At present, there are two common types in the market: heating type and self-adhesive type—upper cover tape

1. Heat activated adhesive
Generally speaking, the heating belt consists of three parts
(1) . polymer film (PET film is generally used)
(2) . interface layer (tielayer)
(3) . adhesive layer

The advantage of heating packaging upper belt is that different peel forces can be obtained with the change of processing conditions during processing, the quality of viscose layer is not easy to be affected by environmental changes, and the cost is low. But the disadvantage is that the processing conditions will vary from brand to brand.—upper cover tape

2. Pressure sensitive adhesive tape
Generally speaking, the composition of self-adhesive tape includes four parts:
(1) . polymer film (PET film is generally used)
(2) . interface layer (tielayer)
(3) . adhesive layer
(4) . polymer film (PET film is generally used)—upper cover tape

The whole PET film is coated with an interface layer and a layer of viscose. Such a structure provides users with an elastic space. The sealing position can be adjusted arbitrarily, but it must also be used carefully to ensure good sealing quality.
The advantage of self-adhesive packaging upper belt is that it does not need to be heated during processing, is less affected by processing, is more convenient, and can be reused without pollution. However, the disadvantage is that the quality of the viscose layer is easily affected by environmental changes. Peel force cannot obtain different values with the change of processing conditions, and the cost is high.