CA2119678A1

CA2119678A1 - Monofilament made from a blend of a polyester having a polyhydric alcohol component of 1,4-cyclohexanedimethanol, and a polyamide

Info

Publication number: CA2119678A1
Application number: CA002119678A
Authority: CA
Inventors: Herbert D. Stroud, Jr.; Paul R. Cadmus
Original assignee: Hoechst Celanese Corp
Current assignee: CNA Holdings LLC
Priority date: 1993-04-26
Filing date: 1994-03-23
Publication date: 1994-10-27
Also published as: FI941916A; FI941916A0; EP0622479A3; ATE168144T1; BR9401568A; JPH0711114A; EP0622479B1; DE69411444D1; DE69411444T2; EP0622479A2

Abstract

ABSTRACT
The present invention is directed to a monofilament made from a blend of a polyester having a polyhydric alcohol of 1,4-cyclohexane-dimethanol, and a polyamide. Additionally, the blend may include a polyolefin. This blend is useful as an article of paper amking machcine clothing used in forming, pressing, or drying sections of a paper making machine when the blend is in the form of a fiber structure. The blends usefulness stems from its dry-heat strength and hydrolysis resistance.

Description

`'l .; A Monofilament Made ~rom A Bl~nd of A Polyester Haviny A Polyhydric Alcohol Component of 1,~-CyclohPxanedi~ethanol, Auld A Polyamide :, , -¦ The present i~vention is directed to a monofilament mad~
from a blend of a polyester having a polyhydric alcohol componant i of 1,4-cyclohexanedim~thanol, and a polya~ida. This invention i~
:, particularly useful as an article o~ paper making machine I clothing used in the forming, pre~sing, or drying section~ o~ a -: paper making machine when the blend i~ in the for~ of a fiber . structure.
:1-~ - Background_Qf th~ ven~ion .,~ .
-~ Paper is co~po~ed of cellulosic fibers that are for~ed into .~ a she~tO A paper ~aking ~achine con~i t~ o~ ~hre~ ~ain sections:
the forming section, the pres~nq s~ction, and the drying sec~ion.

In th~ forDing s~ction, th~ c311ulo~ic p~lp ~lurry or furnish is injected onto a form{ny ~abric which i~ a 19ng, W9V~n mesh bel~. A~ the forming fabr~ ~OV~8 along through the ~or~1nq section, some o~ the water in th~ ~lurry ~rain~ through the '~

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. fabric and a paper web is formed. As thi~ paper web leave~ the .~ forming section, it is composed of about 80~ water and about 20 solids. For many years, forming fabrics were woven from metal .' wirQs and had a lif~ of about one we~k on a paper machine. Thi~
~ short life was due to metal fatigua and abra~ion cau~ed by .s ~ontacting the machine part~ in th~ forming s~ction. In the 1960'æ, experiments were begun to replace the metal fabric with woven, synthetic, monofilament yarn fabrics~ Today, polyester monofilament is the yarn of choic~ for thi~ application and typical fabric life i~ about 60-120 days.

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After leaving the forming ~ection, the paper web move~ into .~; the pressing section where ~ high compre~ive force i~ exerted by a pair of press roll~ to re~ov~ moro water from the paper web.
The press fabric serve~ a~ cushioning and water re~oving media , between the press roll~. As th~ paper leaves the pressing i section, the paper web contains about 60~ water and 40~ ~olids.

