Study On Process Scheme Of Flat-pressuring Of Hollow Particleboard

Currently, extrusion process is used to produce hollow particleboard. Due to the restrictions on extrusion process, surface strength and longitudinal bending strength of the finished product are very low. In view of the existing defects of extruded hollow particleboard, using the method of flat-pressuring to make hollow particleboard. By demonstrating experiment, to find a reasonable method of mat formation. Taking three different solutions of flat-pressuring, and through study on the influence factors of board under these solutions to find the effect among of them. The main content and results included in the following items.1. Study on the method of mat formation, the results are as follows:View of the special structural of hollow particleboard, it adopts the method of layered symmetrical mat formation(core layer 1à surface layer 1à core layer 2à surface layer 2), to reduce the difference between the density of core layer and the surface layer and make the structure symmetry and glue closely of the core layers after the slab shaped.2. The study on the flat-pressuring hollow particleboard by using the smooth steel tubes as the hollow molding mold. The results are as follows:Using the smooth steel tubes as hollow molding mold, the suppressed hollow particleboard has greatly improved on the MOR than the extrusion. Within the scope of the test, the suppressed particleboard by using the thin rod shavings is the best on the mechanical properties, and the MOR increases with the increasing of the solid density and the hollow pitch. When the solid density is 0.7 g×cm-3 and the hollow pitch is 20 mm, the suppressed hollow particleboard by using the thin rod shavings has the greatest longitudinal MOR of 8.24 MPa.3. The study on the flat-pressuring hollow particleboard by using the screws as the hollow molding mold. The results are as follows:Using the screws as hollow molding mold, the suppressed hollow particleboard has significantly improved on the longitudinal MOR than the extrusion, and easy to out of the mold. The suppressed particleboard by using the thin rod shavings is the best on the mechanical properties. Within the scope of the board overall density 0.55g×cm-3, the mechanical properties increase with the increasing of the solid density and the hollow pitch.4. The study on the flat-pressuring hollow particleboard by embedding the PVC tubes as the hollow holesUsing the PVC tubes of 12 mm outer diameter and 2mm wall thickness as the hollow holes, the suppressed hollow particleboard has good Physical and mechanical properties. Under the same density, the board has the best mechanical properties when its thickness reaches 16 mm. While the proportion of core layer is 2/3, the cross section of the PVC tube holes has a minimum of deformation, and the hollow pitch has a significant impact on the mechanical properties of the board.