How does the AQL standard apply for compression sock inspection?

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In international trade, due to the long transportation time which is normally around one month, buyers usually will arrange for a third party to inspect the goods before shipment to ensure the quality of the products.

Then you may wonder if there’s a uniform inspection standard for compression socks?

In fact, the most common standard in the consumer goods industry is AQL (Acceptable quality limit), which is developed by the American National Standards Institute (ANSI) and the American quality Institute (ASQ). This standard mainly uses sampling inspection instead of 100% inspection, it specifies the number of samples under different order quantities and provides 3 different defect standards to meet the inspection requirements of most orders. Click here to read more.

In this article, we will tell the definition of AQL table and help you get a better understanding to inspect compression socks with AQL standard.

To use AQL standard to inspect compression socks, we need to choose the quality level first like AQL 1.5 or 2.5 or else and agree on the standard of defective issues. Here’re some points that may cause defects on socks: size difference, designs, weight difference, shaping, threads issues, toe linking method, needle detector, compression level, stains, and packaging. We can check details below.

What is AQL table

Below is the AQL chart and it divides into 2 parts.

aql 1 1 1 1

Table 1 is the sampling quantity standard, the table will give 3 different sampling numbers according to the number of different orders. For special products or quantity will choose the special inspection level, in this article we mainly talk about the general situation. More samples mean more time for inspectors to examine more products, thus increasing the cost of the inspection. Class I sampling is usually used for relaxation inspection, while III-level sampling is generally used for stricter sampling. Level GII is generally chosen by default as it covers a wide range of goods which can be preliminary detection of the general situation but also to save costs. In addition, if you are confident in the quality of the factory and have worked with them several times, then this standard is feasible.

aql2 1 1

Table 2 shows the number of acceptable defects corresponding to different sampling quantities. There are three grades for defective products: critical, major, and minor.

The following is an example of how these two forms should be used, assuming you placed an order of 5000 pairs of compression socks. We can see that the sampling quantity should be 200 pairs according to the GII standard, and this quantity can be randomly chosen from different cartons.

In the AQL2.5 standard, it usually defaults to critical 0 major 2.5 and minor 4.0, so the acceptable number of critical defects is 0 out of 200 pairs. And major defects are 10 pairs, while 14 pairs of minor defects. We will elaborate the definition of different defective products in detail later.

In addition, for socks or other textile products, 90% of customers will choose the defaulted standard : AQL 2.5 standard critical 0 major 2.5 and minor 4.0.

Main tips for compression socks inspection

Before the inspection, we need to check the completed order quantity. Generally speaking, 80% or 100% of finished goods can be accepted and the inspection can be arranged. The number of finished goods can also be calculated approximately according to the number of cartons placed by the factory to ensure that the goods can be shipped on time after the inspection passed.

If the quantity is not up to standard, then you should double-check the delivery time with the factory. It’s important to ask the inspection company to get an idea of the real situation on finished quantity in case there’s an accident.

I’ve mentioned the notes of socks inspection in my LinkedIn article, refer to this link. It mainly refers to 10 aspects: pattern, size, weight, shaping, threads, toe linking method, needle detector, compression level, stains and packaging. It basically covers the core elements that need to be paid attention to in sock inspection.

So is there anything else to pay attention to for compression socks?

The first thing is the size, because the stretching of compression socks is relatively large, and the relaxed size tolerance can reach ±1.5cm (which is ±1cm for regular socks). In the case of more colors, due to the difference in dyeing temperature and cylinder difference, there will be some differences in the size of socks made out of different colors, but the same size socks will stretch at the same level, which means it will not affect the actual wearing.

If the requirement for flat size is relatively high, you should agree on the tolerance range with the factory before the order is placed, this way the sock factory can adjust the machine of specific color or size during the production process to keep a certain tolerance range. The method of accurate size measurement has also been mentioned in previous articles, read here. We also made a video for you to get a better understanding.

