Clean room presses for molding of highly specialized compounds.
In developing such machines, Wickert understood that this needed to be a wasteless molding process. To achieve these results, they designed a sizeable vacuum chamber that uses extremely fast evacuation times. The vacuum chamber, encompassing the entire heating platen and core lifter brackets (when equipped for multiple plate molds) is capable of a draw down time of within a few seconds to approximately 18 to 25 of mbar pressure. All fittings for electrical and air evacuation that interface with the chamber are specially designed. Furthermore, the vacuum chamber and its peripheral components can handle the "off gassing" environment of these specialized compounds, plus the removal of atomized mold release residue.
For o-ring and precision molding applications, the presses achieve very tight tolerances regarding parallelism and mold carrier deflection. Their down acting hydraulics design uses high quality solid rolled steel. Each machine is tested for parallelism, carried out by qualified technicians.
An area of strength for the clean room press is the ease of access to the mold. This press design allows the lower heating platens to exit from the mold carrier to an operator-friendly location. Wickert machines do not require platforms or pits. For the upper heating platen, a tilting platen can provide access to the difficult-to-reach corners of the tool. The tilting platen also provides excellent visibility.
Desire for precise temperature control over the entire heating platen is paramount. To achieve tight control, specially designed, individually controlled multi-zone heaters are included in each platen. Using several thermocouples, Wickert can hold [+ or -] [degrees]C on even their largest applications.
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The presses are covered with a high grade stainless steel and employ a host of other innovative design features that comply with clean room molding requirements. Wickert is a 100+ year old, family-owned machine producer that specializes in vacuum compression technology.
Wickert is now represented in North America by Desma KDE Sales & Service, located in Hebron, KY. Wickert presses are well known in the North American market by pharmaceutical part producers who compression mold high volumes of medical grade elastomer stoppers and syringes.
By specializing in precision compression technology, Wickert has a tremendous background in demolding tables, ridged automation for vertical presses, and mold plate manipulation. Wickert offers unique designs for their hydraulic systems that provide excellent process control. Due to the size and stability of the presses (heating platens up to 3,000 mm x 3,000 mm and clamp tonnage up to 6,000 metric tons), Wickert is said to be an ideal supplier to elastomer molders of large products, including the recycled rubber industry.
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by Walter Frick, Desma KDE Sales & Service