Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F1/00—General methods for the manufacture of artificial filaments or the like
  • D01F1/02—Addition of substances to the spinning solution or to the melt
  • D01F1/10—Other agents for modifying properties
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/44—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds as major constituent with other polymers or low-molecular-weight compounds
  • D01F6/46—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds as major constituent with other polymers or low-molecular-weight compounds of polyolefins
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/88—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polycondensation products as major constituent with other polymers or low-molecular-weight compounds
  • D01F6/90—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polycondensation products as major constituent with other polymers or low-molecular-weight compounds of polyamides
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/88—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polycondensation products as major constituent with other polymers or low-molecular-weight compounds
  • D01F6/92—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polycondensation products as major constituent with other polymers or low-molecular-weight compounds of polyesters

Definitions

• the present invention is directed to a monofilament made from a blend of a polyester having a polyhydric alcohol component of 1,4-cyclohexanedimethanol, and a polyamide.
• This invention is particularly useful as an article of paper making machine clothing used in the forming, pressing, or drying sections of a paper making machine when the blend is in the form of a fiber structure.
• Paper is composed of cellulosic fibers that are formed into a sheet.
• a paper making machine consists of three main sections: the forming section, the pressing section, and the drying section.
• the cellulosic pulp slurry or furnish is injected onto a forming fabric which is a long, woven mesh belt.
• a forming fabric moves along through the forming section, some of the water in the slurry drains through the fabric and a paper web is formed.
• this paper web leaves the forming section, it is composed of about 80% water and about 20% solids.
• forming fabrics were woven from metal wires and had a life of about one week on a paper machine. This short life was due to metal fatigue and abrasion caused by contacting the machine parts in the forming section.
• experiments were begun to replace the metal fabrics with woven, synthetic, monofilament yarn fabrics.
• polyester monofilament is the yarn of choice for this application and typical fabric life is about 60-120 days.
• the paper web moves into the pressing section where a high compressive force is exerted by a pair of press rolls to remove more water from the paper web.
• the press fabric serves as cushioning and water removing media between the press rolls.
• the paper web contains about 60% water and 40% solids.
• press fabrics were made of 100% wool due to its resilience and water absorbency.
• synthetics have been developed with good resilience that have longer life than woolen felts.
• Fabrics of choice today consist of a base fabric, woven from polyamide monofilaments into which polyamide fibers have been needlepunched to form a felt.
• life of press felts is 30-60 days.
• the drying section consists of large, steam-heated cylinders that dry the paper web to a level of about 6% moisture.
• a dryer felt or fabric is needed to hold the paper in contact with the dryer cylinders. Originally, these fabrics were made from cotton, but as paper making developed, higher speed and temperature shortened the life of the cotton dryer felts.
• polyester monofilament the predominant yarn used in the manufacture of dryer fabrics. See, Luciano, B., Albany International Fabric Facts, Volume 38, No. 4-6. Dryer fabrics made from polyester monofilament operating at normal temperatures (300° to 350°F) last about one year.
• Elevated temperatures tend to adversely affect the hydrolysis resistance of polyester yarns. For this reason manufacturers of dryer fabrics have looked at other fibers and yarns in an effort to increase fabric life at higher temperatures.
• PPS polyphenylene sulfide
• Another fiber solution to the harsh environment of the paper making process is the use of poly(2-methyl-1,5-pentylene) terephthalamide. See U.S. Patent No. 5,162,152, which is incorporated herein by reference. Yet another fiber solution is the use of a copolymer of terephthalic acid, isophthalic acid, and 1,4-dimethylocyclohexane (also referred to as 1,4-cyclohexanedimethanol). See: U.S. Patent No. 5,169,499, which is incorporated herein by reference.
• One embodiment of 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.
• This blend is useful as an article of paper making machine 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.
• Another embodiment of the present invention is directed to a monofilament made from a blend of a polyester having a polyhydric alcohol of 1,4-cyclohexanedimethanol, a polyamide, and a polyolefin.
• This blend as the foregoing, is useful as an article of paper making machine clothing and its usefulness stems from the those mentioned in regard to the foregoing product in addition to it greater ability to be formed into a spiral fabric.
• the inventive blends disclosed herein include a polyester having a polyhydric alcohol component of 1,4-cyclohexanedimenthanol, and a polyamide.
• the blend may include about 70 to about 95 percent by weight of the polyester and about 5 to about 20 percent by weight of the polyamide.
