Melt Viscosity of Hot melt adhesives

2019-12-08

Generally, for Hot melt Polyamide adhesives, Melt Viscosity means the resistance generated by the liquid when it is flowing, that is the resistance generated when painting. The number expressed in a certain unit is the melt viscosity.The unit is 1800~3200 cps/mPa s at 190 degree celsius.

High viscosity for hot melt PA adhesives

1. High viscosity, poor fluidity; low viscosity, better fluidity.
2. There is no absolute relationship between viscosity and solid content.For hot melt adhesives, the adhesives with high solid content may not have high viscosity.
3. There is no absolute relationship between the viscosity and the "brushability" referred to in general operations. A high viscosity does not mean that the brushability must be poor; the brushability and the volatilization rate of the solvent and the glue contained in the brush tool Quantity is more closely related.
4. It is best to use different brushing tools for adhesives with different viscosities. For example, adhesives with lower viscosities should use stronger and softer brushes.

5. Viscosity is an important consideration when selecting adhesives. For porous materials, if the viscosity of the adhesive used is too low, most of the adhesive will penetrate below the surface, and under-adhesion will occur at this time. If the viscosity of the adhesive is too high, the penetration is poor and the drying speed is slow. If the drying time is not enough, it will often affect the bonding effect.

We recommend our ExA 76-380, it is 13000-25000 cps/mPa s at 190℃。 This kind of Hot melt PA adhesives have excellent bonding strength and plasticizer resistance, extra adhesion to plastics, masking tape, hot stamping foil, and assembly, packaging.

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