Injection molding is a technology commonly used for high-volume manufacturing of parts made of synthetic resin, most commonly made of thermoplastic polymers. During a repetitive injection molding process, a plastic resin, most often in the form of small beads or pellets, is introduced to an injection molding machine that melts the resin beads under heat, pressure, and shear. The now molten resin is forcefully injected into a mold cavity having a particular cavity shape. The injected plastic is held under pressure in the mold cavity, cooled, and then removed as a solidified part having a shape that essentially duplicates the cavity shape of the mold.
A typical injection molding procedure comprises four basic operations: (1) heating the plastic in the injection molding machine to allow it to flow under pressure; (2) injecting the melted plastic into a mold cavity or cavities defined between two mold halves that have been closed; (3) allowing the plastic to cool and harden in the cavity or cavities while under pressure; and (4) opening the mold halves to cause the part to be ejected from the mold. In the conventional injection molding of synthetic resin by an injection molding machine, the weight of the injected synthetic resin varies with the molten resin pressure, the molten resin specific volume or the molten resin temperature etc. Therefore, it is difficult to form products of a constant quality.
In general, the setting of molding conditions of the injection molding machine requires a large number of trial molding operations and a long setting time because the setting work greatly depends on the know-how and experience of an operator of the injection molding machine, and various physical values affect one another as well.
Therefore, a virtual molding, i.e., computer-implemented simulation, by use of CAE (Computer-Assisted Engineering) is performed for the injection molding, and the molding conditions are then set based on the virtual molding. In virtual molding by use of CAE, phenomena will occur in a mold cavity within a short period of time, i.e., the result of simulation on resin temperature, pressure, shear rate, etc. can be reflected in molded products. Therefore, if the molding phenomena occurring within a mold cavity can be grasped accurately, using CAE may enable optimization of molding conditions and a stable molding of non-defective products.
This “Discussion of the Background” section is provided for background information only. The statements in this “Discussion of the Background” are not an admission that the subject matter disclosed in this “Discussion of the Background” section constitutes prior art to the present disclosure, and no part of this “Discussion of the Background” section may be used as an admission that any part of this application, including this “Discussion of the Background” section, constitutes prior art to the present disclosure.