Application of Thick Sheet Plastic Absorption Molding in Bus

With the rapid development of transportation network, the demand for passenger cars is increasing, and the requirements for safety and comfort of passenger cars are also increasing. The beauty and luxury of interior decorations have become one of the important symbols of high-grade luxury buses.

According to the process, the suction molding can be divided into two kinds: plate suction and soft epidermis suction. The main materials used for plastic absorption are acrylonitrile-butadiene-styrene (ABS) sheets, and a small part of the parts are PMMA sheets. ABS sheets are used to form the inner panels, the top inner panels, the rear inner panels, some electrical box covers and other covers on the left and right sides of the cab of a bus. Now there is also a trend to use composite ABS sheet instead of general ABS sheet. Composite ABS sheet is to add a layer of foamed polypropylene or polyvinyl chloride material on the sheet and roll together to make sheet with leather lines or feel like leather. Require transparent instrument panel sound cover, anti-aging car body outside the ventilation grille, generally used are made of plexiglass. Soft skin suction technology is mainly used in bus dashboard, the matrix is generally FRP, and the skin is sucked by opening suction holes on FRP. The main material of the skin is polyvinyl chloride and foamed polypropylene (PVC/PPF) composite material.

Now take the inner panel of bus as an example, the process of plastic absorption is briefly described. The dimension of the part is 1200mm x 1000mm x 250mm, and the ABS sheet used is 1400mm x 1200mm x 4mm. First of all, we need to confirm the color of the board, because the color of the interior decoration and the skin pattern are very important. The first thing passengers feel when they get on the bus is the environment inside the car. See if the sheet is removed from the newly opened package. If not, the sheet needs to be dried in the drying room. Because if the sheet is wet, it will cause bubbles on the surface of the sheet when heated, deteriorate the appearance quality, and even cause the sheet to crack in the forming process when it is serious. At the same time, the mould is mounted on the suction machine, and the position and pressure frame are adjusted to pre-set the rising process and time of the mould; the top of the mould can not exceed the working platform of the suction machine, and then the mould is heated to about 60 C. The sheet metal is placed on the automatic feeding device. The machine sends the sheet metal to the working table of the plastic suction machine (if there is no such mechanism, the sheet metal should be put on the working table manually). The pressing frame is pressed from top to bottom. Then the heating mechanism moves to the top of the worktable to heat the sheet, generally heating to 120 C for 2-3 minutes; if it is an advanced equipment, it can also set the regional temperature of the heater and increase the heating temperature appropriately where the stretching is large; after heating, the heating mechanism moves away, and the mould begins to move upward.