Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
  • D06M13/10—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing oxygen
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
  • D06M11/01—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with hydrogen, water or heavy water; with hydrides of metals or complexes thereof; with boranes, diboranes, silanes, disilanes, phosphines, diphosphines, stibines, distibines, arsines, or diarsines or complexes thereof
  • D06M11/05—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with hydrogen, water or heavy water; with hydrides of metals or complexes thereof; with boranes, diboranes, silanes, disilanes, phosphines, diphosphines, stibines, distibines, arsines, or diarsines or complexes thereof with water, e.g. steam; with heavy water
• • 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
  • Y10S273/00—Amusement devices: games
  • Y10S273/06—Nylon

Definitions

• This invention relates to the fluid treatment of filaments for the purpose of enhancing their impact or knotted impact strength.
• the invention also relates to articles of manufacture in or with which are incorporated monofil or multifil strands or strings consisting of or formed g-from filaments so treated, or fabrics comprising the same. More particularly, the invention re lates to the manufacture of strings of the kind used in such stringed instrument or implements as are typified by rackets and viols, or as, in common with them, call for strings that not only possess good tensile strength but also possess a high degree of impact, or knotted impact, strength. Still more particularly this invention relates to the fluid treatment, for the said purpose, of filaments comprising fiber-forming synthetic linear polymers, especially those of the classes described in U. S. 2,071,250, 2,071,251,
• This invention accordingly has as an object the improvement of the said resistance.
• a further object is the improvement of the resistance 1 of the said filaments to the fatigue of repeated impacts.
• a still further object is the enhancement of the moisture and weather resistant properties of the filaments. Additional objects will appear hereinafter. The first two of the said objects may be accomplished, in accordance with the invention, by
• synthetic linear polyamide includes those types of polymers which are derived from poly: merizable monoaminocarboxylie acids and their amide-forming derivatives (ester, halide, anhydride, and amide), those derived from the reac tion of suitable diamines with suitable dibasic carboxylic acids or the amide-forming derivatives of such acids, and those derived from mixtures of the foregoing types of reactants.
• merizable monoaminocarboxylie acids and their amide-forming derivatives ester, halide, anhydride, and amide
• those derived from the reac tion of suitable diamines with suitable dibasic carboxylic acids or the amide-forming derivatives of such acids and those derived from mixtures of the foregoing types of reactants.
• the polyamides On hydrolysis with strong mineral acids the polyamides revert to monomeric bifunctional polyamide-forming reactants.
• a polyamide derived from a diamine and a dibasic carboxylic acid yields on
• the high molecular weight synthetic linear polyamides may be formed into useful filaments which, upon application of tensile stress, are permanently stretched or cold drawn into pliable strong fibers, which show by characteristic X-ray diffraction patterns that they are oriented along their fiber axes. Orientation also may be effected by the application of compressive stress, such as that which takes place in the process of cold rolling, or by a combination of tensile and compressive stresses.
• the properties 'of filaments prepared from these polyamides may depend, to a large extent, upon the conditions under which they are prepared. Filaments formed by the extrusion of the molten polymer generally are rapidly cooled or quenched, in order to impart to them enhanced toughness and pliability.
• the conditions to which the filaments are subjected, after their orientation, have an effect on their properties. For instance, extensive subjection to dry heat, or to heat in the absence of a swelling medium, especially while under little tension, substantially reduces the capacity of the filament to shrink in response to the treatment of this invention; as also does extensive heating 5 even in the presence of such a medium-though often to a lesser extent-in cases where the filament is not free to shrink during such heating.
• tennis racket strings prepared from a synthetic linear polymer should have a tensile strength of at least 80 pounds, preferably 100 pounds, to avoid breakage during stringing, but elongations at break of less than 50%, preferably less than 35%, to facilitate stringing and avoid cold flow during storage or use, and a knot impact strength of at least 30 inch pounds, preferably higher, to avoid breakage during play.
• EXAMPLE I A polyhexamethylene sebacamide filament having a diameter of 113 mils (0.113 inch), prepared from polymer having a melt viscosity of 2880 poises at 285 C., was soaked in water for several days, at room temperature. The filament then wa passed through hot water for a short distance and, next, directly through a die of such siz as to give a drawn filament 52 mils in diameter. The die-drawn filament was next conditioned by heating it in the relaxed condition in an autoclave, for a period of half an hour, in the presence of saturated steam and at a temperature of 151-153 0. Physical properties of the filament, before and after conditioning, respectively, are shown in the following table.
• EXAMPLE HI Polyhexamethylene sebacamid having a melt viscosity of 2275 at 285 C. was prepared in the form of an oriented filament by melt spinning under quenching conditions, followed by die drawing to a diameter of about 53 mils. .A sample of this filament was tested without having been given any conditioning treatment. A second sample was conditioned one-half hour in '10 pounds (gauge) saturated steam, whil allowed to contract freely, and tested. A third sample was given the same steam treatment, but wound on abobbin so thatit could not contract. The
