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Curing method adhesive curing through physical methods, such as solvent volatilization, emulsion condensation and molten body cooling and chemical methods.
(1) hot melt: polymer melts can be cured by cooling after soaking the sticky surface.
(2) solution adhesive: with the volatile solvent, the concentration of the solution continues to increase, gradually reached curing with a certain strength
.
(3) emulsion glue: due to the gradual penetration of water in the emulsion into the porous by the sticky and volatile off, so that the concentration of emulsion is increasing, and finally due to the effect of surface pressure, so that polymer collome particles condense. When the ambient temperature is high, the emulsion condenses into a continuous film, while the ambient temperature is low and the minimum film-forming temperature (MFT) forms a white non-continuous film. The emulsion glue is mainly polyvinyl acetate and its co-polymers and acrylic co-polymers.
(4) thermoset adhesive thermoset resin multi-function cluster monomer or pre-polymer polymerization reaction, with the increase of molecular weight at the same time with molecular chain changes and crosslinking, the formation of insoluble gel or called basic curing. Extending curing time and increasing curing temperature in a certain range is not equivalent, and reducing curing temperature is difficult to compensate with extended time. Because there needs to be some chemistry between the adhesive and the surface of the viscous, that is, a temperature high enough to do so.
Curing pressure:
is conducive to the adhesive to the surface of the full immersion, is conducive to the elimination of low molecular volatiles produced by the adhesive curing reaction, is conducive to the discharge of residual volatile solvents in the adhesive layer, is conducive to the control of the thickness of the adhesive layer, the viscosity of the adhesive tends to be thicker, curing pressure adjustment control of the thickness range of the adhesive layer.
after applying the glue for a period of time, which is called pre-curing. The viscosity of the adhesive is increased and pressure is exerted to ensure the uniformity of the thickness of the glue layer.
curing temperature:
curing temperature is too low, the glue layer cross-link density is too low, the curing reaction is not complete; Heating is beneficial to the molecular diffusion between the adhesive and the adhesive joint, and can be conducive to the formation of chemical bonds.
(1) oven direct heating method: use a blowing device to spread heat evenly.
(2) external heating method: so that heat quickly spread to the inside of the glue layer, greatly reducing the curing time. Sonic heating method: the adhesive with viscosity elasticity, solvent-free adhesive is thermally cured, not suitable for thermostat rigid glue.
.