PRODUCTION OF VACUUM HEAT-INSULATING ARTICLE Russian patent published in 2015 - IPC F16L59/65 

FIELD: process engineering.

SUBSTANCE: this method consists in extrusion of outer shell with inner stiffness ribs of lengthwise insert. End walls are welded to outer shell and outer shell inner cavity is evacuated. Additionally, heated polymer of higher hardness and lower heat conductivity is extruded via female die. The latter follows the lengthwise insert cross-section profile over the length smaller than that of the article outer shell by magnitude making at least dual distance between stiffness ribs. Openings are cut in lengthwise insert to be fitted with guaranteed clearance in between stiffness ribs and inside outer shell with penetration relative to end surface by the depth making at least spacing between stiffness ribs. Outer shell end surfaces and end walls are welded by diffusion friction welding. Outer shell wall is cooled at the distance from the weld making at least spacing between stiffness ribs. Hole is made in any wall of outer shell or in end walls to evacuate outer shell inner cavity to residua vacuum lower than 2 kPa. Then, it is sealed at rarefaction by diffusion friction welding.

EFFECT: higher reliability.

3 dwg