Latch Needle
A latch needle is a knitting machine needle that holds the yarn with a latch that opens and closes at the tip, forming new stitches while releasing the old stitch.
Contents6 sections
Definition and Overview
A latch needle is a knitting machine needle that uses a movable latch attached to the needle tip. As the needle moves back and forth, the latch opens and closes, takes the yarn into the hook, and passes it through the existing loop to continuously form new stitches.
It is a component widely used in circular knitting machines and flat knitting machines, and it is not the name of a fabric structure or a material. Therefore, the latch needle itself does not have fabric properties such as hand feel, shrinkage, or washability.
Effect on the Knitted Fabric
The needle size, thickness, shape, needle arrangement, and machine settings of a latch needle affect stitch size, stitch density, and surface uniformity. Depending on the combination with the yarn, structure, and knitting conditions used, the stretch, thickness, and appearance of the knitted fabric will change.
If the needle tip or latch is worn, bent, or dirty, the yarn may not be held properly, which can cause dropped stitches, needle bars, and yarn breakage. In particular, with fine yarns, yarns with a lot of fuzz, or knitted fabrics containing elastic yarn, it is important to check the effect of needle condition.
Main Processes and Applications
Latch needles are used in processes for knitting circular knitted fabrics such as jersey, circular rib, pique knit, and French terry, as well as sweaters, cardigans, and rib knit made by flat knitting. They are also used for underwear, socks, and knitted fabrics for sports applications.
What determines the season or item is not the latch needle itself, but the type of yarn, knit structure, stitch density, and finishing process. The same needle principle is used according to the design, from lightweight fabrics for spring and summer to heavyweight fabrics for autumn and winter.
Selection and Handling Notes
When selecting a needle, check whether it matches the machine model, gauge, needle bed specifications, and the thickness and type of yarn to be knitted. Using an incompatible needle may lead to knitting defects or machine damage. Needle compatibility should not be judged by appearance alone; confirm it based on the machine specifications.
Shrinkage of the knitted fabric and dimensional changes after washing are affected by the fiber material, knit structure, and finishing. Before production, check the shrinkage rate of the fabric, relax the roll before cutting, and if necessary carry out wetting or trial sewing.
In sewing, select the sewing method, needle, and thread to match the stretch of the knitted fabric. A sewing machine needle that does not suit the fabric may damage the stitches, so perform a test sew to check for seam breakage, puckering, and stretching.
- Regularly inspect the needle for wear, bending, and latch malfunction.
- If abnormal dropped stitches or needle bars appear, check the needles and machine settings in the relevant area.
- Manage washing and shrinkage based on the care tag and test results of the knitted fabric, not the latch needle.
Differences from Similar Terms
A latch needle is a needle that forms stitches, while a sinker is a knitting machine part that holds down the knitted fabric and assists in stitch formation. Both are used in knitting machines, but their roles are different.
Also, jersey and circular rib are knit structures and names, while circular knitting and flat knitting are knitting methods or machine classifications. A latch needle is positioned as a machine component for producing these knitted fabrics.
Frequently Asked Questions
Is a latch needle a type of fabric?
A latch needle is not a type of fabric, but a needle used in knitting machines to form stitches. Fabrics knitted using latch needles include jersey and circular rib, but the hand feel, thickness, and stretch are mainly determined by the yarn, structure, stitch density, and finishing.
How do defects in latch needles appear in knitted fabrics?
Problems with latch opening and closing, worn needle tips, or bent needles can lead to dropped stitches, needle bars, yarn breakage, and irregular stitches. If a defect is suspected, check the abnormal area of the knitted fabric and the corresponding needle, and replace or adjust it.
Does knitwear made with latch needles shrink when washed?
The degree of shrinkage is not determined by the latch needle. It varies depending on the type of material, yarn properties, stitch density of the knitted fabric, finishing, and washing conditions. Before mass production, it is important to check the shrinkage rate with a washing test and reflect it in the pattern and sewing specifications.
