Apr 1, 2019
In injection molding, two different materials (also known as components) are frequently used to produce one part.
The materials can be completely different (hard and soft polymers) or have the same base but with different color.
In the 2 Shot Molding process, the first component is injected into the cavity and cooled down up to a certain point.
Afterwards, the first component is transported, for example, by a rotating dish tool or a robot, to a new cavity to inject the second component on top of it.
It is important to consider the different processing temperatures.
The remelting of the first component is not wanted.
At the same time, both components should stick together.
Injection Molding Process: In the 2 shot molding, the second component (white) is injected on top of the first component (black).
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This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Jan 5, 2019
A powder injection molding (PIM) process in which fine-powdered ceramic is mixed with a thermoplastic binder material to a moldable compound is called ceramic injection molding (CIM). This fine-powdered ceramic builds the so called feedstock. This feedstock can be processed with plastic injection molding. The plastic injection molding process allows competitive manufacturing of mid to high volumes and complexity in repeatable quality.
The molded part is debindered in a second process step. The thermoplastic binder material is removed from the compound.
In a third process step, the debindered part is sintered.
Densities of 99,95 % and higher can be obtained against compact material. Material and mechanical properties of final parts are comparable to the corresponding compact materials.
CIM is very cost competitive against standard multi stage cutting technologies like milling, drilling and grinding.
Best practice examples for CIM-processes: Ceramic grinders, textile industry, medical applications and many others.
Apr 18, 2024
Special requirements apply to sterile packaging in the medicine or food sector.
To ensure certain degrees of product purity, production must take place in a room under controlled conditions. It is particularly important to remove particles from the air by means of filters. This type of enclosed space with controlled environmental conditions is called a clean room. Clean rooms are divided into different air purity classes according to DIN EN ISO 14644-1.
The cleanliness of the classes is defined by the maximum particle count of different particle sizes.
Four classes (A, B, C and D) are distinguished.
Class A is for high-risk activities, such as the production of aseptic compounds.
Class B describes the environment required to ensure class A.
Classes C and D are defined as work areas for the less critical processes.
Injection molding process: Air purity classes (DIN EN ISO 14644-1)
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This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Apr 18, 2024
In order to meet the requirements of cleanroom technology in injection molding, there are various ways of including the machine.
The technically simplest variant is called “machine-in-room”.
In this case, the injection molding machine is placed completely in the clean room. The additional waste heat from the machine is unfavorable here, since the heat load must be dissipated by the air conditioning in the clean room.
In addition, the machine represents a source of particles.
To avoid this, in the “Machine in room II” concept only the closing area of the machine is integrated into the clean room.
In the so-called “outside-drop” variant, the machine is located completely outside the cleanroom.
To nevertheless ensure cleanroom-compatible production, the mold area is equipped with special filter fan units (FFU), also known as laminar flow modules (LFM). This ensures that the mold area is flown through with hall air filtered to cleanroom level.
In the “Room-in-Room” machine setup, the machine is located in the clean room. The mold area is also equipped with an FFU. The costs of machine maintenance and mold changes must be taken into account. These vary depending on the concept selected.
Injection molding process: Machine
setup variants – Clean areas are highlighted in green.
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This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Feb 1, 2019
In the injection molding process the main source of heat inside the mold is coming from the molten plastic.
The coolant flowing through the cooling channels absorbs the heat, which leads to a rise in temperature inside of the coolant.
One indicator of the cooling efficiency is the coolant temperature in between the inlet and the outlet.
For technical parts the temperature difference should be less than 3 °C in order to ensure good part quality.
The coolant temperature help to evaluate the cooling design. It also help to estimate the number of bridges between cooling channels.
Higher flow rates, larger diameters and/or shorter cooling channels help to reduce the coolant temperature.