What is Lay-Up process?

A Lay-Up process is a moulding process for composite materials, in which the final product is obtained by overlapping a specific number of different layers, usually made of continuous polymeric or ceramic fibres and a thermoset polymeric liquid matrix. It can be divided into Dry Lay-up and Wet Lay-Up, depending on whether the layers are pre-impregnated or not.Dry Lay-up is a common process in the aerospace industry, due to the possibility of obtaining complex shapes with good mechanical properties, characteristics required in this field. On the contrary, as Wet Lay-Up does not allow uni-directional fabrics, which have better mechanical properties, it is mainly adopted for all other areas, which in general have lower requirements in terms of performance.The main stages of the Lay-Up process are cutting, lamination and polymerization. Even though some of the production steps can be automated, this process is mainly manual , leading to laminates with high production costs and low production rates with respect to other techniques. Hence, nowadays, it is mainly suitable for small series production runs of 10 to 1000 parts.