Patent GB-1047150-A (GB)
Title: Applying expanded synthetic resin insulation to an article
IPC: B29B7/74
Filed: 1963-05-17
Abstract: 1,047,150. Insulating by moulding; laminates. H. GIESEMANN. May 17, 1963 [Nov. 23, 1962], No. 15745/66. Divided out of 1,041,572. Headings B5A and B5N. [Also in Division B2] A continuous method for the application of insulation to an article comprises introducing a synthetic resin foam, produced by mixing one component containing in solution a urea-, thiourea-, and/or melamine-aldehyde aminoplast with a second component which is a preformed liquid material containing hardening means for the aminoplast to produce a mechanically stable hardening synthetic resin foam product, mixing of the two components being accomplished with the aid of compressed air at a pressure of from 3 atmospheres gauge to 9 atmospheres gauge and at least one of the two components being heated to a temperature between 50‹ and 80‹ C. before mixing, into a cavity between the article to be insulated and a moulding wall disposed at a predetermined distance from the article, in which during the introduction of the foam into the cavity and during setting the moulding wall is continuously advanced along the article and thereby removed from the insulation as it sets. The foam introduced into the cavity maintains a positive pressure in the cavity during the period of its introduction. The insulating coating may be given a grooved structure either at the same time as the coating is applied or subsequent thereto. The method may be performed using an apparatus in which the moulding wall 1 is part of a formwork disposed to be slidable relatively to the article e.g. wall 8, to be insulated and the formwork is closed at the side 5 where the synthetic resin foam is introduced through a pipe 9. As shown in Fig. 3, the formwork may be in the shape of a rectangular box and is positively guided by rails, which may be detachable, along the surface to be provided with the expanded insulation. As shown in Fig. 5, the formwork may be constructed as a jacket 18 which surrounds the article e.g. pipe 17, to be insulated and at the closed end of which is disposed the feed 24 for the synthetic resin foam. The formwork jacket 18, which may be of circular, polygon or oval cross section, may be provided with a guide bush 21 surrounding a pipe 17 to be insulated and in which the jacket and the guide bush are constructed to hinge open. The inner surfaces of the formwork may be provided with a foam-repellent coating. A reel 11 may be mounted rotatably on the formwork 1 and is arranged to feed a web 13 of foil, e.g. plastics or metal foil which may be perforated, or fabric e.g. a wire fabric, into the interior of the formwork to be disposed on the outside of the resultant insulating coating 10. The insulation may be applied to, for example, flat surfaces, shaped elements, packings and tubes. Fine sands, small flakes or fibres, or an adhesive medium, may be sprayed on to the surface of the insulation by a suitable device connected to the formwork. The formwork may be provided with a device for spraying or applying a barrier layer to the article to be insulated to prevent excessively rapid withdrawal of water from the expanded plastics material subsequently applied.