Because of the complexity of manufacturing process, the quality of seamless underwear must be well controlled during every production stage.
The most common quality problems in the production process are changeful size, cross grain, broken yarn, chromatic aberration, excessive thread ends, and the forgotten needle.
It means underwear manufacturers must avoid these issues as much as possible during manufacturing.
From my more than 12 years of experience in seamless underwear manufacturing, a strict and effective quality control system requires at least the following 5 stages:
The 1st stage: Raw material inspection before storage
In the manufacturing industry, the 4 main items that have a direct impact on product quality are usually Design, Raw Material, Manufacturing Process, and Storage. Generally speaking, design accounts for 25%, incoming raw material accounts for 50%, manufacturing process accounts for 20%, and storage accounts for 1%~ 5%. Thus, material inspection is the most important stage.
In order to ensure the uniformity of confirmed samples and mass products, the Incoming bulk materials must be exactly the same as those used for samples.
The 2nd stage: Inspection during the weaving process
The semi-finished products weaved by seamless underwear machine, also known as greige clothes, its quality directly affect the quality of finished products.
Knitters need to make sure the knitting machine runs regularly. They also must be aware of broken needles, abnormal lines, and off-gauge sizes.
If the above quality problems will be found in the next 3 checks, not in the weaving process, your costs will increase greatly. You may have dyed the greige clothes and paid the cost of dyeing; You may have sewn and paid for it…
Picture of how to check greige clothes
The 3rd stage: Examination after dyeing
Although dyeing technology is becoming more and more mature, a certain proportion of loss is inevitable.
There may be a small number of stains, color difference, uneven dyeing after the dyeing process. So, just check them before sewing to avoid unnecessary expenses.
The 4th stage: Inspection after sewing
Thread breakage, excessive thread head, missed stitch, crooked thread and even needle residue may occur during sewing.
The 5th stage: Checkup after ironing
The control of this checking procedure has a direct impact on the final quality of the mass products received by the customers.
The quality inspector shall check whether the size of clothes is within the tolerance range, the color is up to the standard, the position of tags and washing labels is correct, and the thread ends are trimmed clean according to the finished product specification sheet. Only qualified clothing that is up to standard will be allowed to be packed.
After these 5 quality tests, you can rest assured that the final seamless knitting garments in your customers’ hands are 100% excellent products that meet the strict requirements!