Working principle and process of hydrogel coating machine

A hydrogel coating machine is a composite coating system designed for the production of gel-based patches, such as fever-reducing patches, cold compresses, and gel plasters.

The typical process workflow involves the following steps, completed in a single continuous operation: substrate unwinding → dual-roller coating → indentation → longitudinal slitting (using air knives or rotary blades) → transverse cutting (using rotary cutters or guillotine blades) → finished product output. This workflow integrates multiple stages-from raw materials to finished products-onto a single production line, thereby enabling automated manufacturing.

The core process involves utilizing a coating mechanism to uniformly apply the hydrogel material onto a non-woven fabric substrate (the backing layer), followed by the application of a release liner (the anti-adhesion layer). Through a lamination process, this assembly forms a semi-finished product featuring a three-layer composite structure: "backing layer – gel reservoir layer – anti-adhesion layer." Subsequently, the material undergoes post-processing stages-such as indentation and slitting-to be converted into individual, discrete patches. Some advanced models incorporate rotary die-cutting technology, allowing the coating and cutting processes to be executed simultaneously, which contributes to enhanced production efficiency.