Note: Descriptions are shown in the official language in which they were submitted.
; 21~0~
l~ACKGE~OUND ~ SUI~ARY C)F THE PRE~ENT INVE~
1 he present invention is relatcd to cut-r~sistane yams and associa~ed fab~ics,
col~d~e, o~ non wo~en products whic~ mAy be produced with the yarn. It is als~
relntcd to static d;ssipathe materials, materials reinforced for ltrength, and
abrasion-rcsistant mato~ial~. Most partlcularly the prcs~nt in~ ention h rel~ted t~
~;
the abo~e products when contalnment of a core maten~tl ls reqllir~d due to thq
potential ~or ha~td to ehe cmployee, product, or en~rironment lf ~he core maeeria~
is exposed.
:;
,. There has been signl~cant sctlvity in recent years with reBard to the
~anufiacture of yarns ~nd fabri~s for cut-resi~tant pro~ectivc app~rel. Many of
these acti~itlcs deal with the u~ ~f stainless steel wlre in con,~uJlctlon v~ith various
6be~ to B~t~lill an op~imal bal~nce of cut resist~nc~ and ile~dblli~, couplcd with co~t
of production.
tJ.S. Patent No. 4,3~d"4~9 to Byrn~s te~he~ the use oE a 10ngitudinally
po~itioned wi~ strand co~ered with nram~d, and the numerou~ resultin~ advantages
~; oE s~lch wrapped wiro. One ~dYanlage ~5 supenor cue resistance perfonnance, when
compared to UJoves formed of pure ar~mid. Byrncs ~Iso descr~bes ~mproved
knitabillty on ~ conventional ~love lulltt~n~ mnchine, and Impro~ed dcx~erity of a
glove knitted ~om such a w~re yarn.
U.S. Patent 4,470,251 tO Bettcher extends the teachings of the above~
,
mentloned Byrn~ patent by illustr~tlng hvo pr~m~y dlscoveries. Firs~, tha~ two or
m~ro smalhr ~ire stran~s yiold grcater ae~iblli~ ~hnn ono s~r~n~l, whlle allowing a
i)
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larger quantity oE wirc to be usecl, an~ the u~e o~ a longitu~lnatly po~itioned hbrous
strand Jncorporated wlth the wire strands hlrther ~mproves ~e~le mo~ement.
Sccond, Bet~chet demonstrates that an ~uter coverin~ f~rmed of a polyamlde such
as nylon improves the ~omfort of the glove to thc wearer.
KolmcslPlemmons, in U.S. Patents nu~nbered 4,83$, 01~ and 4,7~7,78g, teach
the wrappin~ of arlnealed stalnless steel wire about a core ~ber; wr~pp~n~ the
stran~s of v.~ire in opposing ~irections ~nd hlrther increas~n~ fiexibili~r of the fabric
whil~s malntninln~ cl~ proteetion. KotmeslPlemmons nl30 documented a bfoad
range of fibe~s th~t ~an loe used In th~ cor~ and outer wraps of thc composite yarn.
The cbtabl~shed prlor ~rt referenced here offer~ teaehing!l that have
improv~d thc state of prot~ctive npparel. While each Is repres~ntst~vc of
Improvenl~nt, th~ present invention extends tar beyond these p~ior tea~hin~s a~d
.,
demonstrate3 a novel and un~que approach whlch soh~es a serious and horetofore
unaddrcssed Issue related tO the manufaeture of protec~he appaFcl. One previously
unrecognlzed pro~lem 1~ the Fnct that In the use of wir~ ~omposito yarns, the wlro
strands frequently bre~k, puncturlng the skln of the wearer, contamlnating val~ious
m~nu~cturing and production operations, and e~posing the wearer to ~he possib~lity
of dlsease. Wire will invariably ~ncture aEter repeated flexure ~nd uill penetr~to
.
~he surface of any kno~vn composite yarn.
Th~ pr~sent In~entor ha~ dis~vered thnt the Inven-lon taught h~ro~n
pro~des n method o~ c~ntalnlng w~r~ and olhor materlals such as ~berglass wb~n
thes~ ma~er~als arc uscd as thc 3rarn CDre. To date thor~ has been n~ serhuc
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2~03~2
altempt by the Food and 1: rug A~ministrat;on (F~) or the U.S. r)eyartment oF
A~riculture (USl:)A) to climinate the usa o~ such materials ~ a yarn coro, but the
issuc is volstile and v~l1 eventually nced ~o be resolvcd. The resolution may not ~e
one which Industry 6nds acc~ptable or even practic~l.
Wlro and SberglAss are known to pro-~id~ sdditlonAI cut resistan~e to
composit~ yarns by microscoplcally altet~ng the ~dgo of ~he cuttin~ surface. 7~1is is
due ~o e~ceptional high density snd abra~iveness which dulls the edBe of any cutting
instrumen~ or de~ce that contacts the material. ~Ire and fi~e~l~s~ abo sdd
strength to n yarn. l'he m~terials ~re prehrre~ bccause of thc many beneits tbey
add to a comp~site relative to tho cost. However, lhese same ma~olials ~re
contr~ersial bec~use ~hey cann~t be allow~d to escape ~r~m the compo~ite y~rn
Into the work place for cnv~ronmental and/or health rea~ons. ~o present im~ention
pr~rides a composlte yarn and f~bric whlch m~y ~elcctlv~1y ~ncarporat~ t~vire and/or
~bor~las~ ancVor othor nec059nr~r but potentially hnrm~u~ mate~ials Into the basic
yaln corc, btJt ~vhlch o~ers pro~ect~on lo the worker firom exposure to the Inaterials.
which mat~rlals may h~gment or spllnter and threaten the he~1th o~ the worker ~nd - `~
also ~amage thc end product.