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Traditionally, press fabric3 wer~ mad~ o~ 100% wool due to its re~ilience and water absorbency~ Howev~r, synthetics hav~
. been develo~d with good resiiiænc~ th~t hav~ long~r li~ than woolen felts. Fabrics o~ choic~ tod~y consi~t o~ ~ bas~ ~abric, woven fro~ polya~lde ~onorila~t8 in~o whi~h polyasid~ fib~rs have been needlepunched to fon~ a ~lt. Typically lif~ o~ pr~
felt~ i~ 30-60 day~, '~

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:: The drying section consists o~ large, skeam-heated cylinder~
that dry the paper web to a level o~ about 6% moisture. A dryer felt or fabric is needed to hold the paper in contact with the dryer cylinders. Originally, theZ~e fabrics were ~ade from cotton, ~ut as paper making developed, higher speed and te~perature short~ned the lifeZ o~ thZ~ cotton dryer feltsZ, Many different fiber-~ and yarn~ have been u~ed to develop better-~er~orrZing dryer felt~ so as to i~prove theZ ef~iciency of ; the paper making process. Pre~Zsntly, the predominant yarn uZ~ed in the manufacture of dryer fabrics is polyestZr monofilament.
See, Luciano, B., ~ Volu~Z~ 38, No. 4-6. Dryer fabric~ mad~Z fro~ polye3ter monofilament operating at normal temperatures (300 to 350F) la~t about one year.

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~i In order to i~prove profitability, paper mak~r~ de~ire to increase speed~ of the pap~r ~aking ~achines. To suf~iciently dry the paper at increased throughput, additional he~t i~ used in -. the dryer section and perhap~ in oth~r ~ection~ o~ the paper machin~ as w~ll.

~Elevated te~perature6 tend to ~dv~r~ly a~f~ct th~
hydrolysi3 re3i3tancZ~l o~ polye~tQr ya~n~. For ~hi8 reZa80n manufacturer~ o~ dryer fabric3 h~v~ lookoZd at other ~ib~rs and yarnZ~ in an e~fort to increaseZ ~ bric 1 i~eZ ~t higheZr `

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~ temperatures.
-Moreov~r, i~ a fabric ha~ to be replaced at other than ,7 scheduled maintenance cycle~ due to failure or damage, the downtime cost to the paper maker can be signi~icant. For this . reason, it is desirable to manufacture dryer ~abrics that will .', run with longer and more predictabl~ time~ under increa ed heat , and speed conditions.

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As we move into the next century, an ever increasingemphasis is being put on using recycled paper in the ~cing o~
new paper. In the U.S., Federal and 8tat2 laws ar~ being pas~ed which require a certain amount o~ recycled paper to be used in each pound of paper m~nufactur~dO For the ~Yironmentali t thi3 is a good law, however, for th~ paper maker~ thi law po~es new challenges because the recycled paper ha~ a high l~vel o~
conta~inants. Contaminants includ~ wood pulp residue~, inorganic residues (such as clays and titaniu~ dioxid~), adhe~ives fro~
mailing labels, stick~r~ fro~ hot-~lt adh~lvG~, non-paper ~ilms, and printing ink~. The~ conta~inant~ ~ay ~ith~E ~tick to the paper maXing fabric~ or b~ ca~ri~d on through th~ pap4r machine in th~ paper sheet. I~ ~has~ conta~inant~ cannot b~
ea~ily re~ov~d, th~ fabrics will b~co~ plugg~d ~nd tho quality of the paper will decrease to t~a polnt th~t th~ ~abric ~ust b~
replacedO Due to the eaYe o~ cl~nlng, ~bric~ ~d~ ~ro~ 100 monofilaments are de~ired. Se~: ~uciano, B., Ihid.

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6 ,' ) One ~olution is to use polyphenylene sulfide (PPS) monofilaments in the manufacture of dryer ~elt~. PPS has very ~ good hydrolysis resistance, but un~ortunately, the polym~r is ; difficult to extrude into monofilaments and i~ quite exp¢nsive.
Also, PPS monofilaments are very brittl~ lwhich can cau~ proble~s on the paper machine. An example o~ a PPS monofilam~nt i8 found . , in U.S~ Patent No. 5,162,151, which i~ incorporated herain by reference.

