The technical solution of the equipment for production of samples of composite plastic which would enable simultaneous heating, moulding and cooling was designed by scientists of the Faculty of Civil Engineering of BUT. The advantage of this technical solution is that by using at least two dismountable segments of a cylindrical form, a piston with a punch and a cooling system, the problem with material expansion caused by heat is eliminated.
For production of plastics using mould pressing, heated pressing moulds are used. In the heating of moulds with a cylindrical cavity, appropriate external and internal heating of the cylindrical body has to be determined. There could be a problem if the hot mould is to be handled as other operations follow the heating. Problems which can occur during heating are as follows: material leaks in the hole, or the moulded piece sticks to the cylinder of the bottom of the pressing mould and the heated sample cannot be removed in a standard manner.
For heating in similar equipment, the whole range of heating cuffs or heating cartridges on the principle of resistance heating, which can be used in the cylindrical moulds, is available on the market. Another method of heating of similar moulds involves the begirding of the mould with heating belts. In addition to the heating of the mould, the cooling process has to be resolved so that moulding is optimal.
The inventors of this new technical solution are Doc. Ing. Libor Matějka, CSc, Ph.D, MBA and Ing. Jan Pěnčík, Ph.D., of the Institute of Civil Engineering. The objective of this research work was to design and prepare a device for combined heating, pressing and cooling which would enable reliable operation even at higher temperatures with an option of dismounting the mould. The tool also comprises a pressing piston which is necessary for pressure moulding; it is also heated from inside.
The presented technical solution can be used for laboratory production of samples of developed composite plastics used for e.g. foundation structures under door sills, heat-insulating blocks etc.
The equipment is protected with a patent and utility model.
Source of the picture: Sarang, Wikimedia Commons, 2012