Thc pre~cnt ~nvention prc~ldcs a novel method of forming a cont4~nment
barri~t alound ~ single cornponcnt or multf~omponcnt core of such controvers;al
and pvtentlally cont~minatlng m~terW5, ~nd subst~ntlally d~ereases th~ ~sk o~ ~heso
contamlnatu belng role~sed. The ~oundation of the presen~ ln~rcntion i5 a
compwltc prn whlch USeJ mell~ lble thermoplnstlcs to enc~psulnt6 nnd thercby
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i~olate one or more coro mater~ls which Inay prescnt a throat ~f contamination to
workers or the environn~ent. Thi!~ novel ya~ is basically comprised o~ one or more
core materlals ~hich ~re covered In ~hermoplastics and additional layers of
matcrials which form onc or more ~uter Govels. The con~bination i9 then hcat set
j:,
to hrm a fle~ible fiber barrier whjcl~ surrounds and en~rap9 thc un~af~ core.
The b~ier which contains the selec~ed core l8 creatcd by melt hslng a
~he~moplast~c mnte~al v~jth o~he~ cU~felin~ fiber pro~uc~ In ~uch a way that thoso
undesJrable matèrials are trapped between a shroud oE ~s~d ~ber~ ~nd a Sber
core. In othcr embodim~n~s, ~ate~ials whi¢h ~re longitudinall~ posltioned to ~rm
the core are encapsulated in n continuous ~brous sheath w~th no a~hesion between
thc ~h~ath and aJI inner corc yarn.
It ;s prehrrcd to ~rap w~re In a Fused 6ber lByer having a smooth outer
sl~rFace whlch 15 unllkely to bond with subseguent outer covcr Inyers. Because wire
itself h~s a smoo~h sur~acc unllkely to bond with thermoplastic, il is lmportant ~hat
the core bond ~o ~he lhermnpla~ic and isolate ~he wire therebetwe~n; The
comblnatiol~ bccomes a hi~hly effective containment ~ehicle th~t retains a high l~vel
o~ ~c~dbility. whn~ the end prot~uc~ ~ucll nic a glove mny becomo sll~htly more rl~id
after heat trea~inl3 to t~italn shnpe, the composite y~rn Is hlgllly D~iblo and can
thercfore ~e easil~r kni~tod, wovcn, bralded, or otheru~se ~ormcd In~o a ~love or
other proeluc~. ~ero are many di~ferent materials and- processing methods
available to torm the ~omposlte yarn, dep~ndin~ on ~he on.l use desired.
C:Qnven~hnsl eover~n~ or wlrc~wrappln~ cqulpmcnt is most ~uitnblc to m~nufacture
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th~ composi~e yarn. Other eq!lipm~nt may bc used as needed to preprocess
materials which can later ~ wrapp¢d or used as wraps. Examples ar~ c~mmingl~
machines, twisting cquipment, and ~xtrudin~ machines.
The cor¢ of shc composite yarn is selected Erom a group of hbers or types oE
,
other materials whlch may be spun, continuous, mul~ifilamcnt, Ot m~noffl~ment.
The core Is selectively comprised o a sin~le s~r~nd or multiple ~trand$ of single
er type or a mixtllre of fiber ~rpes. The core structure lc virtu~Jly unllmlted and
mag Includ¢ 6berglass, wirc strands, thermo-plastic~, andlor olh~r su~h c~ntr~vorsial
materl~ls ~r comblnations of ~uch mater~als. The core structure m~y bo of a
plur~Uty of such fibers combined by blend spinning, tvnSting, cxkusion or any other -
method dc~med appropriato lo aeeomplish the deslred corc and end produc~.
S~eral pre~ously unknown b~neEits of yarns Inanufactured In ~ceordancc
uith those methods h~vo been disc~ered. It h~s been found th~t abrasive~ su~h as
vire or fiberglass perfo~n thelr ~unc~lon be~er when locked firmly in place. lhe
~unction of abr~sivw in cut reslst~nt yarns has been oxplalne~ a~ d~lllin~ the culting
edge and thereby in~re~slng ~he p~rformsnce of the other hl~h stre~th fibers.
'Vhen u~r~ ig used, lt tontls to move away from ~he CuttiD6 ~d~e exposing more ~ .
t'iber to the thr~t. Whsn wiro is fus~d in place ~s wlth the present inverltion, it
engases the cdge more dircctl~ an~ ;B more abrasive. I~ effecti~ely shields
~ubseq~lent lay~rs until thc hll abrasiw ef~ec~ is used. T~ls j5 also true with
fiberglass. Flbe~glass is n~t cffective onee lt is ~mented and Ulls occurs quickly
upon con~ct-wlth ~he cuttlng ed~e nnd durln~ normal fle~ e. By bondlng the ~la
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with l11e me~hods dcscnbed, ~t is less easily shattered. ~he ma~dmum abr~si~o
ability is obt~ined by pJesen~ing the gia~ss as a uni~ied and ~Inmo~ng abrasive
su~ce that is not easl~ shattered. By making these abrasi~es moro o~cct~ve, it is
now po~sible to at~ain equ~l ~ut protection with a lower abrasive content o~ ~o
~ncrcas~ protecdon with ec~iual cont~nts.
When the cutt~n~ threat 1~ ~om a chopping blow as opposed to a slash~ng
~ovement, 1h~ presont In~ention 81so exhibits uniquo abilltie3. Tho fu~d Sb~rs of
the ;nvention ar~ pulled in ~he directlt)n of the cutting edge thus Increasing the
concentration of protecti~e fiber and abrasivcs in t}~0 threat ara. Tb~ lncrea~e~
the level of protect~on to this type of threat.
