| 摘要 |
1,168,823. Paper laminate. WEST VIRGINIA PULP & PAPER CO. 19 Oct., 1966 [23 Oct., 1965], No. 46833/66. Heading B5N. In a method of bonding two paper or paperlike laminµ, a coating of raw starch in a liquid carrier is applied to the surface of one of the laminµ, the starch is brought to gel condition, the second lamina is then applied to the coating, and the laminate is consolidated by pressure. As described the raw starch is gelled by heat and/or by chemical additives which reduce its gel point. The raw starch may be raw corn, tapioca, or potato starch and the liquid carrier may consist of polyvinyl alcohol or of water and smaller amounts of cooked starch, borax and caustic soda, the raw starch comprising 10- 40% by weight of the adhesive. In making double-faced corrugated board by the method, single-faced board 1 is fed via a preheater 16 and an adhesive applicator 18 into contact with a liner 5 between belts 20 and rollers 23 constituting a compression section 19. The adhesive is gelled by spraying the coated board 1 with steam from pipes 24. If the heat applied by the preheater 16 is sufficient to gel the adhesive the pipes 24 may be omitted. In an alternative embodiment the adhesive is gelled by spraying with a gel point depressing additive e.g. caustic soda. The belts 20 may be replaced by a series of opposed rollers or air chambers. In a further embodiment further single-faced boards are combined with the board 1 and liner 5. In alternative embodiments two plane laminµ are combined between pressure rolls, adhesive being applied previously to one of the laminµ and gelled, or a plane lamina is passed between corrugating rolls and combined with a plane lamina to which the adhesive has been applied in stripes before gelling, to align with the tips of the corrugations in the corrugated lamina. Alternatively the adhesive is applied direct to the corrugation tips. |
