Preform and knitted tubular item having a retaining edge of a single thickness and method of producing such an item

Abstract

The method of producing a tubular knitted item (10), in particular a leg for a pair of tights, involves preceding the normal basic knit with a start that involves knitting, on only a portion of the needles on p first courses (11, 12) and on all of the needles on q subsequent courses (13, 14), an elastane yarn (21) covered with a water-soluble yarn (22); then, once the item has been knitted, the item undergoes an aqueous treatment, for example combined with dyeing, so as to make the water-soluble yarn (22) covering disappear, whereby the p+q courses (11-14) of knitted elastane that precede the normal basic knit are kept on the edge of the item.

Claims

1. A method of producing a knitted tubular item on a circular knitting machine comprising a plurality of needles and one or more feeders, the method comprising: knitting a first plurality of courses of elastane yarn covered with a water-soluble yarn using less than all of the plurality of needles; after knitting the first plurality of courses, knitting a second plurality of courses of elastane yarn covered with a water-soluble yarn using all of the plurality of needles; after knitting the second plurality of courses, knitting a third plurality of courses; and once the tubular item has been knitted, applying an aqueous treatment to the first plurality of courses and the second plurality of courses in such a manner as to make the water-soluble yarn disappear, leaving a bare knitted elastane at the first plurality of courses and the second plurality of courses.

2. The method according to claim 1, further comprising: applying a dyeing treatment to at least a portion of the knitted tubular item in a combined operation with the aqueous treatment.

3. The method according to claim 1, wherein the aqueous treatment for making the water-soluble yarn disappear comprising washing the knitted tubular item.

4. A preform of a circularly knitted tubular item comprising: a border region comprising a first plurality of courses followed by a second plurality of courses, each of the first plurality of courses comprising less yarn than each of the second plurality of courses; and a body region comprising third plurality of courses, wherein the first plurality of courses and the second plurality of courses comprise an elastane yarn covered with a water-soluble yarn.

5. A circularly knitted tubular item comprising a border region comprising a first plurality of courses followed by a second plurality of courses, each of the first plurality of courses comprising less yarn than each of the second plurality of courses; and a body region comprising a third plurality of courses, wherein the first plurality of courses and the second plurality of courses consist of bare, uncovered elastane yarn.

6. The knitted tubular item according to claim 5, wherein the elastane yarn is of a numbering less than 20 dtex.

7. The knitted tubular item according to claim 5, wherein the elastane yarn is composed of more than 20 filaments.

8. The method according to claim 1, wherein knitting the first plurality of courses comprises knitting at least one course using one out of every four needles.

9. The method according to claim 1, wherein knitting the first plurality of courses further comprises knitting at least one course using one out of every two needles.

10. The method according to claim 1, wherein the water-soluble yarn comprises a PVA yarn.

11. The method according to claim 1, wherein the first plurality of courses comprises at least two courses, and wherein the second plurality of courses comprises at least two courses.

12. The method according to claim 1, wherein the elastane yarn is of a numbering less than 20 dtex and is composed of more than 20 filaments.

13. The method according to claim 1, wherein knitting the third plurality of courses comprises knitting at least one course of a yarn comprising polyamide.

14. The method according to claim 1, wherein knitting the third plurality of courses comprises using at least a portion of the plurality of needles to implement a jersey stitch knitting pattern.

15. The preform according to claim 4, wherein the water-soluble yarn comprises a PVA yarn.

16. The preform according to claim 4, wherein the elastane yarn is of a numbering less than 20 dtex and is composed of more than 20 filaments.

17. The preform according to claim 4, wherein the third plurality of courses comprises at least one course including a polyamide yarn knitted in a jersey stitch pattern.

18. The knitted tubular item according to claim 5, wherein the elastane yarn is of a numbering less than 20 dtex and is composed of more than 20 filaments.

19. The knitted tubular item according to claim 5, wherein the third plurality of courses comprises at least one course including a polyamide yarn knitted in a jersey stitch pattern.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) Other features and advantages of the invention will become apparent upon reading the following description, given by way of non limiting indication, with reference to the accompanying drawing on which the unique FIG. 1 represents in a traditional manner the knitting diagram of a leg for a pair of tights.

DETAILED DESCRIPTION

(2) The leg for a pair of tights of the invention may be knitted by using a knitting machine of the Lonati type 404MJ brand (4 feeders).

(3) FIG. 1 shows a tubular leg 10 in several successive sections: a start part T to which the invention particularly relates, a waistband part C, a panty and thigh part S, an actual leg part J, a part SM called mesh stop and a toe part P. Knitting all the parts except for the start part T is what is called here a classic or normal basic knit for this type of item. It has been illustrated here for the four feeders 1, 2, 3, 4 in a polyamide based jersey stitch 6.6 (PA66) plated or not with elastane (R22). It could consist of other fibers, the invention not relating to making a normal knit.

(4) The FIGURE details the knitting of the start part T and schematically shows the four courses of stitches 11, 12, 13, 14 prior to the aqueous treatment (right part, stage of the preform of the product) and after the aqueous treatment (left part, stage of the end product). According to the invention, the four feeders of the knitting machine are knitted in one same yarn 20 constituted of an elastane 21 of the Roica brand 17 dtex of 31 monofilaments, covered in simple flat covering (SGP) of a water-soluble yarn 22 of PVA (polyvinyl alcohol) of the SOLVRON brand. Such a covered yarn 20 is much easier to knit than a bare elastane yarn, which is very difficult to knit. In order to initiate knitting, it is not easy to knit directly on all the needles in simple feeder; it must be knitted gradually on a quarter of the needles, then on half the needles, then on all the needles. Hence, as the diagram shows, the knitting comprises a first knitted course 11, 1 needle out of 4 (hence on 100 needles out of the 400 needles of the knitting machine), leaving three skipped stitches on three adjacent columns between the formed stitches (each skipped column has been represented by a cross), then a second knitted course 12 1 needle out of 2 (hence 200 needles out of the 400 needles of the knitting machine), then finally two courses 13, 14 or more knitted on the 400 needles. All these courses 11-14 are thereby in elastane covered with water-soluble yarn, at the product preform.

(5) Once a suitable preferably hot, aqueous treatment is carried out, the covering water-soluble yarn 22 is dissolved in water and is eliminated, leaving the elastane 21 bare, in such a manner that the stitches represented on the left part of the FIGURE are obtained, where the first courses of stitches are in bare elastane, first 1 needle out of 4, then 1 needle out of 2, then on all the needles. These courses 11-14 of bare elastane are easily stretched, even for the first two courses which are not knitted on all the needles, due to the fact that the elastane is pure and highly elastic. These first courses, here four courses, hardly visible to the naked eye, do not cause any discomfort to wear and then allow continuing normal knitting. The waistband C may hence be knitted in a single thickness, like the rest of the pair of tights.