There are various production processes of aluminum composite panel, which can be divided into cold composite method and hot composite method according to the composite process of plastic core panel and two-sided aluminum panel; it can also be divided into continuous composite method and intermittent composite method. The first process of producing aluminum composite panel is cleaning aluminum coil. Aluminum coil in the production process because of the need, the surface are coated with lubricants and anti-oxidants, in transport will also be attached to some dirt, these will affect its bonding, so it must be cleaned. Aluminum coil after cleaning and chemical treatment, the surface will produce a layer of dense chemical protection film; this layer of chemical film can improve the resistance to oxidation of aluminum coil and extend the life of the paint film.
The general process of cleaning is as follows.
Aluminum coil → spray degreasing → water washing → neutralization → chemical treatment → water washing → drying → cooling → winding.
The cleaned aluminum coil is fed into the coating machine to coat the outer surface of the aluminum coil with high performance fluorocarbon resin.
The process flow is as follows.
Aluminum coil → feeding → coating fluorocarbon coating → hot air circulation baking → cooling → laminating → cutting → rewinding.
The panels of exterior aluminum composite panels are to be coated with two topcoats and primers each. The top coat of the exterior wall panel is a fluorocarbon resin coating with extremely high weather resistance, namely polyvinylidene fluoride (PVDF), whose excellent UV resistance and resistance to environmental pollution make the surface of the protected aluminum coil maintain a brilliant color. The surface of aluminum composite panel can not only have the color of metal, but also beautiful marble pattern and color. Fluorocarbon coating is usually applied to the aluminum coil by roller coating method, and then baked at high temperature to dry it. The equipment is continuous production, with primer coating first, then top coating, and finally surface varnish. The total thickness of the three layers of paint reaches 30μm, and each layer of paint needs to be baked above 200 ℃ for about 60s to dry, and then cooled rapidly by air cooler after leaving the baking oven. Epoxy resin, polyester resin and acrylic resin can be used for interior wall panel paint. After the primer, top coat and surface varnish are coated, a PE protective film is immediately applied to the surface of the coating layer to avoid the surface coating from being scratched during later processing and transportation circulation and installation.
The protective film is self-adhesive and can be removed after installation. The aluminum coil coated with fluorocarbon resin can enter the process of lamination with plastic core material. The plastic core is essentially three layers, with PE plastic in the middle and adhesive on both sides, and the PE sheet and adhesive can be produced separately or in a three-layer co-extrusion process. The structure of the adhesive/PE/adhesive three-layer co-extruded sheet is produced first, and then compounded with the upper and lower two layers of aluminum sheet, the compounded aluminum-plastic composite sheet is 0.15mm thick aluminum sheet on both sides, the core layer is 3-5mm, and the total thickness is 4-6mm. finally, the sheet is cut into 1220mm×2440mm size.