The second point is stretching. The compression level testing device can only measure the part of the sock body which is the compression between top cuff of socks to the ankle part. So a single sock part is unable to be tested, and we should check manually.

Once the overall compression level of the socks is up to the standard, we also need to test the cuff part separately. Because in the production process of compression socks, the last loop of joint elastic on the cuff should be cut off or it will affect the whole stretching, but sometimes when the machine is unstable, this process may be missing.

This will cause a direct impact on wearing, although you can use brute force to pull, too much stretching can lead the top part of socks to buckle. And this issue is difficult to find if the inspector is not professional.

Thirdly, we should pay attention to the trimmings. In addition to the regular compression sock styles, there are also some with zippers, embroidery or anti-slip dots and so on. So we should pay attention to the work of these accessories, such as whether the zipper sewing is strong, whether the embroidery pattern is correct, and whether the colors of non-slip dots are clear. Below are some photos for reference, you can find the colors of the dot are different in blue socks which should be white. And here’s a product link for our zipper compression socks.

compression socks max hosiery 1
white dots in blue color 1 1

The last thing is hand feel. Sometimes the thickness or softness will be different from the pre-production sample, so you should send an original sock sample to the inspection company to get a comparison during an inspection. If there is no stock material for bulk orders which has to be re-purchased or dyeing, then you should pay more attention to the sock hand feel.

Definitions for 3 defective standards

After understanding the inspection items, we need to clarify the three standards of defective compression socks. Critical defects refer to a major defects or functional defects, a potential safety hazard, or serious impact on appearance. Defects under this condition will be easy to cause consumers to return goods or claims, so it will be judged as Critical, the vast majority of customers to Critical is 0 acceptance, 0 tolerance.

The major problem means that the sock’s appearance is significantly affected, and there is no safety issue, but it is easy for consumers to find and affect their purchase intention. Minor means that the socks have minor defects, which do not affect the use or function, and will not have a great impact on the purchase choice of consumers.

Here are a few specific examples to illustrate. Supposing that there are metal objects such as broken needles on compression socks, it will definitely hurt people, this defect belongs critical and there is no way to tolerate it, so many Japanese customers will require socks to pass the needle detection test.

If there are problems on the appearance like threads or holes on the surface of compression socks which will not affect the function of socks but could affect consumers’ purchase intention,  this will belong to Major.

If there are boarding or shaping issues that cause the socks to look a little crooked, but do not affect the wearing or function of compression socks, and will not cause any impact on consumers’ purchase intention, then this belongs to Minor. Below are photos of the above issues for reference. The logo in the gray sock doesn’t stay in same line on socks, and the heel part is different in the 2 white socks because of shaping problems.

shape problem of socks 1 1

Solutions on defective socks

It happens that there is some controversy about the definition of different degrees of defects in compression socks, so it is best to make an agreement on this situation before the inspection. Generally, for disputed defects, the inspector will give the pending results and let the buyer to check with factory directly. Here’s a suggestion on the solution of such issues. Assuming that the general quality of the factory is a stable type, then you can ask them to replace the defective socks and ask for a second inspection if the shipping time is sufficient, also the inspection fee should be covered by this factory. While if the quality of the factory is not stable, then it’s better to reproduce the bulk to ensure the whole quality.

It is normal that things happen during the inspection, and this is also a test between you and the factory because you can see the attitude of the factory when facing problems and their responsibility and ability to solve problems. So this is a good thing on the other side. If the sock factory is responsible and can provide suitable solutions, then it is a good partner.

So the above is the way to inspect compression socks according to the AQL standard. Inspection is now an essential requirement of international trade, for our factory, we have our own QC department, customers who place orders to us can get a free inspection report. And if there’s quality or other problems occur on our compression socks during selling, we also offer a perfect after-sales service. Quality control is the core element for us to win customers.

Welcome to contact us Max socks – a professional compression socks manufacturer!

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