The invention relates to a method according to the preamble of claim 1 and an apparatus according to the preamble of claim 2.
From EP 802 032, there are known a method and an apparatus of this kind for injection molding a beaker having a label on the outer circumference.
In this known method, the transfer tool requires a certain amount of time for rolling the label before the transfer tool can be moved into the mold cavity, while the injection molding process itself proceeds relatively quickly. Therefore the injection mold must be passively held in readiness for a certain time while the label is rolled onto the transfer tool and delivered to the mold cavity. Due to this long cycle rate for taking up and rolling the label by means of the transfer tool in relation to the cycle rate of the injection molding machine, the capacity of the latter cannot be fully exploited.
The invention is based on the object of adapting a method of the type given above such that the capacity of the injection molding machine can be better exploited. Further, an apparatus is to be proposed by means of which an increase in capacity of the injection molding machine can be achieved.
This object is solved for the method by the features in the characterizing part of claim 1. Before the label is positioned on the circumference of the transfer tool, it is moved into a preforming means and shaped for insertion into the mold cavity. This allows the transfer tool to receive the label from the preforming means and transfer it to the mold cavity at a fast cycle rate, so that during the transfer of a label from the preforming means to the mold cavity of the injection molding tool, a further label can already be preformed in the preforming means and held in readiness to be taken up by the transfer tool. Altogether, the provision of a preforming process of the label allows a higher cycle rate to be used, which allows the injection molding machine to work at a high capacity.
The object of increasing the capacity of an injection molding machine is solved by a preforming means by means of which the label is preformed before being transferred into the mold cavity, so that it can be merely taken over by the transfer tool and delivered to the mold cavity without any loss of time.
An exemplary embodiment of the invention in explained in more detail below with reference to the drawing in which
In contrast to the known method shown in
While the preformed label is being transferred by means of the transfer tool 2 from the preforming means 11 to the mold cavity of the injection molding machine, a further label can already be picked up from the pile 1′ and transferred into the preforming means 11, so that after closing of the injection mold 4 and the injection molding process, a further preformed label is already held in readiness for the transfer tool 2, and altogether a higher cycle rate can be used.
To allow the label to be preformed in a form corresponding to a truncated cone-shaped beaker, the label 1 is cut to the shape of a section of a ring sector is moved onto a circular arc track around a center 17 of a circle, wherein the radius of the guideway 13 corresponds to the radius of the curvature of the label. In other words, the label 1 on the circular arc-shaped guideway 13 represents a development of the inner circumference of the preform cavity 15.
To allow the label to slide along the inner circumference of the preform cavity 15 when inserted in the slit 16 of the forming block 14, a guide sheet (not shown in
It is also possible to form the slit 16 curved so that it opens into the preform cavity 15 approximately tangentially to the inner circumferential wall of the preform cavity 15, to assist the abutting of the label on the inner wall of the preform cavity.
Instead of the described preforming means 11, depending on another shape of an injection molded article, other preforming means can also be provided. Correspondingly, the provision of a preforming means can also be used for the fabrication of a differently shaped injection molded article on whose outside a label or another application is to be attached.
If, for example, large injection molded articles are provided, such as buckets or injection molded articles having a long side length, for example an approximately rectangular container, then it is advantageous to support the preforming process by an auxiliary means.
The supporting core 18 can be inserted in the preform and removed again after the preforming process by means of a gripper (not shown), so that the transfer tool 2 can engage for taking up the preformed label. Hereby, the supporting core 18 can be moved in and out through the one or other side of the preform, which is open on both sides.
Applications or labels preformed in other ways can also be inserted in an already preformed state into the preform 14, 15 and then transformed by the transfer tool 2 into the mold cavity 3 of the injection molding tool. In this way, an increase in the cycle rate of the injection molding machine is achieved.
Number | Date | Country | Kind |
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102 31 654.6 | Jul 2002 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP03/07550 | 7/11/2003 | WO | 12/27/2005 |