Development of stitching jigs for sleeve button placket and sleeve buttonhole placket in men’s formal shirt

The operations in assembling garment from their components, requires lot of energy and skill for the sewing operators. One of such operation is sleeve placket attachment in the construction of men’s formal shirt. Currently, the apparel technologists are working in inventing new jigs for the operations involved such construction both to lower the level of operator skill required and to increase the level of automation possible. However the development of jigs for operations like sleeve placket attachment are difficult to achieve. This work is an attempt to develop two stitching jigs for use in stitching together the components of the sleeve.


I. INTRODUCTION
Automation is the process or technique of doing certain tasks by the use of automatic equipment in the place of human operators during product manufacture. Automation seeks to reduce human intervention to a minimum resulting in saving of labour and energy, improves precision, accuracy, quality of products, and productivity. It has the huge scope in industries where the wages for labour keeps increasing. Thus sewing units in developed countries are shifting to increasing levels of automation of labour-intensive clothing production.
Stitching jigs are work aids which are used where accurate stitching lines are required. It holds fabric layers during sewing which enables easier seam formation and allows semi-automated stitching for the specific garment constructing operations. The fabric is loaded first into the jig and then the jig loaded into the sewing machine. This reduces the complexity of the stitching operations, (Carr and Latham 1999).
However, stitching jigs are not available for many of the garment sub assembly operations. One among these is sleeve placket attaching. Developing a stitching jig(s) for attaching sleeve button plackets and sleeve buttonhole plackets will improve quality and reduces the difficulties of the sewing operation thus will help to increase the level of automation for the sewing operation, (RajkishoreNayak and Rajiv Padhye 2017).

II. OBJECTIVES
 To develop stitching jigs for the sleeve button and buttonhole placket creation operations.
 To make possible a retro fit of such jigs into existing sewing machines.
 To eliminate the need for ironing of the sleeve button and buttonhole placket components.
 To discuss the advantages of replacing analog jigs with digital control in the future.
Work aids are devices that are built into machines, added to them afterwards, attached alongside or made use to improve productivity, improve or maintain quality standards, reduce training time and minimize fatigue to the operator, (Carr and Latham 1999).
The collars where stitching jigs are successful have two identical points. The front and reverse edges of formal jackets and raincoats much match. Likewise patch pockets, cuffs and other small items such as epaulettes and tabs must be in perfect pairs. The only way to ensure this where die cutting is not possible is to control the sewing line in relation to the pattern shape of the garment rather than the edge of the cut material and this is what stitching jigs are meant to achieve (Carr and Latham 1999).  Figure 1) is a type of work aid to be used where accurate stitching lines are required. It uses an edge guide to achieve accurate sewing assuming accurate cutting. Hence run-stitch or profile-stitch operations can be done using a jig or template, (Carr and Latham 1999).
Jigs consisting of two layers of a rigid material such as aluminum or plastic which are joined together by a hinge. A slot is cut out of both layers of material which conforms to the exact sewing line in the garment part and the bottom layer carries a shaped guide close to the hinge to which the edges of the garment parts are aligned, (Carr and Latham 1999). The inside surface of the jig is covered with a strip of non-slip material like emery sheet to have a firm grip on the fabric. The fabric plies are sandwiched in the jig and the jig is sewn in a specially adapted sewing machine where the throat plate has a protrusion to glide through the slot; the double roller presser feet and rubber-covered feed dog guides the jig along the slot. Sewing stackers and bundle clamps are additional devices attached to or outside the sewing table to organize the garment components before sewing, during sewing or after sewing. (Solinger 1988).
The two pieces of the garment part are laid into the jig, along with the interlining if a sew-in interlining is being used, and the jig is closed to hold them firm. If fullness is needed on the top ply to give a piped effect on a part such as a pocket flap, a fulling bar would be included in the jig between the two plies ( Figure 2). This ensures the inclusion of extra length in the top ply so that the lining cannot show on the right side of the finished part. The operator then sews round the slot on a machine with a specially adapted presser foot and feed dog. (RajkishoreNayak and Rajiv Padhye 2015).  The extra fabric for seam allowance is costly and it must be trimmed off, often by hand, afterwards.
 Separate jigs are needed for every style and size and consequently they are only used for long production runs. A minor change of pattern shape can require a new set of jigs.
 Careful training and control are required if stitches are longer than 5 mm.
 Suitable only of sewing identical pieces. Example: Sewing two layers of collar.
 Conventional feeding system has to be replaced by a specially designed presser foot and feed dog.

