摘要 |
Process for manufacturing a calibrated cardboard tube having minimal surface roughness and dimensional stability, involving helically winding a plurality of glued strips or plies around a mandrel and then polishing the exterior surface of the rough tube, coating the exterior surface with a thermosetting resin, cutting the tube, drying and compressing the cut pieces transversely together with applying heat, wherein at least the next-to-last ply and the last ply or strips of a dense material are impregnated with a thermosetting resin and, after coating and heat compression of the pieces, a final coating of a thermosetting resin is applied to the last plies before drying the coated surface and buffing or finish polishing to form a smooth surface, and the apparatus for performing the process.
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