Strip for underground pipe protection - made of mixt. contg. atactic polypropylene, loose filling, fibrous strengthener and rubber soln.

摘要

Strip for mechanically protecting an insulated, underground pipe conduit, e.g. against falling stones, consists of a layer, >=1 mm thick, made of a mixt. contg. (a) 10-99.8% atactic polypropylene, dehydrated by heating to 100-70 degrees C and then cooled by 1-70 degrees C, (b) 0.1-40% loose fillings, reinforced with fibrous material stronger than the mixt. itself, and 0.1-50% rubber soln. in an organic solvent, in wt. ratio 1-50 to 50-99. Mechanical damage in a rocky soil can be reduced without soil pre-treatment and/or without the use of a specific loose material. A cheap, light strip can be obtd. from readily available waste materials.