Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/22—Yarns or threads characterised by constructional features, e.g. blending, filament/fibre
  • D02G3/26—Yarns or threads characterised by constructional features, e.g. blending, filament/fibre with characteristics dependent on the amount or direction of twist
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/22—Yarns or threads characterised by constructional features, e.g. blending, filament/fibre
  • D02G3/40—Yarns in which fibres are united by adhesives; Impregnated yarns or threads
  • D02G3/402—Yarns in which fibres are united by adhesives; Impregnated yarns or threads the adhesive being one component of the yarn, i.e. thermoplastic yarn
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/447—Yarns or threads for specific use in general industrial applications, e.g. as filters or reinforcement
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S57/00—Textiles: spinning, twisting, and twining
  • Y10S57/902—Reinforcing or tire cords

Definitions

• the present invention relates to a thermofixed ply produced from monofilaments of synthetic material and a method of manufacturing said ply.
• a monofilament is by definition a continuous thread made up of a single filament. It is generally used as it is, for example, as a horsehair or a brush, in textile applications such as weaving or knitting of technical fabrics or knits, in the paper industry, for example, as felt loops at the junction of a machine. paper, etc. It can also be used in the form of cords in textile applications such as weaving or knitting of technical fabrics or knits (for example wet felt needling base), in elastomer reinforcement applications (for example tire reinforcement) etc ...
• a cable is defined as the product resulting from the assembly and twisting of two or more twists of monofilaments; the twist being defined as the product, hitherto an intermediate product, resulting from the assembly and twisting of two or more monofilaments.
• the intermediate ply may consist of a single filament to which a twist has been applied.
• the manufacture of a monofilament cable requires several successive operations, in particular the assembly and twisting in one direction (S for example) of the monofilaments then the assembly and twisting in the opposite direction (Z in this case) of several twists , which gives the cable.
• the opposite twists for the twisted and the cabled are intended to create a mechanical blocking of the cabled by opposition and balancing of the untwisting forces.
• this mechanical blockage leaves the cable a certain nervousness; there is a twisting of the cable in the free state, which hinders its transformation for example into fabrics or knits.
• the present invention aims to provide a solution to the above problems.
• a twisted monofilament for applications such as technical textile use, reinforcements of elastomers, paper industry, etc., characterized in that it consists of at least two monofilaments of synthetic material having a title greater than or equal to 20 tex, assembled, twisted and heat-fixed, and that it is practically free of twisting stress.
• the synthetic materials which are suitable are all those usually used in the manufacture of monofilaments and in particular polyesters and polyamides in the form of homopolymers, copolymers or mixtures of polymers, where appropriate.
• the number of monofilaments is not limited, it depends on the characteristics desired for the product produced. However in general this number is between two and nine.
• each monofilament depends on the use for which the twist is intended.
• the titer is preferably between 20 and 500 tex.
• the twisting twist takes the current values in this type of operation, which are to a large extent a function of the unit strength and the number of unit monofilaments.
• the ply is thermofixed under the conditions defined in the manufacturing process claimed below.
• the starting monofilaments are produced according to a conventional spinning, stretching in several phases, relaxation process; however, the relaxation rate is lower than that usually practiced.
• the relaxation rate is advantageously between 0% and 6% instead of 0% to 12%, values usually practiced.
• the dynamometric characteristics are those common for this type of product and depend on the material.
• the elongation at break of the starting monofilaments is advantageously between 10% and 20%. Given the rate of relaxation, the material is in a moderately relaxed state, slightly repelotected macromolecules.
• the assembly of two or more strands is carried out in a known manner continuously; discontinuously, it will be necessary to take the necessary precautions to obtain an assembly with regular thread tension and calculated so as not to generate a winding or twisting fault.
• Twisting will be done from these monofilaments assembled in a single operation on an appropriate machine.
• the assembly is placed for example in a single or double twist twisting pot where it receives the desired twist.
• the assembly is subjected to a tensile stress greater than the elastic limit stress, therefore it undergoes a slight deformation comparable to a further stretching, however with the molecules oriented in the twisted direction. .