It ha~ also been found th~t this ITlethod of mamlf~cturing creates a yarn wlth
Improved abDities lo ab~orb impacts and ~ribration of all types. ~s is due to th~
rcsU~ent properties prescnt in the compounds used for h~sin~ composito
to~ether. Thi8 charactoristlc ls u~cful to dalnpen vibration and pro~ido a meusur~
of protection ~ono blunttrauma. ~ ;
l~e core conta~nment barrier has been foun~ more uso~ul In containing wire
th~n orlgJnally bl!lieved. It wa~ bc1ievcd thnt lon~itundinnlly positioned stran~3 o~
~re should not exceed ,W2 ~nches diameter tluc ~n an increa~ed l~kelihoo~ o~
punctutlng thc cont2inment bartiet. Success wa~ found with longi~udin~l wire
rands of .W6 in~h dlamc~cr without increasin~ ~he overall dlamotor to the ~nl~hed
yarn. Thb ~IIOWS th~ uso o~ hoavler wlre strands with mllllm~l r1~k of barr~er
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Finally, it ha~ bcen obsesvcd ~hat ~mbodi~ents ha~nng c~res fotmed la~ely
of m~lt Eusible thermoplastic~ become hollow af~r heat trefltn~¢nt. ~hese
etnbodiments ~re very unique and exhibit improved ductility. ~his is in1ponant in
apparel applic~tions wher~ w~arer com~ort Is Important.
In some embodim~nts, ralher than bond the core t~ the thermopl~tie, it is
desirnble that the selected core i~ ne~t covered ~ith a layer oE ma~cri~l which
creatu an inner core containment bnrrier separa~ing the core Erom tho ~urroundine
~1t~h~s1bl~ the~noplastics. Thl~ Is necess~ly t~ prcvent the eoro structu~e f~ombondin~ ur~th ~he thermoplastic~ and the~eby restricting ilex~ r. Core materialsthat ar~ particularly brlttl~ wlll dcterioratn qulckly 1~ not allowcd to move ~e~ly
within such A shroud. Tnl~ inner core conlAlnment barri~r layer ma~ be o~ any
materinl ~vhich h~s a highcr melt point than ~he lhennoplastics whlch surround it.
Using the heat~set method rather than li~uid internal coatin~, a pre~erred
embodlment Includes a baslc core, arl~ around the circum~erence of the baslc corc,
the ~rst layer of one or m~re strands o~ wire may ~e wrapp~d t~ provide a s~condcomponent to the ba~c core. The wi~e m~y be wrapped in ono direc~ion with onG
or more strands applled parallel to each other, or the ~nre mny bo twisted or
comb~ne~ ~n ~ny oth~r known way. The wire may nlso be wrapped In oppo~ine
directions relative ~o each other, with one stran~l bell~ clockwlse, and the othcr
counterclockw~sc The pref~rred w~re is an annealed stainless steel 304 v~th a
range of ,00~" diamet~r or smaller. T}le most pre~e~re~ ~s .004S" f~r a ~ingle ~p,
or .003" for ~ double wr~p. Flner ~trnnds may be us~d when ~here i5 ~ ~omblned
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:
plu~ality of w~rG strands. In such embodiments, usin~ ~rire o~ .00~" clfamGtcr or
mnre, wrapping is preferr~d. rhe wir~ wrapp~d about ~he ba~c core may bc
wrapped ~t a pit¢h oE one to 10~ turns per inch as the embodiment r¢quires. It has
been observed thnt the helic~l shape ~hich is thus formcd directs the u ~re's angle
more to the center of ~he composite yarn ttructure. Thls becomes important when
a wire strand fractures. Lon~itudinally positioned w~re strands tend to pr~ect a
rfdd polnt when broken. Thls ri~id pn~nt is then 50 orien~d as to punctur~ the
surfac~ whcn th~ yarn i8 ~e~ed and ls dimcult to wntaln.
Followlng applleation of the ~ire component and/or Ihe eontainment barrlcr,
an ~dditlonal la~er to be added to the con~posite is selected ~om the ~oup of melt~
hlsi~le thermoplA~it~cs. These may be polypropylene; low, hlgh, or ultrn~high~del1sl~y
polyethylen~; low-melt nylon polyam~d; or polyamid blends; or low-melt polyettets,
A nut~lber of hlgher melt t~mpetature thermoplastics e~d5t whlch h~ve not bc~n
...
tested, but are believed to be ~pplicable for hiE~her tempelatu~e appllcations and
embodlment~. Thi5 In~rer may be ~ppJled In several different ~4ays, Includlng
wrapping, t~stlng, ~pinn~ng al~c~ut th~ core and ~he containnlent barr1cr; may bç ~ ~
longitudin~lly positioned with the core, extruded ove~ ~he cole, or blende~ with the i~-
corc, commingle~ h thc ~orc, or any combination oE Ihese mcth~ds. The
thermopl~tic~ also rn~y be ~pplie~ to the wire s~rands prior to wrapping the
strands ar~und th~ b~sic core. ~he ~elected lne~hod of combinlng the thermoptaslic~
with tho w~rc Is depentlent upon the number and size ~f the wire s~rands beln~
utillzed. ThG wlro strand~ may ~e wrapped, twtstedl pa~ led, pnr~lleled and
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wrapped with more the~moplastic, paralieled and ~4rappeci ~ntl~ v¢ry fine denlernon-thennoplastic, or the wire may be coated by means of any of the more
comcntional co~in~ mcthods.
