CS257916B1 - Provision for heating and shaping thermoplastic films or sheets - Google Patents

Abstract

Device for heating and shaping thermoplastic films or plates consisting of a heating system, a lower vacuum cabinet and a clamping system, characterized in that the heating system is provided with closable bottoms, which are mounted in guides, the extension and insertion of which is ensured by a mechanism using couplings and hinges.

Description

The invention relates to an energy-saving power supply. heating for equipment for shaping moldings from foils and sheets of plastics, especially for deep moldings such as various breezes, containers, safe troughs for the mining industry and the like.

So far, thermoplastic foils or sheets have been formed in two basic ways. The first method is based on a contact heating system where the contact hot plate and the cooled mold are provided with channels for supplying compressed air and vacuum. Here, the starting thermoplastic foil is circumferentially pressed by the frame-cooled mold of the desired shape onto the heated plate of the desired temperature, which, after achieving good heat transfer, is sucked in by vacuum and pressed by compressed air introduced into the mold space. and, under vacuum, the film is formed into a cooled mold shape and thereby pressed. This device achieves perfect and fast heating of the foil throughout the entire area, which makes it possible to shape very demanding moldings with high energy efficiency. Vacuum fastening of the film during heating to the heating plate eliminates the undesirable effects of unequal shrinkage of the film and reduces the risk of overheating and degradation of the film by using considerably lower temperatures. Although this method is very energy efficient, it is mainly limited to foil products. 0.6 mm, which are flat. It is not effective for processing plastics with a thickness of the material (plates) and when applied to deep-drawn moldings.

The second method involves the use of vacuum forming machines such as VP-Super, in which an infrared radiation heating foil is used to heat the film. The foil is clamped in the peripheral frame, which places great demands on material consumption. In foil and plate forming in this way, the material is unevenly heated due to inappropriate distribution of the radiated energy.

The lack of IFC heating is the different sensitivity of the heated materials to heat absorption due to the different reflectance of the radiation, which results in poor heating of the material and a considerable amount of energy dissipating into the space.

This lack of high energy consumption of the second method is overcome by the invention, which is based on a device for heating and shaping thermoplastic films or a plate consisting of a heating system, a lower vacuum housing and a clamping frame. The heating system is provided with radiant heating, which consists of heating rods embedded or suitably inserted into the material for secure high heat accumulation, thermal insulation, which is provided with lockable bottoms sliding in the lines, where the bottom is pushed and pushed by a mechanism using couplings and handles .

The new combination of components that make up the heating system in vacuum machines, when the heating system goes up, ensures minimum energy consumption, as the side walls of the heating system prevent lateral leakage of the heating system and prevent heat leakage in off-work positions.

FIG. 1 schematically depicts a new forming device with an energy-saving el. heating according to the invention and from Figs.

The lower part of the housing is provided with a fixed gripping frame 2 on which a molded foil or a thermoplastic plate of portable size 19 is placed. 15 on the table 10 of the lifting device 16. Inlets into the housing space lead in front of the shaping air 17 and the shaping vacuum 1,8. The upper heating system consists of a radiant heater 2 consisting of heating rods embedded in the lonely mass or other suitable material with good thermal inertia. Furthermore, this insulation is provided with the second lower part comprises two days lockable sliding in guides £ · extension and retraction of the closable aperture provides a mechanism 11 using the coupling brackets 2 ^and the eighth stroke ensures heating mechanism 1 · Below the heater is positioned upper gripping a frame 8, which also ensures, in its lower position, the gripping of the molded foil or thermoplastic plate 19 of a precise dimension.

The adjustment function (see FIGS. 1 to 4) is that the inserted molding sheet or plate of exact size 19 is laid on the lower fixed frame X and is attached by sliding off the upper movable frame 6 and heated by radiation heating in such a way that the lowered position 8 joins the coupler 8 and the handles 8 and in the next stage the retractable closable bottom 8 opens the heater β using the mechanism 11 and heats the defined area of the molded foil (plate) 19) See Fig. 2. · The shape of the couplers allows the closing of other shutters while the heating system is lifted. At the same time, preforming air IX is blown into the pressure box of the machine 12 / see Fig. 3 ♦ After preforming the foil with compressed air 17, this is stopped and the mold 15 on the table 10 is pushed into the foil 10 by the lifting mechanism 16 and after reaching the upper position, pre-warping air 17 is replaced by a forming vacuum 18. thus forming the foil on the mold by atmospheric overpressure).

It is a single-purpose device, wherein the upper part of the system is adapted to the size of the product. The advantage of this device is that it can be used in wolf designs per seto, on a single forming mechanism and can mold a plurality of moldings at once.

Claims (1)

Apparatus for heating and shaping thermoplastic films or sheets (consisting of a heating system, a lower vacuum cabinet and a clamping system), characterized in that the heating system is provided with lockable bottoms (5) which are housed in the ducts (4) and and retracted by a locking mechanism (11) using couplers (9) and grips (8).