Another fiber solution to th~ harsh environment o~' the pap~r making process is the use o~ poly(2-~etAyl-1,50p~ntylene) terephthalamide. See U.S. Patent No. 5,162,152, which i~
incorporated herein by re~erenc~. Y~t another ~iber ~olution i~
the use o~ a copolymer of terephthallc acid, i~ophthalic acid, and 1,4-dimethylocyclohexane (al~o re~rred to a~ 1,4-cyclohexanedimethanol). See: U.S. Patent No. 5,169,499, which i3 incorporated herein by refer¢nc~

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Accordingly, there i~ a nQ~d in ~h~ papQr ~king indu~try to develop new fiber~ ~or U8~ in pap~r ~Xing clo~hing.

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Summa~y of_~t~Q..Invent~Qn One embodiment of the present invention is directed to a monofilament made fro~ a bl~nd of a polye~ter having a polyhydric alcohol of 1,4-cyclohexane-dimethanol, and a polyamide. Thi~
blend is useful as an article of paper m~ciny ~achine clothing used in for~ing, pressing, or drying sections o~ a paper ~king machine when the blend is in the form o~ a fiber structure. Th~
blends usefulnes~ stems fro~ it~ dry-heat ~trength and hydroly~i~
resistance. Another embodiment o~ the pre~ent ~nvention ix directed to a monofilament mada from a blend of a polyester having a polyhydric alcohol of 1,4-cyclohexanedimethanol, a polyamide, and a polyole~in. This blend, a~ the foregoing, i3 useful as an article of paper ~aking machine clothing and its usefulness stems from the tho3e ~entioned in regard to the , ., .. foregoing product in addition to it greater ability to be fvr~ed :, into a spiral fabric.
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Th~ inv~nti~e bl~nd~ di~rlo~d h~rQin includ~ a polye~t~r having a polyhydric alcohol co~pon~nt o~ 1,4-~yclohexane-dimenthanol, and a polya~id~. Th~ bl~nd ~ay includ~ a~aut 70 to about 95 percent ~y weight o~ tho polyester a~d ab~ut 5 to about 20 p~rcent by weight of ~h~ poly~id~O The bl~nd pr~ferably .~, ,,,,3~1 ' 6 ,, '', .
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includes about 85 to about 95 perc~nt by weight of the polye~ter and about 5 to about 10 percent by weight of polyamide.
Additionally, the blend may include a hydxolysi~ stabilizing agent. The hydrolysis stabilizing agent ~nay comprise about 0.5 to about S percent by weight o~ th~ blend, preferrably it comprise~ about 1.0 percent by weight of th¢ blend. The blend may also include a thermo-oxidativ~ ~tabilizing agent. The thermo-oxidative stabilizing agent ~ay co~pri~e about 0.05 to about 10 percent by weight o~ th~ blend, preferrably it comprises about 5 percent by weight o~ th~ blend.

The inve~tive blend~ di~clo~d herein al~o includ~ a polyester having a polyhydric alcohol component o~ 1,4-cyclohexanedimenthanol, a polyamida, and ~ polyole~in. The blend may includ~ about 70 to about 95 per~ent by weight v~ th~
polyester, and about 5 to about 20 percent by weight o~ the polyamide, and about 1 to about 6 percent by weight of th~
polyolefin. The blend pre~rably includ~ a~out 85 to about 95 i, perc~nt by weight o~ ~h~ poly~t~r, and about 5 to about 15 ~, percent by weight o~ polyamide, and about 1 to about 3 perc~nt by weight of ~he polyole~in. Addition~lly, th~ blend ~ay includ~
hydrolysi3 ~tabilizing agen~. Th~ hydroly$is st~bilizing ag~nt may comprise about O.5 to about 5 pQxc~nt by weight o~ the bl~d, pre~erably it comprise~ about 1.0 p~rcent by welght o~ thQ bl~nd.
The blend may al~o includ~ a th~r~o-oxldative ~t~bili2ing ag~nt~
The ~hermo-oxida~ive stabilizing ag~nt may compri~e about 0.05 to , .

