Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/005—Synthetic yarns or filaments
  • D04H3/009—Condensation or reaction polymers
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D10/00—Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected
  • D01D10/02—Heat treatment
• • 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
  • D01F6/28—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D01F6/38—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds comprising unsaturated nitriles as the major constituent
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/02—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
  • D04H3/04—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments in rectilinear paths, e.g. crossing at right angles
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
  • D04H3/14—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic yarns or filaments produced by welding
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
  • D04H3/16—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion

Definitions

• This invention relates to the production of a filamentary structure which can be laterally extended to form a network.
• a filamentary structure capable of being laterally extended to form a tow is made by subjecting a tow of stretched acrylonitrile polymer filaments, in which the acrylonitrile content of the polymer is at least 70%, and which are in the formof an aqueous gel containing, for each 100 parts of polymer (reckoned as dry) 100-300 parts of water and at least 0.5 part of an organic solvent for the polymer, to a temperature of at least 65 C. in a moist atmosphere.
• acrylonitrile polymers are meant the homopolymers of acrylonitrile, and also copolymers, graft copolymers and mixtures of polymers containing at least 70% of acrylonitrile and up to of one or more ethylenic monomers copoly-merisable therewith, such as vinyl compounds, for example vinyl chloride and acetate, acrylic and methacrylic acids, esters and amides, methacrylonitriles, vinyl sulphonic compounds such as sulphonated aromatic derivatives, for example styrene sulphonic acid or vinyl hydroxyarenesulphonic acids, other vinyl derivatives of basic type such as vinyl pyridine and its alkyl derivatives, and vinyl ethers of dialkylamines.
• vinyl compounds for example vinyl chloride and acetate
• acrylic and methacrylic acids, esters and amides methacrylonitriles
• vinyl sulphonic compounds such as sulphonated aromatic derivatives, for example styrene sulph
• the filaments in the form of an aqueous gel which are used in carrying out the invention are advantageously obtained by wet spinning into an aqueous coagulating bath. They must have been stretched to give them sutficient strength to make possible their subsequent manipulation in the course of the process of the invention, advantageously 1.5-1.8 or more times their initial length. This stretch may be imparted to them in the spinning zone, namely the coagulating bath or the dry spinning cell, in accordance with the process by which they are obtained. The filaments may undergo a further stretch, which may be of greater extent than the first after they have been washed and before they are treated in accordance with the invention.
• the filaments in the form of the aqueous gel must contain at least 0.5%, and preferably contain 15%, calculated on the weight of the dry polymer, of an organic solvent, usually that which has been used for shaping them; contents up to 20% and 30% may also be suitable, and even be exceeded.
• the organic solvent employed may be chosen from the usual organic solvents used in the manufacture of acrylic fibres. There may be mentioned by way of example the N-formylated amines such as dimethylformamide, and among the many other known solvents dimethylsulphoxide, -butyrolactone, and dimethylacetamide, etc. Of course, mixtures of these various substances with one another or with other products may be employed.
• the filaments In carrying out the process of the invention, it is necessary for the filaments to be treated at a temperature of at least 65 C. Since the filaments are in the form of an aqueous gel which it is desirable to dry, it is advantageous to carry out the treatment during the drying.
• the temperature of the wet filaments may be at least equal to 65 C. in an industrial drying chamber, which is necessarily ventilated, the wet bulb temperature of the dryer should also be at least equal to 65 C.
• the dry bulb temperature of the treatment chamber may vary within wide limits without modifying to any considerable extent the result obtained. It is generally advantageous, for reasons of economy and ease of application, that this temperature should not be maintained too high; it may be, for example, C.- 0., although C. may be reached and even exceeded.
• the duration of the treatment may vary within wide limits, and may be readily adjusted by the operator in accordance with the dry and wet bulb temperatures employed, the size of the tow treated and the result aimed at.
• the treatment may be carried out on a tow for-med of a large number of filaments, for example at least 5000, and it is generally preferred to apply it to tows of from 30,000 to 150,000 filaments; however these figures have no limiting character, and the size of the tow must be chosen in accordance with the use to which the network is to be applied. It is generally advantageous to open the tows of parallel filaments before they are treated, for example by means of an air jet.
• the process of the invention makes it possible to obtain tows whose constituent filaments are adhesively secured together in an irregular manner and from place to place, giving a product that can be opened out into a very wid continuous network, often several metres wide, for example for the protection of crops from insects or other pests.
• the tow obtained in accordance with the invention may be given any desired further treatment, such as stretching, setting, crimping, finishing, dyeing or dressing, provided that care is taken to avoid impairing th structure or appearance of the product.
• Some of these treatments may be applied in order further to enhance the effect of the process of the invention; for example crimping, by taugling the filaments, further increases the effectiveness of the network obtained when the tow is opened out laterally.
