METHOD FOR PRODUCTION OF FOAMED THERMOPLASTIC POLYMERS WITH ADJUSTABLE DENSITY Russian patent published in 2022 - IPC B29C44/34 C08J9/18 C08J9/12 

FIELD: material processing.

SUBSTANCE: invention can be used for the manufacture of vibration- and shock-absorbing materials. A method for the production of foamed thermoplastic polyurethane (hereinafter – FTPPU) material includes the placement of non-foamed thermoplastic polyurethane (hereinafter – TPPU) material to the autoclave, increasing a temperature and total pressure in the autoclave. Pressure in the autoclave is increased by the introduction of a gas mixture, which includes gas soluble in TPPU material and gas insoluble or low-soluble in TPPU material, while the total pressure in the autoclave is 50-250 bar. Non-foamed TPPU material is left in the autoclave at increased pressure and temperature for material saturation with gas. Then, the total pressure in the autoclave is reduced, in the result of which TPPU material is foamed. Partial pressure of gas soluble in TPPU material is less than 100 bar and is in the range from 10 to 90% of the total pressure in the autoclave.

EFFECT: providing the adjustment of FTPPU density due to the adjustment of partial pressure of foaming gases.

13 cl, 3 dwg, 2 ex