| 摘要 |
(1) Tube is made from a sheet material comprising (A) a first layer (forming the inside of the tube) of high density polyethylene; (B) a second layer composed of polymer or adhesive; and (C) an intervening primer layer of polyethyleneimine. The tube has a lap seam extending along its length and covered on the inside of the tube with a strip comprising polyethylene having resin density at least 0.950. Alternatively layer (C) may comprise a major fraction of a Lewis base. - (2) a tube of the above construction is also claimed in which (A) is of polyethylene with resin density at least 0.95, contg. a prod. including a cyanoacrylate-type component is also claimed. Layer (C) may also comprise polyethylene imine and reacted components from the cyanoacrylate-type prod. (3) Prodn. of a tube is also claimed from a sheet having two polymeric surfaces comprises (i) forming the sheet into a tube with overlapping edges at the seam; (ii) positioning a polymer strip over the seam on the inside of the tube; and (iii) applying heat and pressure to form a bonded lap seam.
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