Sandwich injection molding is one
of the newly developed injection molding methods. To accomplish such a molding
method, an additional barrel is added to a traditional plastic injection molding
machine to form an independent double barrel with specially designed nozzle.
During the injection process, this double barrel can concurrently inject two
types of molten plastic, via the same nozzle, into the mold to achieve double
material simultaneous injection. The outer layer of the mixed molten plastic is
called the skin material, while the inner layer is called the core material.
Sandwich molding has the following advantages over traditional injection
molding:
For products with different outer and inner-layer material, traditional two-step
insert molding becomes one-step.
The different color combinations give old products (molds) new life.
Low viscous materials can be used as core materials to reduce injection
pressure.
Recycled and low-quality materials can be used as core materials to increase
product utility.
High-quality materials with anti-magnetic interference properties and high
surface quality can be used as skin materials to increase product utility.
Appropriate core and skin material combinations can reduce the residual stress
and increase product hardness.
Sandwich injection molding machine are able to produced single color which
provides a multifunction and flexible molding method. This increases the
processor's capability to produce high-quality and low-cost products.
Under the pressures of a highly competitive market, how to produce high
value-added products while keeping the costs down has become a critical issue
for plastic processors. After years of hard work and research, FCS has
successfully pioneered the making of the sandwich injection molding machine to
assist processors in upgrading and switching their machinery.
Our sandwich injection molding machine packs several powerful features:
There are two sets of proportional control valves which can simultaneously
control the pressure and speed of both sets.
With an accuracy reaching 0.01mm, linear potentiometers are used in the two
injection sets and clamping molds to accurately control the injection process
and the opening and closing of mold.
With features such as limitations for screw cold starts, broken wire detection,
etc., a PID temperature controller is used to control the temperature at 1C.
The microprocessor control system not only has memory functions, it can also
perform 4-stage injection, 3-stage hold pressure, and 3-stage back pressure.
