Production process of Huashida spray winding insulation pipe production line
During the operation of the spray winding thermal insulation pipe production line, the steel pipe is shot blasted for rust removal, polyurethane spray molding, polyethylene outer protective layer extrusion coating, cooling, and end finishing. The advantage of a continuous process is that it saves production space. The advantage of the batch process is that the polyurethane reaction and curing is stable, the polyurethane spray foaming molding, cooling for 24 hours, the polyurethane is completely reacted and matured, the volume does not change, the strength reaches 300Kpa, and the polyurethane rigid foam cells are not damaged during the winding and conveying process. , without volume deformation. During the winding process, the polyethylene protective layer is extruded and cooled, and there is only one tensile stress. At this time, the tensile stress must exist, and it can effectively solve the shear strength of the polyurethane rigid foam and the polyethylene outer sheath, which is not less than 200Kpa.