Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02J—FINISHING OR DRESSING OF FILAMENTS, YARNS, THREADS, CORDS, ROPES OR THE LIKE
  • D02J1/00—Modifying the structure or properties resulting from a particular structure; Modifying, retaining, or restoring the physical form or cross-sectional shape, e.g. by use of dies or squeeze rollers
  • D02J1/22—Stretching or tensioning, shrinking or relaxing, e.g. by use of overfeed and underfeed apparatus, or preventing stretch
  • D02J1/229—Relaxing
• • 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
  • D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
  • D01F6/62—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyesters
• • 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
  • D02G1/00—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics
  • D02G1/004—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by heating fibres, filaments, yarns or threads so as to create a temperature gradient across their diameter, thereby imparting them latent asymmetrical shrinkage properties
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02J—FINISHING OR DRESSING OF FILAMENTS, YARNS, THREADS, CORDS, ROPES OR THE LIKE
  • D02J1/00—Modifying the structure or properties resulting from a particular structure; Modifying, retaining, or restoring the physical form or cross-sectional shape, e.g. by use of dies or squeeze rollers
  • D02J1/22—Stretching or tensioning, shrinking or relaxing, e.g. by use of overfeed and underfeed apparatus, or preventing stretch
  • D02J1/221—Preliminary treatments

