Over-Molding Parts

The plastic injection overmolding part is a process that can bond different
materials by the injection molding.

Over-molding in HanKing is a technology to combine two different moulds while
we called the combination of different resins in one mould as two-shot.
Knowledge of plastic resin compatibility is very crucial for over-molding,
HanKing's expertise assure the performance of the over-molding part is bonded
strong.

There are many factors in the selection of over-molding resins, it depends on
the properties of the basic resin and on the other hand on the application
properties. Specifically, there are the following:

1. Corrosion resistance.
2. Flame retardant (in line with ecological and environmental requirements).
The eco-friendly logo is a sign that the product meets environmental and social
standards.
3. Wear resistance (to avoid sink or stripping).
4. Shore hardness (in accordance with soft feeling or other requirements).
5. Impact resistance (in accordance with structural requirements).
6. Melting point (Meets application temperature requirements and does not
soften or deform).
7. Bonding method (mechanical interlocking is formed when the two materials do
not match, and chemical bonding is formed when the two materials match).

In general, the matching material should have similar chemical properties or
contain matching composite elements. When the basic resin does not match the
covering material, it usually only forms a mechanical interlocking effect, not
a chemical bonding.

Soft plastic resin can be molded with different materials, but it is more
limiter and stricter when hard plastic is over-molded with other hard resin.

It is acceptable to overmolded parts with two hard resins in small areas, but
it cannot be used in large areas and designed the second hard plastic over-
molded the first hard resin as a closed ring.

From design work as mould base selection, wall thickness, filling balance,
ejector balance, even venting to subsequent manufacturing process, HanKing will
consider all the details in order to make a custom mold & design that will
satisfy the customer.

Hanking Mould Engineering Ltd. is a professional chinese injection molding
companies (overmolding companies), we provide hanking mold, industrial molds,
insert moulding products and etc. Want to know more? Please contact us.

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