OPTIMIZED INJECTION MOLD PLATE, AND INJECTION MOLD COMPRISING SAME

Abstract

An injection moulding tool plate for use in an injection moulding tool for producing a plurality v of preforms having a plurality of handling elements arranged in columns and rows, wherein the distance r between adjacent handling elements within the rows is greater than the distance s between adjacent handling elements within the columns, characterized in that the distance s is less than 50 mm.

Claims

1. An injection moulding tool plate for use in an injection moulding tool for producing a plurality v of preforms having a plurality of handling elements arranged in columns and rows, wherein the distance r between adjacent handling elements within the rows is greater than the distance s between adjacent handling elements within the columns, wherein the distance s is less than 50 mm.

2. The injection moulding tool plate according to claim 1, wherein the distance r is less than 140 mm, preferably less than 120 mm, and preferably between 110 and 115 mm.

3. The injection moulding tool plate according to claim 1, wherein the ratio r/s is between 2.4 and 2.8 and preferably between 2.4 and 2.5.

4. The injection moulding tool plate according to claim 1, wherein a row of handling elements is formed by two row groups of handling elements, and wherein, for a distance z between the row groups of handling elements, the following equation is valid: $z=r\left(1+\frac{a}{n}\right),.$ wherein r stands for the distance of the handling elements within a row group and n,a∈IN where n>1, wherein preferably a=1.

5. The injection moulding tool plate according to claim 4, wherein a<n and preferably n<5 and most preferably n=3.

6. The injection moulding tool plate according to claim 4, wherein each row group comprises exactly four handling elements.

7. The injection moulding tool plate according to claim 1, wherein a column of handling elements is formed by two or three column groups of handling elements, and wherein, for a ‘distance zs between the column groups of handling elements, the following equation is valid: zs≥2s, wherein s stands for the distance of the handling elements within a column group.

8. The injection moulding tool plate according to claim 1, wherein the average distance s between all adjacent handling elements within the columns is less than 50 mm.

9. The injection moulding tool plate according to claim 1, wherein the average distance r between all adjacent handling elements within the rows is less than 120 mm.

10. The injection moulding tool plate according to claim 1, wherein the injection moulding tool plate comprises a work surface having a surface content F, wherein all handling elements are arranged either within the work surface or on the boundary of the work surface, and wherein the number of handling elements is t and the ratio is $\frac{t}{F}>175/m^2\mathrm{and}\mathrm{preferably}\frac{t}{F}>190/m^2.$

11. The injection moulding tool plate according to claim 7, wherein one column comprises three column groups, and wherein preferably either: two column groups each comprise exactly three handling elements and one column group comprises exactly twelve handling elements, wherein the column group having exactly twelve handling elements is arranged between the two column groups having exactly three handling elements each, or two column groups each comprise exactly four handling elements and one column group comprises exactly eight handling elements, or two column groups each comprise exactly three handling elements and one column group comprises six handling elements.

12. The injection moulding tool plate according to claim 1, wherein the injection moulding tool plate has a substantially rectangular mould, and wherein recesses are provided in the corner regions of the injection moulding tool plate in order to receive frame members of an injection moulding machine.

13. The injection moulding tool plate according to claim 1, wherein the handling elements are cavities or cores whose inner and outer contour correspond to the outer and inner contour, respectively, of a preform to be produced.

14. An injection moulding tool for producing preforms, comprising: a first injection moulding tool plate configured as a core plate; a second injection moulding tool plate configured as a cavity plate; a removal plate for removing preforms from the core plate; and a third injection moulding tool plate configured as an after-treatment plate, wherein the cavity plate and the core plate are movable back and forth relative to one another between a closed position and an open position, wherein, in the closed position, the handling elements of the core plate configured as cores are inserted into the handling elements of the cavity plate configured as cavities, whereby moulding spaces are formed between cores on the one hand and cavities on the other hand, whose inner contour corresponds to the outer contour of the preforms to be produced, wherein the removal plate comprises receiving sleeves, wherein the removal plate can be moved back and forth between an outer position in which the removal plate is not arranged between the cavity plate and the core plate and at least two removal positions in which the removal plate is arranged between the cavity plate and the core plate, wherein, in the after-treatment plate, the handling elements are removal elements, preferably removal pins, for removing the preforms from the removal plate, wherein each of the first injection moulding tool plate and the second injection moulding tool plate is an injection moulding tool plate according to claim 13, and wherein the third injection moulding tool plate has a plurality of handling elements arranged in columns and rows, wherein the distance r between adjacent handling elements within the rows is greater than the distance s between adjacent handling elements within the columns, wherein the distance s is less than 50 mm.