• the blend preferably includes about 85 to about 95 percent by weight of the polyester and about 5 to about 10 percent by weight of polyamide.
• the blend may include a hydrolysis stabilizing agent.
• the hydrolysis stabilizing agent may comprise about 0.5 to about 5 percent by weight of the blend, preferrably it comprises about 1.0 percent by weight of the blend.
• the blend may also include a thermo-oxidative stabilizing agent.
• the thermo-oxidative stabilizing agent may comprise about 0.05 to about 10 percent by weight of the blend, preferrably it comprises about 5 percent by weight of the blend.
• the inventive blends disclosed herein also include a polyester having a polyhydric alcohol component of 1,4-cyclohexanedimenthanol, a polyamide, and a polyolefin.
• the blend may include about 70 to about 95 percent by weight of the polyester, and about 5 to about 20 percent by weight of the polyamide, and about 1 to about 6 percent by weight of the polyolefin.
• the blend preferably includes about 85 to about 95 percent by weight of the polyester, and about 5 to about 15 percent by weight of polyamide, and about 1 to about 3 percent by weight of the polyolefin.
• the blend may include a hydrolysis stabilizing agent.
• the hydrolysis stabilizing agent may comprise about 0.5 to about 5 percent by weight of the blend, preferably it comprises about 1.0 percent by weight of the blend.
• the blend may also include a thermo-oxidative stabilizing agent.
• the thermo-oxidative stabilizing agent may comprise about 0.05 to about 10 percent by weight of the blend. If used, it preferrably comprises about 5 percent by weight of the blend.
• shaped article is directed to articles which are made by extrusion or molding techniques, including, but not limited to, fibers, films, injection molded articles, and blow molded articles.
• polyfunctional acid component may be selected from, but is not limited to, the group of: isophthalic acid; terephthalic acid; derivatives of isophthalic acid; derivatives of terephthalic acid; and combinations thereof.
• polyesters may be referred to as polycyclohexlandymethanol terephthalate (PCT)-a polyester from the condensation reaction of cyclohexanedimethanol (CHDM) and terephthalatic acid or its derivatives, or PCTA - the condensation product of CHDM, terephthate acid and isothalic acid.
• PCT polycyclohexlandymethanol terephthalate
• CHDM cyclohexanedimethanol
• PCTA the condensation product of CHDM, terephthate acid and isothalic acid.
• the PCTA material is preferred.
• the fiber processability of these materials may be improved by the addition of a minor portion of polyethylene terephthalate. See: British Patent Specification No. 1,040,470 incorporated herein by reference.
• polyamide is directed to any of the known polyamide polymers.
• the polyamide appears to improve the dry-heat strength and hydrolysis resistance of the yarns made from the blend.
• Exemplary polyamides include, 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 combinations thereof.
• Nylon 6,6 is preferred.
• the foregoing nylon materials are commercially available from the Engineering Plastic Division of the Hoechst Celanese Corporation, Summit, NJ.
• polyolefin is directed to any of the known polyolefin polymers.
• the polyolefin appears to improve the ability of the fiber to be formed into a spiral yarn.
• Exemplary polyolefins include, but are not limited to: polyethylene, polypropylene, polyoctene and copolymers thereof. A copolymer of ethylene/octene is preferred. These materials are commercially available from Dow Chemical Company, Atlanta, GA under the tradename of "ASPUN".
• hydrolysis stabilizing agent refers to an "endcapping agent". Endcapping agents are used to prevent degregation of the polyester polymer. This particular form of degradation results from hydrolysis.
• exemplary hydrolysis stabilizing agents include the class of chemicals known as carbodiimides.
• a preferred carbodiimide is known chemically as 2,6-diisopropylphenyl carbodiimide.
• carbodiimides are commercially available under the tradename "STABAXOL”, “STABAXOL P”, "STABAXOL P-100" from the Rhein Chemie GmbH of Rheinau, Federal Republic of Germany and "CARBO D” from BASF of Parsippany, NJ. "STABAXOL I” and “CARBO D” are preferred.
• thermo-oxidative stabilizing agent refers to a material added to prevent degredation of the polyester when subjected to hot dry heat.
• the preferred material is sold under the commercial name of "KODAR" THERMX 13319 L0001 from the Eastman Chemical Co. of Kingsport, TN.
• the polyolefin-containing alloy monofilaments, disclosed herein, are particularly suited for spiraling end uses.
• Spiraling end uses refer to, for example, fabrics, made from spiraled monofilaments, that may be used in conveyor belts, lay belts, dryer fabrics for paper machines and the like.
• Spiraled fabrics refer to the following, for example: A monofilament is passed through a spiraling machine in order to make an oval shaped spiral. In this spiraling machine, the monofilament is heated and then wrapped around a mandrel of a specific shape. As new monofilament comes into the spiraling machine and is spiraled, the cooled monofilament wrapped around the mandrel is pushed off the end of the mandrel.
• spiraled monofilament coils are then meshed together and a pintle yarn is passed through the intermeshed coils to form an interlocked structure.
