..l~.~....o~hlP relative to the top~l.et;l, and a load carrying fil~ .f.~ network
os~Pd interrn~ tç the b~f L chf~pt and the lop~heel.
The fil~...f n~ n~;~wulL layer can be joined to oppo~ilely facing s~ f ec of
the lopsl,~~ and b~cL~h~~ and can have a plurality of openings there through,
35 wl-erein the fil~ nl~ y nelwu~L can have an open area ratio of at least about 50
percent. The op~ning~ in the fil~...e~ / nelwolk are pl~r~ldbly sized to preventa baby's finger from passing lllluugh the opP~nin~.~ in the network, and therebyprevent the baby from tearing small pieces of the bib from the bib body.
The bib can co",~,;se a tissue paper lopsl,~l having a first o~lwa~dly facing
40 surface and a second oppo.,ilely facing s ~ ., and a polymeric net joined to the
second surface of the l~l-ecl. The polymeric net can comprise a first plurality
- -
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of generally parallel fil~ment.~ e~ten~ing in a first direction and a second
plurality of generally parallel fil~mr~.nt.c ~Yten~ing in a second direction angled
with respeot to the first direction. The maximum spacing between ~djaeent
parallel fil~m.ont.c can be no more than about 2 cm, and in one embo lim~.n~ is no
morç ~an about 1 cm '.o prevent '~e wearer from inserting his finger b~lween
0 the fil~ and tearing off small pieces of the bib.
BRIEF DESCRIPTION OF TH~ DRAWINGS
While the specification concl~ldec with claims particularly po;nling out and
ly r.~ .g the present invention, the invention will be better understood from
the following description taken in conjunction with the acco~l~pan~ing drawings in
which like ~lesi~n~tions are used to ~e~ign~te sub~L~Ilially identi-~l clemt~ s, and in
which:
Figure 1 is a front plan view of the disposable bib of the present invention, with a
portion ofthe topsheet cut away to show a ,eh~.cing fi~ nly network
disposed between the topsheet and the baf L .cheet, wherein the fil~mPntc of
the filAn.~ .. y ncLwul~ extend generally longi1~.1inally and laterally.
Figure 2 is a rear plan view of a disposable bib of the present invention, with a
portion of the bacl~cheet cut away to show a lt;ill['OICing fil~ n..y
l~twull~ ~lis~uosed b~t~,.cen the topsheet and the bae~.chP,et wherein the
2s fil~mPntc of the fi~ a~y network extend generally diagonally with
respect to the longibldin~l direction.
Figure 3 is a partial cross-sectional view taken along lines 3-3 in Figure 1, and
showing the fil~ .y llCLwCIlk disposed between the topshe~L and the
~ b~ chP~pt
Figure 4 is an ~ Cd seII~ ;c illustration of a portion of the fil~m~nt~ry
network.
Pigure 5 is an in use pt;l~e~;Li.~e view of a di~posable bib.
DETAILED DESCRIPTION OF THE INVENTION
3s Figures 1-5 illustrate a disposable bib 20 according to the present invention.
The bib 20 inc~ es a bib body 22 and a pair of ~hn~lldt~r extensions 24 and 26
nA;.~, from the bib body 22 on either side of a bib longih~lin~l centerline 21. The
term "lon~tllt1in~l" refers to a direction or axis which is generally parallel to a line
,n~ , from the wt;~uel~s head to the w~alel~s waist as the bib is worn. The terrn
"lateral" refers to a dile~;lion or axis which is pelpc~ ic~ r to the longit~.din~l
direction and which is generally parallel to a line eYtçn-ling across the w~arel~s chest
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S as the bib is worn.