Sel~cted thennoplastics for this layer may be mono61amellt, multifilament,
SpUIl or blended with other materials. rhe percentage of thelmoplastic conten~ In
this layer 15 limited only to thsî which is necessary to propet~ly qont~ln and stabilize
the un~erly;ng materials. When comblnlng w1lh the wir~ prior to wrapping lhe wirc
~round thc basic core, two bene~ts are attalned. Flrst, prior combining ~llow~ a,~ ~tcp to bc climinated in processing by not requirlng a ~epara~e wrapping oE
thcrmoplast~'c. Secondly, tho lhermoplasti~ is concentrated only in tho ~roa whlch
surrQund th~ wlr~, leavln~ some un~us~d areas to Incrcss~ tho ~c~dbllity ~f the
composlte. Some o~ ~he more effe tivc Ine~hods will be detailcd bolow.
.,
The next lager is the primary core cOnlainn~ent bRrri~r and is selocted h-om
a broad group o synthetic or org~nlc maten'als Includi~g but not llmited to~
pobegter, nylon, aramid, high dcn~lty polyethylene, ultra hlgh molec~la~ wcight
ex~ended chain polyothylene, such as ~lied's Spectra~, colton, wool, polycoteon,rayorl, ~oechsl C:elanese's P~IlM, Dupont's Tc~onTM, and blends. Tho e~ceptions
- are thosc matcrlals which aro the same as thos~ to be contained, and matefials
having melt points which are lower than the selected thcrmoplaslic. This layer
s ~ serves ~e~etul funclions: -
1~ It ~orms the layer oi. fiber ~vhlch 15 ~used with lhe underlyine adh~sivc
l~y~r lo hrm a ~hroud. In cert~ln ombo~lments wrappod wlre is tho material to bo
. .
21~4~)2
:` 11
contain~d and ~hls l~yer l~ utili~cd to ~use wi~h thc b~sic corc matcrisl around which
the wire is wrapped. Thi~ results In ~ sandwich efhct that th~rou~hly traps the uAre
in a ~e~ble cspsule or ~used fibrous material whic~ is almost impenet~abte.
~ ) In embodiments ~sing wrapped wirc, this shtoud ~unct~ons to prevent
the uire ~o~n movlng a~ tl1o composite is heated. Th~ ~clectod ~ber must therefore
be nf rcasona~ly hig~ lenacl~ d not gcnerally susc~ptible tn loss of ~trength atthe ~ushn temperature of the underh,ring then~oplastic.
3) Tbls la~r adds cut reslstance to the ~inished cnmposite yarn.
4) Thls layer se~v~s as a shroud whl~h ha~ ~ufficient thlckness to ab~tb
the underlying m~lt~hu1blo polymcr and prevent the polymeF ~rom passi~g to the ~-~
outer wraps. This is o~ parti~ular importance when subs~qucnt outer covers must
i~ .
be ~ble to function Independentiy of ~he c~re and ba1rier yarns. Indcpond~nt
movement is sometilne~ necessnry primarny for ~exlbilit~, but also ~110~4s the
perfonnance charactoristlcs of th~ yarn not to be impeded by en~rapment. It has
;~ been observed that yarns ~re more cut and/or abrasion resistant when Ule yarns arc
nllowed to move ~eely wllh the cuttln~ or abr~dinu surface. Th}~ is ~mply
lllustrated by obsennn~ tho rela~ive ease ~th ~vhioh a yarn m~y be cut u~d¢r
~enslon, VeFSUS one that i~ cu~ under less ~ension.
In a~dition t~ thc above hrlcti~n~, whton used in ~h~ wrapped wire
embodtmenls, it is proferred that thi~ third l~yor b~ wrapped at the number of turns
pcr Inch whkh provldel nn nngle ~g closo to 90 del~rces reJetlv~ ta tho wire ~5
foasible. Ne~r perp~ndhulnr anglos Qro opt~nlel to ~ w th~ 18h~d eompo~ite
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~ra~n to perfornl. Pres~nt en~bodiments havc attainod 70 deiqree ~n~ie at eight (~)
tums per ~nch uslng 840 denier nylon. In other embodiments It is neco~i3i~ry to
apply a tighter denier at a very high ran~c o~ turns per inch. This ;s par~icularly
true where multiple ends of ~ire are wrapped in opposin~ directions. l'he turns
p6r lnch must bo a comb~nation of optimal angle~, total encapsulation, densi~ ofthe layer and the ~ber's abillty to prcvcnt movement o~ the ~rç durln~ the heat
cycl~. It sbould be noted that ~he type 304 alloy o~ st~tnl~s~ has a coefficient of
t thennal expiansion cqual to 10.1 ~ p~r de~re~ rise In temp¢rature Fahrenhel~.
1~ th~ composfte is processed a~ 295 degrees Fahrenholt then a o~o-inch sectIon
would normally e%pand to 1.00~26846". Whlle t~ amount o~ mcntement n~ny
~ppear smAII, It does have thc ablllty to deform the ~abrlc If not controllod. Tostlng
has 3h~um that wire can push through the tbermopl~stlc l~yer as the w~r~ expandst dur;ng the heat cycle, and thls mol~enlent pre~ents a proper bond i~oln ~rming
because thc thermopla6ti~s t~nd to cool more qulckly than wire, Tbi~ l~yer Ici¢ally
shouid be wrapped with a comparable ran~e oF turns per inch as the underlying
core using i~ yarn oir suf~c~ent weight or dian~e~e to provld~ complete coverage and
denii3ity. H~wev~r, yal`ll5 ~rom 20 to 4800 denier m~y be used and may b~ applled
f~om threo to 200 ~UJ'115 p~r Inch as the cmbodiment requires. This shr~ud layerma~r be on~ or more wraps In slnlilar or opposin~ ~irections relatlve to one another.
