CN
Answer: The sheets used for blister packaging are called hard sheets or films. Commonly used types include: PET (polyethylene terephthalate) hard sheets, PVC (polyvinyl chloride) hard sheets, and PS (polystyrene) hard sheets.
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PS hard sheets:
- Low density and poor toughness.
- Easily flammable, producing styrene gas (a harmful gas) when burned.
- Mainly used to produce various industrial blister trays.
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PVC hard sheets:
- Moderate toughness and non-flammable (flame-retardant), but produces chlorine gas when burned, causing certain environmental impacts.
- Easy to heat-seal, suitable for edge-sealing with heat sealers or high-frequency machines.
- The primary raw material for producing transparent blister products.
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PET hard sheets:
- High toughness and transparency.
- Easily flammable but produces no harmful gases when burned, making it an eco-friendly material.
- Higher cost, suitable for high-end blister products (e.g., blister clamshells in Europe and the U.S. generally require PET hard sheets).
- Difficult to heat-seal, posing challenges for packaging. To address this, PETG (glycol-modified polyethylene terephthalate) is often used. This material combines PVC’s heat-sealing ease with PET’s high environmental friendliness and transparency, though at a higher cost.