The bib 20 has a periphery which can include two generally longit~lAin~lly
ext~n-ling side edges 32 and 34, a generally laterally eYt~ntling bottom edge 36, and a
neck opening 38. The neck opening 38 is disposed intermedi~te the shoulder
eYt~n.~ions 24 and 26, and acco."".odates the wearer's neck as the bib is worn. The
o neck opening 38 is a generally U-shaped opening in Figure 1, but it will be
understood that other neck opening configurations, in~lllAinp various open and
closed shapes, could be used. The following U.S. Patents are incorporated herein by
rt;f~ nce for ~ul~ose of showing various bib shapes: U.S. Patent 4,416,025 issued
November 22, 1983 to Moret et al.; U.S. Patent 4,441,212 issued to Ahr; and U.S. lS Patent 4,445,231 issued May 1, 1984 to Noel.
The bib 20 acco.dil!g to the present invention co-..~ ses a composite
construction having multiple l~min~e In the Figures, the bib comp.;ses an absolbenl,
liquid permeable outer top~l,eel layer 40, a g~",enL facing b~c~cheet layer 80 which
is liquid impermeable relative to the topsheet 40, and a load carrying fil~ A.y
nclwu.~ 60 disposed inte.. e1iA~e the ba~L.cheet layer 80 and the topsheet layer 40.
The topsl.eeL 40 has a first outer surface 42 for receiving spilled food material, and a
second inner surface 44. The bacl~chçet 80 has a first ga,lllenl facing surface 82 and
a second surface 84. The surface 84 of the b~.cheet 80 and the surface 44 of thetopsheet 40 are oppo~ilely facing surfaces. The filA~ y network 60 has a
2s plurality of openillgs 70 ~ .A;~ there through, and can be joined to oppositely
facing surfaces 44 and 84 of the topsheet 40 and ba~ch~et 80.
The fi~ ..c-~lA~y nelwul~ 60 can have tensile s~lel~lh and tensile elongation
pro~ ,s which perrnit it to carry loads exerted on the bib 20, thereby ;..lp~Ling
tear recict~nce to the bib 20. In one embodiment the fil~m~nt~ry network 60
30 co~.p. ;;,ec a polymeric net co"~ ;ng a first plurality of generally parallel fil~m~.nt.c
~ 62 and a second plurality of generally parallel fil~m~ntc 64. The filam~ntc 62 can
extend g.,n~ lly lon~tt~rlin~lly, and the 1~1~".~"l~i 64 can extend generally laterally, as
shown in Figure 1. However, it wili be und~lood that the fil~m~nt.c 62 and 64 need
not extend lon~h)Ain~lly and laterally, nor be generally parallel or muhually
35 p~ Ai~ r. For example, in the embo~im~nt shown in Figure 2, the l~ e~ 62
and 64 can extend diagonally with respect to the lon~h~lin~l axis 21, and can form
an angle of about 45 degrees with the axis 21.
The dispos~ble bib 20 can optionally have a pocket 100 for c~t~hing and
receiving food particles. The pocket 100 can have an open edge 110 and a bottom
40 edge 120 (Figure 2). U.S. Patent 4,445,231, listrd above, is h~ ed hereinby lcirt;l~,nce for the pL.,pose of t~hing suitable constructions for pocket 100.
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s The bib 20 can also have a f~t~nin~ assembly for holding the bib 20 in
place on the wearer. Figure 5 shows the bib 20 held in place on a wearer. In
Figures 1 and 2, the f~t~ning assembly includes f~tening members 202 and 204
disposed on the ga mcnt facing surface 82 of the b~ckchloPt 80. The f~tening
Ille~ ~,7 202 and 204 are positioned on the shoulder extPn~ions 24 and 26, and
can comprise a plurality of fabric eng~ging projections 206, which can be in theshape of a prong or hook. The projections 206 extend from the plane of the bib
20. In one embo~ nel~t, the projections 206 on each of the shoulder eYtPn~ions 24
and 26 can engage the fabric of the wearer's garment to hold the bib 20 in place.
