GB2023678A

GB2023678A - Elastic dressing material

Info

Publication number: GB2023678A
Application number: GB7919559A
Authority: GB
Original assignee: Molinier SA
Current assignee: Molinier SA
Priority date: 1978-06-27
Filing date: 1979-06-05
Publication date: 1980-01-03
Also published as: ES480666A1; SE7904459L; GB2023678B; DE2925165A1; CA1121171A; NL7903793A; FR2429854A1; CH637429A5; FR2429854B1

Abstract

A fully elastic dressing material, that is a fabric band which is elastic in all directions, is knitted on a Raschel machine and comprises warps knitted into chains, and connected by elastic wefts. The fabric may comprise only chains knitted from elastic yarns 1 and laid-in elastic wefts 2 but may also include additional chains of non elastic yarns 3. The elastic yarns may be elastomeric and wrapped with textile yarns and the non-elastic yarn may be cotton or viscose staple. The elastic yarns are knitted under tension and, when the fabric is released, these retract while the non- elastic yarns form loops. The needles of the machine are passed through the bands undergoing formation while omitting periodically at least one needle between two chain warps in the interlacings which form the chain warps and the bindings of the transversal weft yarns with the chain warps in order to provide a retraction space. The bands thereby produced have selvages which are uniform and flat. <IMAGE>

Description

SPECIFICATION Elastic dressing material This invention has for its object a band which is elastic in all directions, more particularly for retention, and the method for manufacturing said band.

The object of the invention belongs to the technical field of care and products for dressings.

It is well known to manufacture bands which are elastic in all directions on conventional looms, with a so-called "light treadle" weave on the whole width of the band.

It has been found desirable to produce such bands which are elastic in all directions on Raschel machines or rectilinear knitting machines, in order to increase and to improve very substantially the production. However, with the Raschel machines, on account of the working of the yarns, and as the wefts of these bands must be elastic, it is not possible to obtain bands with uniform selvedges. The edges of these bands are rolled up.

With the method in accordance with this invention, bands can be made on a Raschel machine which are elastic in all directions, the selvedges of which are uniform and flattened.

It will be well understood that elastic bands in all directions which are manufactured in accordance with this method fall within the scope of this invention.

In accordance with the method of the invention, bands which are elastic in all directions are knitted on a Raschel machine (rectilinear knitting machine) by forming in a known manner endwise chain warps connected by wefts which are constituted by elastic transversal yarns; the needles of the machine are drawn, however in the interlacings which form the chain warps and the bindings of the transversal yarns (wefts) with said chain warps, a needle at least is omitted periodically between two chain warps, in order to reserve a retraction space.

In accordance with a further characteristic, in the interlacings which form the chain warps and the bindings of the transversal yarns (wefts) with said chain warps, all the needles of the machine are threaded while omitting periodically at least one chain warp of non elastic yarns which is not bound to the weft yarn interlaced with the chain warps disposed on either side.

These and other characteristics will be apparent from the following description and from the attached drawings, in which there is shown an embodiment of the invention by way of example and not limitatively.

In the drawings: Figure 1 is a weave of a portion of a band which is elastic in all directions in accordance with a first embodiment of the invention, showing the interlacings of the weft yarns with the chain warps, as well as the needles omitted without chain warp yarns between the said chain warps interlaced with the weft.

Figure 2 is an entirely diagrammatic plan view corresponding to Fig. 1.

Figure 3 is a weave of a portion of a band which is elastic in all directions in accordance with a second embodiment of the invention, showing the interlacings of the weft yarns with the chain warps, as well as the chain warps of non-elastic yarns omitted by the weft between the interlacings of said chain warps with said weft yarns.

Figure 4 is an entirely diagrammatic plan view corresponding to Fig. 3.

The object of the invention will be understood more fully by describing it not limitatively according to the forms of embodiment illustrated in the drawings.

In the form of embodiment illustrated in Figs. 1 and 2 of the drawings, the elastic band in all directions is manufactured on a rectilinear Raschel knitting machine, the weave being shown in Fig. 1.

There may be seen the yarns 1 of the longitudinal chain warps and the transversal yarns or wefts 2 interlaced with two adjacent chain warps.

The yarns 1 are elastic or of elastomeric material, and preferably spiraled in any known manner and with any known textile yarn.

Yarns 2 are elastic yarns which are preferably spiraled.

When the band is knitted, for instance in the way of the weave illustrated in Fig. 1, the chain warps 1 are formed and interlaced with yarns 2.

In the interlacings which form the chain warps 1 and the bindings of the transversal yarns 2, there is omitted periodically, as per in the example shown, a needle 4 between two chain warps. It is thus reserved between the chain warps 1 a space A (Fig. 2) for a free retraction of weft yarns 2. Therefore, a rolling up of the elastic bands in all directions which are manufactured on a Raschel machine is prevented, and a better elastic capacity is provided. The quite higher output on the Raschel machine is thus consistent with a flattened make-up of the bands.

It is also possible to omit more than one needle between two chain warps.

After weaving the elastic bands in all directions on the Raschel machine, some additional operations, known in se, are performed, such as moistening, calendering.

In the form of embodiment illustrated in Figs. 3 and 4 of the drawings, the elastic band in all directions to be manufactured on a rectilinear Raschel knitting machine is made in accordance with the weave shown in Fig.

