GB2085038A

GB2085038A - Method and loom for the production of a fabric, more particularly a sacking fabric

Info

Publication number: GB2085038A
Application number: GB8128140A
Authority: GB
Original assignee: SETAFIN SA
Current assignee: SETAFIN SA
Priority date: 1980-09-30
Filing date: 1981-09-17
Publication date: 1982-04-21
Also published as: FR2595104B1; GB2085038B; FR2595104A1

Abstract

A circular loom for weaving a sacking fabric (1), in which weft yarn thickenings (9) form transverse strips periodically at a given spacing, has a control device (10) controlling the sequence of weft yarn introduction and controlling a device (12) to mark the fabric with a readable or scannable register marking whose individual markings (15) correspond with the longitudinal distances of the transversely extending waft yarn thickenings, to enable the web of fabric (1) to be cut in accordance with the register markings. <IMAGE>

Description

SPECIFICATION Method and loom for the production of a fabric, more particularly a sacking fabric The invention relates to a process for the production of a fabric, more particularly a sacking fabric, on a loom, more particularly a circular loom, in which weft yarn thickenings forming transverse strips follow one another periodically at a given distance, the web of fabric then being parted at those places.

Processes of the kind specified for producing, for example, sacks, have the basic disadvantage that it is difficult to cut the web of fabric every time precisely at the places of the weft yarn thickenings so as to obtain a suitable proportion of the particular weft yarn thickening for both the sack edge and the sack bottom. Hitherto, therefore, a cutting machine had to be used and a particular cutting place selected and monitored by the operative, in a way which cannot meet present-day demands on rational manufacture.

In order to remedy this situation effectively, in the process according to the invention a readable or scannable register marking is applied to the fabric whose individual markings correspond to the longitudinal distances between the weft yarn thickenings, to enable the web of fabric to be cut to be then advanced in accordance with the register marking.

According to another possible feature of the process according to the invention, the register marking is applied to the fabric synchronously with the periodic weft yarn thickening.

Another resulting possible feature is that the register marking is formed by coloured marks and/or electromagnetically readable printed marks.

Clearly, in that case a web of fabric prepared in accordance with the method disclosed hereinbefore can be parted precisely and completely automatically on a conventional cutting machine, so long as it is equipped with suitable, conventional means for scanning or reading the register marking on the web of fabric.

The invention also relates to a loom for the performance of the process according to the invention, with a device for controlling the sequence of weft yarn insertion to form weft yarn thickenings following one another periodically at a given distance.

In the loom according to the invention disposed on the loom in the zone of the web of fabric is a marking device for making register marks on the web of fabric at a distance corresponding to the longitudinal distances between the weft yarn thickenings.

In another possible feature of the loom the marking device is connected synchronously to the control device for the sequence of weft yarn insertion.

Alternatively, the construction on a circular loom can be that the marking device is disposed in the zone of the place where the tubular fabric is laid flat and comprises at least one printing mechanism for applying the register marks along at least one of the folded edges of the laid-flat fabric.

An embodiment of a circular loom for the performance of the process according to the invention will now be explained in detail with reference to the drawing, which illustrates diagrammatically a device according to the invention for applying a register marking on a circular loom.

Fig. 1 indicates a circular loom by a portion of a woven material 1 with a shed formed by warp yarns 2 (upper shed) and warp yarns 3 (lower shed). A weft yarn is inserted through the shed by means of a shuttle 20 which is guided along a horizontal circular path. The weft yarn is inserted in known manner in the zone of an upper 21 and a lower guide ring 22 of the loom, into whose proximation zone a weft yarn positioning ring 23 on the shuttle 20 dips. The upper and lower sheds are opened in known manner by healds 24.

The tubular fabric 1 thus woven is drawn off upwards and laid flat in the zone of the drawingoff rollers 25 (only one shown) and then conveyed onwards in the laid-flat form for further processing in the direction indicated by arrow 26.

In this case, the laid-flat fabric 1 is fed to a cutting machine (not shown).

For the production of transverse-strip-shaped weft yarn thickenings 9, following one another periodically at a given distance, in order to form reinforced edges on the subsequent finished product, the loom also has in known manner a suitable control device 10 for the sequence of weft yarn introduction. In the embodiment illustrated the control device is merely indicated by a cam shaft.

In order then to enable the web of fabric 1 to be cut precisely in relation to the transverse-stripshaped weft yarn thickenings 9, according to the invention steps are taken enabling the weft fabric 1 to be given a readable or scannable register marking whose individual markings 1 5 correspond with the longitudinal distances of the transversely extending weft yarn thickenings 9, to enable the web of fabric 1 to be parted to be advanced in accordance with the register markings. In other words, the successive distances 11 between the transversely extending weft yarn thickenings 9 and the individual markings 1 5 are to be kept constant.

For this purpose a suitable marking device 1 2, disposed on the loom in a manner not shown in detail, can be conveniently actuated by the control device 10 for the sequence of weft yarn insertion, as shown by a chain-dot line 16 in the drawing.

The marking device 1 2 can have onor-two printing mechanisms (not shown) which place the register marks 1 5 along one folded edge of the fabric or along both of its folded edges.

Preferably the marking device 12 (cf. the drawing) is disposed atthe place of the drawingoff roller 25 illustrated, in the zone where the tubular fabric is laid flat.

Of course, the nature of the marking device 12, the place at which it is used on the web of fabric, and its control in the cadence of the weft yarn thickenings can be selected as required according to the invention. For example, the process according to the invention can also readily be put into effect on plain looms.

Similarly, the register marks 5 to be applied can be of any desired kind. For instance, the register marks 1 5 can be coloured marks and/or electromagnetically readable printed marks. In that case, of course, the following cutting machine must be equipped with suitable means for scanning or reading the register marking on the web of fabric.

These steps therefore enable a web of fabric with weft yarn thickenings following one another periodically at a given distance to be cut accurately and fully automatically.

Claims

1. A process for the production of a fabric, more particularly a sacking fabric, on a loom, more particularly a circular loom, in which weft yarn thickenings forming transverse strips follow one another periodically at a given distance, the web of fabric then being parted at those places, wherein a readable or scannable register marking is applied to the fabric whose individual markings correspond to the longitudinal distances between the weft yarn thickenings, to enable the web of fabric to be cut to be then advanced in accordance with the register marking.

2. A process according to Claim 1, wherein the register marking is applied to the fabric synchronously with the periodic weft yarn thickening.

3. A process according to Claims 1 and 2, wherein the register marking is formed by coloured marks and/or electromagnetically readable printed marks.

4. A loom for the performance of the method according to Claims 1, 2 or 3, with a device for controlling the sequence of weft yarn insertion to form weft yarn thickenings following one another periodically at a given distance, wherein disposed on the loom in the zone of the web of fabric is a marking device for making register marks on the web of fabric at a distance corresponding to the longitudinal distances between the weft yarn thickenings.

5. A loom according to Claim 4, wherein the marking device is connected synchronously to the control device for the sequence of weft yarn insertion.

6. A loom, more particularly a circular loom according to Claims 4 or 5, wherein the marking device is disposed in the zone of the place where the tubular fabric is laid flat and comprises at least one printing mechanism for applying the register marks along at least one of the folded edges of the laid-flat fabric.

7. A method for producing a fabric, more particularly a sacking fabric, as hereinbefore disclosed and illustrated in the accompanying drawing.

8. A loom, more particularly a circular loom as hereinbefore disclosed and illustrated in the accompanying drawing.