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about 10 percent by weight o~ the blend. If used, it preferrably comprises about 5 percent by weight of the blend.
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- The term "monofilamentn, as used herein, is directed to any single filament of a manufactured ~iber usually o~ a denier higher than 14. The term n-~haped article", as ~lsed herein, i~
directed to article~ which ar2 ~ade by e~:rusion or molding technique~, including, but not li~it~d to, fibers, films, i~jection molded article3, and blo~ moldecl article~.
;' The term "polyester having polyhydric alcohol component o~
1,4-cyclohexanedi~ethanol", as u~d h~r~in, i~ dir~cted to, but not limited by the polye~ter ~at~rial di~closed and claimed in i U.S. Patent No. 2,901,466, which i8 incorporated herein by .~, reference. The polyfunctional acid co~ponent may be ~elected `! from, but is not limited to, t~e group of: isophthalic acid;
terephthalic acid; derivatives o~ i~ophthAlic acid; derivative~
o~ terephthalic acid; and co~bination~ ther~o~. The~e polyest~r may be referred to a~ polycycloh~xl~ndy~ nol t~r~phthalat~
(PCT)-a poly~ter ~ro~ ~h~ condsn~tion reaction o~ -cyclohexanedim~thanol (CHD~) and t~rephth~latic aGid or it~
derivativai~, or P~T~ - th~ condi~ni~iation product o~ CHD~, tereph~hat~ acid and iso~halic ~cid. Each Or tho foregoing i~i prQducts ar~ commercially av~ilabl~ ~ro~ ~h~ Ea tman ChQ~ical - t Of Kingsport, T~ und~r tho tr~d~n~ Ea~t~an 3879 (th~ PCT
product~ and ~KODAR~ T~ER~X Copoly~it~r Typ~ 13319 ~h~ PCT~

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product). The PCTA material i8 pre~exr~d. The ~ib~r processability of these material ~ay b~ improved by the addition of a minor portion o~ polyethylene terephthalate. Se~: British Patent Specification No. 1,040,470 incorporated herein by reference.

The term "polyamideN, a~ u~ed herei~, i8 direc~d to any Or the known polyamid~ polymers. Th2 polya~id~ app~ars to improve the dry-heat strength and hydroly 18 re~i~tance o~ the yarns ~ade fr~m the blend. Exemplary polyamide~ includa, but are not limited to: nylon 6; nylon 6,10; nylon 6,12; nylon 11; nylon 12;
nylon 4,6; nylon 6,T; nylon 6,6; and co~bination~ th~r~of. Nylo 6, 6 i8 preferred. The foregoing nylon mat~rlal~ ar~ comm~rcially available from the Engineering Pla~tic Division o~-th~ ~oechst Celanese Corporation, Sum~it, NJ.

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The t~rm "polyolefinN, a~ u ~d h~rein, i~ diracted to any o~
'~ the known polyolefin polymers. Tho polyol~in appe~r~ to improv~
the ability of the fiber to b~ ~or~od into a ~pir~l yarn.
:, Ex~mplary polyol~fln~ includ~ but are not li~it~d to:
polyethylena, polypropyl~n~, polyoct~na and copoly~r~ thereoP.
copoly~er of ethylena/octen~ i~ pr~rr~d. Th~o ~t~rial~ ar~
com~ercially availabl~ from DG~ Ch~alcal Co~p~ny, Atl3nta, GA
under the tradename o~ "ASPUN~.
i The ter~ "hydrolysi~ ~ta~iliz~ng ag~nt~ is u~d hQrein, , . .
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refers to an "endcapping agentn. Endcapping a~ent~ are us~d to prevent degregation o~ the polye~ter polymer. T~i~ particular form of degradation result~ fro~ hydrolysi~. Ex~mplary hydrolysis stabilizing agents include th~ cla~6 o~ che~iGals known as carbodiimides. A preferred carbodiimide i8 known chemically as 2,6-diisopropylphenyl carbocliimide. Such carbodiimides ar~ commercially a~ailablQ ~mder the tradena~2 "STABAXOL~, "STABAXOL P", "STAB~XOL P-100~ from thQ Rhein Chemie GmbH of Rheinau, Fed~ral Republic of Ger~a~y and ~C~RBO D" ~ro~
BASF of Parsippany, NJ. '~STABAX01 I" and "CARBO D" ar~
preferred.

