Shrinkable film in roll form can be wrapped around a product, often with heat sealing to tack the film together. Shrinkable centerfold film is supplied on a roll with the plastic is folded in half: product is placed in the center portion, the remaining three edges are sealed to form a bag, and the package then heated which causes the bag to shrink and conform to the product placed in the bag.
Skin pack film is used on skin pack machine with a type of carded packaging where a product (or products) is placed on a piece of paperboard and skin pack film is placed over the product and paperboard. The printed paperboard usually has a heat-seal coating. The skin pack film is softened by heat and draped over the product on the card. Vacuum is sometimes used to assist a firm fit. The film bonds to the heat-seal coating on the paperboard. The skin-packed piece then may need to be cut into individual units.
Vacuum bag is used on vacuum machine or vacuum sealer to remove air from the package prior to sealing. The intent of vacuum packing is usually to remove oxygen from the package to extend the shelf life of products and flexible package forms to reduce the volume of the package. Vacuum packaging is used to conserve or protected products. Every product requires specific vacuum packaging that is the right kind for the characteristics of the product to be packaged.To protect the product and increase its shelf-life is are aspects of a qualitative vacuum bag.
Cap seal is used on Induction sealing machine, known as cap sealing. It is a non-contact method of heating a metallic disk to hermetically seal the top of plastic and glass containers. This sealing process takes place after the container has been filled and capped.