As with the baslc core, thl~ laver can be mal~é up of a multipllclty of ya~ns,
depondin~ o~ the deslred ond cf~¢ct or product.
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In the p~eferred em~odimcnts descll~ed bel~w, it will be sb~rious that the
~1 simpler methods and ysrn comblna~ions achieve the best rGsulls.
A ~nal, or ollter layer may be added. This oute~ l~er i~ of pa~ticular
', importance when ~ho undorlying layer is not capable o~ ~bsorbln~ the molten
thermoplastic nnd preventin~ it ~om risin~ to the surface of th~ Snish product ~ .
~kno~4n as ~wet ou~"). The ~ber content of thls outcr layer may bo sol¢c~ed frDmthe sanle gtoup B5 the wiro.contairlment wrap. Therc may bo ono or more of thescoutcr wrap layer~ and cach may bc slmilar or ~issim~ar. The selected mat~rial wrap
.~ may be of a slngle str~nd, multiple strands oE a single yarn or a multipliciey ~f
d~f~ring yarn ~ib¢rc or typcs. This outer layer mny also be spun over thc
~i~ underlylng layers as with ~Ict~on spinnin~3 cqulpment.
:~ .
Wlth use of such overlying multiple layers lt Is pre~rred, but not requircd,
that each o~ tho layers be wrapped In opposin~ dircctlons~ l'his method oE
wr~pl~lng In opposlnu dlrcctlc)ns 15 known ns counterbalarlclng and has the e~fect of
maklng the yarn balanced, stralght, and with separate coverlns layers that tend to
lock ~o~ether and do not easily ~ay.
The com~ined selectiotl o~yarn ~b~rs and type5 ~5 ~a~ed primarfly on tbc
end u~e o~ the yarn, the fabric ol~ tho pro~lu~:t. Some of the m~rc common
m~t~r~nl~ nrc nylon, p~lye.~ter, nrnmld. extcn~led'chnin polyethylene, rayon. cotton,
or wool. Ho~cv~r, th~ f3~crst~pe~ may bc scl~c~d ~rom any of tlle ~ynthcti~ or
n~turnl mat~rlals group. As~y onc o~ the lay~rs or wraps m~y sen/e any o~ the
functlons of enh~nc~d cut tcslstanc~, abras~n sesl~tance, lmproved com~ort to tho
~ ~.
2:l~3~92
14
wearer, increased thermal pcr~o~mance, enhanced texture ~r handling ~pecial
materials, impr~ved knltabili~, or other s~lch characteristics.
The hnished novel cumposite yarn is applica~le to knittin~, wcavit~g,
~raiding, h~Asting, ~r otherwise ~rmin8 into a ~esir~d fabric or product. Oncc the
en~ product is prov~ded, ~he ~nal step o~ ~hermoplas~ic fusion generally takes plac~.
Treattnent tempera~ure~ and e~rposure times ~ill v~ry according t~ the
characteristiu of lh~ thennoplastic" density oE the composite and th;ckness of t~e
article manufactured. With glovesl ~or ex~mple, a ~ypical heat treating method
s wouid m~ke us~ of a glovo doning machine whlch is dcsigned ~or preci~e
tempcr~ture and e,np~suro time con~ol. Yarns may also be heat treated on the
packa~e in a dry or ~vot yarn condition;n~ oven.
DESCRI~TIONS C)F 1~ l;)RAWl~GS
il~ Figures lA and lB, 2A, 2B and 2C, ~, ~1, and 6 are schçma~ic rcpresen~atiolls
o~ var~ous cmbo~iments of the composite yarn; and ::
Figures 5 and 7 are ~ tive views of a glove made fron the com~
posite yarn.
~ Figures 8 and 9 illustrate further entodinents of a cc~posite yarn.
`~ DESCRIPTlC)~ OF PE~l~FERR~O ~MBO~IMENl`S
These de6ni~ions will be help~ul in identi~ing ~he various designations and
functions oE tho dcscri~ood layers.
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(1) Basi~ Co~e: ~a~ be one or more longitu~inal mateT~als including all
~, thermopl~stic ~bcr~, and carbon fibers or olher po5~(ble~ colltam~nnte ~roups.
~as~c core may hAve thes,~t selected matcrials spun, wrappcd, twl~ted or
coated over one or more longitudinal members.
(2) Inner Cote l ontainmen~ B~r~er This is an optional layer for us~ in those
embodiments that req~lire separa~ion of ~h~ coro andadhesive layers. ~t may
bG ~pun or wrnpp~d over the basie core. Selected matarials only exclude
those contamlna~es of the bnslc core or msterinls with n~elt te~aperatures
equAI to or lowor th~n thc thcrmaplas~lcs oE the heat processed
embodimen~s.
(3) Adhesive layer: This layer may be ~sed as the only ~ourco of ~dhesive~ in
t conJunctiorl ~itb adhesi~es in the basic eore, or not us~d at all whcn
sufficient adhesi~n is avnilable from materials in the baslc coro. l`h~ layer
mny ~c wr~pped, splln, coated, h~s~e~ or iiosit~oned longitudinally to th~
basi~ core or conta~nmcnt b~rrier layers.
