Strictly speaking, board, sheet is a profile, is a special, simple geometry of the profile. However, there is a big difference between the extrusion of sheet and sheet and the extrusion of profile. Sheet can be divided into: single-layer board, multilayer, flat, corrugated board, foam board, board and foam board and so on. According to the degree of soft and hard plastic points can be divided into hard board (including industrial sheet, decorative sheet and transparent sheet) and soft board (transparent and opaque) two.
Extruded plates, sheet used plastic varieties are: PVC-U, soft PVC, PP, PE, ABS, PS, HIPS, PA, POW PC, etc., in many varieties
The first 6 kinds of commonly used. The same kind of plastic extrusion board, the sheet has a single layer and multilayer varieties of points, a flat panel, corrugated board, embossed board, foam board and no foam board points. Finished product width is generally 1.0 ~ 1.5 m. The world's most widely extruded plate up to 4m. Sheet forming methods are: extrusion, calendering, lamination, casting method,
Casting method. Are several characteristics of the plate forming a comparison, as follows:
Rolling method: product thickness 0.09 a 0.8) mm; plastic varieties: PVC; advantages and disadvantages: large output, low cost, high impact plate, thickness uniformity is poor;
Laminating method: the product thickness (1.0 to 50) mm; plastic varieties: PVC-U and thermosetting plastic; advantages and disadvantages: good light board, the surface smooth; large equipment.
Casting method: product thickness (1.0-200) mm; plastic varieties: PMMA; plate smooth, high transparency, high impact resistance; intermittent production, labor-intensive;
Casting method: the thickness of the product (0.02 a 0.3) mm, plastic varieties: cellulose acetate; advantages and disadvantages: sheet optical properties, uniform thickness, low output, large equipment investment.
Thus, among the forming methods of these kinds of sheets, the extrusion and calendering methods have the highest production efficiency; in particular, the extrusion method has a large range of thickness of sheets and strong adaptability of raw materials. Lamination and Casting Although the thickness of the sheet is quite large, the production efficiency is very low, reducing the application of special conditions and special materials.