Molding methods and molds for making a synthetic resin molded product include disposing a curable liquid resin mixture in a recess of a female mold. The curable liquid resin mixture is then simultaneously agitated and degassed by a mixer while under a partial vacuum. More specifically, at least the female mold is orbited around an orbital axis while being rotated about a rotational axis that is eccentric to the orbital axis. After being thoroughly mixed and degassed, the liquid mixture is then cured in the mold unit.

A transparent resin molded product and a mold for molding the product are provided in which occurrence of silver streak in the resin molded product is prevented. The resin molded product includes a design portion and a non-design portion, at least a part of the design portion is molded by transparent resin, and a gate trace (a gate arrangement position during the resin molding) is disposed in the non-design portion (runner portion). A foreign matter restraining portion for restraining foreign matters and bubbles contained in the transparent resin is disposed in the vicinity of the gate trace of the non-design portion. The foreign matters and bubbles are restrained by the foreign matter restraining portion and are prevented from flowing to the design portion, and therefore the occurrence of silver streak on the design portion can be prevented.

A transparent resin molded product and a mold for molding the product are provided in which occurrence of silver streak in the resin molded product is prevented. The resin molded product includes a design portion and a non-design portion, at least a part of the design portion is molded by transparent resin, and a gate trace (a gate arrangement position during the resin molding) is disposed in the non-design portion (runner portion). A foreign matter restraining portion for restraining foreign matters and bubbles contained in the transparent resin is disposed in the vicinity of the gate trace of the non-design portion. The foreign matters and bubbles are restrained by the foreign matter restraining portion and are prevented from flowing to the design portion, and therefore the occurrence of silver streak on the design portion can be prevented.

Apparatus for degassing a plasticizable material, wherein the apparatus has at least one passage having a inlet opening for the feed of the material in the plasticized state. Provided downstream of the at least one passage in the flow direction of the plasticized material is a plurality of substantially parallelly arranged partial passages so that a material flow flowing through the passage is split up into partial flows by the partial passages, and the partial passages open into a free space so that the material expands in the free space, wherein at least one of the partial passages has a taper.

Apparatus for degassing a plasticizable material, wherein the apparatus has at least one passage having a inlet opening for the feed of the material in the plasticized state. Provided downstream of the at least one passage in the flow direction of the plasticized material is a plurality of substantially parallelly arranged partial passages so that a material flow flowing through the passage is split up into partial flows by the partial passages, and the partial passages open into a free space so that the material expands in the free space, wherein at least one of the partial passages has a taper.

A method for producing a foamed molded product includes: using a molding apparatus including a plasticizing cylinder having a high pressure kneading zone and a pressure reduction zone; and a screw; controlling a pressure of the pressure reduction zone to be a first pressure in a state that communication between the high pressure kneading zone and the pressure reduction zone is shut off, the first pressure being not less than an atmospheric pressure and not more than a maximum pressure of the high pressure kneading zone which is reached in a case that a molten resin is brought in contact and kneaded with a physical foaming agent; controlling back pressure of the screw to be a second pressure which is not less than the first pressure; and measuring a predetermined amount of the molten resin from which the gasified physical foaming agent has been separated.

A method for producing a foamed molded product includes: using a molding apparatus including a plasticizing cylinder having a high pressure kneading zone and a pressure reduction zone; and a screw; controlling a pressure of the pressure reduction zone to be a first pressure in a state that communication between the high pressure kneading zone and the pressure reduction zone is shut off, the first pressure being not less than an atmospheric pressure and not more than a maximum pressure of the high pressure kneading zone which is reached in a case that a molten resin is brought in contact and kneaded with a physical foaming agent; controlling back pressure of the screw to be a second pressure which is not less than the first pressure; and measuring a predetermined amount of the molten resin from which the gasified physical foaming agent has been separated.

An injection molding system and method of operating the system are disclosed. The system may include a hopper, a barrel configured to receive injection material from the hopper, a screw disposed within the barrel, and a mold defining a mold cavity configured to receive the injection material from the barrel. A pressure-balancing conduit may connect the mold cavity and a rear end of the barrel and be configured to allow air to flow from the mold cavity to the rear end of the barrel. A mold valve may be disposed between the pressure-balancing conduit and the mold cavity and a barrel valve may be disposed between the pressure-balancing conduit and the rear end of the barrel. The method may include opening the mold valve and injecting a material into the mold cavity from the barrel.

An injection molding system and method of operating the system are disclosed. The system may include a hopper, a barrel configured to receive injection material from the hopper, a screw disposed within the barrel, and a mold defining a mold cavity configured to receive the injection material from the barrel. A pressure-balancing conduit may connect the mold cavity and a rear end of the barrel and be configured to allow air to flow from the mold cavity to the rear end of the barrel. A mold valve may be disposed between the pressure-balancing conduit and the mold cavity and a barrel valve may be disposed between the pressure-balancing conduit and the rear end of the barrel. The method may include opening the mold valve and injecting a material into the mold cavity from the barrel.

A plasticizing unit for a molding machine includes a plasticizing screw arranged in a barrel so as to be rotatably driveable, and the screw is configured to plasticize a material. A feeding device is arranged on a lateral surface of the barrel, and the feeding device is configured to feed the material to be plasticized into the barrel. A dividing device divides the feeding device into two sub-regions. A first sub-region is configured to feed the material to be plasticized into the barrel, and a second sub-region is fluidically connected to a degassing device and/or an opening along the longitudinal axis of the barrel at one end of the barrel, through which opening the plasticizing screw is inserted into the barrel, is fluidically connected to the degassing device. The degassing device is configured to discharge gases generated during the plasticization of the material to be plasticized from the barrel.