3. There may also be seen here the longitudinal chain warp yarns 1 and the transversal yarns or wefts 2 interlaced with two adjacent chain warps. Yarns 1 and 2 are of a nature similar to the form of embodiment shown in Fig. 1 and 2.

However, in the form of embodiment according to Figs. 3 and 4, all the needles of the Raschel machine are threaded and in the interlacings which form the chain warps 1 and the bindings of the transversal yarns 2, there is omitted periodically a chain warp 3which is not bound to the weft yarns 2. The chain warps 3 are therefore relatively free between two bound chain warps 2. As the case may be, more than two free chain warps can be omitted.

As a result, the rolling up of the elastic bands in all directions manufactured on a Raschel machine with high output is prevented.

Preferably, chain warps 3 are of non elastic yarns such as fibranne or cotton for instance.

As the bands are knitted on the Raschel machine with some stress, the yarns 3, after the weaving, when the band is retracted, are looped according to this retraction. The band has thus the appearance of a crimped band, of softer feel and better for the contact with the skin when dressings are made.

It will be apparent from the foregoing that the free intermediate chain warps 3 of non elastic yarns provide a limitation in the longitudinal direction of the contention effect of the band.

This limitation in the longitudinal direction can also be obtained by modifying the overtwisting of the non elastic chain warp yarns 3.

Within the scope of the invention, the use is not excluded, to form the free intermediate chain warps 3, of elastic or elastomeric yarns, or of yarns having an artificial elasticity of shape, with limited and pre-determined elasticity. To do this, it is possible for instance to have the elastic yarns spiraled under conditions which are likely to limit the elasticity to the desired value.

It will be noted that for the knitting of the bands on the Raschel machine: -the elastic chain warps 1 are worked with a normal tension (this tension is normal for the skilled worker, and well known to him); -the elastic wefts 2 are knitted with a mini mal tension, and this in a manner which is well known by reason of the adjustment of the reachers, as it will be observed that is not possible for yarns to be processed without tension; otherwise the yarns would not hold, and would give way when the needles are drawn in; -the none elastic chain warps 3 are knitted under normal tension in accordance with the nature of the non elastic yarns.

The interest and the advantages of the bands which are elastic in all directions and manufactured in accordance with the method will be apparent from the description and from the drawings.

Samples have been filed as examples of embodiment at the French Patent Office: -Sample No 1 is an embodiment of the elastic band in all directions in accordance with the invention, in which a needle has been omitted periodically between two chain warps.

-Sample No 2 is a further embodiment of the elastic band in all directions in accordance with the invention, in which all the needles of the Raschel machine have been drawn in while omitting periodically a chain warp not bound to the weft yarns, some chain warps being thus regularly free between the bound chain warps.

It will be understood that the invention is not limited in any way to the use nor to the embodiments of the various parts thereof that have been more particularly set forth, and that any changes and modifications in the structural embodiment herein will not constitute a departure from the scope of the invention.

Claims

1. Band which is elastic in all directions, more particularly for contention, and method for manufacturing same, characterized in that the elastic bands are knitted on a Raschel machine (rectilinear knitting machine) by forming in a known manner longitudinal chain warps connected by wefts which are constituted by elastic transversal yarns, the needles of the machine being passed therethrough, while omitting periodically at least one needle between two chain warps in the interlacings which form the chain warps and the bindings of the transversal yarns (weft) with said chain warps in order to reserve a retraction space.

2. Method for manufacturing the elastic band of Claim 1, characterized in that all the needles of the machine are drawn in the interlacings which form the chain warps and the bindings of the transversal yarns (weft) with said chain warps, while omitting periodically at least one chain warp of non elastic yarn which is not bound with the weft yarn interlaced with the chain warps located on either side.

3. Band as claimed in Claim 1 or 2, characterized in that the yarns of the yarns of the longitudinal chain warps and the transversal yarns or wefts are elastic or of elastomeric material, and that they are spiraled in any desired manner and with any textile yarn which could be used for this purpose.

4. Band as claimed in Claim 1 or 2, manufactured in accordance with the weaves as shown.

5. Band as claimed in Claim 2, characterized in that the free chain warps which are not interlaced with the wefts are of non elastic yarns such as fibranne, cotton... and provide a limitation in the longitudinal direction of the contention effect of the band.

6. Band as claimed in Claim 2 or 5, characterized in that the limitation in the longitudinal direction of the contention effect is obtained by modifying the overtwisting of the chain warp yarns which are non elastic and not bound.

7. Band as claimed in Claim 2, characterized in that the yarns of the free and not bound chain warps are elastic or of elastomeric material, or have an artificial elasticity of shape, the elasticity of which is limited and predetermined by spiraling the yarns of these chain warps in order to give them a relative elasticity in accordance with the desired value.

8. Band as claimed in any one of Claims 1 to 6, characterized in that during the knitting process on the Raschel machine, the elastic chain warps are worked under normal tension, the elastic wefts are worked with a minimal tension, and the free non elastic chain warps are knitted under normal tension in accordance with the nature of the yarns.

9. Band which is elastic in all directions, substantially as hereinbefore described with reference to, and as shown in, Figs. 1 and 2 or Figs. 3 and 4 of the accompanying drawing.