In another embo~imlont the bib can also include one or more landing
s~rf3l~Ps 210 ~np,~g~able by the projections 206. A landing surface 210, which can
comprise a non-woven fabric, is joined to the outer surface 42 of the topsheet 40,
and positioned on the shoulder loYt~n~ion 24. To secure the bib to the wearer, the
shoulder eY~tPn~ion 26 is positioll~ to overlap the shoulder eYtencion 24 behind the
wearer's neck, with the projections 206 on the f~tening memher 202 eng~-inE the
landing surface 210. Suitdble f~*ni,-p mrmhPrs 202 and 204 are m~n~f~ctl~red
by the 3M Com~y of Mini-e~la under the desig~tion MC-6, Code
KN0513/KN0514. A suitable landing surface 210 is a non-woven web of
polypropylene fibers manufactured by the Veratec Division of the Tl-(e,..alion~lPaper Col~ldlion of Walpole, M~ husetts under the ~leciprl~tion P-14,
2s Supplier Grade #9324369. Suitable hook and loop type f~teners are a!so
available from VELCRO USA of New T-TA--~ . Other s~-it~hle r~ n;ng
..,~...h.~.~ having proiecti~ns are .liscl~s~d in the following U.S. Patents, which are
il~co.~,ated herein by ~f~.~nce; U.S. Patent 4,846,815 issued July 11, 1989 to
Scripps; 4,894,060 issued January 16, 1990 to Ne~t~g~rd; 4,946,527 issued
30 August 7, 1990 to Battrell; 5,019,065 issued May 28, 1991 to Scripps; 5,058,247
issued October 22, 1991 to Thomas et al.; 5,116,563 issued May 26, 1992 to
Thomas et al.; 5,180,534 issued January 19, 1993 to Thomas et al.; 5,318,741
issued June 7, 1994 to Thomas; 5,325,569 issued July 5, 1994 to Goulait et al.;
and 5,326,415 issued July 5, 1994 to Thomas et al. ~ ely, ties, tape, or
3s other adhesive f~t~-n~s can be used to secure the bib to the wearer.
r~ ;np the 1A...;n~l construction of the bib 20 in more detail, the lo~heel
40 can comprise a paper web having a basis weight of from about 10 to about 50
pounds per three tho..~n~ square feet. The following U.S. Patents are
illco~ ~d by rcrclcllce for the pul~se of ~ sin~ how to make tissue paper
40 suitable for use in making a lops~ 40: U.S. Patents 4,191,609; 4,440,597;
4,529,480; 4,637,859; 5,223,096; and 5,240,562. A suitable topsll~l 40 can be
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formed from a single ply or multiple ply paper towel, such as a Bounty Paper
Towel manufacl:ured by The Procter and Gamble Company of Cinninn~ti, Ohio.
The b~cl~hP~t 80 can comprise a liquid impervious film. In on embodiment
the b~t ~chPet 80 can comprise a polyethylene film having a thicknPc5 of betweenabout 0.0076 millimPter and about 0.0508 millimet~Pr. A polyethylene film from
which the bat~chPet 80 can be formed is m~m-f~l~tllred by Tredegar Industries ofTerre Haute, Tn~ n~
The fil~mPnt~ry nclw~ 60 is joined to the surfaces 44 and 84 of the
topsheet 40 and the b~chPet 80 by any suitable means, inclurling but not limitedto mP~h~ni(~l bonding, adhesive bonding, and ultra onic bonding. The
fil~mPnt~ry network 60 is prcfeldbly joined to the su-f~t~c 44 and 84 along
sub5~nl;~lly the entire longit--t1in~1 length and across ~ub.~l 1n~;~11y the entire lateral
width of the bib 20. A suitable adhesive for joining the fil~ t~nli~ y network 60 to
the topsheet 40 and thP b~c~ch~et 80 is a hot melt adhesive such as Findley
Adhesive H2031 available from Findley Adhesives of Elmgrove, Wiccon.cin.
