IES64283B2 - A knitted garment production process - Google Patents

Abstract

In a production process for a knitted garment, a knitting stage 1 involves connection of panels by soluble thread. At a pre-steaming operation 3, there is simultaneous relaxation by up to 25% of the knitted fabric and also disintegration of the soluble thread. This separates the panels, whereafter the shoulder edges of front and back panels are cut 4 at a guillotine-type station which provides a good accuracy for cutting. The shoulder edges are joined at a taping station in which a 5% elasticated tape is fed under tension through a fold-over guide to produce a high-strength join which is hidden to a large extent in the finished product. All material handling takes place by use of fasteners (30, Figs. 3a to 3c) which are extremely simple as they comprise only a length of rope and a jam cleat, the cleat also being used for identification of the bundle as a label is adhered to it. Some operations such as bar tacking 9 and backneck labelling 7 may be carried out on the garments while they are still held together in this manner. An important step is final steaming 11 at which there is further relaxation of the knitted fabric and simultaneously manipulation and tidying for presentation purposes. A high labour efficiency is achieved by the manner in which machines such as the pre-steaming and final pressing machines are used.

Description

A knitted garment production process The invention relates to the production of knitted garments.

Typically, knitted garments are produced by initially knitting blankets of fabric on a machine, for example a flat bed knitting machine such as those described in European Patent Specification Nos. EP 405,115, EP 276,383 and GB 2,180,266 (Stoll H & Co GmbH). Panels for production of garments are separated out by drawthreading, which is an extremely difficult and timeconsuming task. The edges of the fabric are then sealed and subsequently relaxed by tumbling, for example. There is then laying-up of the fabric at which the panels are aligned at edges and at fold lines before being cut by a band knife. In some instances, a stack of such panels are cut simultaneously. Operations such as linking neckbands to the shoulder edges and overlinking are then carried out at individual workstations. Linking of trim such as neckbands is often carried out several stitches in from the edge and therefore the excess must be removed manually.

Various items of equipment have been developed to assist in such processes such as a workpiece folding guide described in British Patent Specification No. GB 2,083,845. This guide is used for folding workpieces prior to being sewn and cut. Various machines for relaxation of the fabric are described in European Patent Specification No. EP 311,897, GB 2,148,342 and WO 85/04198. Such machines may be used after overlinking, or alternatively on the raw fabric output of the knitting machines . It is important to ensure uniform relaxation of the panels to avoid puckering along the seams. - 2 Where there are very high volumes of particular types of garments and where labour costs are cheap, such production methods are probably quite effective. However, where the commercial situation requires that there be very frequent changes in production batches with very short lead times upon receipt of orders, they would prove to be very inflexible. In many situations, lead times can be up to three weeks from production to order.

There is therefore a need for a production process which is more efficient than heretofore by requiring less use of labour, and also which provides more versatility so that the garment type being produced can be changed very quickly. This is particularly true in an environment where labour costs are not low.

According to the invention, there is provided a knitted garment production process comprising the steps of:knitting garment panels on a flat bed knitting machine in which the knitting operation interconnects panels by a soluble thread; pre-steaming the garment panels in a conveyor steam press to cause relaxation of the fabric and simultaneous dissolving of the soluble thread; cutting shoulder edges in each panel individually in turn by use of a press cutter having a blade shaped in the shoulder pattern; taping the shoulders for a garment by sewing a tape against the shoulder line of a pair of panels; linking a neckband to the panels along the shoulder edges; overlooking the panels with sleeve panels; carrying out final trimming of the garment and turning the panels out; carrying out final pressing of the garment by placing the garment on a steam table and simultaneously manipulating and sizing the garment panels, and subsequently conveying the garment to an overhead press station at which it is simultaneously pressed and steamed; and packing the pressed garment.

In one embodiment, the garment is pre-steamed at a steam pressure of 4.5 to 5.5 bar and a temperature in the range of 135-145°C.

Preferably, the conveyor steam press is simultaneously fed with two lines of interconnected panels, the steamed panels being removed, checked, and placed in two stacks, one for each line.

In one embodiment, the steamed panels are placed in a stack on a rope, the rope terminating in a jam cleat, the rope being pulled around the stack and the cleat fastened when there is a pre-set number of panels in the stack followed by labelling of the cleat.

In a further embodiment, steam is outputted in the press station for final pressing at a proportion of approximately 80% from above and 20% from underneath.

Preferably, the steam pressure for final steaming is in the range 4.5 to 5.5 bar and the temperature is in the range 135 to 145°C.

Ideally, two garments are pressed simultaneously in final pressing, and are supported on a linen fabric cover for the press table.

In a further embodiment, the shoulder edges are cut by:placing the garment on a table supporting an upstanding blade shaped in the shoulder pattern, and a resilient pad surrounding the blade and supporting the garment; moving the table into a position in registry with a press head having a substantially flat plate of relatively soft metal; and pressing the garment by action of the press head, moving the table back to its initial position, and conveying the cut panel to an output stack.

