Soft and sticky materials used in cellphone holders, and lint removers can be made of polyurethane gel compounds. Polyurethane based sticky pads can be formulated without using tackifier additive, which is a type of chemical to make polymer materials to be sticky. Thus the sticky pad products made of polyurethane gel compounds are intrinsically sticky inside and outside.
Once the surface is contaminated with dusts and oil, the user can wash off the surface and the product will be sticky again. Cut surfaces of polyurethane sticky pads are also sticky.
Processing polyurethane gel compounds do not involve drying out solvent carrier or need air or moisture to cure. It can be made into practically any thickness. Most of the polyurethane gel formulations can be processed at or near room temperature. The curing rate can be accelerated by addition of catalyst and processing at an elevated temperature.
This makes polyurethane gel based sticky pad materials an ideal material choice for many specialty applications. Northstar Polymers offers GK-7 and GK-22 formulations for sticky pad making applications. GK-7 formulation has stickiness of commonly marketed cellphone holders and non-invasive wall-tack products. GK-22R formulation makes softer/sticker products. Both formulations are made in such a way that the processor can adjust the stickiness of final products by simply adjusting the mixing ratios between the given part-A/part-B component materials.