| 摘要 |
453,676. Paper &c. pipes. LUTZ, A., 1, Rotdornstrasse, Friedenau, Berlin. Dec. 10, 1934, No. 29160. [Class 99 (ii)] Pipes for conveying fluids are made by winding a flexible web 2 of paper &c. upon a mandrel 1 while the latter is immersed in a bath e of mineral adhesive such as bitumen, pitch or tar which is maintained in a molten condition by a burner or heating coil 5. In a modification the burner 5 is dispensed with, molten adhesive from a separate heated tank being circulated through the bath by a pump. The flexible web is preferably heated &c. prior to winding to remove air and moisture therefrom, and reinforcing material may be interleaved with the web during winding. The mandrel is supported in the bath e by arms 10 and is rotated by chain mechanism 12, and pressure is applied to the paper on the mandrel by a spring-pressed &c. blade 18, roller or belt. Upon completion of winding the mandrel is withdrawn from the adhesive bath and the outer layer of paper is subjected to the action of a scraper 19 ; the pipe is then cooled by water from a pipe 20 and finally removed from the mandrel. The mandrel is preferably heated before immersion, and a lubricant such as soap &c. or the molten adhesive itself, is applied to the mandrel so that slipping therebetween and the wound layers may occur during winding in order to relieve excess tension on the paper web. The pipe may be completed by coating it, internally and externally, with additional adhesive. |
