Classification and characteristics of screen-printable pressure sensitive adhesives

I.Characteristics and performance requirements of screen printing process

Screen printing is through a certain pressure to make the printing base material through the holes of the plate to the substrate, the formation of an image or text. In order to achieve good printing adaptability, the physical properties of screen printing base material are required:

1.Viscosity of printing base material: liquid pressure sensitive adhesive

Viscosity has a great influence on the printing effect. General screen printing viscosity requirements between 1000cps to 100,000cps. Too much viscosity will cause problems such as wire drawing or plugging; Viscosity is too small, will make the impression definition is poor or sticky screen version of the problem.

2. Viscoelasticity of printing base material:Pressure sensitive adhesive polymer

Viscoelasticity refers to the mechanical properties of a substance with the elasticity of a solid and the viscosity of a liquid under the action of external forces. Polymers are almost always viscoelastic. Viscoelasticity has a close relationship with the splitting and drawing of the printing base material and the smoothness of the printed surface. There is no viscosity only elastic printing base material, printing is difficult to transfer; No elasticity only viscous printing base material, or serious drawing, or rheology is out of control, can not obtain good printing.

3. Surface tension of printing base material:Acrylic pressure sensitive adhesive

When the surface tension of the printing base material is greater than the surface tension of the printing surface, the printing will shrink, and even appear fisheye holes. In this case, the surface tension of the printing base material can be equal to or less than the surface tension of the printing surface with the help of silicone or fluorine-containing surface additives, so as to obtain good printing effect.Pressure sensitive acrylic adhesive