The term "ther~o-oxidativ~ stabilizing ag~nt~, as us¢d herein, ref~r to a material ~dd~d to prevent degredation o the polyester when subjected to hot dry heat~ Th2 pr~f~rred mat~ri~l is sold under the commercial na~ o~ "KODAR~ THERMX 13319 L0001 from the Eastman Chemical Co. o~ Ki~g~port, TN.
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The polyole~in-containing ~lloy ~ono~ila~n~s, di~cl~d herein, are particularly suit~d ~or spiraling end u~. Spiraling end uses refer to, for exa~plQ, ~abric~, made ~ro~ spiralQd mono~ilaments, that may be u~d i~ conv~yor belt~, lay belts, dryer fabrics ~or paper mac~in~ and th~ lik~ Spiralod ~abric~
refer to th2 following, for exaDpl~: A ~ono~ila~nt i~ pa~s~d through a ~piraling ~achin~ in ord~r to ~ak~ ~n oval ~hap~d spiral. In this spiraling ~ach~n~, th~ ~ono~ nt i~ hea~d .,.-,,, . ~ : ~ , .
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and then wrapped around a mandrel of a specific shape. As new monofilament comes into the spiraling machine and i5 spiraled, ;~ the ~ooled monofilament wrapped around th~s mandrel i~ pu~hed o~
.. the end of the mandrel. These spiraled monofilament coil~ are .~. then meshed together and a pintle yarn is passed through the . intermeshed coils to form an interlocked ~itructure. An entir~
.~ fabric is constructed by building up the nwnber of coiled . structures that are fastened together by pintle yarn~. In the open space between the pintle yarns, it i8 pos~ible to in5ert an additional monofilament in order to control the air permeability of the ~abric. After the fabric~ are made, they are heat set in i~ order to fix the.ir dimension~l stability. A fabric made fro~
, spiraled coils.is a~tractive becaus~ it cost~ less than a woven -, fabric of similar dimensions. It i~ al80 pos~ible to repair a ¦ de~ect in the fabric ~ade fro~ spiraled monofilaments by removing j the pintle yarns on either side of the defect, removing the ,i defective portion of the fabric, and inserting a new section in 1 place o~ the part that was re~ovsd. Se~ generally, UOS. Pat~nt `~ No. 4,423,543 which diseu~e3 spiral fabrics, and which i~
, ~' incorporated herein by referenc~.
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.i 1, 0th OE dotail and asp~ct~ o~ ~h~ invention ar~ ~ore fully ~. described in th~ example set forth ~reina~ter. Wet~hts ar0 -~. given as weight percent unless oth~rwis~ not~d~

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EX~PLES

In the following e~amples, the manufacture of the present invention (without polyolefins) i8 illu~txated, and a physical property a~d performance compari~on o~ th~ present invention to other materials is made. The componQnt~ and weight percentage~
of the tested blends are identified in TABLE 1.

The polyester re~in~ are dried to re~ovQ ~oistureO 1~
moisture content of the dried resin~ should be les~ than 0.007%.
The resins are then transf~rr~d into an oxyg~n free hold ves~l located above a three heated zon~, singl~ scr~w extru~er. The resins are gravity fed into th~ extrud~r. Other components of th2 blend are added by including tha polyamide re~ins, of th~
blend are added by metering devic~ when tho r~sin~ are gravity fed into the extruder. While in ~he ~xtruder, all components o~
the blend ar2 melted and intimately ~ixed. The set temperature~
for each zone ars given in TABL~ 2~ Th~ bl~nd i8 then melt spun through a spin di~ or spinnerett~ to produc~ mono~ilament~
having a diameter o~ O.50 ~. Th~ ~pin d~ t~p~ratur~ and bland te~peratur~ at ex*ru~$on ar~ ~iv~n in TABLX 2. A~tQr leaving t~ ~
spin ~i~, th0 ~ono~ilamenta ar~ quen~h~d in ~ water bath locate~
bene~t~ th~ spin die. A~ter gu~nching, th~ ~ono~ilaments arQ
drawn and heat set. Th~ heat s~tting occur~ in an ovQn locat~
in ~he t~ird draw zon~. The dra~ ratio~ and h~at set oven .

