| 摘要 |
1492328 Tube couplings &C PRODUITS CHIMIQUES UGINE KUHLMANN 16 Sept 1975 [20 Sept 1974] 38056/75 Heading F2G [Also in Division B5] Two polyvinylidene fluoride parts, one part being thicker than the other part, are joined together by coating the part of lesser thickness with a solvent which will dissolve polyvinylidene fluoride when heated or with a solution obtained by disssolving polyvinylidene fluoride in a heated solvent, heating the thicker part to a temperature between 150‹ and 320‹ C., and bringing the parts into contact and holding them in that position during cooling. The thinner part may be a tube and the other part a tube, a sleeve, a straight or elbow joint, a reduction joint, a threaded end, a collar, an expansion joint, a valve or a tap. In Examples, two tubes are joined by heating the inner surface of the thicker tube by the male portion of a heated metal muff, pushing the end of this tube over the end of the thinner tube which has previously been coated with a solvent or a solution of polyvinylidene fluoride in a heated solvent. In another Example, pipes are secured in holes in a sheet. Specified solvents, used either alone or mixed, are dimethyl formamide, dimethyl acetamide, tetrahydrofuran, dimethyl sulphoxide, cyclohexanone, hexamethyl phosphoramide and butyrolactone. |
