Synthetic wood meal, method and apparatus for manufacturing the same; synthetic wood board including the synthetic wood meal, method and apparatus of extrusion molding therefor

A method of manufacturing for a synthetic wood meal comprising the steps of:

• drying a cellulose crushed material, having a mean particle diameter of 20 mesh or less, to a moisture content of 0.1 to 0.3 wt % by frictional heat generated from a rotation of stirring and impact-applying blades, mixing said crushed material;
• stirring and mixing a thermoplastic resin material of 25 to 80 wt % into the dried cellulose crushed material by rotating said blades creating a mixture;
• kneading the mixture with the rotation and impact of said blades generating frictional heat causing said dried cellulose crushed material to be surrounded by the resin forming a gelatinous mixture;
• and
• cooling, pulverizing and regulating the kneaded mixture so that the mixture particles have a diameter of 10 mm or less.

An apparatus for manufacturing a synthetic wood meal comprising:

• flow-mixing and kneading means having stirring and impact-applying blades for stirring and mixing a thermoplastic resin material of 25 to 80 wt % with a cellulose crushed material having a mean particle diameter of 20 mesh or less of 20 to 75 wt % that lies in a moisture content of within 15 wt % and for drying said cellulose crushed material to a moisture content of 0.1 to 0.3 wt % by frictional heat generated from a rotation of said blades, and for kneading said mixed material by the rotation of said blades generating frictional heat and causing the dried cellulose crushed material to be surrounded by the resin forming a gelatinous mixture;
• cooling granulation means having a stirring and crushing blade therein and a cooling jacket for granulating said kneaded mixture by cooling;
• and
• size regulation means for regulating said cooled and granulated mixture to a granule diameter of 10 mm or less.

A synthetic wood board in which thermoplastic resin material of 25 to 80 wt % is stirred and mixed by rotating stirring and impact-applying blades with a cellulose crushed material having a mean particle diameter of 20 mesh or less of 20 to 75 wt %, said crushed material being dried to a moisture content of 0.1 to 0.3 wt % by frictional heat generated by the rotation of said blades, creating a mixture;

• said rotation of blades kneading said mixture generating frictional heat and causing the cellulose crushed material to be surrounded by the resin forming a gelatinous mixture;
• said kneaded mixture being cooled, pulverized and regulated to a particle diameter of 10 mm or less, creating a size regulated synthetic wood material;
• and
• said size regulated synthetic wood material being heated, kneaded and squeezed by a screw or screws into a molding die;
• wherein said material is cooled slowly, while applying a control force against the squeezing force of said material so as to increase the density of said material.

A method of extrusion molding for a synthetic wood board comprising the steps of:

• drying a cellulose crushed material, having a mean particle diameter of 20 mesh or less of 20 to 75 wt %, to a moisture content of 0.1 to 0.3 wt % by frictional heat generated from a rotation of stirring and impact-applying blades;
• stirring and mixing a thermoplastic resin material of 25 to 80% wt into said dried cellulose crushed material by rotating said blades, creating a mixture;
• kneading said mixed material by rotation of said blades generating frictional heat and causing the cellulose crushed material to be surrounded by the resin forming a gelatinous mixture;
• cooling, pulverizing and regulating said kneaded material to have a particle diameter of 10 mm or less, creating a size regulated synthetic wood meal;
• heating, kneading and squeezing said size regulated synthetic wood meal by a screw or screws into a molding die through which it is extruded;
• and
• cooling slowly said squeezed material, while applying a control force against a force squeezing said material so as to increase the density of said extruded material.

An apparatus of extrusion molding for a synthetic wood board comprising:

• flow-mixing and kneading means provided with stirring and impact-applying blades for stirring and mixing a thermoplastic resin material of 25 to 80 wt % with a cellulose crushed material having a mean particle diameter of 20 mesh or less of 20 to 75 wt % that lies in the moisture content of within 15 wt % and for
• drying said cellulose crushed material to a moisture content of 0.1 to 0.3 wt % by frictional heat generated from a rotation of said blades, and for
• kneading said mixed material by rotation of said blades generating frictional heat and causing said crushed cellulose material to be surrounded by the resin forming a gelatinous mixture;
• cooling granulation means provided with a stirring and crushing blade therein and an inlet and an outlet of cooling water in a jacket for granulating said gelled kneaded material by cooling;
• and
• size regulation means for regulating said cooled and granulated wood meal to a size that lies in the granule diameter of 10 mm or less so as to obtain synthetic wood meal;
• wherein an extruding die of an extruder for kneading said synthetic wood meal by heating and squeezing said synthetic wood meal by a screw or screws is connected with a molding die including a lead-in portion for heating said kneaded and squeezed material discharged from said extruding die and a molding portion provided with a molding chamber for molding said extruding material squeezed from said lead-in portion with a predetermined thickness;
• wherein said molding die includes an inner wall layer on the inner wall surface of said molding portion, being formed out of resin having an excellent heat resisting property and low frictional resistance and a cooling means for cooling said molding chamber;
• and
• braking means for applying control force against the squeezing force of the molded article extruded from said molding die.