US 2138950 A
Description (OCR text may contain errors)
Patented 'Dec. 6, 1938 PATENT OFFICE METHOD OF PRODUCING YARN William Whitehead, Cumberland, Md., assignor to Celanese Corporation of America, a corporation of Delaware No Drawing. Application March 16, 1937,
' Serial No. 131,185
expeditious production of plied yarns having a high weaving and knitting efficiency. Another 10 obJect of the invention is the production of a plied yarn having ends of both right and left hand twist which is so balanced that the ends having one twist do not snap, or break, before the ends of 'the opposite twist when the yarn is under ten- 15 sion. Other objects of the invention will appear from the following detailed description.
The plying of a plurality of ends of yarn to form a plied or doubled yarn has been practiced for some time, for the most part for the purpose 20 -of producing a uniform yamunder the theory that the weak or thin places in the various ends would not likely fall together in the plied yarn. This evening up of the yarn is unnecessary with yarns formed of substantially continuous artifi- 25 cial filaments as each yarn is substantially uniform in denier. However, by plying 2, 3, 4 or more ends of such yarn, difierent types of yarn and, therefore, diiferent types of fabric may be produced. Plied yarn at least one end of which 30 has a high degree of twist, say, 20 or more turns per inch, has heretofore been defective in several respects.-, Ordinarily, plied yarn made from con tinuous filaments tends to curl or spiral upon itself in weaving and knitting operations and, also,
35 when the yarn is placed under a stress the end having a high degree of twist tends to snap first.
In effect, the plied yarn containing at least one end having a high degree of twist, as heretofore commonly manufactured, is not as strong as the 40 total strength of the ends, as the end having a high degree of twist snaps first, leaving the other end or ends to bear the load. Furthermore, upon the breaking of the end having a high degree of twist, the broken ends fly out of the yarn and catch on needls, heddles, etc. Even if the yarn isnot completely broken and the ends do not catch in the eyes of the weaving or knitting devices, the 10$ of tension on theend having the high degree of twist produces a defect in the fabric formed from-the yarn.
I have now found that if the plied yarn is built up in such a manner that the twists in the various components are balanced in the yarn as the yarn lies in the fabric, a much stronger yarn is produced. This type of yarn does not curl or spiral upon itself in weaving and knitting operations and, as the strength of the yarn is nearly that of the combined total strength of all the ends, it knits with much better efficiency than the plied yarns as heretofore made.
In accordance with my invention, I form a yarn by twisting together a plurality of ends of yarn in such a manner that there is in the various components of the yarn, as said yarn lies in a fabric,
a balanced amount of twist. This invention, I find, is of particular importance in forming yarns from'a plurality of ends at least one end of which has a high degree of twist and consists of substantially continuous artificial filaments.
Although this invention is applicable to the for-- matlon of yarns from any suitable fiber or filament, or both, it is particularly applicable to the formation of yarns containing fibers or filaments of an organic derivative of cellulose such as the organic esters of cellulose and cellulose ethers. Examples of organic esters of cellulose are cellu lose acetate, cellulose propionate, cellulose formate and cellulose butyrate, while examples of the cellulose ethers are ethylcellulose, methyl cellulose and benzyl cellulose. q Yarns of other materials may be employed in building the yarn in accordance with this invention. The other yarns may be employed alone or with yarns containing organic derivatives of cellulose. Examples of other filaments or fibers which may be employed to form the yarns are regenerated or reconstituted cellulose made by either the cuprammonium or viscose methods, silk, cotton, wool, etc. The fibers and filaments of organicderivatives' of cellulose may be em- 40 ployed alone in forming a single end, or fibers or filaments of an organic derivative of cellulose may be mixed with other fibers or filaments to form a single end or ends, each of which con tains a. single type of fiber or filament.
When artificial fibers or filaments such. as those containing organic derivatives of cellulose or reconstituted or regenerated cellulose are employed, these may have effect materials placed therein during their formation. These effect materials may be dyes, lakes, pigments, fillers, plasticizers, fire retardants, etc.
