How we inspect Sunlens quality

22-08-04 09:50:59    By Bestsea eyewear

 Sunlens are one of the most important parts of a pair of eyewear. Our Sunlens are mainly from some high-quality Sunlens factories, including Zeiss Sunlens, Yueheng Sunlens, crystal Sunlens, etc. They all have a set of strict quality control procedures. When the Sunlens comes to our factory, our IQC will conduct a comprehensive inspection on it again. So, how we test Sunlens quality? Generally speaking, according to the requirements of each customer for Sunlens, there are mainly the following inspection items.

high-quality Sunlens factories

The first step: first item inspection. We will select one or two pairs of Sunlens and the most detailed inspection on them, including color, specification, curvature, thickness, and functional mirror to see if they meet our acceptance requirements. If qualified, we will proceed to the next step. If it is not qualified, we will make a return, or increase the amount of inspection, and then decide the next step.
1.Color inspection: Put the Sunlens under the QC light to check whether the color of the Sunlens is consistent with the sample confirmed by the customer, or whether the color difference is acceptable.
2.Specification check: Because the Sunlens are generally round, we need to use oil calipers to measure the diameter and thickness of the Sunlens.
3.Curve check: use a inclinometer to check the curve of the Sunlens. The check point is the the center of the Sunlens and at least 4 points around it. In subsequent batch inspections, lay flat on the glass to check for even contact on the glass.
4.Coating layer: The coating layer generally includes hardening coating, waterproof coating, anti-oil coating, anti-blue light coating, etc. Check the functions that the tested Sunlens must have. The following is a brief description of the testing method.
A.Hardened coating inspection method. The easiest way to check is to see if there is a layer of transparent glue on the side of the Sunlens, which is the hardening fluid attached to the surface of the Sunlens.
B.Test method for waterproof method. Drop some water on the surface of the Sunlens. If it is a waterproof Sunlens, most of the water will fall off automatically, and the remaining small part will be concentrated into droplets, which can be wiped clean.
C.Anti-oil coating inspection method. The easiest way to test is to smear the surface of the Sunlens with an oil-based pen. For the Sunlens with an oil-proof coating, the black oil will automatically form a drop shape, which can be wiped off with the Sunlens. Conversely, lines drawn with oily brushes will be sharp and difficult to erase.
D.Anti-blue light inspection method. The blue light test identification card is used to verify whether the Sunlens can filter blue light under the irradiation of the blue light pen. The stronger the blue light, the darker the color. This method is simple and fast. In addition, take out a piece of white paper and put the Sunlens directly on the white paper to see that there is obvious chromatic aberration, showing a slight yellow color is the anti-blue light Sunlens.
E.UV protection inspection method. Take a banknote, put the sunglasses Sunlens on the anti-counterfeiting watermark, and take a photo on the Sunlens with a money detector or a money detector. If you can still see the watermark, it means that this pair of sunglasses is not UV-resistant, and if you can't see it, it means that this pair of sunglasses is UV-resistant.
F.Test method for coating adhesion. The surface grid test is to use a blade to draw a small square on the surface of the Sunlens, then stick it with transparent glue and tear it off, repeating several times to observe the effect.
G.ball drop test. The impact resistance of the Sunlens is tested with a falling ball tester. The test method is to drop a 16g steel ball directly into the center of the Sunlens from a height of 1.2 meters, and then check whether the Sunlens is broken.
H.Polarization function test. The easiest way to test whether the Sunlens are polarized is to stack two polarized Sunlens vertically without light passing through, that is, Poly Sunlens. 
Or test with a polarize machine. 
Or open the WORD file on the computer, and then turn the Sunlens clockwise, the color of the Sunlens will be light to dark and then completely black, and if you continue to rotate, it will gradually turn from black to light. That is the Poly Sunlens. Pay attention to observe the uniformity of the color, etc., and whether it is dark enough when it is opaque to judge the quality of the polarizing function. 
Step 2: Check each pair of Sunlens. After the first inspection, each pair of Sunlens is then inspected. The main thing is to carry out a detailed visual inspection of each Sunlens. Inspection items include color, surface pitting, scars, deformation, etc. If any piece is found, it must be taken out and returned to the Sunlens factory for replacement.
As a professional eyewear factory in ShenZhen, our main product include acetate glasses, metal glasses, titanium glasses, horn eyewear and wood eyewear, etc. Our main customers are some middle and high-end eyewear brand customers in Europe, America and Japan. The quality requirements of eyewear frames are very strict. So, we must ensure that the Sunlens are also of high quality.


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