In case, you do not see blue navigation panel at left, please click here and then locate this page on the blue navigation panel at left.
Any manufacturing activity would like to have optimised productivity and quality. In injection moulding of plastics, if quality is taken care of by part design, mould design and mould precision, then productivity is also ensured on account of zero defect moulding with out rejection and optimised cycle time.
Cycle-time optimisation starts at design stage. Cooling time takes up over 50% of cycle time. Therefore understanding of cooling in the mould becomes very important.
Cooling Channel Design for Mould- Design tips
Moulds are usually built with cooling channels. These channels are usually connected in series with one inlet and one outlet for water flow. The water flow rate may not be enough for turbulent flow because the water pump capacity itself may not be adequate. This obviously leads to random temperature variation on the mould surface. With the result, uncontrolled temperature drift, varying part dimensions and irregular warped surface appears on mouldings.
The mould designer should take care of following points:
The mould has to be heated or cooled depending on the temperature outside mould surface and that of environment. If heat loss through the mould faces is more than the heat to be removed from moulding, then mould has to be heated to compensate the excess loss of heat. This heating is only a protection for shielding the cooling area against the outside influence. The heat exchange takes place during cooling time. The design of cooling system has to depend on that section of part, which requires longest cooling time to reach demoulding temperature.
Cooling Channel layout depends on :
The sizing of cooling channels is dependent on the rate of cooling and temperature control needed for controlling part quality. CAE software like MOLDFLOW or C-Mold can be used to determine the optimised dimension of cooling channel and distance from mould surface, distance between cooling channel, flow rate.
|HOME||Contact-to buy this book||Things to know- Process||Things to know- Polymers||Things to know- Part Design||Things to know- Mould|
|Things to know- Machine||Injection Moulding Process||Screw Plasticating||Moulding||Key factors influencing proces||Shear strain curve|
||Thermal stability||Balancing melt Flow||Balancing Heat||Freezing||Quality Problems|
||Moulded-in Stress||Shrinkage||Inconsistent Dimension||Sink-mark||Weld-lines|
||CYCLE TIME||Plastics Part Design||Flow Analysis||..||..|
|Engineering Basics in Machine||Glossary of technical terms- Physics||Glossary of technical terms- Polymer process||Myth||Understanding Mould Cooling Channels||Ideal Moulding Shop|