A METHOD FOR PRODUCING A COMPOSITE PLASTIC SHEET, THE COMPOSITE PLASTIC SHEET AND THE SEAT BACK OF A CHAIR MADE OF THE COMPOSITE PLASTIC SHEET

摘要

A method for producing a composite plastic sheet comprises: (1) producing an upper shell with a desired shape by vacuum processing a plastic sheet directly according to the design, a connection wall extends downwardly from the edge of this upper shell in a direction substantially vertical to the surface of the shell; (2) producing a lower shell with a desired shape by injecting a plastic sheet directly according to the design, a connection wall extends upwardly from the edge of this lower shell in a direction substantially vertical to the surface of the shell. The lower surface of the shell is smooth, while the upper surface of the shell has many reinforcing ribs integrally manufactured, and the top surface, which is composed of these ribs, is coincided with the lower surface of the upper shell; and (3) connecting the lower face of the upper shell and the top surface of the lower shell by a binder or ultrasonic welding; at the same time, connecting the connection walls of the upper shell and the lower shell by a binder, ultrasonic welding, a buckle, or a screw thread. The composite plastic sheet includes an upper shell with a desired shape made by vacuum processing a plastic sheet directly according to the design, a connection wall extends downwardly from the edge of this upper shell in a direction substantially vertical to the surface of the shell; and a lower shell with a desired shape made by injecting a plastic sheet directly according to the design, a connection wall extends upwardly from the edge of this lower shell in a direction substantially vertical to the surface of the shell. And the lower surface of the shell is smooth, while the upper surface of the shell has many reinforcing ribs integrally manufactured. The top surface, which is composed of these ribs, is coincided with the lower surface of the upper shell. And the connection walls of the upper shell and the lower shell are jointed together to make a closed composite sheet. The top surface is under the lower surface of the upper shell, and within the composite sheet. The seat back of a chair includes the above composite plastic sheet.