Tape cutting and lamination

Tape cutting is to cut the adhesive tape into a certain size (press size). The cutting equipment can be continuous fixed length slicer or manual cutting. The shearing size of adhesive tape should be accurate, not too long or too short. Stack the cut adhesive tape in order, stack the adhesive tape with different glue content and fluidity separately, and make marks for storage. In order to avoid the increase of volatile matter and the decrease of soluble resin content, the adhesive tape should be stored in the drying room.

The cutting methods of different applications are also different: the laminating adhesive tape is cut according to the production specifications, and the margin for processing the burr is reserved; for the tape winding, the adhesive tape is first cut into the tape required for winding, and then it is used by sewing, lapping, rewinding to form a certain diameter tape.

The lamination process of adhesive tape is very important to the quality of laminate. If the lamination is not proper, the laminate will crack and the surface of the laminate will be affected. Therefore, attention should be paid to the following points in the specific operation:

1) Two to three sheets of surface adhesive tape should be placed on each surface of the laminated plate, and its glue content and fluidity should be slightly higher than that of the rib.

2) The content of volatiles should not be too high. If the volatile content is too large, it should be dried before reuse; otherwise, it will affect the electrical properties and heat resistance of the products, and it is easy to produce corner bubbles and hemp.

3) Calculation of collocation. In order to make the pressed plate thickness accurate, the quality method is generally used to determine the amount of adhesive tape. The quality of adhesive tape (or adhesive paper) required for each plate is related to the thickness, area, density after forming and scrap rate after cutting.

The formula P = FHD × (1 + a) / 1000

Where p is the total mass of adhesive tape (paper) to be laminated, G;

F - area of pressed plate, cm2;

H-thickness of pressed plate, cm;

D-density of finished board, g / cm3;

A-correction coefficient.

The density is 1.40-1.45 for cloth and paper board, and 1.65-1.70 for epoxy phenolic glass cloth board (depending on glue content and green weight of impregnating material). The size of α depends on the thickness of finished plate. When h < 5mm, α is 0.02 ~ 0.03, when H > 5mm, α is 0.03 ~ 0.08.

For large area laminates, several pieces of adhesive tape (paper) can be taken first, and the weight is weighed to determine the thickness of adhesive tape (paper) required for 1 mm, and then the number of sheets shall be cleared according to the required thickness.