About 3 milligrams of the H2031 adhesive per square inch of bib area can be usedto join the fil~....~n~ / network 60 to the lops!leet 40 and the b~c~chPet 80.
The fil~mPnt~ry network 60 increases the tensile strength of the bib 20, to
thereby provide the bib with tear recict~nce. The fil~mPnt~ry network 60 can have
a ...~ .", tensile ~llcnglh (the tensile strength measured in the direction along
2s which the tensile strength of the fil~mPnt~ry nelwolh 60 is Ill~X;IIIIIIll) greater than
that of either the of top.h~l 40 or the b~chP,et 80. The tensile strength can bemeasured using a conct~nt rate of Plong~tinn tensile test m~t~hinP" as ~lesl rihed
- below.
~irÇ~;~c~l net m~tPri~lc, such as dirr~ l polymeric m~teri~lc, can be chosen
30 to provide the bib with dirrercl t strength, elonE~tion, and fleYibility propellies.
t'.PnP~lly, higher levels of ~ n lh result in lower levels of flexibility. The cross-
S~P~ti~ li,..t-3~ior~ of the fil~mPntc and the spacing ~clween ~ljaC~nt fil~mPntc
can be SPl~tP~d ~eppntling upon the strength and flexibility of the m~tPri~l from
which the fil~mPntc are made. Por m~tPri~lc having a relatively high strength and
3s a relatively low flexibility, fil~mentc with a relatively small cross-sectional
~li",~.n~:on can be used, and the spacing belw~n ~tlj~r~nt fil~mPntc can be
relatively large. For m~tPri~lc having a relatively low strength and a relatively
high fle~ibility, fil~mPntc with relatively large cross-se~tioll~l tlimPn~iollc can be
used, and the spacing belw~ll ~tlj~r~nt fil~mPntc can be relatively small.
The opPnin~s 70 ~elw~n ~tlj~Pnt fil~mPnt~ of the fil~mt~nt~ry network 60
are si~d to prevent infant WWt;l:j from gr~cping unl~lror~d areas of the
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5 topsheet 40 overlying the op~Pningc 70 and tearing such unreinforced areas of the
topsheet 40 from the bib. The openings 70 preferably can be sized to be smaller
than the fingertip of a wearer to prevent the wearer from poking a finger through
the lo~,~l,ect 40. Acco~lingly, the opPning.c 70 can have a maximum width 74
(Figure 4) of no more than about 2 centimP~t~prs. In one y~felled embodiment, the
lO openings 70 can have a maximum width 74 which is no more than about l cm,
~eÇtl~bly no more than about 0.5 cm, and most preferably no more than about
0.25 cm.
The fil~ment~ry l~lwo-k l)lefe dbly provides tear r~cict~nce without
subst~nti~lly increasing the stiffnPcs of the bib 20, without subst~nti~lly ~ffecting
l~ the ability of the topsheet 40 to absorb spilled food m~teri~l, and withoLlt
~ l,s~ t;~lly increasing the amount of m~tPri~l 1CqU~1Cd to construct the bib.
Some m~teri~lc, such as thermoplastic m~tceri~lC exhibit both relatively high
strength and relatively high flexibility. Accordingly, for the range of width 14listed above, the fil~m~,nt,c can h~ve a relatively small cross-sectional dimP.ncion 72
20 (Figure 4). For in.ct~nce, the cross-sectional ~limencion 72 can be less than about
2 mm, and in one embo~limPnt the cross-~tion~l (3imPncion 72 can be less than
about .25 mm, thereby providing the fil~mPnt~ry network 60 with a relatively
large open area ratio. The open area ratio increases with increasing spacing
~elwee~ ePnt fil~mentc, and the open area ratio decreases as the cross-sectional2s ~ ;on 72 of the fi~ .l' increases.
