GB/T 14214-2019 Eyeglasses Spectacle Frame Sweat Test Instructions
The sweat corrosion test of eyeglass frames is to detect whether the eyeglass frame samples will have corrosion spots, discoloration, coating rust, peeling or shedding under the conditions of simulating artificial sweat corrosion.
At present, the test method standards for sweat corrosion of eyeglass frames mainly include GB/T 14214, ISO 12870, etc.
This article mainly introduces China's GB/T 14214 sweat corrosion test for eyeglass frames.
Experimental Apparatus and Reagents
- Heating box: can provide test temperature 55℃±5℃
- Container: Glass or inert plastic, at least 200 mm wide and 90 mm high, capable of being closed
- Volumetric flask: 1L, measurement grade A
- Water: Meet the requirements of GB/T 6682 Grade 3 water
- Artificial sweat: weigh 50g ± 0.1g lactic acid and 100g ± 0.1g sodium chloride, dissolve in 900mL water, and use a volumetric flask to make 1L solution:
- Lactic acid: ρ = 1.21 g/mL, purity > 85%
- Sodium chloride (analytical grade ≥99%)
- Impurities
- Pb≤0.001%
- Fe≤0.001%
- Br≤0.020%
- I≤0.010%
- Water
- Sample holder: Glass or inert plastic, placed in the container to support the sample and keep it above the artificial sweat. The holder can be designed to allow multiple spectacle frame samples to be stacked or placed side by side, but the samples should not touch each other.
Experiment Procedure
Add artificial sweat to a depth of at least 10mm in the container, and the lowest point of the sample (including when stacked) is at least 12mm away from the liquid surface.
Place the sample on the sample holder, keep the eyeglasses temples open naturally (the spring holder is opened to the maximum state where no external force is applied to the spring device), and place the lower edge of the temples on the holder to ensure that there is no contact between the samples or between the samples and the container wall.
Close the container and put it in the heating box to maintain the temperature at 55℃±5℃.
8h Sweat Test
8h±30min, remove the sample and immediately wash it with water, then dry it with a soft cloth without friction. Within 30min, check each sample without the aid of a magnifying glass, and record whether there are corrosion spots or color changes by comparing it with a pair of samples that have not been subjected to this test.
24h Sweat Test
Put the sample back into the container, close the container, and maintain the temperature at 55℃±5℃ for 16h±30min. After completing the second test phase, take out, clean and dry the samples, and check the parts of each sample that are likely to come into contact with the wearer's skin for a long time, and record whether there is any corrosion, surface fading or shedding of the coating.
Test result judgment
In the sweat corrosion test, visually inspect the specified parts at 8h and 24h of the test. The samples should:
- After 8 hours of testing, no spots or discoloration (excluding surface gloss loss) appear on any part of the frame (excluding hinges and screws)
- After a 24-hour test, the parts that are likely to come into contact with the skin for a long time during wear, namely the inner side of the temples, the bottom and lower part of the frame, and the covering layer on the inner side of the nose bridge, showed no corrosion, surface degradation or shedding.
If the spectacle frame is made of natural organic materials and the manufacturer recommends the use of grease or wax for maintenance in the instructions for use, the frame should be pre-treated according to the manufacturer's instructions before the test.
If the surface discoloration or surface degradation of the frame does not meet the requirements after the test, the surface pre-treated frame should be placed for 1 day and then checked again for surface discoloration or surface degradation. If the frame is restored to its original state, it is judged that the frame has passed the test. If discoloration or degradation still remains, it is judged that the frame has failed the test.