Plastics Technology Practice - The Hong Kong Polytechnic University

Plastics Technology Practice
3.1.4 Mould Design
The mould is an important element in the moulding machine, apart from
determine the shape of the product, the mould vents the entrapped gas, cools
the product and ejects the product. The quality of the product and the
manufacturing cost are largely determined by the mould.
The mould is comprised of mould base, core and cavity that determine the
feature of the product, sprue, runner and gate that deliver the melt to the cavity,
cooling system and ejection system.
• Mould Base: As a matter of fact, nearly all moulds consist of the same
basic components. There are some standard mould bases in the market
that provide cheaper and more reliable than custom design mould base.
The followings are some standard mould bases.
In very broad sense, moulds can be classified as cold runner and hot runner
moulds. Two-plate mould and three-plate mould are most common in cold
runner moulds.
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