Deskilling of Cuff Runstitch and Trimming Operations with Integrated Automats

Integrated automats for cuff runstitch and trimming operations not only help in improving productivity but also help in deskilling the operations as they combine both the operations and restrict an operator’s task to loading off cuff panels to feeding clamps.

Integrated cuff runstitch and trimming automats combine the two operations, helping not only in improving the productivity but also in deskilling the job by restricting an operator’s task to loading off cuff panels to feeding clamps. Integrated cuff runstitch and trimming automats available in the market can be classified into two types: those in which panels are stitched (runstitch) and trimmed sequentially on separate stations; and those in which runstitch and trimming is done on single head. In all the methods, these integrated workstations are fully mechanized with automatic dispose and stacking devices.

Conventional method for cuff runstitch and trimming operation

The conventional method of cuff runstitch operation is completely manual, where all the tasks like cuff folding, positioning, sewing and disposing are manually performed. This necessitates the use of skilled manpower, thereby increasing human dependency and hence the chances of human-induced errors. The operation also requires subsequent trimming, which is manually performed. The observed average cycle time for cuff runstitch and trimming operation on conventional machines is indicated in Exhibit 1.1.

Exhibit 1.1: Cuff Runstitch and Trimming Operation

Technology behind automatic cuff runstitch & trimming

Duerkopp Adler, MAICA and YUHO are prominent brands in the market offering integrated cuff runstitch and trimming work-stations. The Duerkopp Adler 971-01 is Two-thread chainstitch machine while the U-3101-E/01 from YUHO and UAM 03 from MAICA are single needle lockstitch machines. MAICA’s UAM 03 facilitates cuff and collar runstitch and trimming on a single machine. The operational versatility (collar/cuff applicability) and high productivity of MAICA’s UAM 03 can be utilized by factory for cuff runstitch and trim for half the time followed by collar runstitch and trimming, thereby eliminating the need of additional workstation and manpower. All these automats comprise of 4 distinct zones – feeding zone, sewing zone, trimming zone and stacking zone – through which the product moves sequentially. This sequential movement facilitates high productivity and improved manpower utilization.

Duerkopp Adler 971-01 for runstitching and trimming of cuffs

A rotary sewing unit, the 971-01 facilitates runstitching and subsequent trimming of cuffs. The operator’s task is limited to folding the pre-creased cuff cut panels and loading them on feeding clamps, which guide the cut panels through four stations, viz. stitching (runstitch) unit, trimming unit and stacking unit (which is the 4th). The operator, in the meantime, continuously feeds the sewing units with fresh cuff cut panels, guaranteeing a high output.

The cuffs are placed in the material template, a part of the feeding unit, by the operator. The material template open and close automatically. The cuffs in the feeding template are processed in a fully overlapped condition. Intermediate lifting for accurate placement of the cuff panels is possible by actuating the foot pedal. The templates are size adjustable and can be easily exchanged. The sewing head sews precisely along the counters of the material clamp and the entire operation is microprocessor-controlled. The trimming head also follows the control CAM and precisely trims the seam allowance of the cuff. The thread chain is cut at the seam beginning and seam end. On the completion of the operation, the material template opens automatically and the grip arm of the stacker pulls the finished cuffs out of the template into the stacker.

Productivity of the machine is 545 cuffs per hour, i.e. around 4,339 cuffs per shift (refer Exhibit 1.1). Given the high production rate, the machine can be set up as external operation with one machine feeding several sewing lines else the operator can be allocated other task on completing the daily targets.

YUHO U-3101-E/01 cuff sewing machine with knife

The U-3101-E/01 from YUHO Sewing machine company Japan, is an innovatively designed cuff sewing and trimming machine, which promises accurate cuff sewing with precise trimming margins. The machine provides facility of left/right cuff sewing at the same time, thus producing two cuffs in one operation cycle and the operator’s job is restricted to loading off the cuff on the feeding table. The pattern length and width can be adjusted and changed as per the requirement (length 200-350 mm, width 40,100 mm). The manufacturer claims that the entire size conversion task can be completed in 30 seconds. The sewing unit comprises of a sewing head from Juki’s DDL- 5550N single needle lockstitch machine or Juki’s DLM-5200N single needle lockstitch machine with trimmer. On the former, trimming operation has to be performed separately after cuff runstitch operation. The knife ensures precise trimming of cuff pieces during runstitch operation. The trimmed waste is gathered in a dust box through a suction unit. The stacking unit can be adjusted as per cuff sizes. Cuff pieces moved from sewing head are pushed out of the tray in bundles automatically. The machine is provided with a user-friendly touch screen interface. The productivity of the machine is around 318 units per hour or 2,547 pieces per shift (refer Exhibit 1.1).

MAICA UAM 03 collar and cuff sewing automat

The UAM 03 offers flexibility of performing runstitch and trimming operation for cuff and collar on a single workstation. The machine is electronically controlled and facilitates change in stitch parameters as desired. The machine comprises of 4 separate stations: The loading station, the sewing station, the trimming station and the stacking station. Operator’s task is limited to loading of cuff/collar panels on the clamps. The fabric holding clamps are designed to accommodate a wide range of sizes. Collar and cuff trimming is performed separately from the sewing phase and different cuts can be made with respect to stitching. The sewing zone comprises a sewing head that produces single needle lockstitch followed by trimming zone that trims precisely as per the contours of the template. Trimmed waste is collected in the dust box. The machine is equipped with automatic disposing and stacking unit. The loading and sewing cycle permits two machines to be allocated to a single operator which leads to drastic improvement in productivity. The machine productivity in 1:1 (man to machine) configuration is around 4,267 cuffs per shift; while in 1:2 configuration, the productivity is around 8,533 cuffs/shift (refer Exhibit 1.1). The high productivity permits this operation to be set up as external operation, working first on cuffs and then on collar as per the requirement.

The operational versatility (collar/ cuff applicability) and high productivity of MAICA’s UAM 03 can be utilized by factory for cuff runstitch and trim for half the time followed by collar runstitch and trimming.

Conclusion

Use of technology has been successfully demonstrated in improving productivity and improving manpower utilization for cuff runstitch and trimming operation. Use of automat in deskilling the job, by minimizing human intervention is also demonstrated. Though the automats are more suitable for bulk manufactured products that offer longer runs; for smaller orders, these machines can be utilized as an external task by designing the line plans accordingly.