Lamination of Bamboo for BMI
Lamination is a crucial process to produce BMIs with advantageous stability, strength, and appearance. Simply put, it is a process of gluing substrates such as bamboo, and then pressed. Prior to lamination, it is necessary that bamboo undergoes preparation (e.g., splitting, planing, edging, and sanding) to ensure favorable bonding.
Depending on the glue spread, a pre-determined amount of adhesive is coated on the surface of the bamboo slats and equally distributed all throughout the surface. Upon gluing, bamboo, laminates are mechanically pressed.
Pressing of laminated bamboo is classified based on the chemistry of the adhesive applied. For cold-setting adhesives such as polyvinyl acetate (PVAc) and polyurethane (PUR), cold-pressing is performed, which specifically uses pneumatic press. On the other hand, laminates with hot-setting adhesives such as phenol formaldehyde (PF) and urea formaldehyde (UF) carries out hot pressing, which uses a hydraulic hot press. It is important that further machining of the glued laminates to assemble BMIs should be done after at least 24 hours to allow complete curing of the adhesives.