The Monosandwich process is a simple variation of multi-component technology. Since it can significantly reduce manufacturing costs its popularity is growing. It is also an excellent value-added retrofit for machines already in service.
The characteristics of parts made with the monosandwich process are the result of combining different core and skin materials. The result is an economical way to manufacture functionally complex parts. The monosandwich process also offers manufacturers the cost-saving option of using recycled materials for the core and virgin material for the skin. The result: lower material costs for part with perfect, unblemished surfaces. Core material with a soft skin material can be given an easy-to-grip ‘soft touch’ surface.
Other material combinations can have vibration- or sound-absorbing properties (foam process). In the manufacture of electronic components, for example, there is growing trend towards producing parts which have an antistatic high grade polymer skin and a conventional, non-conductive core. This process has benefits for the auto part industry, consumer goods and electronics. Go to applications technology to learn how we can help.
The Process
The conventional sandwich process is straightforward. First the mold is partly filled with the surface material which will forms a skin on the wall of the mold. Then the core material is introduced displacing the remaining surface material and forming the core. The standard sandwich process requires a fairly complex design. Two complete injection units must be installed each with separate valves for skin and core material. The process is demanding and surface faults will often result if it is not properly implemented.
Our patented monosandwich procedure simplifies the process considerably. Firstly the injection unit prepares the core material. Once that is complete the secondary extruder is engaged to the injection unit and the skin material is extruded into the injection unit. The melt components are then situated one behind the other in the machine’s injection unit and are injected into the mold cavity just like a normal injection procedure. This allows the core material to continue flowing through the middle of the flow channel while the skin component is deposited evenly on the outer wall of the cavity. Another variety of the monosandwich process involves "core back" technology and uses a switching valve in the sprue. The end result is a classic 2K injection-molded part.
Solutions You Can Rely On
The monosandwich process can be adapted on all Ferromatik machines, and thus used for the production of a wide range of parts. The large MAXIMA machine series makes the monosandwich process possible for large parts such as are needed in the auto parts industry. The monosandwich process is also available for the fully electric ELEKTRA machine series. Ferromatik is the only European company to offer this for fully electric systems. The MAXIMA topline and the K-TEC models are ideal for demanding applications requiring high-performance machines.
