The hot melt adhesive is melted and mixed with inert gas or air at the same time into the metering pump and output to the glue gun. Through the glue gun external circulation part of the return flow to the melt cylinder, re-entering the gear pump. Foaming rate how much through the nitrogen or air regulation, the use of special foaming adhesive foaming efficiency of up to 55%. Achieve glue saving 30-50% (depending on the type of glue selected). Make the rubber softness is better, not broken, the product sealing is better, similar to the sponge body. The host drive adopts servo drive. The machine is mainly used in air purification filter, household appliances and electronic foam sealing filling.