There are three popular materials for graphic overlay: PC, PVC and PET. There are two surface types, matte and glossy.

 

PC has good physical and chemical properties. It is suitable for a wide range of inks. PC is the most commonly used material for graphic overlays. It is available for matte and glossy surfaces. People choose matte surface because the control system does not want to be disturbed by light. Matte surface only reflects diffusely. It does not produce bright reflections. In addition, matte surface can hide scratches.

 

On the contrary, glossy PC does not have the above features. However, it has more vivid and eye-catching colors. In occasions that have high decorative requirements and no need to be touched frequently, glossy surface is a better choice. Due to special needs of certain display areas such as LCD screens, it is good to choose glossy PC.

 

PVC has lower price, about half of that of PC. You can reduce production cost when choosing PVC. There is another advantage for PVC: good ductility. It can be processed into three-dimensional pattern by cold pressing.

 

The thickness of glossy PVC is usually more than 0.5mm. Both sides are protected by water-based paper. PVC is often used to make decorative panels. The thickness of matte PVC is usually less than 0.3mm. It is supplied in fixed-length sheets, not coils.

 

Since the general properties of PET can be replaced by PC, it is not often used as material of graphic overlays, except in some special occasions, such as when other materials cannot meet the requirements of insulation, resilience, solvent resistance, etc..

 

PET surface is usually glossy transparent. In a few cases, there are also matte products such as the KB product of Japan's Kimoto Company. It has very fine matte surface. This kind of PET surface is not obtained by mechanical means like PC by a sanded roller in mechanical calendering. So its surface is not as obvious as matte surface of PC.

 

Pros and cons

 

PC

 

Pros

 

1. It has strong processing adaptability, and can make different patterns on its surface.

 

2. It has good chemical resistance. We are talking about dilute acids, weak bases, alcohols and alcohol ethers. Besides, PC is insulating, non-directional. It has high brightness and low atomization.

 

3. Within temperature range of -30℃~130℃, PC does not change much when the temperature changes suddenly.

 

4. It has good mechanical properties. PC has high impact resistance, the yield point is about 60N/square millimeter, which is the good impact-resistant plastic today.

 

PC is suitable for a lot of occasions. It is moderately priced.

 

PET

 

Pros

 

PET has a long service life and insulation properties.

 

Cons

 

The price is slightly higher than PC. It is not UV resistant.

 

You can see PET graphic overlays on instruments and home appliances with high requirements.

 

PVC

 

Pros

 

Low price, good chemical corrosion resistance and insulation performance.

 

Cons

 

Low temperature resistance (about 60°C), poor tensile strength and poor wear resistance.

 

You can see PVC on signage panels. It's not suitable for membrane switches and touch panels.