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temperatures are given in TABLE ~. .

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The phy~ical properties of tha foregoing monofilament~ are given in TAB1E 3. ~'Denier" was calculatecl by weighing one ~et~r length~ of the monofila~ent. "Hot air shrinkag~" wa~ calculated by placing a ~ample (one meter in length, coiled into a loop of about lO-ll cm in diameter) into a ~orced hot air oven set at . .;
. 200C for 15 minutes, then re~oving ~he sample fro~ the ov~n, .
letting the sample cool and finally ~ea uring t~ ngth o~ the sample. "Relative elongation at on~ gra~ per denier~ (Rel.
Elong. ~ lG/D); 'lelongation at break" (Elong ~ Break); and "tenacity" are measured using an In~tron Tensile Tester Model #4201 set with a 500mm gauge length, a cros~ head speed of 500 mm/~inute, and using flat faced cla~p~ (thQ ~onofila~ent running over the top of the top cla~p to kalow thQ botto~ of the bottom clamp). "Loop strength~ and ~knot ~trength~ ar~ ~ea~ured using the Instron setup noted abov~, ~he e~ception~ being: for "loop~ -two monofilaments are joined by inter~cting loop~; and for "knot~ - the monofila~ent is ti~d wi~h an ov~rh~nd knot.
"Abrasion cycle~ to failur~ wa~ ~a~ur~d by utilizing a 8c~ui~r~1 cage apparatus to abrad~ weight~d ~ono~i~a~ent 3a~ples. T~
sc~uirrel cagQ Sdia~t~r 8 3/8 ln~h~,o wit~ ~iXt~en 0.2024 inch Precision Brand Product Ind. T302 stainle 8 ~t~ pring temp~r~d wire equally spaced about the p~riph~ry o~ the cage). Th~
squirrel cag~ i~ rotated at 60 r~volutlon~ p~r minute. Th~
mono~ila~ent~ are drap~d over ~h- ~quirr~l cag~ ~ro~ ~ bar ., .... . .

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located above top dead center o~ the cage and weightQd with either 50 gram~ (monofilament diameter le~ than 0. 50mm) or 100 gram (monofilam~nt diamet~r 0. 50m~ or mor~ . The r~sults ar~
't~' reported as the number o~ cycles lapsed at the moment o~

'......... monof ilament breakage .

', In TABLE 4, "hydrolysi~ resistance" of th~ exa~ple~ is set forth. The hydrolysis resistancs ias laea ur~d a~ th~ percent strength retentic~n as a function of day~ in a hydrolysi~ pot.
Samples (about on~ meter in length) ar~ coil~d into 3 inch diameter loops. Samples are needed ~or th~ lnitial and each sample day. Sampl~s are placed on a rack insid~ a consolidat~d sterilizer autoc:lave. The autoclave is set to 15 psi and 250P
~; (121C) for continuous operation with a 60 mim~ta exhaust tim~
(cool down cycle~. On days~ when aDiple~3 ar~ to be te~ted, tha autoclave is cooled down and sa~Qples are re~ov~d ~nd allowed tt~
cool and equilibrate for one day prior to In~tron te~ting~
~, Samples for future test day~ are~ rehR~ted in th~ autoclav~ af~
discussed above. Measure~ent o~ tho w load tc~ bre~k~ on samples is performed on an In~;tron T~n~ Te~ter Mod~l ~4201, gaug~
length-500~, cro ~ head ~pead~500 ~/DIin, and uE~ng ~lat, leather faced C121~1pl~- Th~s pQr~lullt strength ret~ntion i~
;. calculated again~t th~ initial load to br~ak.

