Why Does The Fabric Sample of The Knitting Machine Have Holes?

Holes in knitted fabric often occur when the yarn is subjected to forces greater than its breaking strength during the knitting process. Here are some common causes and adjustments to consider when setting up the circular knitting machine to prevent these issues:

1. High Yarn Feed Tension

If the yarn tension is too high during feeding, it can cause holes in the fabric. This situation arises when the yarn is fed too slowly, while the needle pressure remains constant, leading to increased tension on the yarn. When this tension approaches the yarn’s breaking strength, holes can form. As the tension increases, not only do the holes get larger, but the yarn may also break, causing the circular knitting machine to stop knitting. This is commonly known as "yarn breakage."

Adjustment Tip: To reduce yarn tension, increase the speed of yarn feeding or adjust the needle pressure to maintain a balance. Regularly check and calibrate the yarn feed tension to avoid excess force on the yarn.

2. Machine and Yarn Mismatch

Using a machine that doesn’t match the type or thickness of the yarn can lead to holes. Different yarns require specific machine settings, and a mismatch can cause improper tension and handling, leading to fabric defects.

Adjustment Tip: Ensure that the machine settings, such as needle size and gauge, are compatible with the yarn being used. Adjust the machine settings based on the yarn’s specifications to prevent tension-related issues.

3. Improper Loop Formation

During the knitting process, if the yarn doesn’t form loops correctly, it can slip off the needles and catch on the newly formed loops, leading to holes in the fabric. This can happen if the needle action is not synchronized or if there’s excessive yarn tension.

Adjustment Tip: Check and ensure the proper synchronization of needle movement and yarn tension. Make sure the yarn is being fed consistently and that the needles are forming loops correctly.

4. Incorrect Yarn Guide Position

If the yarn guide is installed too close to the needles, especially if it’s closer than the diameter of the yarn, the yarn can get squeezed between the guide and the needles. This can cause excessive tension and lead to holes.

Adjustment Tip: Position the yarn guide at an appropriate distance from the needles, ensuring that it does not press the yarn against the needles. The distance should be adjusted based on the diameter of the yarn being used.

5. Floating Yarn Triangle Adjustment

In certain knitting setups, such as those using both cotton and wool, some needles do not knit on every pass but carry the yarn. The position of the floating yarn triangle needs to be carefully adjusted to ensure that the yarn does not get caught or pulled, leading to holes.

Adjustment Tip: Adjust the floating yarn triangle position to ensure it does not interfere with the yarn path. Regularly check and fine-tune the position based on the type of fabric and yarn being used.

6. Double Jersey Machine Adjustments

For double jersey machines, the relative positions of the needle disc and the needle cylinder triangle must be correctly set. Incorrect positioning can lead to tension discrepancies and holes in the fabric.

Adjustment Tip: Ensure the needle disc and needle cylinder triangle are aligned correctly. Regularly inspect and adjust their positions to maintain proper knitting tension and fabric quality.

7. Adjusting Bending Depth

Ensuring the correct depth for yarn bending is crucial. If the depth is too shallow or too deep, it can cause excessive tension on the yarn, leading to holes in the fabric.

Adjustment Tip: Adjust the bending depth to ensure that the yarn forms loops at the correct depth. This helps in maintaining consistent tension and preventing holes.

8. Other Common Causes

Bent Needle Tongues: Needles with bent tongues can cause irregularities in loop formation, leading to holes. Inspect and replace bent needles promptly.

Excessive Needle Wear: Worn-out needles can fail to form loops properly, causing holes in the fabric. Regularly check for needle wear and replace as needed.

Loose Yarn Storage Belts: If the belts holding the yarn are too loose, it can cause inconsistent yarn tension, leading to holes. Ensure the belts are properly tightened and secure.

Excessive Fabric Tension: Too much tension on the fabric can pull on the yarn, creating holes. Adjust the fabric tension settings to prevent undue stress on the yarn.

Tight Needle Grooves: If the grooves for the needles are too tight, the yarn can get pinched, causing holes. Make sure the needle grooves are clean and appropriately sized to allow smooth needle movement.

By addressing these factors, you can reduce the likelihood of holes in your knitted fabric and ensure a smoother, more reliable knitting process.