Preferably, the machine comprises a resilient skirt positioned to prevent movement of the cut panel back with the table in its return stroke.

In another embodiment, the shoulders are taped by use of a tape having approximately 5% elasticity and being fed through a tensioning device and a fold-over guide to a sewing head.

In a further embodiment, the process comprises the further steps of bar tacking excess chain fabric at panel joints after overlooking.

In one embodiment, small projections are knitted as in integral part of front and back panels to.provide a guide for alignment of panels during overlinking.

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:Figs. 1(a) and 1(b) are flowcharts illustrating in outline format a knitted garment production process of the invention; Figs. 2(a) and 2(b) are perspective and diagrammatic side views respectively of a pre-steaming machine used in the process; Fig. 3(a) is a perspective view of a fastener used in the process, while Fig. 3(b) shows a cleat of the fastener and the labelling method, and Fig. 3(c) shows the manner in which the fastener is used to hold a bundle of fabric panels; Figs. 4(a), 4(b) and 4(c) are perspective, diagrammatic side and detailed cross-sectional views of a cutting machine used in the process; Fig. 5(a) is a perspective view showing front and rear panels to be connected at the shoulders, Fig. 5(b) is a perspective view showing a shoulder taping machine, Fig. 5(c) is a detailed view showing a tensioning device of the machine, Fig. 5(d) is a diagrammatic view showing the manner in which the tape is cut after stitching, and Fig. 5(e) is a perspective view showing a bundle of panels after shoulder taping; Fig. 6(a) is a diagrammatic view showing the overlinking operation of a garment and Fig. 6(b) is a perspective view showing the manner in which excess trim is removed at an overlinking station; Figs. 7(a) and 7(b) are perspective views of final pressing operations; and Fig. 8 is a perspective view of a packed knitted garment.

Referring to the drawings, there is shown a knitted garment production process of the invention having major steps 1 to 12, inclusive. The process is outlined in block diagram form in Fig. 1(a) and in illustrative schematic form in Fig. 1(b). Initially, flat bed knitting machines are used to produce panels according to the desired patterns. The machines are programmed so that at least the sleeve panels are shaped in exact conformity with the end design. The programming provides for knitting to the level of detail of knitting buttonholes and in addition, projections are knitted into the panels along the seam edges to provide datum indicators for subsequent attachment of panels together. These projections are very small and are only provided at edges in positions where they will be concealed in the finished garment. The fabric which is knitted by the machines is in the range of 6 to 12 gauge. An important aspect of the knitting operations is that panels are produced sequentially in a manner whereby they are interconnected by a soluble thread. Some panels are quite difficult to produce in this manner such as large front or rear panels for jerseys and these are interconnected in the traditional manner using draw-thread which must be manually removed at a later stage. However, the proportion of such panels is quite small. These panels are prepared in step 2 by removal of the draw threads and the forming of any required trimming and manipulation as indicated by the step 2 in Fig. 1.

The next major step of the process is pre-steaming 3 which is carried out using a machine 20 illustrated in Figs. 2(a) and 2(b). The machine 20 has a frame 21 to which is connected a steam duct 22 for delivery of steam to conveyor belts which are used for simultaneous conveying and steaming of the knitted panels. The machine 20 comprises a lower conveyor 23 and an upper pressing conveyor 24, between which two lines 25 of interconnected panels are conveyed. Simultaneously, steam from the duct 23 passes through the surfaces of the conveyors 23 and 24 at a temperature of approximately 140°C and preferably in the range of 135° to 145°C. Pressure is preferably 5 bar and generally in the range 4.5 to 5.5 bar and the time duration is in the region of 8 to 12 seconds, depending on the gauge of the fabric. This operation causes the fabric to be relaxed by up to 25% and so the major part of the relaxation has occurred at an early stage in the process. The end product is a set of panels 26 which have been separated from the adjacent panels in the line 25 because the heat has caused the soluble thread which interconnects them to disintegrate.

As shown in Fig. 3(c), a fastener 30 comprising a jam cleat 31 and a length of rope 32 is used to hold together a bundle 33 of panels. At the output of the pre-steaming machine 20, there is a platform associated with each line 25 of panels. The fastener is left in the open position across the platform, the panels are stacked on top, and as a pre-set number of panels is stacked, the rope 32 is pulled around the stack and engages with the jam cleat 31 to fasten the stack together. The label 34 is then adhered to the jam cleat 31 to identify the bundle 33 with a particular batch and style number, etc. From that stage onwards, the bundle is immediately identifiable and further processing operations take place on all panels in that particular bundle together. Efficiency is achieved because a single operator can remove panels 26 from two lines 25 of panels to simultaneously create two stacks. The output of the pre-steaming machine 20 therefore provides not only an efficient way of sorting the panels but also a quality control check at the same time.

