(Classified by "Basic Information → Process Characteristics → Usage & Maintenance")
 
I. Basic Information
 
1. What is the core function of laminating PVC on the back of the sheet?
The core is to improve the overall performance of the sheet: first, enhance mechanical strength to make the PS sheet more impact-resistant and less prone to deformation; second, optimize moisture resistance and corrosion resistance to prevent damage caused by direct contact of the back with environmental moisture or mild chemicals; third, some PVC layers can increase the light-shielding property of the back or provide basic adhesion, adapting to subsequent pasting and installation scenarios.

2. Can the color or thickness of the PVC layer be customized?
Yes, it can be customized. The conventional thickness of the PVC layer is 0.2-1.0mm, which can be adjusted according to requirements (the thicker the thickness, the stronger the overall rigidity of the sheet); in terms of color, conventional PVC colors such as black, white and gray are available, and PVC layers matching the front iridescent laser, orange, etc. can also be customized (minimum order quantity needs to be confirmed).
3. Compared with a single surface-hardened PS sheet, are there any changes in the cost and weight of this composite sheet?
 
- Cost: Due to the addition of PVC materials and composite processes, the cost is 10%-20% higher than that of a single hardened PS sheet (depending on PVC thickness and customization requirements);
- Weight: Slightly heavier, the weight per square meter increases by about 100-300g (varies with PVC thickness), which does not affect regular installation and transportation.
 
II. Process Characteristics
 
4. Will the laminated PVC layer affect the light transmittance of the sheet?
No. The PVC layer is only laminated on the back of the sheet, and the front is still a transparent surface-hardened layer. The light transmittance can be maintained at 88%-92%, which is consistent with ordinary surface-hardened PS sheets and does not affect the front observation and display effect; if the back also needs to be transparent, a transparent PVC composite layer can be selected (needs to be customized in advance).
5. What is the adhesion between the surface-hardened layer and the back PVC layer? Will delamination occur?
Adopting professional composite processes (such as hot pressing, adhesive lamination), the two layers are closely bonded and pass adhesion tests such as cross-hatch test. Delamination will not occur under normal use (avoid extreme high temperature and severe bending); however, long-term exposure to high temperature above 80℃, frequent temperature alternation, or violent tearing and impact may lead to edge delamination risk.
6. Is the weather resistance and corrosion resistance of this composite sheet better than that of a single PS sheet?
Yes. The back PVC layer can block moisture and a small amount of acid-base substances from contacting the PS substrate, significantly improving moisture resistance and resistance to mild corrosion (such as daily cleaning agents and slight industrial dust); however, the overall weather resistance is still limited by the PS substrate. Long-term outdoor exposure is not recommended (it will accelerate aging and slight yellowing), and additional UV-resistant treatment is required for outdoor use.
7. How to judge if the sheet is of the "surface-hardened + back PVC-laminated" structure?
 
- Appearance: The back has an obvious PVC texture (not the original transparent/white of PS, slightly rough to the touch, different from the front hardened layer), and products with a green protective film are surface-hardened;
- Simple test: Gently scratch the back with a fingernail, the PVC layer is not easy to leave scratches (slightly harder than the PS substrate), and the back has no light transmittance (for non-transparent PVC models); or observe through the cross-section, you can see a clear two-layer structure (thin front hardened layer + back PVC layer).
 
III. Usage & Maintenance
 
8. Are there any precautions for the composite structure during cleaning and installation?
 
- Cleaning: For the front, follow the requirements of the hardened layer (soft cloth + neutral detergent); for the back PVC layer, avoid using strong solvents (such as acetone, banana water) to prevent cracking and discoloration of the PVC layer;
- Installation: When drilling and cutting, handle the front hardened layer and the back PVC layer simultaneously to avoid delamination caused by one-sided force; when pasting and installing, select glue compatible with both PS and PVC (such as acrylic glue), and do not use highly corrosive glue.