Double-sided adhesive tape is paper, cloth, plastic film as a substrate, and then the elastomer-type pressure-sensitive adhesive or resin-type pressure-sensitive adhesive uniformly coated in the above substrate made of rolls of adhesive tape, is composed of substrate, adhesive, isolation paper (film) three parts.

1、Coating method

Transfer coating: After the adhesive on the peeling paper is dried in the oven, it is laminated with the laminating material so that the adhesive is transferred to the laminating material. Applicable to double-sided adhesive tapes, labels, single-sided adhesive tapes and foam substrate tapes.  

Characteristics: The thickness of the adhesive film is uniform and the total thickness of the tape depends on the thickness deviation of the laminating material;

Peeling is required for the finished tape or for the process; the maximum oven temperature can be controlled up to 120°C when using peeling paper.

Direct application: the adhesive is applied directly to the substrate and rolled up, also known as self-backed rolled up. Suitable for packaging tapes and re-peelable tapes.

Characteristics: Adhesive easily penetrates into the interior of the substrate, good adhesion;              

The total thickness of the tape is consistent, and when there is a deviation in the material, the change in the thickness of the adhesive layer is exactly reversed;              

Drying speed and temperature depend on the type of base material.

2、Drying process and principle

Drying refers to the adhesive coated on the substrate, with a certain speed so that the moisture in the adhesive, solvent evaporation to get dry film.

Drying process is an important part of the production of adhesive tape, the product quality has a great impact. Drying process of heat and matter at the same time in the change, the initial drying stage is mainly heat from the air into the adhesive, so that the solvent continues to diffuse from the inside of the adhesive layer to the surface, in the surface to reach saturation, this section is known as the constant rate of drying.

The rate of movement of the substance depends on how much heat is transferred into the adhesive. After the solvent is vaporised on the surface, the drying enters the reduced rate stage, the surface temperature of the adhesive rises in a short time and enters the oven at a higher temperature, the bottom solvent is gradually diffused outwards through the surface adhesive film, if the initial temperature is high, the surface adhesive film hardens prematurely, then it will affect the volatility of the internal solvent vapour, when the temperature is higher than the boiling point of the solvent, the solvent gas in the adhesive layer will appear to expand and the problem of foam will occur, and ultimately affect the adhesive layer The cohesive strength of the adhesive layer will be affected. Therefore, it is often required to monitor the adhesive surface to see if there is any foaming phenomenon. At the same time, it is necessary to check whether the odour of the adhesive is too strong, and on the other hand, it is necessary to check whether the thickness of the adhesive layer is normal and whether the drying effect is sufficient.

Excessive amount of solvent residue will result in high initial adhesive force of the tape, and the performance of the tape will be easily changed after aging, and it will increase the peeling property of the peeling paper, and excessive amount of solvent will affect the adhesive or printing layer which has poor solvent resistance, and excessive odour will have an impact on the working environment during the use. Adhesive drying effect depends mainly on the transfer of heat, in order to achieve sufficient heat supply must ensure that the oven hot air circulation, so it is necessary to carry out regular inspection of the oven filter and timely cleaning.

3、Winding  

The design of the winding section needs to consider the tension control, the tension of the substrate with the change in the diameter of the winding changes, a gradual decline in the trend, the general use of slope to adjust to reduce the trend of the tension down to overcome the problem of the entry of air when the winding is too loose and too tight to run the volume of the problem of the design of the winding section of the use of a special drive device and the press device. When producing double-sided adhesive tapes and PE protective film tapes with single-layer peeling paper, if air is involved, it will cause pattern-like traces on the surface of the adhesive layer, and if there are traces of air bubbles on the appearance of the protective film tapes, it will limit the scope of application of the products (the products with high appearance requirements can not be used), and the air involved in the double-sided adhesive tapes (there is moisture in the air) will affect the effect of the cross-linking of the hardener of the L-45 type, which will result in the decline in the performance of the product's holding power. Problems (especially when the air humidity is too large), so it is best to use the compression shaft to eliminate the air involved in the roll-up.

4, double-sided tape peeling method   

Double-sided adhesive tape second project production, through the peeling paper (engineering paper) coated with adhesive transferred to the first project after peeling, in order to achieve the smoothness of the adhesive surface and does not appear transverse wrinkles, it is necessary to consider the use of which through the paper route is more reasonable, when the first project surface peelability is relatively small or the adhesive layer is thin and easy to deformation, the use of engineering paper direction of the peeling, especially in the case of too much winding tension, the adhesive layer is easy to be pulled up into the air, so the use of tape direction is more reasonable, so the tape direction is more reasonable. So the tape direction is more reasonable, and reduce the winding tension can improve the adhesive layer is pulled up, such as the production of foam double-sided adhesive tape in order to avoid wrinkles in the engineering paper, can also be used in advance of the tape down the peeling method. But the general double-sided tape using engineering paper direction peeling easier to control.

5, to improve the adhesion of adhesive and substrate methods 

Adhesive and substrate adhesion, reflecting the adhesion of glue and substrate, especially re-peeling type (low viscosity protective film type) tape must meet the standard requirements, otherwise there will be adhesive residue to the adhesive after peeling.