• An entire fabric is constructed by building up the number of coiled structures that are fastened together by pintle yarns. In the open space between the pintle yarns, it is possible to insert an additional monofilament in order to control the air permeability of the fabric. After the fabrics are made, they are heat set in order to fix their dimensional stability.
• a fabric made from spiraled coils is attractive because it costs less than a woven fabric of similar dimensions.
• the polyester resins are dried to remove moisture.
• the moisture content of the dried resins should be less than 0.007%.
• the resins are then transferred into an oxygen free hold vessel located above a three heated zone, single screw extruder.
• the resins are gravity fed into the extruder.
• Other components of the blend are added by including the polyamide resins, of the blend are added by metering devices when the resins are gravity fed into the extruder. While in the extruder, all components of the blend are melted and intimately mixed.
• the set temperatures for each zone are given in TABLE 2.
• the blend is then melt spun through a spin die or spinnerette to produce monofilaments having a diameter of 0.50 mm.
• the spin die temperature and blend temperature at extrusion are given in TABLE 2.
• the monofilaments After leaving the spin die, the monofilaments are quenched in a water bath located beneath the spin die. After quenching, the monofilaments are drawn and heat set. The heat setting occurs in an oven located in the third draw zone. The draw ratios and heat set oven temperatures are given in TABLE 2.
• the squirrel cage (diameter 8 3/8 inches; with fifteen 0.2024 inch Precision Brand Product Ind. T302 stainless steel spring tempered wire equally spaced about the periphery of the cage).
• the squirrel cage is rotated at 60 revolutions per minute.
• the monofilaments are draped over the squirrel cage from a bar located above top dead center of the cage and weighted with either 50 grams (monofilament diameter less than 0.50mm) or 100 gram (monofilament diameter 0.50mm or more). The results are reported as the number of cycles lapsed at the moment of monofilament breakage.
• hydrolysis resistance of the examples is set forth.
• the hydrolysis resistance is measured as the percent strength retention as a function of days in a hydrolysis pot.
• Samples (about one meter in length) are coiled into 3 inch diameter loops. Samples are needed for the initial and each sample day. Samples are placed on a rack inside a consolidated sterilizer autoclave. The autoclave is set to 15 psi and 250°F (121°C) for continuous operation with a 60 minute exhaust time (cool down cycle). On days when samples are to be tested, the autoclave is cooled down and samples are removed and allowed to cool and equilibrate for one day prior to Instron testing. Samples for future test days are reheated in the autoclave as discussed above.
• dry heat strength of the examples is set forth.
• the dry heat strength is measured as the percent strength retention as a function of days in a forced air circulation oven. Samples (about one meter in length) are coiled into 3 inch diameter loops. Samples are needed for the initial and each sample day. Samples are hung from a steel sample holder located eight inches from the top of the inside of the chamber of the forced air circulation oven. The oven is set at a temperature of 175°C for continuous operation. Samples are removed on test days and allowed to cool. Measurement of the "load to break" on samples is performed on an Instron Tensile Tester Model #4201, gauge length-500mm, cross head speed 500mm/min, and using flat, leather faced clamps.
• the polyester resins are dried to remove moisture.
• the moisture content of the dried resins should be less than 0.007%.
• the resins are then transferred into an oxygen free hold vessel located above a three heated zone, single screw extruder. Zone 1 was heated to 299°C, Zone 2 to 305°C, and Zone 3 to 305°C.
• Zone 1 was heated to 299°C
• Zone 2 to 305°C
• Zone 3 to 305°C.
• the resins are gravity fed into the extruder.
• Other components of the blend including the polyamide resins and polyolefin resins, are added by metering devices when the resins are gravity fed into the extruder. While in the extruder, all components of the blend are melted and intimately mixed.
• the blend is then melt spun through a spin die or spinnerette to produce monofilaments having a diameter of 0.70 mm.
• the spin die temperature was 310°C and blend temperature at extrusion was 327°C.
• the monofilaments are quenched in a water bath located beneath the spin die. After quenching, the monofilaments are drawn and heat set. The heat setting occurs in an oven located in the third draw zone.
• the draw ratios are, respectively, 3.2, 1, 1, and heat set oven temperature was 155°C.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Textile Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Artificial Filaments (AREA)
• Paper (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Materials For Medical Uses (AREA)
• Coloring (AREA)
• Polyesters Or Polycarbonates (AREA)

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Citations (3)

• 1994
  • 1994-03-23 CA CA002119678A patent/CA2119678A1/fr not_active Abandoned
  • 1994-04-22 EP EP94106271A patent/EP0622479B1/fr not_active Expired - Lifetime
  • 1994-04-22 DE DE69411444T patent/DE69411444T2/de not_active Expired - Fee Related
  • 1994-04-22 BR BR9401568A patent/BR9401568A/pt not_active IP Right Cessation
  • 1994-04-22 AT AT94106271T patent/ATE168144T1/de not_active IP Right Cessation
  • 1994-04-25 FI FI941916A patent/FI941916A/fi unknown
  • 1994-04-26 JP JP6088215A patent/JPH0711114A/ja not_active Ceased

Patent Citations (3)

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