CZ2010471A3 - Process for producing shaped parts from three materials using injection molding tool - Google Patents

Abstract

Thermoplastic molded parts (A, B, C) are formed of a first soft or semi-soft structural material (A), a second soft material (B) and a third hard, outer material (C). The injection molding tool (1) comprises a lower rotatable tool half (2) provided with cavities (3) spaced at a constant distance of 120 degrees and the upper portion (4, 4 ', 4' ') arranged in each of three injection sites (5, 6, 7). The injection molding tool turns 120.degree after each injection process. and at the sites (5, 6, 7), the first material (A) is simultaneously injected at the first station (5), the second material (B) at the second station and the third material (C) at the third station (7), is removed at this last location (7).

Description

Improved production method

La AUA Μ X i.

parts / using injection molding tools

Field of the invention

As the name suggests, the present invention relates to a method for manufacturing trimaterial moldings by means of an injection molding tool, which in turn brings significant benefits in detail, which represent an improved alternative to previously known manufacturing systems and manufacturing processes for the same purpose.

More specifically, the present invention relates to a method for producing trimaterial moldings by means of an injection molding tool consisting of three different thermoplastic materials and therefore requiring different casting phases, which process is characterized in that one of these phases is

has a great effect on production costs and thus on the final price of the product.

These molded parts are intended, without limitation, to be advantageously used in automotive production, since the times used for their production are important because they are part of a production chain with a usually high number of pieces. Therefore, time savings in such processes are a very important factor that must be taken into account and in many cases may even be decisive.

The field of application of the present invention falls within the technical field of injection molded parts, in particular the trimaterial molding industry, and relates in particular to the automotive sector and hence to related businesses.

BACKGROUND OF THE INVENTION

Multicomponent injection molding technology includes a wide variety of techniques known and can be defined as injection molding of more than one material or more than one component into one and the same tool and in a process without additional steps outside the machine, most of the commonly used techniques being multicolored and multimaterial. techniques using two or more thermoplastic materials.

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In general, the traditional manufacturing processes of multimaterial moldings for the material used require an injection phase into the tool while maintaining the necessary drying times, thereby avoiding any mixtures or undesirable results, and the object of the present invention is to allow moldings to be manufactured from three different materials in a single injection molding. phase instead of three phases, as would be the case in a normal process, and in order to achieve a substantial reduction in the total time spent on obtaining the moldings.

On the other hand, it should be pointed out that the applicant is not aware of any other method which is similar to the one recommended herein or exhibits similar technical features.

SUMMARY OF THE INVENTION

The improved method for manufacturing trimaterial moldings of the invention using an injection molding tool is a remarkable novelty in its field of application, the characteristics of which make this possible and distinguish it from another known method will be described in detail and properly captured at the end of the description claims.

More specifically, the method of the invention relates to the manufacture of trimaterial moldings that are formed from a first material, for example a bodywork material, which may be hard, but preferably soft or semi-soft, from a second soft material, such as a sealing material, such as such as the side rubber cuffs, and the third hard material that forms the outer part and, for example, has an aesthetic character.

The method according to the invention is carried out in a three-station tool in which the core is not moving but the tool can be rotated and other three radially arranged recesses for producing molded parts, wherein in one single injection process the material is simultaneously injected into each of three recess, so that the injection cycle lasts exactly as long as the molded part is manufactured from a single material.

To this end, the method comprises a first station in which the first material or construction material is injected into one of the tool cavities, a second station in which the second or soft material is injected, and a third station in which the third, hard, aesthetic injection is injected. · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·· outer material. These injection molding processes occur simultaneously in each of the stations described for each different molding and when finished, the tool is rotated by 120 ° and the process is repeated, with the next material being injected into the adjacent cavity so that one 120 ° each injection after the second, first, second and third material, whereupon the finished molding is ejected from this last station.

This achieves that in the second station, while the second or soft material is injected, which - as mentioned earlier, for example, may be a lateral rubber cuff, the first material already injected or construction material has time to cool, thereby injecting the third or aesthetic material can be performed without problems without introducing the first or construction material.

The above-described improved process for producing trimaterial molded parts using an injection molding tool therefore constitutes an innovation in structural and structural features, as hitherto not known for this purpose. These reasons, in a sufficiently reasoned manner, together with its practical applicability, ensure that the privilege of exclusivity required is maintained.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, the drawings are appended to the description, by way of example and not limitation, of an embodiment of the present invention that provides an improved method for manufacturing trimaterial moldings using an injection molding tool as claimed.

