Abstract: A method for producing a large-size light transmitting plate is provided. The method comprising (1) connecting a cylinder of an injection device with a cavity in a mold; the mold having a space with a non-uniform height and comprising a mold body and a cavity block, the cavity block having a fluid channel, the fluid channel being connected with a fluid switching means for changing a fluid medium and allowing a heating medium and a cooling medium, (2) passing the heating medium through the fluid channel; (3) supplying the resin to the cylinder; (4) filling the molten resin into the cavity; and (5) passing the cooling medium through the fluid channel after the filling of the cavity, to cool the cavity surface to a temperature lower than the glass transition temperature of the resin.

Abstract: The present invention provides a light transmitting plate formed by injecting melted transparent resin into a mold having a pattern on at least one surface of a cavity, wherein the light transmitting plate has a diagonal dimension from 14 inches to 30 inches, a pattern for reflection or diffusion of light on at least one surface, a birefringence value of 9×10?6 or less in the thickness direction, and the variation in the birefringence values is within ±3×10?6 from the average. The pattern of the present light transmitting plate is transferred from the pattern on the surface of the cavity at a transfer ratio of 90% or more, and the variation in the transfer ratios is within ±2% from the average. The light transmitting plate of the present invention has a reduced molding strain and hence a low birefringence value, and uniform distribution of the birefringence values and is obtained with low production cost because of the omission of printing process.

Abstract: The present invention provides a method for producing a light transmitting plate, comprising the steps of: using a molding equipment composed of an injection equipment and a mold for producing a light transmitting plate wherein a cavity of the mold communicates with a cylinder in the injection equipment; feeding a transparent resin into the cylinder; melting the transparent resin in the cylinder; and injecting the molten resin into the cavity of the mold from the cylinder; wherein a viscosity of the molten resin at the inlet of the mold is about 50 to about 5,000 Pa·sec and an injection rate is about 1 to about 15 cm3/sec, which method can be produce excellent light transmitting plate, specially large-size ones, further ones with a reflection layer pattern or a light diffusion pattern transferred, in transparency and dimensional stability.

Abstract: There is provided a process for producing a light transmitting plate comprising the steps of:

Abstract: The present invention provides a light transmitting plate formed by injecting melted transparent resin into a mold having a pattern on at least one surface of a cavity, wherein the light transmitting plate has a diagonal dimension from 14 inches to 30 inches, a pattern for reflection or diffusion of light on at least one surface, a birefringence value of 9×10−6 or less in the thickness direction, and the variation in the birefringence values is within ±3×10−6 from the average. The pattern of the present light transmitting plate is transferred from the pattern on the surface of the cavity at a transfer ratio of 90% or more, and the variation in the transfer ratios is within ±2% from the average. The light transmitting plate of the present invention has a reduced molding strain and hence a low birefringence value, and uniform distribution of the birefringence values and is obtained with low production cost because of the omission of printing process.

Abstract: The present invention provides a method for producing a light transmitting plate, comprising the steps of: using a molding equipment composed of an injection equipment and a mold for producing a light transmitting plate wherein a cavity of the mold communicates with a cylinder in the injection equipment; feeding a transparent resin into the cylinder; melting the transparent resin in the cylinder; and injecting the molten resin into the cavity of the mold from the cylinder; wherein a viscosity of the molten resin at the inlet of the mold is about 50 to about 5,000 Pa·sec and an injection rate is about 1 to about 15 cm3/sec, which method can be produce excellent light transmitting plate, specially large-size ones, further ones with a reflection layer pattern or a light diffusion pattern transferred, in transparency and dimensional stability.

Abstract: A resin molded article having a highly expanded undercut shape and a uniform wall thickness distribution is produced with good productivity by forming a parison as an intermediate molded article by injection molding a thermoplastic resin, expanding said parison in open molds prior to blow molding of the parison in the final shape, then closing the molds, and blow molding said parison in the closed molds to form the final shape of the article.