Plasma treatment of plastic film or decorative veneer and its effects on the peel strength and curling deformation of plastic film-reinforced pliable decorative sliced veneer (PR-RP-DSV)

Abstract

Abstract A new type of plastic-film-reinforced pliable decorative sliced veneer (PF-RP-DSV) for wood product surface finishing was developed. The plastic film served as both the reinforcing and adhesive material. Consequently, the veneer did not need adhesives during preparation and wood surface finishing. However, the interface bonding strength between the two composite was low and the curling deformation was serious because of the large difference in polarity and thermal expansion coefficient of the two materials. In this paper, low-density polyethylene (LDPE) plastic film (PF) and a decorative sliced veneer (DSV) from Brachystegia laurentii were treated with plasma to improve interfacial adhesion and reduce curling deformation. The plasma-modified (PM) PF and DSV increased the bonding strength of the resulting composites and generated an evenly distributed quasi glue layer between the two materials. The PM-PF had more influence on the interface bonding strength than the PM-DSV. This effect can be attributed to the great decrease in crystallinity and increment of oxygen-containing functional group in the PM-PF. The veneer from B. laurentii can achieve good gluing performance and small curling deformation at a hot pressing temperature of 120°C, pressing time of 150s and pressing at 0.6 MPa.