15. An injection moulding machine having an injection moulding tool according to claim 14, wherein the injection moulding machine is provided for the simultaneous production of a plurality of PET preforms and applies on the injection moulding plates a closing force of less than 30 kN per PET preform to be produced simultaneously.

16. The injection moulding machine according to claim 15, wherein the injection moulding machine comprises four frame members arranged on four vertices of a rectangle, and the handling elements are arranged between the four frame members.

17. The injection moulding machine according to claim 16, wherein: the clearance between two frame members arranged on adjacent vertices of the rectangle is less than 1000 mm, and at least 136, preferably at least 144, handling elements are arranged on the core plate as well as on the cavity plate, or the clearance between two frame members arranged on adjacent vertices of the rectangle is less than 800 mm, and at least 120, preferably at least 128, handling elements are arranged on the core plate as well as on the cavity plate, or the clearance between two frame members arranged on adjacent vertices of the rectangle is less than 750 mm, and at least 88, preferably at least 96, handling elements are arranged on the core plate as well as on the cavity plate.

Description

[0048] Further advantages, features, and possible applications of the present invention will become apparent from the following description of preferred embodiments. Here:

[0049] FIG. 1 shows a schematic view of a first tool plate according to the invention,

[0050] FIG. 2 shows a schematic view of a second tool plate according to the invention,

[0051] FIG. 3 shows a schematic view of a third tool plate according to the invention,

[0052] FIG. 4 shows a schematic view of the pressure ratios between the handling elements,

[0053] FIG. 5 shows a schematic view of the distances upon a bending of the tool plates, and

[0054] FIG. 6 shows a schematic view of the situation upon a tilting of the tool plates.

[0055] FIG. 1 shows a schematic view of a first tool plate 1 according to the invention. The tool plate 1 comprises a substantially rectangular mould having recesses 2 in the corner regions. These recesses serve to create space for frame members 3 of an injection moulding machine. The frame members 3 are not part of the injection moulding tool plate, but are still shown in FIG. 1.

[0056] The injection moulding tool plate 1 comprises a plurality, namely 144, of handling elements, which are depicted as circles. The handling elements 4 are arranged in rows, which are depicted horizon-tally in the figure, and in columns, which are depicted perpendicularly in the figure. Within the columns, the handling elements 4 have a distance s from one another, which is 45 mm in the embodiment shown. Within the rows, the distance between the handling elements 4 is designated r and is 111 mm in the embodiment shown.

[0057] A total of eight handling elements 4 are arranged in one row. In the embodiment shown, the eight handling elements 4 are formed in one row by two row groups consisting of four handling elements 4 each. Between the two row groups, the distance z is greater than the distance within the row groups. In the embodiment shown, the distance z is 148 mm.

[0058] The distance between the two outer handling elements 4 of one row is designated r.sub.max in the drawing and is 814 mm in the embodiment shown.

[0059] In column direction, three column groups are provided, each consisting of a plurality of handling elements 4. Two column groups, namely the column group shown in the figure at the top and bottom, each comprise exactly three handling elements, while the middle column group comprises twelve handling elements. Because the distance between adjacent handling elements within the column groups is equal and is 45 mm for each, the distance between adjacent column groups zs is at least twice as large. In the embodiment shown, it is 50 mm larger than the distance between adjacent handling elements within the column groups, i.e. it is 95 mm in total. This results in a distance of 865 mm between the two outermost handling elements 4 of a column, which is designated as s.sub.max in the drawing.

[0060] In FIG. 2, a second embodiment of a tool plate is shown. This embodiment comprises only 128 handling elements arranged in 8 columns and 16 rows. The rows here comprise only one row group of handling elements. In column direction, three column groups are provided, each consisting of a plurality of handling elements 4. Two column groups, namely the column groups shown in FIG. 2 at the top and bottom, each comprise exactly four handling elements, while the middle column group comprises eight handling elements.

