FAQ
See frequently asked questions
Frequently asked questions
When sewing elastic materials, cutting of the yam in the fabrics often occurs. To avoid that, it is in principle recommended to use ball point needles which push the yarn or thread aside instead of cutting or perforating it. At the same time, please use a thinner size needle.
For sewing leather the cutting point needles (sometimes called “leather point needles”) are generally used. There are many kinds of cutting points for the operators to choose a different form of point for each grade of leather and each class of work. 
The most serious problem in the process of sewing synthetic materials lies in the low heat resistance of the synthetic fibres. Their softening point is between 180°C and 230°C, and the melting point is between 230°C and 260°C. In high speed sewing, the temperature of the needle reaches the melting point of the synthetic fiber soon, and then it begins to melt and adheres to the groove or eve of the needle. As a consequence, stitch skipping and thread breakage occur and naturally the sewing operation will stop. To cope with these troubles is as follows:
1. Choose the suitable needle which can minimize the surface friction of the needle. In our products, we can recommend the SUPER-FINISHED NEEDLES specially made by coating phosphate and fluor resin based materials on the needle surface.
2. Decrease the needle temperature either by oiling the sewing material or sewing thread with a special lubricant or by using a lubricated sewing material or sewing thread for smoothness and radiation.
3. Prevent the rise of the needle temperature by com- pulsory cooling with air-blowing on the needle.
4. Reduce the heat generated on the needle below the melting point of the synthetic fibre by lowering the revolutions of the sewing machine.
5. Increase the heat-resistance of the sewing thread and sewing material to be used.
This happens when the looper or hook fail to enter the thread loop during the stitch formation. Possible causes are:
- Incorrect timing of the looper or hook
- Incorrect setting of the take up or pull off devices
- Needle vibration or staggering
- Wrong size needle hole plate
- Needle deflection by resistance of the material
- Loss of thread control due to the wrong size needle being used for the thread used in sewing.
This is almost the result of some kind of interference with the needle thread. It can be caused by any un- smooth edge in the area of the path where the needle thread travels along or by too tight tension and ex- cessive needle heat.
To avoid thread breakage or fraying
• Check the parts such as the throcad guides, nccclc, needle hole plate, presser foot, feed dog, hook and looper are free of burrs or sharp edges.
• Use lighter tension
• Check for the corect needle size: Test with the next larger size needle.
Seam Puckering, often appearing when sewing synthetic fabrics, is a distortion of yam fibres and thread along the seam. To avoid or reduce puckering we recommend the following:
1. Use the smallest size of thread and needle possible
2. Use a smaller ball point needle.
3. Use the same type of material in the thread and fabrics.
4. Use minimum pressure on the presser foot.
5. Tension of the needle thread and the bobbin or looper thread should be minimal.
6. Use feed dogs with finer teeth.
7. Reduce the number of stitches.
