summary of blow molding machine
The object of the present disclosure is therefore to make available a blow molding machine that is as compact as possible and operates with the greatest possible precision.
To obtain the simplest possible mechanism and be able to manufacture the most accurate articles possible, a blow mold part is stationary in the blow mold in comparison with the position of a finished blow molded article.
The position of a finished blow molded article in the blow mold is predetermined, for example, by a compressed air valve outlet, a stretching rod, a holder or the like, which are used in the blow molding operation.
Due to the fact that this blow mold part does not move in comparison with the position of the finished blow molded article, there are no inaccuracies due to the relative mobility of this blow mold part. Due to the movement of the other blow mold part in a lateral movement, much less space is needed in comparison with a move ment downward. This movement may possibly also include a component upward or downward because a more compact design is possible already due to the movement with a lateral component. Movement only in the lateral direction is preferred.
The two blow mold parts may advantageously be opposing blow mold parts, which means that with the blow mold closed, they are on opposite sides of the position of a finished blow molded article.
The blow mold is advantageously arranged on the whole so that one blow mold part revolves farther inward than the other blow mold part. Since some space is needed to open the blow mold, such an arrangement makes it possible to achieve the result that the opening includes at least a significant component of movement in a radial direction, so that the blow molds can be arranged as close together as possible in the tangential direction. Only relatively little space is needed between any other blow molds that might be present in order to open the blow mold.
The blow mold machine that can be moved away laterally is advantageously pivotably mounted on the blow mold holder and preferably has a pivot axis that is vertical. This yields a movement with an exclusively lateral component.
The blow mold part that can be moved away is advantageously moved forward in the direction of rotation of the blow mold holder when opening the blow mold. Therefore, parisons and finished blow mold articles can be inserted into the blow mold and extracted from it at the rear as seen in the direction of revolution.
In addition, it may be provided that the two blow mold parts can be pivoted together in the same direction.
The blow mold is advantageously arranged on the whole so that one blow mold part revolves farther inward than the other. Some space is still needed to open the blow mold, so with such an arrangement it is possible to achieve the result that the opening includes at least a significant component of movement in a radial direction so that the blow molds can be arranged as close together as possible tangentially. For the opening of the blow mold, only a relatively small amount of space is needed between multiple blow molds that might b e present.
The blow mold part that can be moved away laterally is advantageously pivotably mounted on the blow mold holder and preferably has a pivot axis that is horizontal. This yields a movement with an exclusively lateral component.
Advantageously the blow mold part that can be moved away is moved forward when opening the blow mold in the direction of revolution of the blow mold holder. Therefore, parisons and finished blow molded articles can be introduced into the blow mold from the rear and extracted from it from the rear as seen in the direction of revolution.
In addition, it is possible to provide for the two blow mold parts to be pivotable together in the same direction.
Due to the joint pivoting of the two blow mold parts in the same direction, it may be possible to simplify the insertion of the parison or the removal of the finished blow molded articles because a better alignment of the blow mold with respect to the corresponding transfer means for the parisons or the finished blow molded articles is possible.
However it is also possible that the blow mold part which is stationary in comparison with the position of a finished blow molded article may be held immovably on the blow mold holder. This yields an especially simple design.
The two blow mold parts have contact surfaces with which they come in contact with one another to form the cavity of the blow mold. These contact surfaces are advantageously arranged tangentially with respect to the circumference of the blow mold holder. Therefore, one half- mold with its half-cavity faces directly outward, so that access here is readily possible.
However, under certain conditions, it may also be advantageous to align the contact surface at a clearance angle with respect to the tangent. Therefore this may provide some relief in the design for the transfer of the parisons and the finished blow molded articl es.
In addition, it is advantageous to provide a blow mold whose blow mold parts have multiple sections for multiple blow mold articles. This allows an increase in capacity. This is readily possible in particular in the case of a blow mold with which multiple blow mold articles are arranged side by side, as seen in the radial direction because these can then be removed more easily and more rapidly.
In addition, transfer star mechanisms for transferring the parisons and receiving the finished blow molded articles are advantageous also provided. These transfer star mechanisms must be designed in such a way that they allow movement tangentially in relation to the blow mold. Thus, for example, the parison may be inserted from the rear into the blow mold, which is opened at the rear, and the finished blow molded article may be removed at the rear accordingly.
The blow molding machine is preferably designed for manufacturing con tainers such as bottles, in particular plastic bottles, preferably PET bottles.