[0061] The distance between the two outer handling elements 4 of one row is designated r.sub.max in the drawing and is 777 mm in the embodiment shown.

[0062] In column direction, three column groups are provided, each consisting of a plurality of handling elements 4. Two column groups, namely the column group shown in the figure at the top and bottom, each comprise exactly three handling elements, while the middle column group comprises twelve handling elements. Because the distance between adjacent handling elements within the column groups is equal and is 45 mm for each, the distance between adjacent column groups zs is at least twice as large. In the embodiment shown, it is 50 mm larger than the distance between adjacent handling elements within the column groups, i.e. it is 95 mm in total. This results in a distance of 775 mm between the two outermost handling elements 4 of a column, which is designated as s.sub.max in the drawing.

[0063] In FIG. 3, a third embodiment of a tool plate is shown. This embodiment comprises only 96 handling elements arranged in 8 columns and 12 rows. The rows here comprise only one row group of handling elements. In column direction, in each case three column groups are provided, each consisting of a plurality of handling elements 4. Two column groups, namely the column groups shown in FIG. 3 at the top and bottom, each comprise exactly three handling elements, while the middle column group comprises six handling elements.

[0064] The distance between the two outer handling elements 4 of one row is designated r.sub.max in the drawing and is 777 mm in the embodiment shown.

[0065] In column direction, three column groups are provided, each consisting of a plurality of handling elements 4. Two column groups, namely the column group shown in the figure at the top and bottom, each comprise exactly three handling elements, while the middle column group comprises twelve handling elements. Because the distance between adjacent handling elements within the column groups is equal and is 45 mm for each, the distance between adjacent column groups zs is at least twice as large. In the embodiment shown, it is 50 mm larger than the distance between adjacent handling elements within the column groups, i.e. it is 95 mm in total. This results in a distance of 595 mm between the two outermost handling elements 4 of a column, which is designated as s.sub.max in the drawing.

[0066] In FIG. 4, the pressure ratios between handling elements of adjacent injection moulding tool plates are shown. If an injection moulding tool plate comprises a neck ring 11 and a core 14 and the adjacent injection moulding tool plate comprises a cavity 12 into which the core 14 penetrates in order to form the moulding space and the two tool plates are displaced in the direction of the arrows, then, upon closing of the injection moulding tool, the centring of the handling elements takes place via conical portions of the neck ring 11 and cavity that are configured so as to correspond to one another. Due to the offset (shown by the arrow), the conical portions will always meet at the same point, and there is increased compression in a region 13.

[0067] Due to the measures according to the invention, the offset can be significantly reduced so that wear can be reduced.

[0068] FIG. 5 shows a schematic view of two injection moulding tool plates 21, 22 arranged adjacent to one another. Both injection moulding tool plates 21, 22 comprise corresponding handling elements 4. Larger distances between the handling elements 4 are provided on the right side of the figure, as is the case in the prior art. On the left side, the distances between the individual handling elements 4 are reduced according to the invention. As a result, more support points are provided by the handling elements 4, so that there is less bending of the injection moulding tool plates. In the figure, the bending of the injection moulding tool plates is significantly exaggerated. In fact, the bending is so small that it is barely visible to the naked eye.

[0069] FIG. 6 shows a schematic view of two injection moulding tool plates 21, 22 arranged one above the other. Due to the dead weight of the injection moulding tool plates and due to thermal effects, there can be a tilting, i.e. a rotation of one injection moulding tool plate 21 relative to another injection moulding tool plate 22 (shown by a dashed line) about an axis that is perpendicular to the injection moulding tool plates.

[0070] In the right part of the figure, the distances between the handling elements are selected so as to be larger than in the left part of the figure. It can be seen that, due to the greater number of handling elements, a less pronounced tilting of the plates towards one another occurs in the left part of the figure.

[0071] The measures according to the invention can therefore reduce the bending and tilting of the injection moulding plates.

REFERENCE NUMBERS

[0072] 1 Injection moulding tool plate [0073] 2 Recess [0074] 3 Frame members [0075] 4 Handling element [0076] 11 Neck ring [0077] 12 Cavity [0078] 13 Region [0079] 14 Core [0080] 21 Injection moulding tool plate [0081] 22 Injection moulding tool plate