A balanced amount of twist in the plied yarn means that in the said yarn the ends make up substantially equally sized cross sections of yam of opposite and substantially equal twist. For instance, two 40 denier ends having 45 turns per inch left hand twist may be plied with 5 turns per inch left hand twist with one end of 80 denier having 55 turns per inch right hand twist. As this yarn lies in a fabric there will be 80 denier of yarn having 50 turns per inch right hand twist and 80 denier of yarn having 50 turns per inch left hand twist. An absolute balance is not necessary but it is preferred within the limits of modern machinery and large scale production methods. A yarn is balanced, insofar as this invention is concerned, when the right hand twist is within 8%. of the left hand twist. This limit also holds for the overall denier of the end or ends of the right hand twisted sections as compared with the left hand twisted sections.
The invention is applicable to the plying of ends of yarn each end of which may have any degree of twist from to 100 or more turns per inch, and each end may be of any suitable denier or count so long as there is a balancing component in the plied yarn. This invention is par ticularly applicable to the production of a four component yarn made entirely of continuous filaments containing an organic derivative of cellulose, which yarn has ends of crepe twisted or tightly twisted yarn and ends of normal twist or small amount of twist. For instance, the invention is applicable to the production of yarns containing four ends, one end of right hand twist and one end of left hand twist having more than 20 turns per inch, say, between 60 and 90 turns per inch, while the other ends have less than 20 turns per inch.
As an illustration and not as a limitation, the following example is given. All .the ends in the following example are 100 denier and all are formed from continuous filaments of cellulose acetate.
Example A two end plied yarn is formed from one end having 65 turns per inch right hand twist doubled with 6 turns per inch of right hand twist with an end having turns per inch right hand twist. Another two end plied yarn is formed from one end having 65 turns per inch left hand twist doubled 16 turns per inch left hand twist with one end of yarn having 5 turns per inch left hand twist. These two plied yarns are then plied with 5 turns per inch righthand twist. This produces a yarn having a balanced twist, as said yarn lies in the fabric. To aid in visualizing this example the following graphs are given wherein S means right hand twist and Z means left hand twistz- 1 end 65 turns x 6 turns S 1 end 5 turns S 1 end 8512111115 Z i and 5 turns Z As the yarn lies in the fabric, the twist is then:
76 turns S 76 turns z 11 turns 2 16 turns Z The yarns may be steamed on the bobbin, spool, quill, etc., before, between and/or after each plying operation. The yarn may also be steamed during the actual insertion of the twist in the same. The steaming of the yarns is of especial importance when the yarns contain a thermoplastic derivative of cellulose and there is inserted into the yarn a twist of more than 20 turns per inch; The steaming of the yarns may be accomplished by leading the yarns through a steam chamber mounted on the twisting or plying device. In place of steam other methods of heating the thermoplastic yarn may be employed, such as contacting the yarn with a heated roller or other element.
Obviously, the adding or subtracting twist in I plying operations influences thelength of the ends and, therefore, indirectly the amount of twist per unit length.
It is understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of my invention.
Having described my invention, what I desire to secure by Letters Patent is:
1. In a method of producing a balanced yarn by plying four ends of yarn together, the steps of" twisting separately two ends in opposite directions equally and to more than 20 turns per inch, twisting separately two ends in opposite directions equally and to less than 20 turns per inch, plying the two ends of the same direction (direction A) with a direction A twist, plying the two ends of the oppositedirection (direction B) with a direction B twist equal to the plying twist inserted inplying the direction A twisted end plus two times the amount of twist to be inserted in plying the two plied ends and plying the two plied ends with a direction A twist.
2. In a method of producing a balanced yam by plying four ends of yarn together, the steps of twisting separately two ends in opposite directions equally and to more than 20 turns per inch, twisting separately two ends in opposite directions equally and to less than 20 turns per inch, steaming the yarns, plying the two ends of the same direction (direction A) with a direction A twist, plying the two ends of the opposite direction (direction B) with a direction B twist equal to the plying twist inserted in plying the direction A twisted end plus two times the amount of twist to be inserted in plying the twoplied ends, plying the two plied ends with a direction A twist and steaming the yarns.