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
  • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
  • D01F2/06—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from viscose
• • 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
  • Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
  • Y10S264/27—Process of spinning viscose where viscose has high degree of polymerization

Definitions

• the present invention relates to the manufacture of artificial filaments and provides a novel process.
• the invention relates to the manufacture of artificial yarn admirably adapted for use as reinforcement in the manufacture of rubber goods such as automobile tires and especially adapted for use in heavy-duty truck tires and the like.
• the yarn produced by the process of the present invention exhibits fatigue Application DecemberlZ, 1944, N Serial No. 567,898 3 Claims. e (Cl. 18-54) 2 teristics to the product and to insure successful spinning.
• the usual concentration of analytically determinable cellulose, in the viscose or spinning solution is approximately 7.5%.
• the usual viscosity of the spinning solution is, as determined for instance bythe time of fall of a /8 steel ball through cm. in a viscosity tube of 1.4 cm. diameter (test made at 0.), about seconds (46.5 poises).
• the cellulose concentration may be as low as 7% or as high as 8% or 8.5%, and in such instances the It is therefore an object of the present invention to provide a process for the manufacture of artificial filaments of unusually high fatigue resistance.
• the raw material is usually steeped in a caustic soda-solution of mercerizing strength, normally about 18%, pressed to remove a certain amount of thecaustic soda and shredded preparatory to the'xan'thation step.
• the alkali cellulose is normally aged for a definite period of time in order to establish a desirable spinning viscosity in the spinning solution.
• the aged or unaged'alkali cellulose is then xanthated'by treatment with carbon disulphide.
• the xanthated cellulose is then dissolved in dilute caustic soda to form the spinning solution which is ordinarily knownflas viscose.
• the vscose Prior to spinning, the vscose isnormallyripened. and filtered to impart deSiIeQ Oh a aging period of the alkali cellulose must be suitably adjusted to establish the usual spinning viscosity.
• any of the usual spinning methods it is not possible to secure successful spinning of viscose solutions having cellulose content below 6.5% because as the cellulose content is lowered the filaments produced become increasingly discontinuous, harsh, brittle and weak. This condition is emphasized if it is attempted to subject the filaments to substantial stretching between godets. Examples will be cited herein of attempts to spin viscose containing less than 6.5% cellulose in accordance with usual spinning methods. A concentration of above 8.5% is not normally used because of the tendency toward high viscosity and the necessity for unduly long aging periods.
• such artificial filaments are produced from viscose of very low cellulose concentration, namely in the range from somewhat morethan 3% to about 6.5%, which is adjusted to normal spinning viscosity and is spun under specific conditions to be set forth herein into a special setting bath and is subjected to considerable stretching between godets.
• the number of cycles automatically registered is the, bend test. Sincethelo'garithmof the bend test is inversely proportional to the load applied to the thread it is understoodthat comparison has to be,,made within thesame denier range with the same number of filaments andwith the same load per denier. Thedenier'range of the: yaljlfiswhose tests, are shown in thesetables. is'betwe en 1150 and 1250, with 480 filaments, and"th'e loa'dper n er s 9:37 1 mt .Bend tests are give for yarn in skeins and yarn wound on cones.
• a viscosesolution of normal spinningviscosity of approximately 45 poises is prepared by the usual steps of steeping, shredding, Xanthating and dissolving a chemical wood pulp qorexample, that sulfite wood pulp sold under the, trade name Te'riacellf by Riordon Sales Qorporation Ltd., of 'Montreal, Canada).
• the viscose is ripened for 48 hours at a ripening temperature of 19 C., during which time suitable filtering takes place, and is spun under the following conditions: a spinneret having holes of .0025" diameter is employed and the viscose emerges from the spinneret into a setting bath containing from 8% to 9% sulphuric acid and 4% zinc sulphate, the specific gravity at 20 C. of said setting bath being 1.30.
• the yarn emerging from the spinning bath is then stretched between godets at elevated temperature in a manner well known in the art. Preferably a high degree of stretch is imparted, and We have found it desirable to stretch the yarn about 77 with a temperature in the intermediate bath of about 87 C.
• the yarn produced in accordance with this specific example exhibits a dry strength of 3.49 grams per denier with an extensibility of 20.8%, a wet strength of 2.22 grams per denier and a tensile factor of 161.0.
• the tensile factor is a useful empirical value, the product of g./d. dry times g./d. wet times extensibility (dry) in percent.
• the bend test carried out on the Schopper bending tester aforementioned shows 850 bends required to break the skeined yarn and 2000 bends required to break the coned yarn, and the average of these results is 1425 bends.
• the yarn produced in accordance with this specific example spins without difiiculty. Furthermore, there is no evidence of milkiness or milky streaks in yarn if bleached as for textiles. It will be appreciated from the characteristics discussed herein and tabulated in Table I under test No. 2 that this yarn shows Wet and dry strengths and other characteristics of commercially acceptable standard for tire yarn, and that in addition the bend test demonstrates a resistance to fatigue more than four times that of yarn spun under the same conditions from a viscose containing 7.5% cellulose. (See test No. 8 in Table I.) 7
• Example 2 A viscose solution is prepared an spun under conditions identical with those in Example 1 except that the cellulose concentration is 4% and the alkali cellulose is aged for only three hours to establish in the viscose of this concentration a normal spinning viscosity.
• the yarn produced in accordance with this example exhibits characteristics of strength comparable to those of the yarn in Example 1 and exhibits an average bend test of 944, derived from a bend test in skeins of 604 and a bend test in cones of 1284. No difficulty was experienced in achieving continuous spinning under the conditions specified for this specific example.