Definitions

• Crimped filaments of terephthalate polyester are prepared by wetting unoriented filaments of terephthalate polyester with a non-solvent for the polyester, drawing the wetted filaments uniformly in the longitudinal direction but non-uniformly in the cross-sectional direction of the filaments, and subjecting the drawn filaments to an elevated temperature under conditions which will allow shrinkage or contraction of the filaments.
• a pin is used which has a specified convex surface and is maintained at a specified temperature.
• This invention relates to a process for making crimped polyester filaments and fibers.
• polyester filaments having threedimensional crimps by the process comprising non-uniformly quenching as-melt-spun polyester filaments by, for example, applying a unidirectional, horizontal cooling gaseous current to the filaments, thereby forming filaments having different birefringences in its transverse direction, drawing the same, and heat-treating the same under the conditions as will allow shrinkage thereof.
• the imparted crimp exhibits insufiicient stability, and the product shows such shortcomings as low initial modulus and yield point, and excessively great breaking elongation.
• the object of the present invention is to overcome the aforesaid drawbacks inherent in the conventional practice.
• the invention provides a process for making crimped filaments of terephthalate polyester which comprises wetting terephthalate polyester filaments having a birefringence of 0.001 to 0.012 with a non-solvent for the filaments, drawing the wetted filaments at a draw ratio within the range of 1.5 to 6.0 while contacting them with a pin which has a convex surface portion with a radius of curvature ranging from 1 to 5.5 (l+0.0lV) /D mm. and which is heated to a temperature ranging from (Tg) C.
• Tg represents the glass transition temperature of the filaments
• V represents the drawing velocity expressed by m./min.
• D denotes the denier of a single filament.
• potentially crimpable, drawn filaments are prepared by uniform stretching of spun filaments which have been imparted the internal microstructures non-uniform in the direction of radii through their spinning and quenching steps.
• the basic concept of the invention resides in the stretching of uniform spun filaments, which stretching is uniform in the longitudinal direction but nonuniform in the sectional direction of the filaments, thereby providing potentially crimpable, drawn filaments which are uniform in macroscopic or configurational view, but
• the terephthalate polyester mentioned in this specification and claims refers to the polyester of which at least preferably at least of recurring structural units is expressed by a general formula
• G stands for a divalent organic radical of 2-10 carbons, which is bound to the adjacent oxygen atom through a saturated carbon atom.
• the intrinsic viscosity of the polymer or filament mentioned in this specification is defined by the formula below:
• 1 1- is normally referred to as relative viscosity, the value being obtained by dividing the viscosity of a dilute solution of the test specimen in a solvent by the viscosity of the solvent employed, measured at the same temperature using the same unit; and C is the concentration of the polymer in gram per cc. of the solution.
• the viscosities are measured at 35 C., using ortho-chlo rophenol as the solvent.
• glass transition temperature (Tg) mentioned in the specification and claims is determined by the method described in, for example, US. Pat. No. 2,556,295.
• Tg of polyethylene terephthalate as-spun filaments having an inherent viscosity of 0.65 is approxi mately 70 C.
• the draw ratio referred to in the specification and claims means the ratio of wind-up rate of the filaments to their supply rate in the drawing step.
• the starting filaments to which the subject process is conveniently applied possess a birefringence ranging from 0.001 to 0.012. With the birefringence less than 0.001, it is difficult to draw the filaments with configurational uniformity. Whereas, the optimum draw ratios of the filaments having birefn'ngences substantially higher than 0.012 are extremely low, and the filaments non-uniform drawing in the sectional direction is difiicult. It is discovered that satisfactory potential crimpability cannot be imparted to the filaments having such high birefringences.
• the starting filaments are preferably substantially amorphous, having a, crystallinity not exceeding 10%.
• the preferred starting filaments composed of polyethylene terephthalate possess a density of 1.35 g./cc. or below.
• the starting filaments may be the as-spun yarns which have been melt-spun and quenched, i.e., undrawn yarns, or they may be those which have been incompletely drawn.
• the starting filaments may possess the total denier of up to approximately 10,000 deniers, and a single filament denier (D) or titer of approximately 1 to 600 deniers. Normally the starting filaments have circular cross-sections, but they may have other modified cross-sectional configurations. From the starting filaments having Y- shaped or trilobal cross-sections, lustrous, soft and silky products having excellent hand can be obtained.
• the temperature of the water or other non-solvent liquids is not critical, but the temperature range of 60 C., particularly room temperature minus 40 C., is effective for development of excellent crimp at the final stage.
• any suitable means can be optionally employed; for example, the filaments may be passed through a bath of the wetting agent and withdrawn, or the agent may be applied to the filaments with a roller.
• the wetted filaments are drawn at a draw ratio within a range of 1.5 to 6.0, while keeping contact with a heated pin.
• the drawing atmosphere is the air.
• the temperature of the pin may range from (Tg-ZO) to (Tg+25) C., in broadest term, Tg being the glass transition temperature of the filaments expressed by degree in centigrade. In practice it is recommended that the optimum drawing temperature should be selected from the range of (Tg10) C. to (Tg+20) C. When the pin temperature is too low, configurationally uniform drawing cannot be performed, and the products contain considerable undrawn portions.
• the pin temperature is too high, uniform drawing is given also to the microscopic structure, and an internal fine structure which is non-uniform in the sectional direction cannot be obtained.
