GB828415A - Paper tube form for pouring concrete columns - Google Patents

Abstract

828,415. Paper tubes. SONOCO PRODUCTS CO. July 16, 1958 [May 20, 1958], No. 22874/58. Class 99(2). In a wound, multiply, paper tube for moulding concrete columns the innermost ply liner 10 consists of water permeable paper of a porous nature and treated with a suitable chemical, which permits uniform penetration therethrough of water from wet concrete with consequent uniform wetting of the other plies of the tube in order that the tube may be stripped easily from the concrete column after hardening thereof, and providing a smooth uniform surface on the poured concrete column free of paper from the paper plies, the liner having a sufficiently high wet strength to avoid disintegration of the liner and to permit the latter and the remaining plies to be stripped substantially intact from the column. As shown, the plies are convolutely or helically wound strips having abutting or overlapping deckled edges, and the liner is coated with, for example, resin such as melamine resin or urea formaldehyde resin catalyzed with alum. A water barrier 12 of parchment paper, non-moisture proof "Cellophane" (Registered Trade Mark), glassine, grease-proof paper or paper coated with starch or polyvinyl alcohol retains water permeating the liner until the concrete has initially set. The outermost ply 17 is coated with wax or other water-resistant material to protect the tube against weather conditions and to prevent the concrete from drying out too fast. Specification 751,490 is referred to.