(4) Primary C~ore C:ontainment Barrier: Prom the same yroup oEmaterial~ ;
selecled for the Inner core conta;nment bar~ier; may be wr~pped or spun
over the Inner l~yen and ~e slngulnr of a plur~ r of yarns comblned in any
S way,
t5) C)uter Layers: Prom the same ~roup of contnlnment barr~er fi~ers: thi~ luyer -
or 1uyerJ Is optlonnl to enllanco perhrnlanc¢ a~ nc~d~d.
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Looking ~rst ut Pigure lA, ~ first embodirnent is detailed ns baving ~ basic
c~re 2~ i'ormed o~ 840 denier industrial gr~de ~ylon. A single wrap 2S o'. .0045"
diameter ~nne~led stainless wire is nppl~ed over core 20, npplied At approx~ma~ely
ei~ht turns per in~h of c~ro length. ~rapped about this sl~lc w~re wrap 25 Is a
loq~melt-tempcrature the~moplastic adhesive layer 30 oE a ~pc such as .OU6"
Shakespeare mono~lament ~1C 101~ ~erpolyamide Eorming a wire/thetmoplastic
layer 3~. The thcrmoplastic 'aarr~er layer 30 is appliod over wire 2S at
appro~rimateb 100 turn5 per tnch of w~re core 1en8th. A prtmary core co~alnment
b~rrier, 3~ i5 ~pplicd in tho oppos~te diroctlon ~relative to the wlre/th~rmopla~tic
Isy~r 32) an~ is prefer~bly formed o~ 84~ denle~ industrial grade nylon; again
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wr~pped at approximately ~ht turns per inch of core or yarn length. A final outer
a layer ~0 is cump~.ised o~ one strand, ~ pped in a direction opposite to the
~! und~rlyln~ laycr 35, or ~pproximatcly ei~ht wrap~ per Inch oE coro ~r yarn, formcd
~:~ of 840 den~er industr~al grade nylon.
While thls embodiment in Figure lA is one oE ~he b~sic approae~es, it
-i c~mbincs ~he the~noplastic Eiber with the wire wrElp prlor ~o wrapping ~he wir~
around ~ho core. Thus th~ ~dhesi~e action o~,the thermoplastic is concentrated in
the c~ilical area~. B~ wrapping lhe u~ire wl~h 840 denier nylon, tb~ wire and nylon
inters~ct ~t nn optimal angle to ~ont~in the thermal expnnsioll of the wire while stUI
` I malntainin~ t~l~l covcr~g~ of the wire. T~st rcsulls of this cmbodtn~ent Indlcate
that tb~ composite yarn is equally ~u~resistant to any ~ther kn~wn wire y~r~
product~, ~nd exhl~its n~ dotrlmental tigidi~ resultinF ~om thc unlq~ e
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en~apsula~ion of the wire.
Usin~ the samo b~sic st~uctu~e of Inyers shown in Figure i~, snother
embociiment shown in Fi~ure lB fe~tures a core ma~er~al 20' o~ 120() denier
extended chain poly¢~hylene wrappcd with a strand ~5' of .0045" diameter anne~led
stalnless ste~ approximately iive turns per inch. ~he .004S" diamet~r steel wire2S' is itse'f wrapp~d with comrentional mul~iiil~mcnt or m~noillament polyethyleno
3 30' o~ appro~dmately 200 denier before lhe wjr~ Is wrapped ~round the core 20'. A
subs~quont wr~p 3S~ i9, In thls embodiment, formed of ~50 cienlor extended chainpolyethylene at a ra~8e of iive or six wraps or turns per Inch to complotely covor
the wire l~yer. The ~nal outer wrapping 40' is formecl of 840 denier i`ndustrialrade nyloll wrapped at approximA~ely ~ ht lurns pi~t inch of core or g~
It ~hould be not~d tba~ this second basic embodiment described with
rc~eren~c tO th~ lay~r~d stmcture of Fiber lB utilizes an e~ended ch~in
? palyethyl~no having n melt po~nt of approximately 297 de~ree~ Pahrenheit to form
layer 3S', to wrap or covcr the wire whlch has been pre~iously wrapped w~th a
conventiona1 polyethylene 30' havlng a melt poin~ of approximately ~00 degrees
Fahrenhoit, to ~nsure f~rm~tion oE an adhesive bond between the encaps~llating
prima~y corc contairlment barrier 35 and the core. Such a structure is preferredbecau~e ~he con~entional po~o~hy1ene helps compcnsate ~or the poor adhe~ive
per~ormanc~ of u~tend~d chain polyethylene. This structùre also offers an
exceptionally hlgh level o~ cut resis~nce and an equal1y gwd ability ~o cncapsul~te
the wlre becl~u~e o~ exLended chLlln pobclhylene'c un~urpnsted ~uen~LLh ~ind CL~
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~csistance. Nylon is used as ~l~e outer wrap 40' becQuso of it~ dissimilan~ ~rom the
core. 1~ the he~t applicat~on Is not precisely corltrollod the cxt~ndcd chain
polyethylene nlaterlal can re~ch Ihe soRenln~ polnt and bond ~th the outer cover5,
thus increa~jng ~ lik~lihood of l~igidlty In the cnd product.
I ookin~ next at Figure 2, nnd cross-sectional vfews 2A, ~B, ~ third
embodimellt h~ a core SO ~ormed o~ a sfn~le strand of 900 denlor ~erglass.