• the optimum pin temperatures are within the range of (Tg10) C(Tg+8) C., when the drawing velocity is relatively low, for example, 500 m./min. or below. In case the operation is performed at higher drawing velocity, a higher pin temperature than the above upper limit can be employed.
• the optimum pin temperature is also affected by the storage period of the filaments to be drawn. Filaments which have been stored for a prolonged period are recommendably drawn at relatively higher temperatures.
• the pin In order to impart the transversely non-uniform, internal fine structure to the filaments by the drawing, the pin must possess a convex surface portion having a radius of curvature within the range of 1 mm. to 5.5
• the filaments are drawn while keeping contact with the pin along the circumference of said convex portion.
• the filaments are drawn while keeping contact with the pin along the circumference of said convex portion.
• the filaments are drawn while keeping contact with the pin along the circumference of said convex portion.
• the pin may be columnar of cylindrical, but so far as it possesses the convex surface portion having a radius of curvature within the specified range, its shape as a whole is not critical.
• the contact of the filaments with the convex surface portion of the pin may be secured by winding the former around the latter by one or two turns, but the winding is not necessarily required.
• the drawing velocity itself is not critical, but in individual practice the optimum pin temperature and radius of curvature of the pin are necessarily selected from the above-specified ranges in accordance with the drawing velocity employed. Normally the greater is the velocity, a greater radius of curvature and/or higher drawing temperature may be employed.
• the drawing is operable at the velocity as low as 50 m./rnin. or even below, but such is not only commerically disadvantageous, but also with such low speed the radially non-uniform, internal fine structure is difficult to obtain. For this reason normally a drawing velocity of at least 50 m./min. is advantageous.
• the upper limit of the velocity depends on the drawing techniques. For example, it is not impossible to operate at a drawing velocity as high as approximately 2,000 m./min., or even higher. Practical velocity ranges approximately 50 to 1,500 -m./min., preferably approximately 300 to 800 m./min.
• the drawn filaments possess potential crimpability, and can be converted to crimped products by treating the same under the conditions as will allow their shrinkage, at a temperature no lower than C.
• This crimpdeveloping treatment may :be given to the filaments without further processing, or to the staple fibers obtained by cutting the filaments.
• the filaments or staple fibers may first be formed into textile goods such as yarn, woven or knitted fabrics, non-woven fabrics, carpet, etc., and thereafter subjected to the heat treatment.
• the conditions as will allow shrinkage of the filaments include not only the tension-free treatment in which the filaments can freely shrink, but also such conditions under which the filaments can shrink by a certain limited amount.
• the treating temperature is too low, not only is the number of crimps developed less, but the crimps are unstable. Also the filaments treated at relatively low temperatures are occasionally irregular in size along the longitudinal direction. Thus a relatively higher temperature range is preferred for the crimp-developing treatment, as long as melting of the filaments can be avoided. Normally, a temperature of at least C., particularly those exceeding ap proximately 200 C., are preferred. A treating temperature ranging approximately from 205-240 C., particularly from approximately 220240 C. is recommended. Dry heat is preferred and more advantageous in the heat treatment for crimp-developing, although wet heating is usable.
• the crimped products obtained by the subject process produces crimps of higher stability than those in the conventional products.
• the products of the subject process also exhibit medium initial modulus (normally ranging approximately 300-500 kg./mrn. and not excessively high breaking elongation (normally approximately 80% or less).
• the products of the invention form clear contrast to the conventional crimped products based on cooling anisotropy. Again the subject process is simpler in operation and less expensive, compared with the conventional art.
• crimp density number of crimps per 1 inch
• EXAMPLE 1 Polyethylene terephthalate having an intrinsic viscosity of 0.65 was molten at 295 C., and spun at a rate of 700 m./min. to provide spun filaments at 280 deniers/ 36 filaments, having a birefringeence of 0.0045.
• the spun filaments were wetted with 40 C. water, and wound by one turn onto a cylindrical pin of 10 mm. in radius and which was heated to 65 C.
• the filaments were thus drawn by 4.3 times at a rate of 300 m./min., and subsequently shrunk as exposed to the air of 230 C. under substantially no tension. Uniformly crimped filaments having no irregularity along their longitudinal direction were obtained.
• Non-oriented filaments composed of substantially amorphous polyethylene terephthalate having an intrinsic viscosity of 0.65 were wetted with 30 C. water, and wound around a cylindrical pin of 8 mm. in radius by one turn. The pin temperature was varied in each run as indicated in the table below. The filaments were thus drawn at various draw rates as indicated in the same table. The optimum draw ratios for each combination of the drawing conditions are also shown. In each run the filaments were drawn by the indicated, optimum draw ratio. The drawn filaments were shrunk as exposed to 230 C. air under substantially no tension.
• EXAMPLE 2 Polyethylene terephthalate having an intrinsic viscosity of 0.65 was molten at 295 C., and spun at a rate of 900 m./min. to provide the spun filaments of 150 deniers/ 20 filaments in size, having a birefringence of 0.0055 The filaments were wetted with C. water, and wound by one turn onto a pin of equilateral triangular cross-section, having a circular portion of 1.5 mm. in radius. One side of the triangle was 12 mm. in length, and the pin was heated in advance to 68 C. Thus the filaments were drawn by 4.1 times at a rate of 250 m./min., and subsequently heat-treated in 220 C. air, under no tension. Thus the filaments with very fine crimps were obtained, which gave evenly dyed woven or knitted goods of pleasant hand.
