The two-sided glue coating process is explained in detail.

Double-sided tape is based on paper, cloth, plastic film, and then the elastomer type pressure-sensitive glue or resin-type pressure-sensitive adhesive uniformly coated on the above substrate made of rolled adhesive tape, is composed of substrate, adhesive, isolation paper (film) three parts.
1, coating method
transfer: peeling paper glue after drying by the oven, and the cladding material, so that the glue transferred to the cladding material. Suitable for double-sided tape, label-type single-sided tape and foam-like substrate tape, such as

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features:
film thickness is the same, the total thickness of tape depends on the thickness deviation of the cladding material


: the adhesive is rolled directly on the substrate, also known as from the back. Suitable for packaging tape, peeling tape.
characteristics:
glue easily penetrates into the inside of the substrate, good denseness,
tape total thickness is consistent, the material deviation, the thickness of the glue layer changes exactly the opposite,
drying speed and temperature depends on the type of substrate.
2, drying process and principle
drying refers to the adhesive coated on the substrate, at a certain speed to make the adhesive moisture, solvent volatile to get dry film. The drying process is an important part of the production of tape, which has a great impact on product quality. Heat and substances change at the same time during the drying process, the initial drying phase is mainly heat from the air into the adhesive, so that the solvent constantly from the inside of the adhesive layer to the surface, in the surface to reach saturation, this is called constant drying.
of the substance depends on how much heat is passed to the adhesive. Solvent vaporization on the surface, drying into the rate reduction stage, adhesive surface temperature in a short period of time, and into a higher temperature oven, the bottom solvent gradually spread out through the surface film, such as the initial temperature is high, surface film premature hardening, will affect the internal solvent vapor volatilization, when the temperature is higher than the boiling point of the solvent, the liquid gas in the layer will expand and foaming problems, and ultimately affect the internal strength of the adhesive layer. At the same time to confirm whether the smell of the glue is too heavy, from the other side in the inspection of the thickness of the coating layer is normal and drying effect is sufficient.
Drying speed and drying time change trend (illustration)
excessive amount of residual solvents will cause tape initial adhesion, tape aging performance is easy to change, while increasing the peeling paper peeling, for use, excessive solvent volume will affect the solvent or printing layer with poor solvent resistance, the use of excessive odor on the operating environment. Our company produces A-500 tape residual solvent volume of about 1.5%. The drying effect of adhesive mainly depends on the transfer of heat, in order to achieve sufficient heat supply must ensure the circulation of the oven hot air, so it is necessary to the oven filter for regular inspection and timely cleaning.
3, roll
roll part design needs to consider the pressure control, the volume of the substrate with the volume diameter changes, showing a gradual downward trend, generally using slope to adjust to reduce the downward trend of the pressure, can overcome the roll over the loose air entry and too tight when running the problem, the roll part design using a special drive device and pressure-pressing device. When the production of single-layer peeling paper double-sided tape and PE protective film tape, if involved in air will cause the surface of the glue layer has pattern marks, protective film tape appearance if there are bubble marks, will limit the scope of application of the product (the appearance of high requirements of the product can not be used), and Double-sided tape involved in the air (moisture in the air) will affect the L-45 class hardener cross-linking effect, will cause the product to maintain the adhesive performance of the problem (especially when the air humidity is too large), so it is best to use the press shaft fit to eliminate air involvement.
4, double-sided tape stripping mode
double-sided tape second project production, by peeling paper (engineering paper) after applying glue transferred to the first project product and then peeling, in order to achieve the smoothness of the glue surface and do not appear horizontal wrinkles, need to consider which paper route is more reasonable, when the first surface peeling is relatively small or the glue layer is thin Easy deformation, the use of engineering paper direction peeling, especially in the case of too much roll-up pressure, the glue layer is easy to be pulled up and into the air, so the use of tape direction peeling is more reasonable, and reduce the roll-up pressure can improve the pull-up of the film layer, such as the production of foam double-sided tape to avoid wrinkles in engineering paper, can also be used in advance tape peeling method. However, the general double-sided tape using the direction of engineering paper peeling is easier to control.
5, improve the adhesive and substrate tightness method
Figure A above indicates the adhesive and substrate bonding, reflecting the adhesive and substrate adhesion, A and B values greater than C value is the ideal state, especially the re-stripping type (low viscous protective film class) tape must meet the requirements, if the A value is smaller than B or C, after peeling will appear glue residue to the mucous.
In order to meet the requirements of A greater than B, the following methods can be considered:
is treated with a base coating agent,
corona treatment, plastic general surface energy is low with inert, wetting is not good, after treatment can improve surface energy to improve subsequent and printing. After discharge through the corona, the surface molecules of the material are destroyed and become polar, so that the surface pressure rises. The processing effect depends on the discharge power and operating speed.
Note:
conductive materials cannot be processed;
needs to test the surface strength of the original material and confirm post-treatment changes before processing;
treatment discharge power should not be too large, material thin may break through the material,
treatment immediately eliminate static electricity to avoid damage to the back material.
treatment effect decreases gradually as the placement time increases, and surface stress must be confirmed before processing.
the surface of the pre-fit material is warmed or warmed up by the heating shaft when the coating is applied, and
the final oven temperature is increased to increase the collage temperature or to increase the bonding metal shaft temperature.
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