In TABLE 5, "dry heat stre~ngth' o~ th~ QX2111pllB13 i3 ~t . .
:~ for~h. The dry heat strength i~ D~a~urQd ~ tho p~rc~ ;trengtlh , 1~

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retention as a function of days in a forced air circulation oven.
Samples (about one meter i~ length) are coi1ed into 3 inch diameter 1Oops. Samp1es are needed ~or th~ initial and each sample day. Sample~ are hung froD ~ stee1 sa~pl~ hold~r 1Oc~ted eight inches from the top o~ the i~side ol' the chamb~r of th~
forced air circu1ation oven. Th8 ov~n i3 set at a temperatur~ o~
175C for continuous operation. Sample~ arQ removed ~n test days and allowed to coo1. Measurement o~ the "load to break~ on samples is performed on an In~tron Ten~i1e Tester ~odal ~4201, gauge length-500mm, cros3 head ~peed 500~/min, and u~ing f}at, leather faced clamp~. The percent ~trength retention i~
calcula~ed against the inltial load to brea~.

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polyester 100 90 99 95 94 89 84 79 74 . - . _ _ . - _ ._ ~ _ ~_ _ _ 10 _ _- _ 5 10 15 2t~
. %5hy illy~3i53 _ _ ~ 9 ~ ~ 9 ~ 9 ~ 9 ~ 9 ~ 9 . . _ _ _ __ _ ~ ~ thermo-oxidative _ _ _ 5 5 5 5 5 5 .,.'~ ~ ,................. __ I_ __ _~ ~
1. Polyester (CHD~) "KODARW THERMX copolyester type 13319 by Eastman Che~ical Co., Kingsport, TN.

2. Polyamide - nylon 6,6 by Engineering Plastic~ Divi~ion, :~ Hoech~t Celanese Corporation, Sum~it, NJ.

3. Hydrolysi~ stabilizer - Stabaxol3 1 by ~hein Che~ie GmbH, Rheinau, Federal Republic of Germany.

4. Thermo-oxidative stabiliz~r - nPCTA 13319 LOOOl~ by East~an Chemical Co., Kingsport TN.

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In the ~ollowing example, the manufacture o~ the pre~ent invention (with polyole~in) and its physical propertiets are illustrated. Th~ components and weight percentagets of the t tsted blends are as follows: PCTA ~THEhRX 13319) - 87%, Nylon (N186 from Hoechst Celanese) - 10%, polyolefin (ASPUN 6830A, ethylene-1-octene copolymer with 0.1% maleic anydr:ide and 0. 05% calcium sterate) - 2%; and hydrolysis stabilizing agent (BAS~ Carbo D)-0.9~.

The polyester resins ar~ dried to reDlove moistur~t. Thqmoisture content o~ the dried re~in~ should be less than 0. 007%.
The resins are then transferred into an oxygen free hold vest~tl located above a three heated zon~t, si~glQ ~cr~tw extruder. Zon~ 1 was heated to 299C, Zone 2 to 305~, and Zon~t 3 to 305C. Th~t resins are gravity fed into the extruder. Other ~o~ponentEt o~
.
the blend, including the polyamide resins and polyrtle~in re~in~, -are added by metering device~ when th~t re~in~ ar~ gravity fed into the extruder. Whil~ in the extruder, all co~ponent~ of t~t blend are melted and intimately laixed. Th~t blçtnd i~ stn laelt spun through a spin die or ~pir~n~rettQ to produc~t monofila~tent~
having a diaDIeter o~ 0. 70 m~. Th~ Rpin die t~mperature wa~ 310DC
and blend temperature at extn~ion wal~ 327C. After le~ving thR
spin die, the ~ono~ilament~ ar~ quonch~d in ~ w~t~r ba~h loc~t~d beneath the ~pin die. After gu~tnchi~g, th~t ~ono~lla~nt~ ar~t ,. ~ .
~i drawn and heat sek. Th~t heat ~ttt~ng orcur~ ln an ov~ locat~d ~ in ~he third dxaw zoneO Th~t dr v r~tlo~ are, re~pectlv~tly, 3.2, r~

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1, 1, and heat set oven temperature was 155C.

