Analyze the common problems and reasons of sewing thread in use for you!

Sewing thread is a thread that must be used in the knitting industry now, but in the process of use, sometimes due to the machine, there are often some small problems, which affect the normal use of the machine. Today, sewing thread manufacturers will give you an analysis Reasons for jumping thread during the sewing process of the sewing machine:

1. Check whether the upper thread is threaded incorrectly or less than a certain thread passing position.

2. Check whether the needle is installed correctly, such as the long groove of the needle is installed backward or skewed.

3. Check whether the needle type is suitable, whether the height of the needle bar is accurate, and whether the needle is close to the top of the needle bar. If the needle is installed too high or too low, it will affect the hook thread take-up.

4. Check whether the needle is twisted. When sewing with a crooked needle, the hook cannot pick up the suture because the loop formed is far away from the hook. Slightly bent needles are difficult to identify directly with the naked eye, but can be identified by placing the needle on the platform and turning it.

5. Check whether the timing of the needle and hook movements is consistent. The movement time of the needle and the hook is completely matched, so that the hook can accurately pick up the suture.

6. Check whether the thickness of the needle and the sewing thread are suitable. Using a large needle with a fine sewing thread can also cause skipped threads. This is because the needle eye of the large needle is longer and wider, and the hole for piercing the fabric is larger, so that the fine sewing thread has a larger space to move.

7. Check whether the needle eye of the machine needle is blocked due to the fusion and adhesion of chemical fiber sewing shavings, so that the suture cannot be conveyed normally and cannot form a coil.

Check that the presser foot is not installed too high and that the cloth feed speed is not too fast. If the presser foot is installed too high, the force of the presser foot to press and feed the fabric will be insufficient. At this time, the fabric will vibrate with the presser foot, so that the upper thread cannot be pressed to form a coil; The upper thread is taken away quickly with the fabric, and the hook cannot catch the upper thread.

1. Check whether the sewing thread is too thick, uneven thickness or the texture of the sewing thread is too soft.

2. Check whether the tension of the upper thread is too tight. The tension of the upper thread is too tight, the needle loop formed under the machine is too small, and the hook cannot be hooked.

Other questions

1. Check whether the hook is missing. Defective hooks cannot be sutured.

2. Check whether the needle plate hole is too large. Many manufacturers did not replace the matching needle plate in time after switching to smaller needles when producing thin materials. The large needle plate hole causes the fabric to be brought into or out of the round hole by the needle, and it cannot press the sewing thread to form a loop, which will also lead to skipping.

3. Check whether the feed teeth, shuttle beds, etc. are deposited with cotton dust and dust, and should pay attention to keep them clean frequently so as not to affect the formation of stitches.

1. Check whether the quality of the sewing thread is qualified. Moldy, spoiled, or nodular sutures can easily break.

2. Check that the selected sewing thread matches the needle. If the sewing thread is too thin, it will be easily broken due to insufficient toughness; if the thin needle is used with too thick sewing thread, the sewing thread will not be able to pass through the needle hole smoothly and will be cut off.

3. Check if the upper thread tension is too tight. If the tension is too tight, it is easy to break the thread.

4. Check whether there is debris accumulated in the needle hole of the machine, which causes the sewing thread to be broken and not conveyed smoothly.

1. Check whether the suture is fused due to the heat of the needle, especially when using chemical fiber suture, due to the high-speed operation of the sewing machine, the machine needle repeatedly punctures the fabric to generate friction and heat, so that the chemical fiber suture with a lower melting point is fused.

2. Check whether the hook line position is appropriate. The hook is too close to the needle hole, and it is easy to break the suture when taking the thread.

1. Check whether the needle and needle plate are securely installed. Loose needle or needle plate will make the needle and needle plate touch each other and grind the broken thread.

2. Check all the places where the upper thread passes (including loops, needle eyes, hooks, needle plate holes, presser foot holes and other parts) for bending and defects, so as to avoid the sewing thread being hooked off.

3. Check whether the bobbin bobbin is too full or the winding is uneven, the bobbin bobbin is too full or the winding is uneven, and the bottom thread is not conveyed smoothly, which may easily cause the bottom thread to break.

In addition, if the operator's gesture is poor or the speed of the vehicle has no sense of rhythm, the fabric will be pulled and the upper thread will be cut by the feed dog, or the thread take-up hook will move unevenly up and down, which will tear the upper thread.

Solution:

To solve the problem of jumper and disconnection, it is necessary to take different measures according to the cause of the jumper and disconnection:

1. Do not use needles with blunt tips, which should be checked regularly and replaced in time.

2. A blower is installed next to the needle to accelerate the heat dissipation of the needle.

3. Select the machine needle with special surface treatment, which is covered with Teflon (Teflon) film, which can reduce the frictional resistance between the machine and the fabric during sewing, suppress the machine needle from generating high heat, and prevent the needle from being melted due to heat. wire and melt-bonded chemical fiber shavings to avoid jumpers and wire breakage.

Conditional manufacturers can purchase some special needles, such as needles with slightly protruding needle eyes, which can achieve the purpose of faster heat dissipation.

The high-speed machine needle has a slightly protruding eye position and a slender shape design of the needle bar, so that only the prominent needle eye can quickly contact the fabric during stitching, reducing the friction surface between the needle and the fabric, and suppressing the temperature of the needle. The high temperature is only generated at the needle eye position, and the heat energy can be quickly dissipated to ensure smooth stitching and improve production efficiency.

The curved back needle can make the loop formed between the sewing thread and the machine needle larger during sewing, so as to facilitate the hook to pick up the sewing thread and effectively prevent the jumping thread. At the same time, the factory also cast the needle into a circular groove-shaped needle bar shape, which can better protect the sewing thread from being worn and broken.

1. Use Z-twist blended yarns and core-spun yarns that can absorb heat, have strong toughness and are not easy to break.

2. Spray silicone oil lubricant on the machine needle, sewing thread and the sewing edge of the fabric to enhance the flexibility of the sewing thread, make the sewing process smooth, reduce resistance, and avoid high heat generated by the machine needle.

3. Adjust the position of the hook so that the tension of the upper thread is moderate. When the needle is lowered onto the stitched fabric, the sewing thread must not sag. When the position of the spring hook is low, the upper thread cannot be tightened, and the needle loop formed under the machine tool is too large, which will loosen the hook and cause the jumper. When the spring hook is in the position, the upper thread is drawn too tightly by the spring hook, and the needle loop formed under the machine tool is too small, and the hook cannot be hooked.

4. Adjust the shuttle to match the movement time of the needle and the hook. When adjusting, pay attention to observation. When the needle goes down to the lower point and then rises by 0.2-0.3cm, the hook tip is about 0.15cm away from the groove on the needle eye.

5. Properly adjust the density and loosen the stitches to increase the flexibility of the stitches. At the same time, select chain stitches (category 400), overlock stitches (category 500) or mesh stitches ( 600 class) and so on.

For small garment factories with limited conditions, the running speed of the locomotive can be reduced, and at the same time, a thin and brittle strip of paper can be placed at the seam edge of the clothing material to be sewn, and sewed together with the fabric, and the paper can be torn away from the fabric after sewing. This method can well prevent jumpers and disconnections, and is very suitable for small garment factories with fast money transfer.

Jumpers and disconnections caused by other problems can be solved by adjusting, replacing related parts or standardizing operations for different reasons.