• the product remains very nervous because it is subjected to an internal stress of detorsion.
• the fixing zone includes a heat treatment oven and it is advantageously delimited by two capstans: an entry capstan (which also marks the exit from the twisting zone) calling the plies at constant speed while keeping torsion blocked, a exit capstan rotating at a speed lower than the entry speed, thus allowing the relaxation of the plied.
• the reception of the twisted is done for example on a reel with parallel crossing.
• an additional step of surface treatment for example coating, is integrated between the twisting and the fixing. For this it is necessary to keep the twisted blocked during this operation which can be achieved by means of an additional capstan.
• the process is carried out at the usual wiring speeds, that is to say generally between 20 and 50 m / min approximately.
• the method is economically advantageous in that it allows the elimination of a twisting step.
• it allows the continuous integration of an additional step such as coating, which until now was carried out discontinuously and required a cable recovery.
• the standard wired control product which the twist according to the invention proposes to replace is produced from shrinked polyamide 66 monofilaments, according to the procedure described below.
• the monofilaments After extrusion, the monofilaments are cooled in water to 35 ° C, then undergo a series of three phases of hot drawing:
• the monofilaments After stretching the monofilaments are subjected to relaxation and thermal fixation, relaxation rate 12%, fixing temperature 215 ° C (passage through a hot air oven). The monofilaments are finally wound, winding speed: 180 m / min, weight of the windings: 2 kg.
• Twist is measured by the method described in French Standard G07 314, it corresponds to the number of loops formed after having unrolled 1 meter of cable or twists and joined the ends.
• This cable can be used in applications such as a base for stationery felts and in some cases as a weft on the loom to form the felt joining loop, this loop then being in the direction of operation on a paper machine.
• a twist according to the invention is then produced for comparison.
• the monofilaments are manufactured by the same process as the control with the same parameters, except for the relaxation rate which is 6% instead of 12% and the assembly by three in this case.
• a twist according to the invention is produced by the method according to the invention.
• a modified twisting machine is used for the implementation of the method, it comprises in particular a thermal fixing oven, a first call capstan located upstream of the oven (leaving the twisting area) and a second capstan located downstream from the oven (leaving the fixing area).
• the spool of triwires is placed in the twisting pot of the machine where the assembly receives a S240 twist. Twisting is carried out with the application of a tension of 400 CN, ie a stress of 2.2 CN / tex, greater than the elastic limit stress. Continuous, twist kept blocked by the capstans, the plied is subjected to a thermal fixing by passage in the oven at the temperature of 200 ° C, higher than the thermal past of the material, with application of a relaxation rate of 8% .
• the speed of the upstream capstan is 21.6 m / min, that of the downstream capstan 20 m / min, that is to say identical to that of production of the control cable, hence no loss of productivity.
• the twisted is received on a spool with parallel cross winding, winding weight 2 kg.
• the plied has the following characteristics:
• the twist according to example 1 is used for the production of joining loops on felt at the junction of the paper machine, press section. This junction is made by a loop at each end of the felt favoring its mounting during its change, for this a rod is introduced between the loops, thus binding the felt.
• thermofixed ply according to the invention replaces a 200 tex monofilament, it provides the characteristics of flexibility and longitudinal regularity in section.
• the coating material consists of a rou water lapping.
• the product to be applied is a polymerizable silicone with rapid polymerization in the form of a liquid.
• the heat treatment oven is used both for the thermofixing of the plied (fixing of the twist) and the polymerization of the coating.
• the speed of the process is between 20 and 50 m / min.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Artificial Filaments (AREA)
• Paper (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9410128

Family Applications (1)

Country Status (6)

Cited By (8)

Families Citing this family (9)

Citations (4)

Family Cites Families (6)

• 1991
  • 1991-02-21 FR FR9102309A patent/FR2673202B1/fr not_active Expired - Fee Related
• 1992
  • 1992-02-18 CA CA002061428A patent/CA2061428A1/fr not_active Abandoned
  • 1992-02-18 EP EP92420053A patent/EP0500480B1/de not_active Expired - Lifetime
  • 1992-02-18 DE DE69200975T patent/DE69200975T2/de not_active Expired - Fee Related
  • 1992-02-20 FI FI920741A patent/FI95288C/fi active
• 1993
  • 1993-11-23 US US08/156,351 patent/US5442903A/en not_active Expired - Fee Related

Patent Citations (4)

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