WO2005012622A1

WO2005012622A1 - Apparatus for imparting stretch to fabrics

Info

Publication number: WO2005012622A1
Application number: PCT/GB2004/003163
Authority: WO
Inventors: Paul A. J. Morris
Original assignee: Profit International Limited
Priority date: 2003-07-26
Filing date: 2004-07-23
Publication date: 2005-02-10
Also published as: GB0317580D0

Abstract

An apparatus for the treatment of fabric is disclosed which comprises transport means for effecting relative movement between a heat and pressure application means and the fabric (12), whereby the passage of the fabric through the apparatus results in the yarns substantially across the width of the fabric being forced closer together, thus imparting semi-permanent “ease” or “stretch” into the fabric, characterised by additional heating means (28) adjacent the transport means (20) for heating those areas of the transport means which, in use, support the fabric (12). The heating means may be selectively applied to those areas of the transport means (20) which supports the fabric strips (12) in use; alternatively, means may be provided to oscillate the strips (12) from side to side as they pass through the apparatus so that they progressively cover all parts of the transport means (20). The heating means may comprise electric or gas heaters, or preferably jets of hot air (28) which can be directed specifically at the required area. Alternatively, where the fabric is oscillated, the heating means may comprise an additional heated roller.

Description

APPARATUS FOR IMPARTING STRETCH TO FABRICS

This invention relates to an apparatus for imparting stretch to fabrics and in particular relates to a heating system for such an apparatus.

In our EP patent publication number 0705356 there is described an apparatus for imparting stretch to fabrics which comprises means for applying heat and pressure to a woven fabric, transport means for effecting relative movement between said heat and pressure application means and said fabric whereby passage of the fabric through the apparatus results in the yarn strands substantially across the width of the fabric being forced closer together, thus imparting semi-permanent "ease" or "stretch" into the fabric. The fabric is subsequently fused to an interlining.

The fabric is generally in the form of strips, and a number of strips may be processed simultaneously going side by side through the apparatus.

It has been found that, particularly where the fabric strips are of relatively high density, the cooling effect of the fabric strips is such that the speed of throughput needs to be lowered to allow heat from the heated roller to fully bring the strips up to operating temperature, which is essential to the proper operation of the process. Moreover, variations in temperature as the apparatus reaches equilibrium can cause variations in the properties, e.g. degree of stretch, of the product so-formed.

The present invention seeks to provide an apparatus having improved heating means so as to maintain a higher and even throughput, even of heavyweight fabrics.

According to the present invention, there is provided an apparatus for the treatment of fabric which comprises transport means for effecting relative movement between a heat and pressure application means and the fabric, whereby the passage of the fabric through the apparatus results in the yarns substantially across the width of the fabric being forced closer together, thus imparting semi-permanent "ease" or "stretch" into the fabric, characterised by additional heating means adjacent the transport means for heating those areas of the transport means which, in use, support the fabric.

As mentioned above, the fabric is normally in the form of strips and the areas in between the strips are not subject to cooling by the fabric. Accordingly, it is not necessary to heat up these areas and, indeed, it would be disadvantageous to do so as they may become too hot. Accordingly, the heating means may be selectively applied to those areas of the transport means, i.e. rubber conveyor, which supports the fabric strips in use. Alternatively, means may be provided to oscillate the strips from side to side as they pass through the apparatus so that they progressively cover all parts of the transport means. This has the added advantage of evening out wear on the transport means also.

Since the fabric being processed cools the transport means there will be variability in the product until a steady state is reached. In general terms, this can be addressed by altering the temperature, pressure or throughput speed of the process. Where material is being fed on to other processing machinery, it is inconvenient or impossible to vary the processing speed during operation and it is also difficult to compensate through altering the pressure as this often leads to other problems. Accordingly, the apparatus of the invention inputs heat to compensate for that taken up by the fabric being processed.

The heating means may be in any suitable form, for example, electric or gas heaters, but is preferably jets of hot air which can be directed specifically at the required area. Alternatively, where oscillation of the strips is carried out, an additional heated roller can be provided

The invention will be described further, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a diagrammatic plan view of an apparatus modified in accordance with the invention; and

Figure 2 is a side view corresponding to Figure 1. Referring to the drawings, apparatus according to our above mentioned European patent publication number 0705356 B comprises a rubberised conveyor belt (20) driven by conveyor rollers (22,24) and a heated roller (26) which is held against the belt (20) in close proximity to roller (24) so as to apply heat and pressure to fabric strips (12) passing through the nip formed between the rollers (26) and (24). The strips (12) are placed onto the conveyor by an operator and the fabric strip direction is at right angles to the axis of the heated roller (26). The strips are progressed through the nip of the roller (26) and the conveyor (20) (Figure 2).

The result of this treatment is to force the strands which pass substantially across the width of the strip to draw closer together, as discussed in our above mentioned European patent publication, imparting stretch to the fabric.

In accordance with the invention, this apparatus is modified by the provision of hot air blowers (28) which are located adjacent to areas where the strips (12) contact the sleeve (20) and locally cool it.

The extra heating effect provided by the air blowers (28) ensures that the heat provided by heated roller (26) can penetrate the strips (12) without needing to slow down the throughput speed of the apparatus. The heat provided can be reduced or discontinued as the temperature of the sleeve (20) reaches equilibrium, and adjusted if a lighter or heavier fabric is to be treated.

Thus, in accordance with the invention, the process can be carried out at a commercially fast speed, even with thicker fabrics which have a greater heat capacity, and variability in shrinkage owing to alterations in temperature may be reduced or eliminated.

Claims

1. An apparatus for the treatment of fabric which comprises transport means for effecting relative movement between a heat and pressure application means and the fabric (12), whereby the passage of the fabric through the apparatus results in the yarns substantially across the width of the fabric being forced closer together, thus imparting semi-permanent "ease" or "stretch" into the fabric, characterised by additional heating means (28) adjacent the transport means (20) for heating those areas of the transport means which, in use, support the fabric (12).

2. An apparatus as claimed in claim 1 wherein the heating means is selectively applied to those areas of the transport means (20) which supports the fabric strips (12) in use.

3. An apparatus as claimed in claim 1 wherein means may be provided to oscillate the strips (12) from side to side as they pass through the apparatus so that they progressively cover all parts of the transport means (20).

4. An apparatus as claimed in any of claims 1 to 3 wherein the heating means comprise electric or gas heaters, or jets of hot air (28) which can be directed specifically at the required area.

5. An apparatus as claimed in claim 3 wherein the heating means comprises an additional heated roller.