• Eflect of conditioning temperature on the physical Properties of interpolumer filaments EXAIMPLE IV An interpolymer prepared by the condensation polymerization of a mixture of 30 arts of hexamethylenediammonium adipate and 70 parts i Break Break mun Sample and treatment (0.5 hr.) in length Diameter strength elongation Knotted Straight Percent Mile Pounds Percent 1 Original 49 97 24 10 14 2 Boiling water 14 53 104 31 19 62 3 Steam, 151bs./in. 17 54 100 40 22 70 4 Steam, 30 lbs./in. 56 87 43 31 67 6 Steam, 45 lbs/in. 23 57 83 61 73 88 6 Steam, 60 lbs/i113. 29 59 64 81 52 84 Diameter before drawing: 106 mils.
• EXAMPLE v An interpolymer was prepared in the usual 5 manner, by the condensation polymerization of 7 the invention appears to be in connection with the said polyamides.
• polyhexamethylene sebacamide, polydecamethylene adipamide, polydecamethylene sebacamide, and the interpolymers prepared from sebacic acid, adipic acid, and hexamethylenediamine, and from adipic acid, hexamethylenediamine and 6-aminocaproic acid or 12-aminostearic acid are preferred types.
• the invention also is practiced to particular advantage with those polyamides or interpolyamides which are formed with azelaic acid or its derivatives, since very large oriented filaments can readily be prepared from such materials.
• the polymers of greatest utility have intrinsic viscosities 0 above 0.6, as defined in U. S. P. 2,130,948, and melt viscosities, at 285 0., above 400 poises, preferably above 1000 poises.
• the polymer viscosity and the method and extent of drawing each have an important hearing on the physical properties of the final filament.
• the most desirable combination of high tensile and impact strengths, and low elongation at break are obtained by multiple-die drawing" (explained hereinbelow) of filaments made from polymer having a viscosity of 1500 to 3000 poises at 285 C., until the diameter of the filaments has been reduced to about 0.46 that of the filaments before drawing.
• Conditioned filaments having satisfactory impact strengths may be obtained, however, from filaments of lower viscosity (400 to 1500 poises) which have been drawn to only 0.49-0.47 their original diameter.
• a reduction of the filament diameter to 0.46 of the original value by a single draft of the undrawn filament through a die will result, at times, in latent embrittlement, which will become manifest after conditioning.
• embrittlement can be avoided by multiple-die drawing.” 1. e., by drawing the filament through a tandem arrangement or "nest of two or more dies of such sizes that at least half of the reduction in crosssectional area is accomplished before reaching the last die.
• the last five or six mils of taper is more gradual than that of the usual type of die. For the best results, die surfaces must be clean and well polished at all times.
• cordage, woven or knitted fabrics, or sheets and ribbons wherever resistance to sudden or repeated impacts is needed, for instance to lacrosse stick strings, parachute cloth, and certain kinds of sewing threads, but the invention appears to be most uniquely useful for the hereinabove emphasized treatment of large polyamide monofils for use, or used, as strings in tennis, squash, or badminton rackets, and the like.
• the preferred sizes of filaments for use in tennis and squash rackets are 45 to 60 mils in diameter, and in badminton rackets 25 to 40 mils in diameter.
• a process for improving by at least 25% the impact strength of an oriented synthetic linear polyamide filament which comprises multiple die-drawing said filament to about 46% of its original diameter with at least one-half of the reduction in cross-sectional area of said filament being accomplished before the last die-drawing, subjecting said filament to treatment with a nonsolvent swelling agent therefor, heating said treated filament in a relaxed condition for at least .2 hours while permitting free axial shrinkage of the filamentand terminating said heating prior to a dec'rease in tensile strength of said filament of more than 30%.
• a strung racket containing strings comprising oriented synthetic linear polyamide filaments having a high impact strength, said filaments being those obtainable by subjecting the filaments to treatment with a non-solvent swelling agent therefor, heating said treated filaments in a relaxed condition for at least .2 hours while permitting free axial shrinkage of the filaments and terminating said heating prior to a decrease in tensile strength of said filaments of more than 30%.
• a strung racket containing strings comprising oriented synthetic linear polyamide filaments as set forth in claim 3 wherein said polyamide ,has a melt viscosity of at least 1000 poises.
• a strung racket containing strings comprising oriented synthetic linear polyamide filaments ments are those obtainable by multiple die-drawas set forth in claim 3 wherein said polyamide ing the filament to about 46% of its original (11- is polyhexamethylene sebacamide. ameter with at least one-half of the reduction 7.
• a strung racket containing strings comin cross-sectional area of said filament being acprising oriented synthetic linear polyamide flla- 5 complished before the last die-drawing. ments as set forth in claim 3 wherein said fila- WILLARD E. CA'I'LIN.

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

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

Family

ID=23277813

Family Applications (1)

Country Status (4)

Cited By (8)

Families Citing this family (1)

Family Cites Families (1)

• 1940
  • 1940-04-03 US US327735A patent/US2298868A/en not_active Expired - Lifetime
• 1941
  • 1941-03-30 DE DEI69264D patent/DE766441C/de not_active Expired
• 1945
  • 1945-12-18 FR FR919131D patent/FR919131A/fr not_active Expired
• 1946
  • 1946-01-03 BE BE462190D patent/BE462190A/xx unknown

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