The open area ratio of the fil~mPnt~ry network 60 is c~k~ t~d by mP~cl~ring
the area of opPningc 70 in a lO c~ t~ ~ by lO c~ el square sample of the
fil~ helWOl]- 60, and dividing the area of the opPnin~c 70 in the sample bythe sample size (lO0 square C~ J~). For the range of widths 74 and
30 ~l;",f-nc:~n 72 listed above, the open area ratio of the fil~mPnt~ry network 60 can
be at least about 50 percent, and in one embo~imPnt is at least about 75 percent.
The fil~n.~,nl;..,y nelw~Jlk 60 can comprise a net of Ihtll~loplastic material,
WhG~e~l~ the ~ n~ ?lp~l;e m~tP,ri~l is SPl~tP~ from a group in~luding
poly~l~ylene, poly~,r~lene, polyvinyl chlori~le, polyvinyl ~ t~t~, nylon,
35 pol~e~t~ l~, polyethylene vinyl ~et~te, polyethylene methyl meth~-~rylate;
~ polyelhylene acrylic acid, pûl~lu~lene Illelhyll~pth~t~rylate~ polypropylene
acrylic, acid, polyvinyliliene chlor dP, polyvinyl ~lcQh--l, c~llulose acetate,
cPlll~lose bul~la~, poly~ul~nates, and alkyd CPlllllosicc, whcrèin the
afole..~Pnl;onP~ thermoplastic polymers are con~i~iered to be illllctrative but not
40 limitin~ n~l;vely~ the fil~ nt;..y network can comprise a web made from
natur;~ fibers, synthetic fibers, or ccll.bi~-~l;onc thereof. Suitable natural fibers
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W 096/20613
s include, but are not limited to, cotton, flax, wool, and silk. Suitable synthetic
celll-lo~ic; synthetic modified cellulosic or synthetic mineral fibers inclllde, but are
not limited to, rayon, acetate, lyocell, and fiberglas.
The fil~ment~ry network 60, which is scll~nn~ti~lly illustrated in Figure 4,
can be formed by a nu~l~bcr of s~it~hle techniques, in~h)-~ing but not limited to
10 casting, molding, weaving, and knitting. Each fil~mFnt 62 and 64 can comprise a
single strand, or two or more strands twisted together. Fcsenti~lc of Textiles,
Third Edition by Marjory L. Joseph, (1984) page 237 describes net construction,
and is hereby inco~ alcd by ,efcf~ nce.
In one embo~limpnt the fil~mF~nt~ry network 60 can comprise a knitted nylon
5 net comrricing the first plurality of gemPr~lly parallel fil~mentc 62 e~ctF-n~ling in a
first direction and the second plurality of genPr~lly parallel fil~mFntc 64 e~tencling
in a second direction angled with respect to the first direction. Each of the
fil~mPntc 62 and 64 co...l.. ;c~ s two nylon st~ands. The individual strands have a
mF tPr of belween about 0.02 mm and about 0.10 mm, and the filaments 62 and
64 have a maximum cross-section~l width ~limencion 72 of between about 0.04
mm and about 0.20 mm (about twice the ~ r of the individual strands). The
IlI iXilll~lll width 74 of the openingc 70 is bclwGcu~ about 0.05 cm and about 0.20
cm. Adja~nt fil~mPrltc of the first plurality of generally parallel fil~mPntc 62 are
spaced apart to provide l~d~n about 6 and about 14 fil~mPntc 62 per centimeter,
and ~ c~Pnt fil~mPntc of the second plurality of generally par~lel fil~mPntc 64 are
spaced apart to provide between about 6 and about 14 fil~mPntc 64 per cP-ntimeter~
such that the nylon net has ~ct~ce1l about 25 and about 200 ope,.ih~s 70 per square
cm. The nylon net has a basis weight of about 10.8 grams per square meter, and acaliper of about 0.17 mm under a co,~ g p. e~ , e of 0.1 psi. A suitable nylon net
~ 30 iS CC"~ e;a~ly available as nylon tulle from fabric wholesalers and retailers. Such a
nylon net is cO...i~,F cially available from Fabri-Centers of America of Hudson, Ohio
under the dçc-~n~tion SKU 040-1703.