The physical propexties of the foregoing monofilaments are given in TABLE 6. The test procedures are the same a3 previou~ly discussed above.

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TA~LE 6 .~

Denier 4254 4254 Rel . Elong . Q lG/D ( 9c ) 4 . 7 4 . 2 HAS ~ 200C (%) 12 . 5 12 . 6 :.
- Tenacity (G/D) 2.21 2.38 Loop (G/D) 1. 83 1. 68 Knot (G/D) 1. 58 1. 42 l Elong. ~ Break ~%)26 . 7 26 . 6 Diareeer (mm) 0.709 0.71 .~ .

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. The present invention may be embodied in other specific forms without departing from the spirit or essential attributes - thereof and, accordingly, reference should be made to the appended claims, rather than to th~ ~oregoing sp~cification, a~
: indicating the scope of the invention.

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Claims

1. A shaped article comprising a blend of a polyester having a polyhydric alcohol component of 1,4-cyclohexanedimethanol, and a polyamide.

2. An article of paper machine clothing used in the forming, pressing or drying sections of a papermaking machine, said article comprising a fiber structure, said fiber structure being a blend of a polyester having a polyhydric alcohol component of 1,4-cyclohexanedimethanol, and a polyamide.

3. The blend according to claim 1 or 2 further comprising a polyolefin.

4. The blend according to claims 1 or 2, wherein said polyester comprises about 70 to about 95 percent by weight of said blend and said polyamide comprises about 5 to about 20 percent by weight of said blend.

5. The blend according to claims 1 or 2, wherein said polyester comprises about 85 to about 95 percent by weight of said blend and said polyamide comprises about 5 to about 10 percent by weight of said blend.

6. The blend according to claims 1 or 2, further comprising a hydrolysis stabilizing agent, said hydrolysis stabilizing agent comprising from about 0.5 to about 5 percent by weight of said blend.

7. The blend according to claim 6 wherein said hydrolysis stabilizing agent comprises a carbodiimide.

8. The blend according to claim 7 wherein said hydrolysis stabilizing agent comprises about 1 percent by weight of said blend.

9. The blend according to claims 1 or 2, further comprising a thermo-oxidative stabilizing agent, said thermo-oxidative stabilizing agent comprising from about 0. 05 to about 10 percent by weight of said blend.

10. The blend according to claim 9 wherein said thermo-oxidative stabilizing agent comprises about 5 percent by weight of said blend.

11. The blend according to claims 1, or 2, or 3 wherein said polyamide is selected from the group consisting of: nylon 6, nylon 6,10; nylon 6,12; nylon 11; nylon 12; nylon 4,6; nylon 6,T;
nylon 6,6; and combinations thereof.

12. The blend according to claim 12 wherein said polyamide is nylon 6,6.

13. The blend according to claims 1, or 2, or 3, wherein said polyester having a polyhydric alcohol component of 1,4-cyclohexanedimethanol further comprises a polyfunctional acid selected from the group consisting of: isophthalic acid;
terephthalic acid; derivatives of isophthalic acid; derivatives of terephthalic acid; and combinations thereof.

14. The blend according to claim 3, wherein said polyester comprises about 70 to about 95 percent by weight of said blend, said polyamide comprises about 5 to about 20 percent by weight of said blend and said polyolefin comprises about 1 to about 6 percent by weight of said blend.

15. The blend according to claim 3, wherein said polyester comprises about 85 to about 95 percent by weight of said blend, said polyamide comprises about 5 to about 15 percent by weight of said blend, and said polyolefin comprises about 1 to about 3 percent by weight of said blend.

16. The blend according to claims wherein said polyolefin is selected from the group consisting of: polyethylene polypropylene, polyoctene, copolymers thereof and combinations thereof.