Cotton Yarn Strength Research Articles

メリヤス用綿糸の強力と糸結びに関する一考察

It is difficult to represent the performance requirements of knitting yarns by a few mechanical properties. This article makes some pertinent suggestions as to strength of cotton yarns, strength and size of various kinds of knots, and knittability . The main results are as follows : 1) When tied yarns are stretched, these do not always break at the points where yarns are tied. Because knot strength of cotton is comparatively high. The round knot is the highest in breaking strength, but is too large and bulky in size for fine yarns.2)The single weaver's knot is less bulky and less slippery.3)The single weaver's knot is best in knittability. It causes the least trouble in knitting.4)To make a knot successfully, pay attention to the following items.a) Tie a knot as tight as possible.b) Don't damage the yarn to make a knot.c) Reduce the number of knots as few as possible.

Degradation of Cellulosic Fibres in Contact with Rusting Iron

INSTANCES of rapid degradation of textile materials in industrial use have been noted, the cause of which could not be attributed to the more usual degrading agencies, that is, micro-organisms, heat, light or acids. It was significant that in each of these occurrences there was evidence that the cellulosic material had been in contact with corroding iron under damp conditions. Similar degradation was observed in laboratory experiments in which cellulosic fibres were placed in contact with a clean iron surface and kept moist, a rapid fall in tensile strength being found as corrosion proceeded. The curves in Fig. 1 show the loss in strength of cotton yarn (8's × 5) damped with distilled water (curve A) and with 0.02 per cent sodium chloride solution (curve B) when wound on polished mild steel rods and kept in a moist atmosphere. Yarn wound on glass rods and exposed under the same conditions showed no significant change of strength in the same period (curve C).

綿漁網腐朽に関する粘度的研究

The weakening of cotton netting cords, being immersed in sea water, may be due mainly to bacterial decompositions of cellulose chains. A continuous reduction of average degree of polymerization (??) of the cellulose chains should then be expected to occur with increasing the period of immersion. In this investigation, such reduction of ?? occurring in cotton netting in cotton netting cords immersed in sea water was pursued by measuring intrinsic viscosities of cellulose nitrate om acetone and by comparing them with the tensile strengths of single yarns. It was found that the tensile strengths of single yarns began to decrease after 30 days immersion, reach one half of the initial value after 60 days and dropped to zero after 90 days; on the contrary, the average molecular weights showed slow reduction and reached no more than one half of the initial value for the peirod of 90 days. The linear relationship between the tensile strength and the reciprocal of average degree of polymerization which was often found to fit well for linear high polymers could not be obtained in the present investigation. It is considered that the tensile strength of cotton yarns may be responsible not only for the rupture of primary valence bond and the slippage of the cellulose chains with respect to each other, but also for the more macroscopic structures.

A New Method for Predicting Cotton Yarn Strength from the Observed Strength of a Single Count

A New Method for Predicting Cotton Yarn Strength from the Observed Strength of a Single Count

Increased Card Speeds

An increase in cotton yarn strength was the unexpected result obtained in a number of mills when card speeds were raised. This phenomenon—as reported by Pro fessor Dunlap, who is supervisor of the research pro gram being carried out by the Southern Textile Associa tion and the Arkwrights under sponsorship of the Textile Foundation—was discussed briefly in the January issue of TEXTILE RESEARCH. Following is a more detailed re port of some of the tests and the results obtained.

The effects of waterproofing materials and out-door exposure upon the tensile strength of cotton yarn

The effects of waterproofing materials and out-door exposure upon the tensile strength of cotton yarn