They show it:

Figures 1 to 3: three cross-sectional views of the tool during the injection molding process, in which each of the three radially arranged stations, each of which three different materials will be injected, is seen separately.

Figure 4: View of the open tool showing the arrangement of the cavities into which material is to be injected at each site.

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DESCRIPTION OF EMBODIMENTS OF THE INVENTION

It can be seen from the figures and in accordance with the accepted numerical designation that the process according to the invention is based on an injection molding tool 1, which consists of a rotatable lower tool half 2 with three identical, radially spaced 120 ° spaced regions with the cavities 3, and the upper portions 4, 4, 4 at each of the three pre-prepared injection stations 5, 6 and 7. with which the injection molding tool is provided, the upper portions having cavities whose shape varies as they fit, to be taken up by each of the trimaterial moldings constituting the thermoplastic materials A, B and C.

Said materials consist of a first, preferably soft or semi-soft material A or construction material, a second material B or soft material, and a third material C or aesthetic outer material that is hard. This tool 1, or more precisely the lower tool half 2, rotates 120 ° in each injection phase, so that each of the cavity areas 3 is placed in one of the three injection stations 5, 6 and 7 for each of the three materials A, B. and C.

In this way, the process comprises a first station 5, shown in FIG. 1, in which the upper part 4 is mounted on one of the tool cavities 3 and the first material A or construction material is injected, the second, soft material and at the third station 7 the third upper part 4 of the tool is inserted and the third material, or aesthetic material, is injected.

These injection molding processes take place simultaneously in each of the three stations 5, 6 and 7 in three radially arranged tool regions, and at the end of the same, the lower half 2 of the tool is rotated by 120 ° and the procedure repeated, the next material being injected onto the previous injection molding. that is, after the 120 [deg.] rotation, the first material injected at the first station 5 is placed in the second station 6, where the second material B, namely the side sleeve, is sprayed and simultaneously sprayed on the first tool area and the second material in the third station 7 the third material C.

Now that the tool is rotated again by 120 °, the first material A had enough time to dry in the second station 6 and tolerate without problem the injection of the third material C in the third station.

In this way, the tool is rotated 120 ° after each injection process and one injection process is performed at each of the three stations 5, 6 and 7, the first material A is injected in the first station 5, the second material B in the second station 6 and In the last station 7, the finished molding is then extended.

Once the characteristics of the present invention, as well as the practice of practicing it, have been sufficiently described, it is not considered necessary to broaden the scope of the disclosure, as any person skilled in the art will understand its scope and advantages, while maintaining the invention it can also be put into practice in other embodiments that differ in detail from the example shown, and just as it is required protection if the basic principle is not modified or changed.

Claims (2)

PATENT CLAIMS An improved method of manufacturing trimaterial moldings using an injection molding tool, of the type of trimaterial moldings of thermoplastic materials (A, B, C), as found advantageously for use in the manufacture of automobiles, from a first, preferably soft or semi-soft material ( A) or construction material, a second or soft material (B) such as a side rubber cuff, and a third material (C) or a hard, aesthetic outer material, characterized in that a mold (1) is used in the injection molding process, which consists of a rotatable lower half (2) of the tool with three identical, radially 120 ° spaced cavity regions (3) on one side and upper portions (4, 4 ', 4) on the other side, the upper portions having cavities , the shape of which varies according to the shape to be taken by each of the trimaterial moldings thermoplastic materials (A, B and C), the upper parts of which are each located at one of the three injection stations (5, 6 and 7) provided with the injection molding tool so that the tool rotates by 120 after each injection process. ° and simultaneously injects the first material (A) at the first site (5), the second material (B) at the second site (6) and the third material (C) at the third site (7) at each of the three sites (5, 6 and 7). whereupon the finished molded part is removed in this last station (7). An improved method for producing trimaterial moldings by means of an injection molding tool according to claim 1, characterized in that in a first station (5) in which one of the cavities (3) of the injection molding tool is closed with the upper part (4), injecting the first material (A), inserting another upper portion (4 ') onto the injection molding tool in a second station (6) and injecting a second material (B) and inserting a third upper portion (4) in a third station (7) ) onto the injection molding tool and injecting a third material (C), thereby injecting three materials simultaneously in one of the three stations (5, 6 and 7) and rotating the lower part of the tool half (2) 120 ° and the process is repeated.