DE20112690U1 - Press for ceramic moldings for pressing with rigid plastic mass - Google Patents

Description

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Monika Hellwig .:!,,:",* /' ^: *

Press for ceramic moldings for pressing with stiff plastic mass Description

The invention relates to a plant for pressing ceramic shapes with high demands on the product, e.g. small sculptures.

There are presses with similar tasks for different purposes. The system described here uses very high pressure to achieve greater detail accuracy and homogeneity.

In contrast to other systems, the pressure is not exerted on a mold, but directly on the rigid plastic mass in order to fill the mold with high pressure.

Usually, for the production of shapes such as small sculptures, etc. made of ceramic masses, multi-part plaster molds are used. These allow for quick demolding and thus high work productivity due to the removal of water, while at the same time allowing the model to be molded in great detail without great effort. These plaster molds can only withstand a certain amount of pressure. Since they are hollow molds, the permissible pressure depends not only on the material, but also on the shape of the model.

The high pressure required to fill the mold, to create homogeneity and to achieve the level of detail can only be applied by the invention to be protected by patent claim 1 without destroying the mold.

This system allows the use of a stiff, ceramic mass with a low water content. This reduces shrinkage and allows the molds to be emptied quickly. This requires fewer molds in the production process and therefore lower costs.

Another advantage is the low reject rate when firing the molded parts. This is because the homogeneity means that no large air pockets remain in the mass, which would cause the molded parts to burst apart during the firing process.

A further advantage is the quick loading and removal of the mold from the holding device.

Further advantages will become apparent from the following description of a preferred embodiment, which will be explained in more detail below with reference to the drawings, in which:

Monika Hellwig , T .'...".* ^;

Fig. 1 is a section through the region of interest of a press according to the invention through the holding device in the state of loading with the mold, and Fig. 2 is a section corresponding to Fig. 1, but in the position of maximum filling of the mold, and

Fig. 3 a top view of a possible variant of the holder.

Fig. 1 shows the loading state. The holder (3) is brought into its starting position by means of a lock in the form of a plate with a lever (2). The multi-part mold (4) is then loaded. The mold is secured against displacement by mold locks incorporated into the mold. The mold is placed in the holding device ( ). The lock (2) is then released. The holder closes slightly due to the weight of the mold and thereby securely encloses the mold. Using a lever system (1), the rigid-plastic mass is now pressed by means of a piston plate (5) from a cylinder (7) previously filled with the appropriate amount of ceramic mass (6) via a filler neck (8) into the mold (4). The cylinder (7) including the filler neck (8) is mounted so that it can move in a vertical direction. The pressure causes the mass to systematically penetrate the mold (4) and fill it completely. At the same time, the vertical movement increases the pressure on the mold from the outside via the holding jaws (3). The internal pressure is thus increased proportionally to the external pressure. The filling of the mold (4) can be controlled via an outlet opening (9) and the pressing process can be ended accordingly. The size of the outlet opening (9) is only approx. 1/3 - 1/5 as large as the filling opening (10). The small opening size is necessary in order to be able to increase the pressure inside sufficiently. The vertical movement of the holding device can only take place due to the movable bearing. The holding jaws (3) are articulated to the base plate (12) via legs (11). When the mold (4) and thus the holding jaws (3) move vertically, the horizontal pressure resulting from the forces of the legs increases on these same holding jaws (3). The other force point transfers the vertical forces to the base plate (12). This process can be carried out up to a maximum pressure, which is generated when the leg is at 0°. In this case, the resulting forces are equal to the horizontal force and the vertical force is equal to 0. To avoid further movement into negative angle ranges, which would reduce the pressure again, the base plate (12) is designed with a raised area at this point.

Monika Hellwig

To enable faster removal of the mold, springs (13) are installed to support the system's desire to avoid the greatest pressure. After the pressing process has ended, when the vertical pressure is 0, the mold returns to its original position and can be removed.

Claims (3)

1. Press for ceramic moldings with a holding structure ( 3 ) elastically mounted in the vertical direction for producing moldings from a stiff-plastic, ceramic mass with a low water content, characterized by a lever press with filling cylinder and filling nozzle, by the spring-loaded holding structure with holding jaws ( 3 ), articulated legs ( 11 ) and a base plate ( 12 ) and a locking device ( 2 ). 2. Press according to claim 1, characterized in that the locking device is replaced by a spring bearing. 3. Holding construction for multi-part molds with elastic mounting of the holding jaws ( 3 ) and purely mechanical pressure generation via a force triangle by means of articulated legs ( 11 ).