Construction of Sleeve Placket
The construction of the sleeve placket involves following major operation.
a. Ironing of sleeve button placket and sleeve button hole placket fabric components.
b. Sewing of sleeve button placket.
c. Sewing of sleeve buttonhole placket.
The sleeve button placket attaching is always performed first and then followed by sleeve buttonhole placket.

Materials
The stitching jigs for sleeve buttonhole and sleeve button placket is made from acrylic. To create the groove along the edge of the slot, thin aluminum sheet of thickness 0.01mm is used along the edges of the slot.
A sliding plate is used for inserting and folding the seam allowance of sleeve buttonhole placket and sleeve button placket. The sliding plate is also made up of aluminum sheet of thickness 0.01mm.
To move to the acrylic jig during sewing, a rubber coated feed dog is used.    The elastomeric material is urethane coated over the surface of the feed dog (Figure 15 -b).
 The teeth are covered and hence results in flat toothless surface. The presser foot is attached with a projection called stopper. The projection is cylindrical in shape, less than or equal to the thickness of the top plate of the jigs. In the sleeve button placket jig and sleeve buttonhole placket jig, the top plate is 1.5mm and hence the projection length is 1.5 mm. The outer diameter of the hollow cylindrical projection is 3.9 mm.  The presser foot exerts pressure that is necessary to keep the jig in the closed position during sewing.

Fig. 18 Presser foot projection engaged with the slot of the jig
The cylindrical shaped projection can only have a maximum diameter of 4mm since the space between the two rows of feed dogs on either side of the needle hole is 4mm.

Methods
The sewing using jig is similar to the manual method yet more comfortable and also involves the stitching of sleeve button placket at first using sleeve button placket jig and followed by the stitching of sleeve buttonhole placket using sleeve button hole placket jig.

Jig Driving Mechanism
The jig is moved over the rubber coated feed dog and guided through the track of the slot by the projected stopper attached to the presser foot (Figure19).  The top edge of the slider is pushed along with the flexible sheet to lock into the grooves (Figure 22).
 The sleeve component is placed in such a way that the slit is positioned properly and ensuring that the stitching is to be done on back of the sleeve.
 The middle plate is closed over the edge of the slit (Figure 23).
 Then the top plate is closed (Figure 24).  Once the jig is positioned properly, the presser foot is lowered and the projection in the presser foot will be locked into the slot of the jig.
 Start the sewing and stop when it reaches the right-angled corner of the slot.  The sleeve component is placed in such a way that the slit is positioned properly and ensuring that the stitching is to be done on back of the sleeve.
 Then the sleeve is folded at the slit line (Figure 28 (a)).
 The sleeve is then folded at the top (Figure 28 (b)).
 The middle plate is closed over the edge of the slit (Figure 28 (c)).
 The sleeve is unfolded (Figure 28 (d)).   Once the jig is positioned properly, the presser foot is lowered and the projection in the presser foot will be locked into the slot of the jig.
 Start the sewing and stop when it reaches the right-angled corner of the slot.
 Rotate the jig to 90 degrees toward your side and sew until it reaches the end of the slot.
Unloading of material from the machine  Lift the presser foot.  From the comparison of samples, it is observed that the accuracy of the stitch line is good and the defect in the sample is negligible.

Time Study
A time study is conducted for the sewing of sleeve placket using jig and without jig. The results are given below. The time study data was statistically analysed and it is observed that the time taken by the operator for sewing the sleeve placket using the jig is independent of the skill level of the sewing operator. Clearly the time taken by the operator for sewing the sleeve placket using jig is lower than that of operations carried out without using jig.

IV. CONCLUSION
In this work, the stitch jigs are developed for one of the critical sewing operations i.e. sleeve placket attaching. The developed stitching jigs include (i) stitching jig for sleeve button placket attaching and (ii) stitching jig for sleeve buttonhole placket attaching. The samples from the stitching jigs are taken out and compared. The time study for sleeve placket attaching operation using jig and without jig is done and compared. It is found that the average cycle time for the completion of sleeve placket is lower and independent of the skill level of the sewing operator using the developed jig. The stitching jig contributes greatly to perineal levels of quality,