Provided is an injection molding machine (1) including a plasticizing unit (2), an injection unit (3), a communication path (5a) configured to communicate therebetween and having an opening (5b) on the plasticizing unit side which is located on an axis of the screw (21), and a backflow prevention mechanism part (6) configured to close and open the opening on the plasticizing unit side by advancing and retreating the screw (21) in the axial direction, wherein the backflow prevention mechanism part (6) includes a tapered wedge portion (61) having an inclined surface (61a), a driving portion (63) which moves the wedge portion in the forward and backward directions, and a pressing member which is pressed against the inclined surface (61a) by forward movement of the wedge portion and moves the screw toward the opening on the plasticizing unit side.

A thermosetting composition comprising: (A) a (meth)acrylate compound having a viscosity at 25 C. of 1 to 300 mPa.Math.s with which a substituted or unsubstituted aliphatic hydrocarbon group including 6 or more carbon atoms is ester-bonded; (B) spherical silica; and (C) a white pigment, and having a shear viscosity at 25 C. and 10 s.sup.1 of 1 Pa.Math.s or more and 500 Pa.Math.s or less and a shear velocity at 25 C. and 100 s.sup.1 of 0.3 Pa.Math.s or more and 100 Pa.Math.s or less:

A thermosetting composition comprising: (A) a (meth)acrylate compound having a viscosity at 25 C. of 1 to 300 mPa.Math.s with which a substituted or unsubstituted aliphatic hydrocarbon group including 6 or more carbon atoms is ester-bonded; (B) spherical silica; and (C) a white pigment, and having a shear viscosity at 25 C. and 10 s.sup.1 of 1 Pa.Math.s or more and 500 Pa.Math.s or less and a shear velocity at 25 C. and 100 s.sup.1 of 0.3 Pa.Math.s or more and 100 Pa.Math.s or less:

A process for drying polymeric granular material (2) comprises the steps of: introducing into said drying hopper (10) a process gas having a predefined flow rate so as to heat and dry the polymeric granular material, discharging a portion of the heated polymeric granular material into a transformation unit (100) for the polymeric material; loading an amount of fresh polymeric granular material (2a) into the drying hopper. The process gas flow rate is regulated by measuring the inlet temperature of the fresh polymeric granular material (2a) and comparing it with a predefined inlet temperature of the fresh polymeric granular material, on the basis of which the predefined process gas flow rate has been calculated. If the measured inlet temperature is different from the predefined inlet temperature, the flow rate of the process gas is regulated on the basis of the measured inlet temperature.

A thermosetting composition comprising: (A) a (meth)acrylate compound having a viscosity at 25 C. of 1 to 300 mPa.Math.s with which a substituted or unsubstituted aliphatic hydrocarbon group including 6 or more carbon atoms is ester-bonded; (B) spherical silica; and (C) a white pigment, and having a shear viscosity at 25 C. and 10 s.sup.1 of 1 Pa.Math.s or more and 500 Pa.Math.s or less and a shear velocity at 25 C. and 100 s.sup.1 of 0.3 Pa.Math.s or more and 100 Pa.Math.s or less.

A thermosetting composition comprising: (A) a (meth)acrylate compound having a viscosity at 25 C. of 1 to 300 mPa.Math.s with which a substituted or unsubstituted aliphatic hydrocarbon group including 6 or more carbon atoms is ester-bonded; (B) spherical silica; and (C) a white pigment, and having a shear viscosity at 25 C. and 10 s.sup.1 of 1 Pa.Math.s or more and 500 Pa.Math.s or less and a shear velocity at 25 C. and 100 s.sup.1 of 0.3 Pa.Math.s or more and 100 Pa.Math.s or less.

The present invention discloses a biaxial or tri-axial eccentric rotor volume pulsed deformation plasticizing method and device. The method is characterized in that: the conveying volume of materials formed between two or three engaged eccentric rotors, which are formed by spiral structures and eccentric cylindrical structures connected alternately, and an inner surface of a stator changes periodically along the axial direction and the radial direction of the rotors, achieving the volume pulsed deformation plasticizing and conveying of the materials during engaged rotation of the two or three engaged eccentric rotors. The device's eccentric rotors are all formed by length-varying spiral structures and eccentric cylindrical structures connected alternately; the spiral structures of the eccentric rotors are engaged to each other; the axial positions of eccentric cylindrical structures of the two or three rotors are the same. The present invention can implement extrusion of polymer materials or implement, in combination with a plunger injection unit, injection molding of polymer materials, and have many features such as desirable mixing and plasticizing effects for materials, a short thermo-mechanical course, low power consumption, and wide adaptability.

The present invention discloses a biaxial or tri-axial eccentric rotor volume pulsed deformation plasticizing method and device. The method is characterized in that: the conveying volume of materials formed between two or three engaged eccentric rotors, which are formed by spiral structures and eccentric cylindrical structures connected alternately, and an inner surface of a stator changes periodically along the axial direction and the radial direction of the rotors, achieving the volume pulsed deformation plasticizing and conveying of the materials during engaged rotation of the two or three engaged eccentric rotors. The device's eccentric rotors are all formed by length-varying spiral structures and eccentric cylindrical structures connected alternately; the spiral structures of the eccentric rotors are engaged to each other; the axial positions of eccentric cylindrical structures of the two or three rotors are the same. The present invention can implement extrusion of polymer materials or implement, in combination with a plunger injection unit, injection molding of polymer materials, and have many features such as desirable mixing and plasticizing effects for materials, a short thermo-mechanical course, low power consumption, and wide adaptability.

An injection apparatus including a plasticizing unit (2) that plasticizes a raw material resin and an injection unit (3) that injects a plasticized molten resin. The plasticizing unit includes a heating cylinder (20) having a foaming gas injection valve and a screw (21) provided inside the heating cylinder. The rotation and advance and retreat movements of the screw are controlled such that a raw material resin is plasticized by the screw and a foaming gas injected from a foaming gas injection valve is dissolved in the plasticized molten resin. After the screw retreats to a prescribed position according as the molten resin accumulates in the front end side of the heating cylinder by the screw that is rotating, the screw advances with rotating to cause the molten resin which has been accumulated in the front end side of the heating cylinder to be transferred to the injection unit.

An injection apparatus including a plasticizing unit (2) that plasticizes a raw material resin and an injection unit (3) that injects a plasticized molten resin. The plasticizing unit includes a heating cylinder (20) having a foaming gas injection valve and a screw (21) provided inside the heating cylinder. The rotation and advance and retreat movements of the screw are controlled such that a raw material resin is plasticized by the screw and a foaming gas injected from a foaming gas injection valve is dissolved in the plasticized molten resin. After the screw retreats to a prescribed position according as the molten resin accumulates in the front end side of the heating cylinder by the screw that is rotating, the screw advances with rotating to cause the molten resin which has been accumulated in the front end side of the heating cylinder to be transferred to the injection unit.