Suction Card Packaging For Vacuum Formed Foam Shells

What issues should be paid attention to in card packaging?
Card suction packaging refers to the heat sealing of blister packs onto the surface of paper cards with vacuum formed oil, which is commonly used in supermarket battery packaging. Its characteristic is that it requires vacuum sealing equipment to encapsulate the product between the paper card and the blister.
The issues that should be noted are:
1. It is required that the surface of the paper card must be coated with vacuum forming oil (in order to be able to heat bond with the PVC foam shell);
2. The foam shell can only be made of PVC or PETG sheets;
3. Because the blister only sticks to the surface of the paper card, the packaged product is not easily too heavy.