| 摘要 |
A round thermoplastic tube, partic. for use as a surgical transplant, is corrugated along its length, it is produced e.g. as follows: by heating to softening temp. applying a circular former under press. cooling, placing on a smooth cylindrical shaft, applying press, from >=1 end to shorten it, fastening it to the shaft, reheating and recooling to make the corrugation round and uniform. The corrugations, which are necessary for stiffness and flexibility and for a good key to blood vessels, are not spiral so that the tube does not tend to rotate under tension, the tube is uniform and cheap to produce. |