• EXAMPLE 3 Polyethylene terephthalate having an intrinsic viscosity of 0.65 was molten at 295 C., and spun through a spinneret having Y-shaped orifices at a rate of 1,000 m./min., to provide spun filaments of 150 de./36 fil. in size, each having Y-shaped cross-section. Their birefringence was 0.0057.
• the filaments were wetted with water of ambient temperature, and wound around a cylindrical pin by one turn. The radius of curature of the pin was 30 mm., and the pin was heated in advance to 80 C.
• the products developed 19 crimps per inch, and wherein each single filament was appropriately twisted.
• the products furthermore had silky luster and soft hand, were uniform in size along longitudinal direction, and could be dyed very evenly.
• the drawing temperature is preferably no lower than approximately 60 C.
• the drawing temperature is preferably not higher than approximately C. when the draw rate is low, such as 200 m./ min. or 400 m./min.
• relatively high drawing temperature such as 80 C. or C.
• EXAMPLE 5 Polyethylene terephthalate having an intrinsic viscosity of 0.65 was molten at 295 C. and spun at a rate of 1,000 m./min. to provide spun filaments of 220 de./36 fil. in size. The birefringence of the filaments was 0.0058. The filaments were wetted with 30 C. water, and wound onto a cylindrical pin of 10 mm. in radius by one turn, the temperature of the pin being 70 C., to be drawn by 4.1 times at a draw rate of 300 m./min. and heated at various temperatures as specified in Table II, with substantially no tension. A tricot knitted good was prepared from the above filaments. The knitted good was dyed blue with Eastman Polyester Blue BLF, under the conditions as follows: dyestuif, 4% OWF; non-ionic activating agent, 0.5 g./liter; bath ratio, 1:100; and temperature, C.
• the samples which were shrunk at relatively low temperatures were unevenly dyed. The uneveness was caused presumably by the fact that the shrinkage in the longitudinal direction was not fully performed.
• the dyed samples were rated by comparison with a separately prepared standard set.
• the standard set consists of seven grades of 0, 1, 2, 3, 4, 4.5 and 5, the greater index denoting more favorable dyed effect. Thus, index 4 stands for good, and indices 4.5 and 5 stand for excellent.
• Table II The results are given also in Table II.
• V represents the drawing velocity expressed by m./min.
• D represents the denier of a single filament.
• the dye exhaustion in the above dyeing of the sample treated at 230 C. was approximately 90%, whereas that of the sample treated at 130 C. was about 65%.
• EXAMPLE 6 Polyethylene terephthalate having an intrinsic viscosity of 0.65 was molten at 295 C., and spun to provide the filaments of 280 de./36 fil. in size, having a birefrigence of 0.0045.
• the filaments were wetted with methanol of ambient temperature, and thereafter drawn by 3.9 times at a draw rate of 200 m./min., as wound onto a 70 C. cylindrical pin of 10 mm. in radius.
• the drawn filaments Were heat treated in substantially tension-free state in a 220 C. cylindrical hot blast store of 50 cm. in length, and wound-up at a rate of 100 m./min.
• the resultant products had crimps per inch, and both excellent feel and hand.
• EXAMPLE 7 Unoriented filaments of 200 de./34 fil. in size, composed of a polyethylene terephthalate-adipate copolymer (containing 2.5 mol percent of polyethylene adipate) having an intrinsic viscosity of 0.60, were wetted with 30 C. water. Thereafter the filaments were drawn by 4.0 times at a rate of 400 m./min., as wound onto a 65 C. cylindrical drawing pin of 6 mm. in radius of curvature, by one turn. The unoriented filaments had a birefringence of 0.0035, density of 1.338, and a glass transition temperature of 64 C.
• the drawn filaments were passed through a 500 mm.- long cylinder through which hot air of 220 C. was circulated, in substantially tension-free state, and were wound up at a rate of 100 m./min. Uniform crimped filaments which were uniform in size along the longitudinal direction and could be dyed very evenly were obtained. The products had crimps per inch, and excellent feel as well as pleasant hand.
• a process for making crimped filaments of terephthalate polyester which comprises wetting terephthalate polyester filaments having a birefringence of 0.001 to 0.012 with a non-solvent for said filaments, drawing the wetted filaments at a draw ratio within the range of 1.5 to 6.0 while contacting them with a pin which has a convex surface portion with a radius of curvature ranging from 1 to 5.5 (1+0.001V) /D mm. and which is heated to (Tg20) C.
• a process for making crimped filaments of terephthalate polyester which comprises wetting filaments of terephthalate polyester having a birefringence ranging 0.001 to 0.012 and a crystallinity not exceeding approximately 10%, with a liquid having no dissolving action to the filaments, drawing the wetted filaments at a draw ratio Within a range of 1.5 to 6.0 by means of a pin which has a convex surface portion having a radius of curvature ranging from (1+0.001 V /D mm. to 5.5
• a process for making crimped filaments of polyethylene terephthalate which comprises wetting polyethylene terephthalate filaments having a birefringence of 0.001 to 0.012 with a non-solvent for said filaments, drawing the wetted filaments at a draw ratio within the range of 1.5 to 6.0 while contacting them with a pin which has a convex surface portion having a radius of curvature ranging from 1 to 5.5 /D mm. and which is heated to a temperature ranging 60 C. to 78 C., along the circumference of said convex portion, at a drawing velocity ranging approximately 50 to 500 m./mm., and developing crimp in the filaments by treating the drawn filaments at a temperature within the range of 150 C. to 250 C. under the conditions as will allow the shrinkage thereof, where D represents the denier of a single filament.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Artificial Filaments (AREA)

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Publications (1)

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Cited By (2)

Citations (4)

• 1968
  • 1968-12-24 GB GB1230430D patent/GB1230430A/en not_active Expired
  • 1968-12-24 US US786730A patent/US3538566A/en not_active Expired - Lifetime
  • 1968-12-30 FR FR1602923D patent/FR1602923A/fr not_active Expired
  • 1968-12-30 DE DE19681817492 patent/DE1817492A1/de active Pending
  • 1968-12-30 NL NL6818801A patent/NL6818801A/xx unknown

Patent Citations (4)

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