As indicated by the step 4, cutting of the panels at the shoulders then takes place. Flat bed knitting machines generally do not work efficiently at producing large panels in a shaped manner. Accordingly, it is necessary to shape the shoulder edges by cutting before the front and rear panels are joined by taping.

The cutting operation is carried out at a cutting machine 40 which, as shown in Figs. 4(a), 4(b) and 4(c) has an input table 41 which supports an upright blade 42. As shown in Fig. 4(a), the blade 42 is in the shape of the shoulder and neck line. A panel 43 is indicated by interrupted lines. The machine 40 further comprises a press head 44 having a brass plate and an output conveyor 45 for delivery of a cut panel to an output stack. As shown in more detail in Fig. 4(c), the table 41 supports a layer of foam 46 within which the blade 42 is embedded. The surface of the foam and cutting edge of the blade 42 are at approximately the same level. The frame of the machine 40 also supports a rubber skirt 47 which is mounted on the input table side of the head 44.

In operation, a panel 43 is placed on the table 41 in correct alignment by a skilled operator so that it is in the correct position in relation to the blade 42. The table 41 is then controlled to move inwardly as indicated by the arrows so that it is in position in registry underneath the press head 44. At this stage, as indicated by the arrows of Fig. 4(b), the press head 44 moves downwardly. The stroke of the press head 44 is set so that the brass plate moves to a position less than 1 mm lower than the tip of the blade 44. Because brass is a relatively soft metal, the blade cuts the panel 43 by engagement with the brass plate surface. The table 41 then returns to its original position, while the skirt 47 prevents the cut panel being returned with it. This feature is also helped by the fact that the surface of the foam 46 has a low friction value. The machine 40 is constructed so that at the next input stroke of the table 41, the upper conveyor 45 is operated to convey out the cut panel 43. It has been found that by cutting each panel individually, there is very good accuracy of the cutting location while efficiency is not sacrificed because of the speed with which the machine 40 operates. The cutting stroke is very effective by impingement of a brass plate onto a hardened steel blade and because the blade 42 is located at the operator end of the table 41, the operations may be carried out very quickly and accurately.

The front and rear panels are joined together along the shoulder edges in step 5. This is carried out by a taping machine 50 which has a stitching head 51 for stitching the two edges to a tape placed between them. The tape is indicated by the numeral 52 and runs through a tensioner 53. The tensioner 53 has a guide member 54 for sliding contact with the tape 54 and this is biassed downwardly by a spring 55 to ensure that the tape 52 always remains in tension. An adjustable base 56 may be used to assist in pre-setting the machine 50 for a particular spool. The tape 52 then runs through a loop-shaped folding guide 57 and in combination with the tensioner 53 helps to ensure that the tape 52 is folded over along its length in a uniform manner. The shoulder edges are guided by guides 58 for accurate alignment. Accordingly, the stitching operation which takes place is through the two shoulder edges and the tape 52 when folded over. The tape 52 has an elasticity of approximately 5% and because it is folded over there is both a very high strength and a certain degree of elasticity which is ideal for joining of panels at the shoulders. Further, by virtue of the fact that the tape is folded over on itself, it is quite narrow, with a width of only 1.5 to 2 mm. It is, therefore, quite well hidden in the shoulder seam. As indicated by Fig. 5(d), the excess tape 52 is then cut away by the operator who then places the panels 43 back into a fresh bundle 59 held together by a fastener 30.

A general feature in the whole production process is use of the fastener 30. As will be clear from the drawings, it is very effective at holding together bundles of panels, but it also has the following major advantages:1. The fact that it may be very easily opened and closed in a matter of approximately 1 to 2 seconds. Therefore, bearing in mind that during the whole production process, the bundle must be accessed on many occasions, there is an appreciable labour time saving per garment. 2. Because the fasteners 30 engages around the central part of the panels as shown in Fig. 5(e), the edges of the panels may be easily accessed for some operations without the need to open the jam cleat 31. 3. The jam cleat provides a very effective way of holding a label which is adhered to it to ensure that the batch may be easily identified.

It will be appreciated that these advantages are achieved in an extremely simple and inexpensive manner.

After taping of the shoulders, in step 6, there is primary and final application of neckbands to the panels 43. This is carried out by mock-linking, or alternatively by true linking, depending on the nature of the garment to be produced. If mock-linking is used, a process such as that described in European Patent Specification No. EP 175,509 may be used. There is accordingly no need to describe this particular step in more detail other than to say that the neckband application stage 6 involves final stitching at awkward edges and any necessary trimming.

