1. Tear resistance test: two binder clips tell the difference
Take a 20cm wide sample, fix both ends with binder clips (15cm apart), and hang 4.5L bottled water (about 4.5kg). Qualified products should be hung for 30 minutes without breaking, and inferior products usually have radial cracks within 5-10 minutes. The industry sampling in 2023 shows that the tear strength of A-grade products with a thickness of 0.5mm must be ≥18N/mm², which is equivalent to the impact of a 10-jin pet dog suddenly stepping on it.
2. Temperature difference violent test: refrigerator and hair dryer combination method
Low temperature test: -15℃ freezing for 2 hours and then rapid bending, qualified products have no cracks (cold-resistant type can reach -40℃)
High temperature test: Use a hair dryer to continuously heat the local area to 80℃ (monitored by a temperature gun), and it should not shrink or deform within 30 seconds
In 2022, a car visor customer ignored this item, resulting in the product curling and deformation in the car in summer, with a loss of more than 200,000 yuan.
3. Prediction of ultraviolet aging: sunlight exposure comparison method
Put the sample and A4 paper on the sunny windowsill at the same time, and record the changes every day. The yellowing value of qualified anti-UV materials is ΔE≤3 after 7 days (it is difficult to distinguish the change with the naked eye), while ordinary materials are obviously yellowed in 3 days. A customer of an outdoor light box found that the service life of PVC sheets after anti-aging treatment was extended from 6 months to 3 years.
4. Wear resistance verification: key scratching experiment
Use a nail file (Mohs hardness of about 5) to scratch the surface at a 45-degree angle with a force of 3kg. High-quality products should have no permanent scratches and will return to transparency after wiping. Scratch-resistant products can even withstand scratches from a utility knife, which is essential for transparent table mats and equipment protective covers.