Figures 1, 2 and 4 show a fil;~ y ne~wu,k 60 comprising a generally
uniform re~ P,~l~r grid of 1~1~"..?~ In other embo-limentc the fil~ y
35 n~ lwo~l~ 60 can COIIIPIISG fil~m~ntc ~langed in a non-uniform manner.
TEST PROCEDURES
The following p10Ce-lUlGs are used to measure the tensile strength, fler~r~l
rigidity, and impact reCict~n~ of a sample of a base bib having a topsheet and
40 b~ch~t The same p,ucedu,~s are used to measured the col"~able ~lo~,lies
of a sample of a bib of the present invention having the same to~allec~ and
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WO 96/20613 PCT/US96/00217
s b~ch~t construction as the base bib, but also inco~dling a nylon net between
the topsheet and b~ hPet The topsheet comprises a Bounty brand paper towel,
the b~k~h~t comprises a polyethylene film having a thickness of about 0.025
mm. The fil~m~nt~ry network 60 comprices the nylon net described above
available from Fabri-Centers of ~mPric~ as SKU 040-1703. In both the base bib
and the bib having the nylon net according to the present invention, about 3
milli~ mc of the H2031 adhesive per square inch of bib area is used between the
top;,hoet and the b~rkch~t to join the bib co.-.~ouenls Logclhe~. In the bib having
the nylon net according to the present invention, the fil~ments 62 and 64 are
ol;~nl~ diagonally at about a 45 degree angle to the lon~itutiin~l axis 21, as
shown in Figure 2. Bib s~llples are con~litioned at 50% RH and 73~F for at least2 hours before testing.
Tensile Test
The tensile SLIcllglll of the bibs and of the fil~ n~.y network is measured
with ~rcrellce to the INDA sl~ d test IST 110.1-92 of the ~c.~oci~tion of the
No~lwovell Fabrics Industry, which standard is in~,~l~ted herein by reference.
Bib samples are cut into 1.00 inch wide sample strips. The s~mpl~s are placed
squarely in the jaws of an Instron Model 4201 consl~nt rate of elnnE~ti~n tensile
tester. One inch, line-contact grips are used to avoid any sample slippage. The
2s ~mples are pl~ten~;oll~i to ~ro load at a 1.0 inch gauge length. Force is
mcas~,lcd with a 100 N load cell and locor~lcd continuou~ly as the sample is
~lon~l~ at a ,;loc~l~f~ speed of 12.0 inches per minute to comr'cte failure. In
all cases a local ...~ occurs in the first inch of ek~ lion This initial peak isr.,f~lcd to as the tensile ~LI~n~lh of the bib. This pcak typically coincide~s with
the failure of the tu~llcel or fil~m-ont~ry nelwulk, if present. In some cases, the
- load on the polyethylene film just before the polyethylene film breaks ~Y~ffllS the
initial peak; The strength values recorded are lcpollcd in grams per 1 inch widestrip (grams/inch). ~ pCl~ S are rc~llcd as an average of at least two
Ill&S~
3s Results of tensile testing of the base bib and the bib having a nylon net
Ol;kQIf~d as shown in Figure 2 are listed in Table 1. ~u~llies are reported for
~-- '~s cut from a bib such that the sample gauge length is generally
p~ ;r,~ r to the bib a~is 21 (gauge length angled 45 degrees with respect to
fil~ment~ in the bib having a nylon net), and also for san~le~ cut to have a gauge
length angled about 45 degrees with respect to with the bib asis 21 (gauge length
aligned parallel and perpen~ ul~r to fil~ment~ in the bib having a nylon net).
