Laminating Processes of Thermoset Sandwich Composites
摘要整理
The multitude of assembly methods for sandwich composites can be put into two categories: dry lamination and wet lamination. If the skins (metal, wood, plastic, FRP) are fabricated before laminating, the process is considered to be “dry.” On the other hand, if the facings are formed during assembly, laminated with the core, it is a “wet” process. Most large sandwich composite products are made by using reinforcing fabrics and thermosetting liquid resin in wet laminating processes. In this chapter, dry processes are introduced, including hot pressing, vacuum bagging, pinch roller pressing, and continuous pressing, to bond the facings and core into an integrated structure. Wet lamination, presented in the second section, combines the processes of wetting out the fiber reinforcement and bonding all the various layers together in one co-curing step. Wet lamination is conducted either in the open process by hand, by machines of chopping, spraying, and consolidating, or in a closed process, which includes vacuum infusion with or without positive pressure, resin transfer molding, and pultrusion. Prepreg may be considered wet or dry and may be combined with other processes such as infusion if the laminate will be cured at elevated temperatures. 3D printing is covered briefly in the last section as a new development for making sandwich structures by additive manufacturing.