Posltioned longitudinalty of thi~ co~e SQ is an adhcslve lay~r S2 o~ three ~paccd
apart ~t~ands of .006" Shakespear~ ~ 101~, strand~ S2n, 52b, and ~2~, having
melt polnt oE 2'7S degree~ Fah~enheit. A single oncapsul~ti~n8 shroud or coro
contalnmant bA~er 54 i~ ~ormed of $40 denie~ high ~enacl~ nyl~n wrapped ~ve~
the underly;ng materla~s at ~pproxfm~tely eiuht turns pcr Inch of core o- yarn. A
.
s subs~qu~nt outer cov~r 5~ o~m~d o~ thc same 840 denler nylon wrapped in the
opposftc direction (relativo to ~4) at ~pproxlma~ely cight turn~ pe~ inch. In thls
e~ample the ~erpolyamlde (mclt h~ible nylon~ doe~ not conlphtety contain the core
prlor to appl~catfon of he~t. Howe~er, dur~n~ ~he hcAt cycle the soanposite has a
~utflclent quan~ft~r o~ thls melt fuslblc matet~al to flc)w around thc cntfrc
;~3, circlJmferenco o~ tho cor~ ~Fl~ure 2C). Becau~ the 840 deni~r nylon enc~psulallon
~. shroud Sd, 1~ h polyamid~, ~n ~ ellent b~nd i~ formed wlth the melt hsible
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eerolyam~de 52~,b.e. Residual pol~ner will aclhere ~o th~ ~bergl~ss core. The outer
~: wrap 5~ Is no~ Pused to the zncapsul~tion shroud S4 beeause there is su~ficicnt la~er
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~ oE the Inner urrap to absor~ th¢ melt fusible m~tetial. ~ ~
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~ igure 3 illustrat~s a ourth embodiment which utili~es f~urte~in strands of 3
micron st~inI~Yss st~el type 304 to form a lon~l~udln~lly oriented bs~ic core 70. The
core 70 i5 wrapped with 6S0 d~nier extended chain polyethylene at ~ve turn~ per
inch to form an inner core containment barr1er 72. TheTI rnultiple ~trands ~.005"
Iow den~l~y poiyeth)~lei~e n~no~l~ment iR~e ~dded to lon~itudin~ sutround the
wrapped core, parallel ~o th¢ ~ur~een strands of steel which ll~n e~ro 70, thus
~ormlng ~dheslv~ l~yer 74. A final outer layer o~ 200 d~nier TF~ nurocarbon (such
as that made by I:)upont C:orporRtion ~nd sold under the tradem~rk TefionlM) Is
wrapped in the nppos~te dl~ecdon (relatlve to wtap 72) at appro~m~tely twelve
.
~j turn~ per Inch, to form the outer ccver or pri~ary cotc c~nt~inmont bnrrier 16. In
`. thls cxnmplc, unusually ~ne strand~ of wire arc used ~o create a hlgbly aox~ble ba~ic
core 70 which has a ~esulting denier eqlJivalent to 1000 denior; yct e~cb of the
Indhridusl strsnds Is ~n4bh t~ puncture the relati~ely ~nc barrior layer 72. Thecontain~ncnt barr~er of extended chain polyethylene which Eorms the inner core : :
contalnlllcnt ~arrier 7~ is preferably ~Ulied Signal's product 301d under the
~; ~rademarkSpectr~ 1000~
Thls fi~ure 3 cmbodlment Js ~omewhat unique when compared to the ~ther
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mbodiments taught herein, in that the final wrap 76 Is in dlrect cont~ with the
`~ adhes~te l~yer 74 ~nd l~ therefore ~sed to the other materials. It ha~ been ~ound
~hat due to Te~on's~M lubricity It must be Fu~d in ~rder lo prevent the Te~onlM
lay~r ~orn movln~ and e~po~lng the m~ter~als beneath. Furthe~mare, Teaor~'M
doos no~ neod to hnc~lol~ Indop~ndently in ord~r to adequately per~orm ~n this
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embodiment. The unusually heavy la~er prevcnts the therm~pla8tic 74 ~om ~owing
to the isudac~. Thi~ cmbodim~nt ~s particularly sllited to use in productior~ of ~ cut
rcsistant surgeon's ~lo~o which wou1d ~e worn so as to underlic tho conventionalsterile late~ glove used in most surgical facilitie~.
Figure 4 Illuiq~rates a ~ft~ ernbodirnent wherein a core gO is formed o~ 1000
denler K~lar ~gTM (~ramid) made by l:)upont Co~poratioa. Po~itfoned
lon~ftudlnall~ to this oore 90, are conta~ne~ by a layer 94 formed of ~upont
Corporathn'J type ~8 pol~ei~ter of approxim~tely 1000 deni~r .~vhich has bcen
r modi6ed to Incorpoîate hv~ pnr~llel strands ~Sa ~ncl OSb ~nd 160 denl~r
polyethylene. This laycr 94 is ~rapped at approxlmatel)~ 6~e tur~s p~r irlch In the
opposlto directfon to the wrap of the outGr wire la~rer 92b. A ~nsJ ~ut~r covcrlng
i' ~6 Is formed ~ the same polyester and Is wruppe~ at spprox~lnately five turns por
inch In a dircctlon oppo8ite thnt ~ th~ contained layer 94. This composito yarn is
suitable for produc~lon of gloves ~hich nre knlt~e~ ~nd then heat treated ~r
appro~dmately ~ mlnu~es at 340 dc~rccs Fahrenheit in a convontional g~ove
dotling machinc. ~:
In thls embod~ment of P'lgure ~, thc ~dhesive layers 91,a,b,c are boneath tho
qirc layers. Additional thormoplastlc ls comn~in~led wlth the prlmn~y cor~
containln~nt barrler 94 ~or ease of processln~. Becau~e h~o ~tr~nds of ~vire 9~a and
92b are used in opposin~ directions, the prim~ry ool~e containment b~rrier Y4 isapplicd outslde ta the outcr ~Ivlre wrap g2b. Since the ffrst, or lnnor wire ~trand is
J wrnppod w~th tho snrnc numbor of turns and In tho same directl~n u tho ban~er 94,
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it w~uld normally pu~h Ulrou~h the commonly orientcd filamonts o~ polycste~ ~
~.