In step 7, there is backneck labelling whereby a label is stitched to the back of the neckband. This is one of the operations which can be carried out very efficiently by an operator using the panels bundled as shown in Fig. 5(e). Indeed, there is no need to disconnect the fastener 30 and each pair of panels 43 can be processed very quickly in sequence beginning with the lowest one.

As illustrated in Figs. 6(a) and 6(b), there is then overlinking as indicated generally by the numeral 8. This involves either at one workstation or at a sequence of workstations, stitching of a sleeve 65 to a front and back panel pair 64, and also stitching of these panels together. These operations are carried out using stitching machines and one aspect of the various workstations used in the process is shown in Fig. 6(b). This aspect is removal of excess trim by use of a vacuum funnel 62 mounted on a table 61, the funnel being connected to a vacuum hose 63 which is connected to a primary hose serving all of the workstations for the process. This prevents build-up of excess fabric and helps to keep the workplace tidy and helps to ensure accuracy and efficiency of various tasks which are carried out.

It has been found that during the overlinking operations, it is better to use an excess of knitted chain to ensure that there is no puckering. The most effective way of dealing with this excess is to fold it over within the seam and to tack it in place, as indicated generally by the numeral 9. This is referred to as bar tacking.

In step 10, the garment is clipped and trimmed and is then turned from the inside-out position to the final position. This stage involves a quality control check.

As indicated generally by the numeral 11, the next operation carried out is final steaming, which is illustrated in more detail in Figs. 7(a) and 7(b). For final steaming, a machine 70 is used. This has an initial steaming table 71 having a cotton covering for conveying the garments and upon which two operators each place a garment 72. Steam is supplied underneath the table 71 so that it rises through the surface of the table 71. The steam pressure is 5 bar and the temperature is 140°C. A very important aspect of the final steaming step is that while the garments 72 are on the initial steaming table 71, they may be manipulated and tidied while the steaming is taking place. Very often, a small steam device is placed around the neck area to ensure that this is aligned correctly. Two people can work simultaneously at the initial steaming table 71. The conveyor on the table 71 is then operated to move the two garments 72 underneath a press 73 which descends over the garment so that steam is effected from both above and below the garment. The ratio is biassed towards the upper part of the garment as 80% of the steam comes from the press and only 20% from underneath through the conveyor. This ensures that the garment 72 is uniformly pressed and relaxed and avoids any puckering along the seams. One operator can take both steamed garments 74 to create a neat stack or pile 75 for packing to produce the final product 76.

It has been found that by steaming the fabric both at the beginning of the process and at the end, the vast majority of the relaxation occurs at an early stage, while at the same time there is sufficient steaming at the final stages for further relaxation and pressing to provide a neat appearance in the end product. Control for these two major operations may be achieved quite simply because similar temperatures and pressures are involved and accordingly the fabric is not subjected to widely different conditions.

In general, it will be appreciated that the invention provides a production process which achieves a highquality finished product without the requirement for a large labour force working under difficult conditions. There are relatively few man-hours involved and the work is more skilled than is traditionally the case.

The invention is not limited to the embodiments hereinbefore described, but may be varied in construction and detail.

Claims (5)

1. A knitted garment production process comprising the steps of:knitting garment panels on a flat bed knitting machine in which the knitting operation interconnects panels by a soluble thread; pre-steaming the garment panels in a conveyor steam press to cause relaxation of the fabric and simultaneous dissolving of the soluble thread; cutting shoulder edges in each panel individually in turn by use of a press cutter having a blade shaped in the shoulder pattern; taping the shoulders for a garment by sewing a tape against the shoulder line of a pair of panels; linking a neckband to the panels along the shoulder edges; overlooking the panels with sleeve panels; carrying out final trimming of the garment and turning the panels out; carrying out final pressing of the garment by placing the garment on a steam table and simultaneously · manipulating and sizing the garment panels, and subsequently conveying the garment to an overhead press station at which it is simultaneously pressed and steamed; and packing the pressed garment.

2. A production process as claimed in claim 1, wherein the garment is pre-steamed at a steam pressure of 4.5 to 5.5 bar and a temperature in the range of 135145°C, and preferably the conveyor steam press is simultaneously fed with two lines of interconnected panels, the steamed panels being removed, checked, and placed in two stacks, one for each line, and preferably the steamed panels are placed in a stack on a rope, the rope terminating in a jam cleat, the rope being pulled around the stack and the cleat fastened when there is a pre-set number of panels in the stack followed by labelling of the cleat.

3. A production process as claimed in any preceding claim, wherein steam is outputted in the press station for final pressing at a proportion of approximately 80% from above and 20% from underneath, and preferably the steam pressure for final steaming is in the range 4.5 to 5.5 bar and the temperature is in the range 135 to 145°C, and preferably two garments are pressed simultaneously in final pressing, and are supported on a linen fabric cover for the press table.

4. A method substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings .

5. A garment whenever produced by a process as claimed in any preceding claim.