METHOD FOR THE PRODUCTION OF PLASTIC PARTS

Abstract

A method for the production of plastic parts, in particular of composite parts, utilizes at least two components to be mixed in a mixing chamber and a cavity formed between a first and a second mold half of a molding tool. The cavity comprises a mold part section and a sprue section, and the sprue section or the mold part section is used as mixing chamber.

Claims

1. A method for the production of plastic parts, in particular of composite parts, utilizing at least two components to be mixed in a mixing chamber and a cavity formed between a first and a second mold half of a molding tool, wherein the cavity comprises a mold part section and a sprue section, wherein the sprue section or the mold part section is used as mixing chamber.

2. The method according to claim 1, wherein a semi-finished fiber product is placed in the mold part section of the empty cavity, the semi-finished fiber product optionally having a through opening or being locally thinned out.

3. The method according to claim 1, wherein the sprue section is filled and the filling is fully polymerized to a sprue part and the sprue part is demolded together with the plastic part.

4. The method according to claim 1, wherein -caprolactam components are used.

5. A molding tool for the use in a method according to claim 1, wherein the molding tool comprises a cavity with a mold part section and a sprue section and a mixing chamber for mixing at least two components (A, B to be mixed, wherein the mixing chamber is formed by the sprue section or by the mold part section of the cavity.

6. The molding tool according to claim 5, wherein the molding tool comprises supply conduits for the at least two components, which supply conduits can each be closed by a shut-off needle.

7. The molding tool according to claim 6, wherein each shut-off needle seals the supply conduit directly at the sprue section.

8. The molding tool according to claim 1, wherein the molding tool comprises supply conduits for the at least two components, which supply conduits are arranged together with the sprue section in only one of the first mold half and second mold half of the molding tool.

9. The molding tool according to claim 1, wherein the molding tool comprises supply conduits for the at least two components, which supply conduits are thermally decoupled from the molding tool, preferably by isolations or casings, which particularly preferred are made of plastic of ceramic.

10. The molding tool according to claim 9, wherein separate tempering devices are provided for the supply conduits on the one hand and for the mixing chamber on the other hand.

11. The molding tool according to claim 1, wherein the sprue section is arranged rectangular to a parting plane of the first and second mold half of the molding tool.

12. The molding tool according to claim 1, wherein a closable cleaning or flushing conduit or a switchable drain bore is connected with the sprue section.

13. The molding tool according to claim 1, wherein an ejector and/or a vacuum module are/is provided for the sprue section.

14. The molding tool according to claim 1, wherein the molding tool comprises a mixing calotte being formed in one mold half or in both mold halves and adjacent to the part of the mold part section forming the mixing chamber and/or a convex wall area projecting into the mold part section.

15. A molding machine comprising a molding according to claim 1.

Description

[0058] Embodiments of the invention are discussed based on the drawings, wherein:

[0059] FIG. 1 shows a schematic view of a molding machine according to the invention,

[0060] FIG. 2 shows a detail of the molding tool of the molding machine of FIG. 1 in a first variant of the invention,

[0061] FIGS. 3a, 3b show a detail of a molding tool of the molding machine of FIG. 1 in a first variant of the invention for two different points in time during the production process,

[0062] FIGS. 4a-4e show a detail of a molding tool of the molding machine of FIG. 1 in a second variant of the invention for several different points in time during the production process and

[0063] FIGS. 5-8 show several embodiments of the molding tool for the second variant of the invention.

[0064] FIG. 1 shows an exemplary molding machine for the production of a fiber-reinforces plastic part with a molding tool with a first mold half 1 and a second mold half 2. The molding tool is mounted on two mold mounting plates 6, 7 which are movable relative to each other. An insert part in the form of a preform (semi-finished fiber product 5) is already placed in the opened molding tool. For A control 8 is provided for controlling the molding machine; only two control lines are shown exemplarily. Lines, which transfer information to the control 8, are not shown.

[0065] The activating component A and the catalyzing component B are provided by a metering aggregate by means of two plunger injection units 9, 10. Alternatively, this can be carried out by means of a high pressure or low pressure metering device (not shown). By means of supply conduits 11, 12 (for example the supply conduits 11, 12 are formed as material-feeding hoses beyond the molding tool and as channels in the molding tool) the components A, B are supplied to the injection nozzles (not shown) and further into the mixing chamber for the purpose of mixing.

[0066] FIG. 2 shows that part of the cavity (sprue section 4) which acts as mixing chamber in the first variant of the invention and in which the components A, B are brought together.

[0067] FIG. 3a, 3b show the use of nozzles with shut-off needles 13 which are controlled by the control 8. The movement direction of the shut-off needles 13 is illustrated by arrows. FIG. 3a shows the position of the shut-off needles 13 in the closed position. Here, the shut-off needles 13 directly seal at the sprue section 4 so that there is no fluid-conducting connection between the nozzle side and the sprue section 4. FIG. 3b shows the position of the shut-off needles 13 during the injection. Here, the shut-off needles 13 are moved at least thus far rearward so that a discharge opening is exposed, through which the respective component A, B can flow into the sprue section 4.

[0068] The FIGS. 4 to 8 are related to the second variant of the invention in the case of which the mold part section 3 acts as mixing chamber. Here, a semi-finished fiber product 5 with a through opening 14 located the mixing section can be used (alternatively, the semi-finished fiber product 5 could be thinned out in the mixing section). A one-sided or two-sided mixing calotte 15 can be formed in the mixing section (compare FIGS. 6 to 7). A convex wall area 16 can be provided alternatively or additionally (compare FIG. 8). Finally, the mixing section can be smooth on the outer side as well as on the inner side. This means, no additional geometric adaptations are made in the mixing section.

[0069] FIG. 4a shows the molding tool in the opened position. The shut-off needles 13 close the supply conduits 11, 12.

[0070] FIG. 4b shows the molding tool in the position of FIG. 4a, wherein a semi-finished fiber product 5 for the production of a fiber-reinforced plastic part is placed in the molding tool.

[0071] FIG. 4c shows the molding tool in the closed state. The shut-off needles 13 close the supply conduits 11, 12.

[0072] FIG. 4d shows the molding tool in the closed state. The shut-off needles 13 have been moved thus far away from the cavity-facing openings of the supply conduits 11, 12 so that the components A, B can be injected (FIG. 4e).

LIST OF REFERENCE SIGNS

[0073] 1 first mold half of the molding tool [0074] 2 second mold half of the molding tool [0075] 3 mold part section of the cavity [0076] 4 sprue section of the cavity [0077] 5 semi-finished fiber product [0078] 6 first mold mounting plate [0079] 7 second mold mounting plate [0080] 8 control [0081] 9 plunger injection unit for component A [0082] 10 plunger injection unit for component B [0083] 11 supply conduit for component A [0084] 12 supply conduit for component B [0085] 13 shut-off needle [0086] 14 through opening in the semi-finished fiber product [0087] 15 mixing calotte formed in the molding tool [0088] 16 convex wall area formed in the molding tool