during the heat cycle. ~3y wrapping opp~site the oute~ wire str~n~, and thc~e~y
controlllng its expanslon, the inner u lre strand is thus al~o controlled. Poly¢ster i~
usePul as an erlcapsulatin~ s~lroud and as a tlnal wrap du~ to ~ts shr~nk~ge o~
~3 appro~dmately fourteon p~rcent of tho hent-set tempcrature oF 340 degrecs
Fahre~heit. Shrinknge causcs the polyester to c~ntr~c~ A6ainst thc e~psnding wirc
and Eo~rn more closely with the cole ma~erial, cstablishing a st~ong adhe~ive bond.
. Thc embodimcnt ~n Figure 6 d~mon~tratcs there aro a ~arlety of yarn
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constnlctlon~ ~hat fall wilhin the teachings ot ~his di~closure ~n~ claim3, nnd can bo
1~ usod ~o crc~te the ~mo or c~milar products; Thlo embodimont 15 c~mpr;oed of a
.~ core 110 ~ormed of Appr~ tely ~ourteen strands of 35 mlcron ~pe 304 s~ainloos
r~ such ~s that n~nnuhctured b~ ~eckert Company. Wrapped abou~ tbis core 110
~ Is a Inyer ~1S f~r~ned by comblning a wrnp~ing 115a o~ ~00 denior indu~tnal gr~lde
-~ multi~ilamcnt nylon, wrnpped a~ sppro~nm~tely ~hir~r turns per inch of eore, nth a
p~r~llcled strand 115b of .006" ~rand of melt hsible tcspolyam~do mono61amcnt.
'~ Th~ profemd te~polyamide monofilament is Shakespearo ~X 1012 which has a
~. mel~ point of 27S de8rees Fnhrenheit. Posilioned parallol to the coro 110 and
...,~
overlyin~ 11S i~ a ~ingle strand 11~ of 12W denier TFE ~urocarbon such as
eDonsM~ The Te~nT~I is carefully fed lhrou~h ~ devic~ ~hlch ~irst ~ares the w~dth
oE the multifila~nent, then ~apers around ~he core so as to surround tho inner
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~1 surf~cc of ~hc coro 110 al~d 115 ~th Tc~on~ nen~. A ~nal outor wrap llfi of
`~ 20 d~n~er nylon ~ wrApp~d at A ran~e of ~v~ to eight lurn~ p~r inch ~n tho opposito
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direct~on relative to the intler layer 115. l'his Einal wrap 116 holds the l'e~lonlM in
plac6 un~ e compo~itc yarn ls he~t treated.
Fi~ure ~ illustrates a ynm constnl~tio~ wherein tha cor~ formed of an
in~ust~ial grade polyestor tS00 denier) 202 combined w~th a sin~lo strand o~.0~3",
type 304, stalnl~s~ s~eel wire 205. The adhcsive layer 21~ i9 helically wrapped about
tho b~slc core 200 at ~pprox~mat~ly ~even lurll5 p~r inch, prcferably folmed of 3S~
den~er, '1~ ~lament, lo~lv den~ity polyethylene. Over this adhesivo l~y~r 15 a primary
core contalnment barr~e~ 21S f~rmed of ~00 d~ni~r )ndustrial ~radl~ polyester which
is helically wrapped ~t app~o~dlnat~ly nln~ turns pet Inch. A final outer layer 220 o~ -
1000 donier Industrial ~ade polyegt~r is wrapped In the oppositc ~irec~ion at a
pitch o~ appro~mately ~Ight tUltl5 per inch. The ~inished ynrn Is then heAt ~t ~or
appro~dmately two and one~hal~ to ~o and lh~e-quar~r hours, at 280 degrees P`.
In a stc~m conditlaning uni~ e y~rn of this embodimer~t is hlghly suited for usc
~n construction ~t Indwtrl~l gloves ~nd olher cut-re~lstant fabrics.
Fig~lre g Illus~rates a ba~lc core 300 of 1sn denler textile grade polye~ter 302
and 100 den~er, 70 filament low-density polyethylene 305. Wrspp¢d about thJ~ basic
core is a single strand 310 oE.00Z", type 304, stninless steel wirc which is wrapped :~
at a pitch of twen~-~our turns per Inch. The prilnn~y core con~ainment bartier 31S
(the ~inul layer) is 300 denler textile ~rade poly~ster w~apped in ~ direiction
oppo~it0 that of the w~r~, at a pftch of appro~imately terr turns per ~nch. The - :
6nished yarn Is ~hen heat set for onc and lhree~quarter hours a~ 280 ~ee~ in a
steam condltl~nlng unift. ll~is embodlment Is b~st sulted for finer cut-resi~tant
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Eabrics and most p~nicularly for cut-resistant surgical glovcs.
Figures 5 and 7 i~ ctrates a cut-resistant glovesnade from any one of the
embodiments oE the composite y~n~ descrlbcd above. It dem~ns~rates improvcd cut
rcsistance, nexibility e,nd comfort. Olher end products are anticipated to be msde
Erom thc novel y~rn described hereln, other embodiments of the yarn are
anticlpated, and all ar~ believed to be within the scopc of the claims below.
Figure 5 illustrates a half cut-resistant glove.
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