Method of forming an article

摘要

A method is described in which a composite tape or sheet is processed such that it has an improved drapability when applied to a former having a complex geometrical form. The tape or sheet is selectively perforated across its width as it is dispensed, with a suction force being subsequently applied over the tape's surface to thereby cause stretching of the tape. The degree of stretching varies across the width of the tape in proportion to the degree and local density of the selective perforations.

主权项

1. A method of forming an article from a composite material, the composite material provided in sheet form and comprising a plurality of tows embedded within a matrix material and arranged widthwise across the sheet, each of a plurality of tows comprising a plurality of filaments, the filaments extending continuously lengthwise along the composite material, the method comprising steps of:
a. selectively perforating the composite material to split, slit or sever at least one, but not all, of the filaments of each of one or more of the plurality of tows; b. exerting a force on an upper surface of the composite material in a direction substantially normal to a plane of the composite material thereby extending each of the one or more partially split, slit, or severed tows, and deforming the one or more extended tows out of the plane of the composite material, a degree of perforation being chosen to result in a pre-determined extension, the force being exerted by applying a suction force across an area of the composite material, the area corresponding to a three-dimensionally shaped former; c. placing a surface of the composite material into contact with the three-dimensionally shaped former, such that each of the extended tows conforms to a respective lengthwise surface profile of the former to form a shaped body; and d. curing the shaped body to form the article.