. CA 02208404 1997-06-20
W O96/20613 PCTrUS96/00217
s The results in Table 1 show that the tensile strength of the l~min~te bib
having a nylon net exceeds the tensile strength of the base bib. The l~min~te bib
according to the present invention can have a tensile strength greater than about
2000 grams/inch, more particularly, greater than about 2500 grams/inch, and in
the embodiment tested, greater than about 3000 grams/inch.
l~npact R~ nre Test (dropping projectile)
Impact reci~t~nc~ provides a measure of a bib's rç~i~t~n-~e to puncturing.
Impact resi~t~nce of a bib sample is measured by dropping a projectile having a
known weight from a known t~i~t~nre to impact upon a circular sample of the bib.S A bib sample is positioned, then tightly clall,ped in an annular pr~ellm~tic grip
having an intern~ .,.ele~ of 3.0 inches to form a 3 inch ~i~metçr bib sample
SU~J~JUll~d at its edges by the p~ ;c grip. A projectile having a ~cifi~d mass
and shape is allowed to fall freely onto the center of the 3.0 inch ~i~met~r bibsample from a height of 15.0 inches, where the 15.0 inch ~ t~nce is measured
from the sample surface to the center of mass of the projec~le. The st~inlp~ steel
projectile weighs 100 g, has a 19 mm ~i~mPt~r sph~-ic~l end, and has a total
length of 67 mm, with the center of mass of the projectile located about half way
along its length, so that the rounded tip of the ~rhe i.~l end is about 348 mm from
the surface of the s~lll,le. Five samples are imr~cted for the base bib construction
2s and a bib accofding to the present invention. Each im~ct~l sample is chP.c~ for
puncture (any visible hole through the entire thir'~n~ of the bib.) A bib
construction is con~dPred to have an impact resi~t~nce equal to one half the mass
of the projectile times the square of the velocity of the projectile as it imp~-~t~ the
sample if none of the five imr~t~ ~I~ples is punctured by the ~lu;ectile. W~hen
~e base bib is tested with this impact test, each of the five base bib samples is
~)UnC~ d. yVhen a bib having a nylon net according to the present invention is
tested, none of the five ~ 5iS ~JUIICIUled. The velocity of the ~loje~;lile is
c~lc~ ted using ~e e l~Lions of projec~le motion for a drop t~ict~nce of 15 inchand ~.. ;ng no air re~ict~nee For a 100 gram mass dlupped 15 inches (38.1
3s cm), the impact re~i~t~nr-e is reported as 1.86 million gram-cenlilll~t~r~ squared/
second slu~Gd, or 186 gram-meters squared/second squared. Accordingly, the
bib having a nylon net accolding to the present invention has an impact re~Ci~t~nrR
of at least about 186 gram-meter squared /second squared.
~E~URAL RIGIDITY (I~ proportional to flexibility)
The relative flexibility of ~mrlP-s of a base bib and ~~ lPs of a bib
CA 02208404 1997 - 06 - 20
WO 96/20613 PCT/US96/00217
11
according to the present invention are measured using I~DA standard test IST
90.1 - 92 as lcfe.ence, which standard test is incol~ldted by reference. This test
measures the flexural rigidity of a sample in terms of drape stiffness. A samplem~ming 2.54 cm by 20 cm is cut from the bib and slid m~nll~lly at a rate of
about 4.75 in per minute in a direction parallel to its long ~im~n~ion~ so that its
o leading edge projects from the edge of a horizontal platform surface. The length
of the overhang of the sample is measured when the tip of the sample is dt;~-essed
under its own weight to the point where the line joining the tip of the sample to
the edge of the pla~r~ ll makes a 41.5 degree angle with the hori70nt~l The
flexural rigidity of the sample is the cube of this overhang length multiplied by the
15 basis weight of ~mrle. The flexural rigidity is reported in grarn-centimeters as an
average of at least two me~ur~ nt~. The flexibility of the sample is inversely
pn~pollionai to the lepolled flexural rigidity. Results of flexural rigidity testing of
the base bib and the bib having a nylon net ori~nt~A as shown in Figure 2 are
listed in Table 2. The fleYl~r~l rigidity is reported for samples of the bib cut to
20 have a long ~iim~n~ion gen~r~lly pel~n~lic~ r to the axis 21 of the bib (long axis
angled 45 degrees with respect to fil~m~nt~ in the bib having a nylon net), and for
~ es of a bib cut to have a long ~lim~n~ion angled about 45 degrees with
respect to the axis 21 (long a~cis parallel and perpçn-licul~r to fil~ments in the bib
having a nylon net).
