Injection molding machine is divided into 2 units i.e. a clamping unit and an injection unit. The functions of the clamping unit are opening and closing a die, and the ejection of products. There are 2 types of clamping methods, namely the toggle type shown in the figure below and the straight-hydraulic type in which a mold is directly opened and closed with a hydraulic cylinder.

A molding consists of a sprue to introduce molten resin, a runner to lead it to cavities, and products. Since obtaining only one product by one shot is very inefficient, a mold is usually designed to have multiple cavities connected with a runner so that many products can be made by one shot.

Maspi reuses in each of its products, thanks to Restylon co-injection technology, certified post-industrial recycled material that allows to drastically cut CO2 emissions by one-third and to avoid having to dispose of waste from the production area, which is instead stored and reinserted when needed.

The screw is rotated to melt plastic introduced from the hopper and to accumulate molten plastic in front of the screw ( to be called metering ) . After the required amount of molten plastic is accumulated, injection process is stared.

Maspi aspires to be among the best plastic molding companies in the use of recycled plastic materials. Reuse of discarded waste elements is an unavoidable driver for the company, this in fact generates value not only from an economic point of view but also in terms of sustainability.  Maspi reuses in each of its products, thanks to Restylon co-injection technology, certified post-industrial recycled material that allows to drastically cut CO2 emissions by one-third and to avoid having to dispose of waste from the production area, which is instead stored and reinserted when needed.  Each recycled material in order to be properly reused must be carefully separated and identified exactly so that it can later be properly reprocessed.

Molten plastic flows into a mold through a sprue and fills cavities by way of runners and gates. Then, the mold is opened after cooling process and the ejector rod of the injection molding machine pushes the ejector plate of the mold to further eject moldings.

Injection molding is a method to obtain molded products by injecting plastic materials molten by heat into a mold, and then cooling and solidifying them.

Sprues and runners among moldings are not products. These portions are sometimes discarded, but in other cases they are finely reground and reused as materials for molding. These materials are called reprocessed materials.

While molten plastic is flowing in a mold, the machine controls the moving speed of the screw, or injection speed. On the other hand, it controls dwell pressure after molten plastic fills out cavities.

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For the properties when reprocessed materials are used, please refer to "reprocessing capability" in the plastic data base.

Post-industrialrecycled materials are the residual and discarded materials from the first production of a plastic items in companies. They are the most widely used materials in the plastic recycled sector because of their greater availability and facility of certification. At Maspi, each plastic material is carefully certified to be reused in a second production. This type of recyclate is the most used by Maspi for the Restylon Co-injection production.

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Post-consumer recycled plastics are items used and consumed by humans such as, plastic bottles, tetrapak, or food tubs. Even these can be reused for the production of new items as long as one is able to properly separate the different types of plastic. In the furniture industry, this type of recyclate has not yet been used frequently, so Maspi is engaging in the study and analysis of a new polymer from tetrapak recycling in order to create new more sustainable designs.

Post-industrialrecycled materials are the residual and discarded materials from the first production of a plastic items in companies. They are the most widely used materials in the plastic recycled sector because of their greater availability and facility of certification. At Maspi, each plastic material is carefully certified to be reused in a second production. This type of recyclate is the most used by Maspi for the Restylon Co-injection production.

A mold is a hollow metal block into which molten plastic is injected to from a certain fixed shape. Although they are not illustrated in the figure shown below, actually there are many holes drilled in the block for temperature control by means of hot water, oil or heaters.

If the length of the runner to each cavity is different in this case, the cavities may not be filled simultaneously, so that dimensions, appearances or properties of the moldings are often different cavity by cavity. Therefore the runner is usually designed so as to have the same length from the sprue to each cavity.

Molding condition means cylinder temperature, injection speed, mold temperature etc. set in a molding machine to obtain required moldings, and the number of combinations of conditions is innumerable. Depending on the conditions selected, the appearances, dimensions, and mechanical properties of the molded products change considerably.

Each recycled material in order to be properly reused must be carefully separated and identified exactly so that it can later be properly reprocessed.

The standard molding conditions for our materials are shown below. Please click the mouse at the following names of plastics.

Post-consumer recycled plastics are items used and consumed by humans such as, plastic bottles, tetrapak, or food tubs. Even these can be reused for the production of new items as long as one is able to properly separate the different types of plastic. In the furniture industry, this type of recyclate has not yet been used frequently, so Maspi is engaging in the study and analysis of a new polymer from tetrapak recycling in order to create new more sustainable designs.

Maspi aspires to be among the best plastic molding companies in the use of recycled plastic materials. Reuse of discarded waste elements is an unavoidable driver for the company, this in fact generates value not only from an economic point of view but also in terms of sustainability.

Reprocessed materials are not solely used as materials for molding but usually used after blending with virgin pellets, since there is possibility of deterioration in various characteristics of the plastics because of the initial molding process. The maximum allowable limit for the ratio of reprocessed materials is about 30 %, because too high ratio of reprocessed materials may spoil the original properties of the plastics used.

The method is suitable for the mass production of products with complicated shapes, and takes a large part in the area of plastic processing.

The position of change from speed control to pressure control is set at the point where either screw position or injection pressure reaches a certain fixed value.