Sleeve closing automats available in market can be classified into two types: semi-automatic and integrated workstations. The semi-automatic machine performs only the folding of sleeve and loading of the panel onto the clamps. The clamps then move the fabric under the needle bar. Unloading and stacking operations are again mechanized. As the operator’s task is restricted to loading of panel, it helps in deskilling the task and hence reduces the manpower dependency. In the integrated workstation, after the sleeve closing operation, the sleeve is also turned automatically.
In the integrated version, after loading of the sleeve onto the machine, firstly it is hemmed, then automatically folded, after which it is closed. Operator’s task in each of these systems is restricted to loading of the panel on feeding device. Long sleeve closing machine from AAC – AP264, deskills the task by restricting the operator’s task to loading the feeding clamps; AP264T performs sleeve turning operation in addition to sleeve closing thereby eliminating one operation.
Conventional method for sleeve closing
A conventional sleeve closing machine is completely manual in operation, where almost all the tasks like sleeve folding, loading, sewing and disposing are manually performed, thereby necessitating the use of skilled manpower. This increases human dependencies and the chances of human induced errors. The observed average cycle time for sleeve closing operation on conventional machines is indicated in Exhibits 1.1 and 1.2.
Technology behind automatic sleeve closing
Although earlier Yamato, Pegasus and Union Special had been offering automats for sleeve closing, the most popular automat solutions available today are from Atlanta Attachment Company Ltd., one of the prominent manufacturers of sleeve closing attachments in the market. AAC provides automats for both long and short sleeve closing operations and is targeted for sleeve closing operations in knitted Tee/Polo shirts. High productivity allows the use of these machines as external operations (tasks), feeding multiple sewing lines simultaneously. Increased production rates allow operators to be utilized for other tasks on completion of their daily targets. Four of the most commonly used options are:
AP264 — Automatic Long Sleeve Closing machine
AP264 is an electronically controlled sleeve closing machine exhibiting features such as the automatic bundle return, automatic backlatch, automatic thread cutter and thread saver. This machine has an electronic active edge guiding system, providing the capability to sew both straight and contoured seams. In this machine, the operator aligns the hemmed end and presents it to the presser foot.
A photo cell senses the beginning edge, drops the presser foot and starts sewing with an automatic backlatch. The electronic active edge guiding system also controls the sleeve until the operator presents the next sleeve. Once the sleeve is closed, the machine stops, thread chain is cut and the sleeve is stacked automatically. Productivity per hour for an AP264 machine is 1,190 sleeves, while productivity per shift is 9,520 sleeves (refer Exhibit 1.1).
AP264T — Automatic Long Sleeve Closing Workstation with Sleeve Turner
An upgraded version of the earlier variant, the AP264T is an electronically controlled sleeve closing and turning machine with automatic backlatch. This unit includes electronic active edge guiding system, providing the capability to sew either straight or contoured seams. In this machine, the operator folds the sleeve, aligns the hemmed or cuffed end and presents it to the presser foot. A photo cell senses the beginning edge, drops the presser foot and begins the sewing cycle with an automatic backlatch. The electronic active edge guiding system controls the sleeve during the sewing cycle, while the operator prepares the next sleeve. When the seam is completed, the thread chain is cut; the sleeve is turned and stacked automatically. Productivity per hour for an AP264T machine is 643 sleeves, while productivity per shift is 5,143 sleeves (refer Exhibit 1.1).
Exhibit 1.1: Long Sleeve Closing Operation in Knits |
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| Brand | Machine Model/Serial No. | Machine/Operation Type | Loading for Stitching (with allowance) | Sleeve Stitching (with allowance) | Automatic Sleeve Turning | Unloading after Stitching (with allowance) | Total Average Cycle Time (Secs) (with allowance) | Production/ Machine/Hr. x No. of machines manned (No. of sleeves) | Production/Shift (Sleeve Units) |
| Juki | - | Manual | 20.0 | – | – | – | 20 | 180 | 1,440 |
| Atlanta Attachment Corporation | AP264 | Semi-Automatic | 2.0 | 3.0 | – | 1.6 | 3 | 1,190 | 9520 |
| Atlanta Attachment Corporation | AP264T | Semi-Automatic | 5.6 | 2.6 | 3.4 | 0.8 | 5.6 | 643 | 5143 |
AP263 — Automatic Short Sleeve Closing Machine
Specially designed for short sleeves in a knitted garment, the AP263 exhibits features such as the automatic thread cutter, thread saver, automatic bundle return, piece counter and stacker, besides being electronically controlled. Its automatic backlatch has been exclusively designed to close short T-shirt sleeves. Its electronic active edge guiding system provides the capability to sew straight and contoured seams. In this machine, the operator first folds the sleeve, presents it to the presser foot, after which a photo cell senses the beginning edge, drops the presser foot and begins sewing with an automatic backlatch. The electronic active edge guiding system also controls the sleeve during sewing, until the operator prepares the next sleeve. Once the seam gets completed, the machine stops, the thread chain is cut and the sleeve gets stacked automatically. Stacker selection is available with both single and double stacking options. Productivity per hour for an AP263 is 814 sleeves, while the productivity per shift is 6,510 sleeves (refer Eehibit 1.2).
411, Automatic Hemmer/Seamer
Model 411 of Atlanta is an electronically controlled automatic workstation consisting of a conveyorized hemming system, fold-in-half station, a closing station with automatic backlatch and a programmable indexing stacker. The machine has a unique automatic fold-in-half system that allows sleeves to be overlapped during sewing cycle, thereby increasing production. It has a self-contained waste removal system. In it, the operator places parts to an edge guide, initiates the sewing cycle and continues loading. The sleeves are automatically trimmed, folded, hemmed, folded in half, transported to closer, backlatched, closed and stacked. Stacker indexing is accomplished through programming of the number of sleeves in a bundle. Productivity per hour for Model 411 is 665 sleeves, while the productivity per shift is 5,324 sleeves (refer Exhibit 1.2).
Exhibit 1.2: Short Sleeve Closing Operation in Knits |
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| Brand | Machine Model No. | Machine/Operation Type | Folding & Loading for Stitching (with allowance) | Sleeve Stitching (with allowance) | Unloading after Stitching (with allowance) | Loading for Stitching (with allowance) | Automatic Hemming and Folding | Sleeve Closing (with allowance) | Unloading and Stacking (with allowance) | Total Average Cycle Time (Secs) (with allowance) | Prodn./ Machine/Hr. Sleeve Units (No. of Sleeves) | Prodn./Shift Sleeve Units |
| Yamato | - | Manual | 10.0 | – | – | – | – | 10 | 360 | 2,880 | ||
| Atlanta Attachment Corporation | AP263 | Semi-Automatic | 4.4 | 1.2 | 2.2 | – | – | – | – | 4.4 | 814 | 6,510 |
| Atlanta Attachment Corporation | 411 | Inegrated Workstation | – | – | – | 2 | 2.2 | 1.6 | 1.6 | 1.6 | 2.2 | 1,607 |
Conclusion
Improvement in productivity and manpower utilization is very critical to garment manufacturing today and using automats not only offers a solution, but also helps in deskilling difficult operations by minimizing human intervention. With the use of technology available, there is measurable improvement in the average cycle time and productivity, for both the short and long sleeves of the knitted garments. Though the automats in the garment industry are more suitable for bulk manufactured products with longer runs, in case of smaller orders, these machines can be utilized as an external task by designing the line plans accordingly.
