gwk cyclic mould heat and cooling vario cs and vario wh
Cyclic temperature control systems are advancing
gwk “weld-line competence centre” presents overview of actual processes
Technological focus of the gwk exhibition stand at the Fakuma 2014 is the “weld-line competence centre”. Here gwk presents by means of demonstrators, graphics and sample parts an overview of actual processes by means of which moulded parts with excellent surfaces without visible weld-lines, flow lines and sink marks can be produced.
In addition a panel for a white goods product is produced in a MuCell application on an all-electric KraussMaffei injection moulding machine. In order to achieve the requested high surface quality in structural foam moulding, the cyclic and close-to-cavity mould temperature control is realized by gwk integrat 4D mould inserts in a mould by Krallmann and a gwk integrat vario wh temperature control system with water up to 200°C.
Furthermore an integrat vario cs is presented in a live demonstration at the Arburg exhibition stand. By means of particle foam composite injection moulding the machine manufacturer produces a composite part out of a particle foam and a thermoplast component. The cyclic cavity temperature control with water up to 160°C that is adapted to a mould by Krallmann ensures an efficient production process.
Dynamic mould temperature control is a temperature control method that allows temperature variations within the cycle and is also known as “variotherm temperature control”. While this method has been known for almost forty years, it has only undergone a dynamic development in the last few years. This is due to the increasingly exacting quality requirements of consumers (e.g. prevention of visible joint-lines, gloss variations and other surface defects) and the use of plastic materials in new applications. When a temperature control system is selected it is important to mind that it matches exactly with the application and that the economic benefit justifies the technical efforts as well as the energy consumption.
For all applications gwk has got the right temperature control system that can reach fast heating and cooling rates with low energy consumption. Systems of the integrat vario cs series are working with water up to 160°C whereas the integrat vario wh realizes water temperatures up to 200°C. The systems are built in modular design and principally consist of three modules.
The heating process of the mould wall to a high temperature level is affected through a pressurized hot water temperature control with maximum outlet temperatures of 160°C up to 200°C. The hot circulating medium is pumped through the close-to-cavity temperature control channels, until a sensor indicates the reaching of the desired temperature of the cavity walls and releases the injection process.
The cooling of the mould wall happens through a temperature controller with highly efficient plate heat exchanger and very low supply temperature. Hereby an intensive and short cooling phase is ensured. The start of the cooling phase is initiated by a machine signal. After the end of the cooling phase, the mould opens and the heating phase for the next cycle begins.
The high energy consumption through alternating heating and cooling of the flow medium, is clearly reduced by the close-to-cavity installation of the valve unit with integrated energy storage unit. A highly dynamic control system is responsible for the precise switch-over.