• Example 3 A viscose solution is prepared and spun under the conditions set forth in Example 1 except that the cellulose concentration of the viscose is 4.9% and the aging time for the alkali cellulose necessary to establish in the viscose of this concentration a normal spinning viscosity is 19 hours.
• the yarn produced in accordance with this example exhibits strength characteristics fully comparable to those of the preceding examples and exhibits an average bend test of 1109, derived from a bend test of 819 in skeins and 1399 in cones.
• Example 4 A viscose solution is prepared and zinc sulphate is illustrated.
• the yarn produced in accordance with this example exhibits strength characteristics fully comparable to those of the preceding examples and exhibits an average bend test of 1047, derived from a bend test of 795 in skeins and 1300 in cones.
• Example 5 A viscose solution is prepared and spun under the conditions set forth in Example 1 except that the cellulose concentration of the viscose is 6% and the aging time for the alkali cellulose necessary to establish in the viscose of this concentration a normal spinning viscosity is 35 hours.
• the immersion in the setting bath is 30 in this example and for higher cellulose concentrations in accordance with our finding of slightly improved results with the longer path for concentrations of 6% and higher.
• the yarn produced in accordance with this example exhibits strength characteristics fully comparable to those of the preceding examples and exhibits an average bend test of 897, derived from a bend test of 735 in skeins and 1058 in cones.
• Example 6.-A viscose solution is prepared and spun under the conditions set forth in Example 1 except that the cellulose concentration of the viscose is 6.5% and the aging time for the alkali cellulose necessary to establish in the viscose of this concentration a normal spinning viscosity is 43 hours.
• the immersion is 30 as in Example 5.
• the yarn produced in accordance with this example exhibits strength characteristics fully comparable to those of the preceding examples and exhibits an average bend test of 4-67, derived from a bend test of 466 in skeins and 467 in cones.
• Example 7 A viscose solution is prepared and spun as set forth in any of Examples 1 through 6 except that cotton linters is used as the source of cellulose instead of wood pulp.
• the yarn produced in each instance exhibits slightly higher tensile properties than wood pulp yarn and also slightly higher bend test as can be seen in Tables I and III.
• Table II also shows the results achieved in two tests wherein the only difference over the preceding tests is that the setting bath contained 4% zinc sulphate instead of the 1% zinc sulphate in the normal setting bath.
• the setting bath contained 4% zinc sulphate instead of the 1% zinc sulphate in the normal setting bath.
• 4% zinc sulphate the 4% cellulose, 6.5% NaOII viscose, aged 56 hours or more at 19 C. was spun without diiliculty of any nature, both with and without stretching.
• the unstretched yarn shows very good strength characteristics and a high tensile factor of 124.5. Its extensibility of 39.5% of course renders it unusable in the manufacture of tire yarn, but this yarn is an interesting, semihigh-tenacity yarn of rather unusual type which should have commercial possibilities.
• the yarntthus produced with stretching and 025 spinneret holes shows a high degreeof'strength and'a highden'sile factor and an extensibility of 19.4%.
• the bond 'test on thisp'artic'ul'ar yarn was 943; which while "considerabiy less than that achieved with yarn rip- 'ene'd for-somewhat longer periods; is still far in excess “of "the bend test achieved in yarnspun from” viscose containing about "I or'more of cellulose (see Table I).
• this range is the limiting range for soft yarn when 6.5% caustic soda is used in the viscose.
• Table III also shows a comparison of the results of using cotton linters and wood pulp as the source of cellulose. It will be observed that with the spinning bath containing 1% zinc sulphate no spinning was possible with either a linters or wood pulp viscose. When a spinning bath containing 4% zinc sulphate is used excellent spinning is achieved with either form of viscose.
• the viscose solution has contained varying concentrations of cellulose but the concentration of sodium hydroxide has remained constant at 6.5%. It is not critical that the percentage of NaOH be limited to 6.5%. Higher concentrations of NaOH may be used and the results of such use are about those to be expected as a result of experience in varying NaOH concentration in viscoses of the usual cellulose content of about 7.5%.
• Table IV sets forth the results of a series of tests in which the effect of changing the concentration of NaOH is examined. Table IV is also important to the present disclosure in that it makes a very thorough comparison between the yarn spun from a viscose containing 6% cellulose in accordance with our invention and a yarn spun from 7.5% cellulose viscose under the same conditions.
• Such commercial yarns are made from viscose containing a large proportion, and in many instances containing 100%, of cotton linters cellulose. We have never found a commercial yarn exhibiting a bend test above 600 when such bend test is made under the conditions specified herein or corrected for denier, slashing, and the like.
• bend test value are used. These words define the average number of bends required to break the yarn on the Schopper bending tester D. P. 5 under the conditions specified above and in the denier range specified.
• the improvement in bend test due to low cellulose concentrations, is relatively similar for textile yarns of lower denier, for example 100, 150, 300, 400 and 600 deniers, but of course the absolute value of the bend test at the same load per denier increases as the denier decreases.

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

Priority Applications (3)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

Country Status (3)

Cited By (3)

Citations (10)

• 1944
  • 1944-12-12 US US567898A patent/US2479218A/en not_active Expired - Lifetime
• 1945
  • 1945-05-17 FR FR940888D patent/FR940888A/fr not_active Expired
  • 1945-12-07 GB GB33130/45A patent/GB603131A/en not_active Expired

Patent Citations (10)

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