2s The results in Table 1 and Table 2 show that the 1~---in~ bib of the present
invention can have a fl~u~l rigidity which is only slightly greater than that of the
base bib, while at the sarne time providing the above m~nti- ned increase in tensile
~lle.~ and punclul r~r~i~t~lr~ The l~min~te bib according to the present
invention ca~i have a flloYU~l rigidity which is less than about 20 g-cm, more
30 particularly, less than about 15 gram-cm, and in the embodil"~nt tested less than
about 12 gram~m. Accordingly, the l~...io~le bib according to the present
invention has relatively high tensile strength (for providing tear re~i~t~nre) with a
relatively low level of fl~oYu~l rigidity (for providing softness and comfortable
confo~,nability of the bib to the wearer's body).
3s
.
-
CA 02208404 1997-06-20
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12
S Table 1: Tensile Strength:
Gauge Length Pe,~en~icu'~ to Bib Gau~e Len~th at 45 degree an~le
Axis 21 to Bib axis 21
init peak init peak
load load
(~mfinch~ l~mfinch~
Base Bib 1690 1810
1610 1700
1490 1750
1470 1800
1380 1900
avg 1528 1792
11) ~2)
Laminate 3000 3250
Bib With 3030 3310
~ Nylon 3300
Net
3170
2950
av~ 3090 3280
(1 ~ gauge length angled 45(2~ ~auge length parallel and
de~rees with respect to fila...enl~ pl:.,ue,n~ a~ to ri6...enl~ in the
in the la--- .dle bib with nylon net laminate bib with nylon net
~
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13
5 Table 2: Flexural Rigidi~:
basis wt ov~.. l.an~ overhangflexural flexural rigidity for
length for len~th for ri~idity for sample length at 45
sample length sample len~th sample length de~rees to bib axis 21
perpendicular at 45 de~rees per~.en ~ic~
to bib axis 21 to bib axis 21 to bib axis 21
(m~/sq
cm) (cm) (cm) ~-cm g-cm
base bib 7.1 10.8 11.0 8.94 9.45
7. 1 11.5 1 0.8 1 0.80 8.94
7. 1 1 1 .3 1 1 .0 1 0.24 9.45
7.1 10.1 10.5 7.32 8.22
7 . 1 11 .7 1 0.6 11 .37 8.46
avg 9.73 8.90
std dev 1.62 0.56
(1) (2) ~1) (2)
Laminate 8.7 10.3 10.4 9.51 9.79
Bib With 8.7 10.4 10.9 9.79 11.27
Nylon 8.7 11.0 11.58
Net
avg 10.29 10.53
std dev 1.12 1.05
1~ Overhan~ len~th angled 45 degrees with respect to tilalllehla in
6... Iale bib with nylon net.
(2) Overhan~ length parallel and P61~JI3n '-'UI;?' to ri6--.enls in Id--.- .alebib with nylon net.
~ While particular embo~lirnents of the present invention have been illustrated and
des~;l;l,ed, it would be obvious to those skilled in the art that various other CI~A~1~;S
and m~ ific?~tit)n~ can be made without depdlling from the spirit and scope of the
15 invention: It is int~nded to cover in the ~ppen~led daims all such ~ An~,l3S and
mod;l~c~l;Qns that are within the scope ofthe invention.
