What are the commonly used plastic sheets for blister packaging?

Sheets used for blister packaging are called rigid sheets or plastic films. Common types include: PET (Polyethylene Terephthalate) rigid sheets, PVC (Polyvinyl Chloride) rigid sheets, and PS (Polystyrene) rigid sheets. PS rigid sheet has low density, poor toughness and is flammable, releasing styrene gas (a harmful gas) when burned. Therefore, it is generally used to produce various industrial blister trays. PVC rigid sheet has moderate toughness and is not easy to burn. However, it releases chlorine gas when burned, which has certain environmental impacts. PVC is easy to heat-seal and can be sealed with sealing machines and high-frequency machines, making it the main raw material for transparent blister products. PET rigid sheet features good toughness and high transparency. It is flammable but does not produce harmful gases, making it an eco-friendly material. However, it is costly and suitable for high-end blister products. Blister clamshells in European and American countries usually require PET sheets. Yet PET is difficult to heat-seal, causing great challenges in packaging. To solve this problem, a material called PETG (Glycol-Modified Polyethylene Terephthalate) is adopted. This material combines the easy heat-sealing property of PVC and the high environmental friendliness and transparency of PET, but at an even higher price.