Types of puckering
In this article, we will talk about different types of puckering.When the smooth fabric appearance turned wrinkled by the way of seam is called Pucker.Types of puckering means that how many ways are there that cause puckering in fabric. Therefore, different types of puckering and their causes are as below.
The reason for this is different friction conditions during transport of the fabric. When using a machine with the hopper, transport puckering occurs under the following conditions:
- High friction between feed dog and fabric (R1)
- Low friction between upper and lower fabric (R2)
- High friction between upper fabric and presser
foot (R3) R1+R2+R3 = Transportation puckering A combination of these three cause transportation puckering. This puckering can be prevented by different measures. For example one can use Teflon coated presser foot to decrease friction between upper and presser foot. Another way out is to use sewing machines with top and drop feed.
The insertion of the sewing thread in the fabric displaces the yarns near the stitch hole resulting in tension that leads to puckering. The higher the fabric count and the thicker the sewing thread, the higher the chance of puckering.
Proposals that have been made to solve this problem are controversial (use of needles with cutting points) or can only be carried out with additional expenditure (positioning of the seam at an angle of 15 degrees to the warp direction).
This is limited to seams stitched with every elastic sewing thread and high thread tension. The thread which has been inserted with high tension will pucker after sewing (this may take several hours). Variations in humidity and temperature can also play a role. Relaxation Puckering A detailed treatment of the causes of seam puckering and solutions are given below. Fit needle size. Needle hole, Presser foot pressure too high. Reduce presser foot pressure. Machine does not use compound feed. Use machine with compound feed.
Occurs due to: incorrect sewing tension
Tension pucker is caused while sewing with too much tension, thereby causing a stretch in the thread. After sewing, the thread relaxes. As it attempts to recover its original length, it gathers up the seam, causing the pucker, which cannot be immediately seen; and may be noticeable at a later stage.
Tension is also referred to as seam shrinkage or thread relaxation pucker.
Test to identify
Carefully cut both the top and bottom threads of all stitches along a few centimeters of the seam, without distorting the thread loops in the fabric. If the pucker is relieved over this length, then it was caused by thread tensions.
- Reduce the tension applied to the thread while it is being wound onto the lock stitch bobbin.
• Set the needle thread tension to be as light as possible while achieving a balanced stitch at the same time. This will reduce the amount of puckering while the thread is stretched and improve the sewability.
• Use a high-quality sewing thread with a low-friction lubricant applied to it. This will allow the thread to run smoothly through the thread guides and tension controls.
• Use a high-quality sewing thread with even unwinding tension for smooth flow of thread to the sewing area.
• Ensure that the sewing machine feed timing is correctly set, as incorrect feed timing can lead to the need to apply excessive tension to the needle thread. Incorrect timing may lead to an imbalanced stitch.
Occurs due to: structural jamming
If the fabric is densely woven, there may be insufficient space to accommodate a sewing thread without distorting the woven yarns. Stitching along a straight line will distort and stretch the adjacent fabric yarn(s), setting up stresses which cause the seam to pucker. This is known as structural jamming or inherent pucker.
The severity of this condition depends primarily on the characteristics of the fabric fibre, the closeness of the weave or knit and the fabric finish.
Relatively coarse fabrics of natural fibres are less likely to experience inherent pucker than tightly woven synthetics, delicate microfibers or fabric with pucker-sensitive finishes or treatments.
Test to identify
Carefully cut and remove the stitches in a short length of the seam, after first checking for the tension pucker. If both faces of the seam revert to a smooth surface, structural jamming has occurred.
- Cut and sew on the bias when possible. By sewing at a biased angle, the needle displaces different sets of wrap and weft yarns, thereby significantly reducing the incidence of pucker.
- Opt for finer needle and thread sizes.
- Reduce the stitch density (stitches per inch), thereby reducing the yarn displaced in the stitch line.
- A chain stitch or an over edge stitch will produce less structural jamming than a lock stitch.
- Avoid multiple rows of stitching which cause more pucker because the stresses in each row are cumulative.
- Use the finest thread size possible to assemble the panels prior to the topstitching operation when top stitching a seam.
Pucker caused by fabric and thread .
This is a major problem faced in the cutting department while spreading. Variation in the width of the fabric, which form an arc shape during spreading is said to be bowing effect.
Leaning is occurred during manual spreading. In leaning the top ply of the fabric will be slightly inside the previous ply. It is occurred due to improper laying.
It is also a problem faced in the cutting room. On every spread there is a plus/minus variation of the edge of the fabric from the below lay of the fabric.
The fabric that extends beyond the marker patterns end is called as end loss. This occurred due to improper laying of fabric lays.
Here in the cutting room we are getting end bits almost for all fabric Takas. After complete laying of one fabric Taka, at the end we get a small piece of fabric that cannot be used for laying which is said to be end bits.
It is a spreading defect that arisen only when the layers lay fabric under improper tension and creases are formed on spread surface.
Misalignment of plies
It is a spreading defect that arises when all the plies of the lays are of different length and not lay exactly of same length as per table marker.