• Example 1 A tow of 15,000 tex (135,000 denier) formed of 45,000 filaments of 3.4 d. tex (3 denier) is obtained by wetspinning a copolymer containing 94% of acrylonitrile and 6% of methyl methacrylate, using dimethylformamide as solvent, and a mixture of dimethylformamide and water as coagulating bath. After washing with water and stretching, the filaments obtained are in the form of an aqueous gel containing 180 parts of water to 100 parts of polymer (reckoned as dry) and 1.2 parts of dimethylformamide.
• the tow thus obtained is opened by the action of a turbulent gas and then introduced into a ventilated chamber on a perforated travelling belt.
• the temperatures in this chamber are 100 C. (dry bulb) and 6570 C. (wet bulb).
• the average speed of the air circulating through the chamber and through the perforated belt is 1.20 m. per second, which enables the wet filaments to have a temperature at least equal to that indicated by the Wet bulb thermometer.
• the treatment in the chamber lasts 40 minutes. During 7,
• the resulting tow may be stretched laterally to a width of 4 to metres, and forms a very fine network similar to a spiders web. Its strength is sufficient to support considerable loads without tearing, even in the wet state. It may be used to cover crops such as vines, in which its resistance to weathering is very valuable.
• Example 2 A tow of 15,000 tex (135,000 denier) comprising 30,- 000 filaments of 5.6 d. tex (5 denier) is obtained in the same way as in Example 1.
• the filaments are obtained in the form of an aqueous gel containing 200 parts of water to 100 parts of dry polymer and 3 parts of dimethylformamide.
• the tow is passed into a ventilated chamber as in Example 1, in which the temperatures are 110 C. (dry bulb) and 78 C. (wet bulb).
• Example 3 A tow of 90,000 filaments in the form of an aqueous gel containing 220 parts of water to 100 parts of the same polymer as in Example 1 and 0.8 part of dimethylformamide is passed into a ventilated chamber, in which the temperatures are 120 C. (dry bulb) and 70 C. (wet bulb). The tow obtained is thereafter crimped in a compression chamber. A tow of 30,000 tex (270,000 denier) is obtained, which is formed of 90,000 filaments of 3.4 d. tex (3 denier), which are sufiiciently stuck together at intervals to enable it to be opened out into a very fine and very wide network.
• Example 4 A tow identical to that employed in Example 2 is passed into a ventilated chamber, in which the temperatures are 80 C. (dry bulb) and 68 C. (wet bulb). The tow thereafter enters a relaxation zone at 130 C. and a crimping device of the stuffing box type.
• the tow obtained can readily be spread out int-o a very fine continuous network.
• Example 5 A tow of 135,000 filaments is obtained by wet-spinning a copolymer containing 97% of acrylonitrile and 3% of methyl acrylate into a bath consisting of water and dimethylformamid using dimethylformam'ide as solvent.
• the tow in the form of a gel containing 250 parts of water and 2.5 parts of dimethylformamide to 100 parts of dry polymer, is passed through a ventilated chamber at a temperature of 95 C. (dry bulb) and C. (wet bulb).
• a tow of 45,000 tex (405,000 denier) is obtained which can be opened out into an extremely wide network.
• Example 6 A tow of 60,000 filaments in the form of an aqueous gel containing 180 parts of water and 3 parts of dimethylformamide to 100 parts of a copolymer consisting of 72% of acrylonitrile and 28% of vinylidene chloride is passed into a ventilated chamber, of which the first zone is moisture-saturated at a temperature of C. The tow circulates slowly through this zone, in which it stays for 30 minutes, whereafter it enters a second zone in which the temperatures are C. (dry bulb) and 40 C. (wet bulb). The total duration of the treatment is 45 minutes.
• the tow is then steamed in the relaxed state at 130 C., and crimped in a stufiing box.
• Example 7 A tow of 45,000 filaments is obtained by wet-spinning a 20% solution of an acrylonitrile homopolymer in dim-ethylformamide into a coagulating bath consisting of a mixture of 40% of dimethylformamide and 60% of water. After counter-current washing with water and stretching by a total of 6.25 the filaments obtained are in the form of an aqueous gel containing parts of water to 100 parts of polymer (reckoned as dry) and 0.56 part of dimethylformarnide.
• the tow thus obtained is opened by the action of turbulent gas jet and then introduced into a ventilated chamber on a perforated travelling belt.
• the dry and Wet bulb temperatures are both 75 C. at the inlet to the said chamber, whereafter the dry bulb temperature is raised to 100 C. and the wet bulb temperature lowered to 40 C.
• the tow is stabilised by an oven treatment at C. and then oiled and crimped in a cripming device of the compression chamber type.
• Process for the production of a filamentary structure capable of being laterally extended to form a network which comprises opening by means of an air jet a tow of stretched acrylonitrile polymer filaments, in which the acrylonitrile content of the polymer is at least 70%, and which is in the form of an aqueous gel containing, for each 100 parts by weight of polymer, 100-300 parts by weight of water and at least 0.5 part by weight of an organic solvent for the polymer, and subjecting the opened tow to heat treatment in a moist atmosphere wherein the wet bulb temperature of the atmosphere is 65-120 C. for a period of time sufficient to bring the temperature of the filaments to at least 65 C.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Artificial Filaments (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (6)

Cited By (2)

Citations (3)

• 1963
  • 1963-07-03 FR FR940254A patent/FR84282E/fr not_active Expired
• 1964
  • 1964-05-06 GB GB18896/64A patent/GB1012535A/en not_active Expired
  • 1964-06-01 US US371763A patent/US3433866A/en not_active Expired - Lifetime
  • 1964-06-05 CH CH735764A patent/CH430198A/fr unknown
  • 1964-06-05 NL NL6406396A patent/NL6406396A/xx unknown
  • 1964-06-05 BE BE648928A patent/BE648928A/xx unknown

Patent Citations (3)

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