DE2925738A1 - METHOD AND DEVICE FOR MOLDING WITH MULTIPLE COMPONENTS OF ARTICLES OF PLASTIC MATERIAL WITH ONLY ONE MIXING HEAD - Google Patents

Description

"METHOD AND DEVICE FOR MOLDING WITH MULTIPLE COMPONENTS OF ARTICLES MADE OF PLASTIC MATERIAL WITH ONLY ONE MIXING HEAD. "

The present invention relates to a method and apparatus for compression molding articles of plastic material, such as shoe soles, using two or more resins or components which have different properties from each other and which are mixed and molded by a single mixing head be injected or poured in. There are compression molding machines such as for shoe soles in polyurethane or other plastic material known, in which a first component, such as a resin or polyol and a second, interacting with the first component, such as an isocyanate, are fed simultaneously to a mixing head that is above a or a plurality of molds is attached which are carried by a turntable or other rotatable support. If with this system and the known machines articles are to be produced from different colored materials or materials with different properties, it is necessary to have several mixing heads, i.e. one for each component of a different color or property than the others, in order to carry out the different pressing phases to be able to.
Machines of the above type are more complex and expensive

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Construction and also require a lot of space Dimensions because of the need to place the different heads at a sufficient distance from each other to accommodate the material to be able to hold out between one pressing phase and the other.

The purpose of the present device is to provide a method and to provide a device for compression molding with machines of the type mentioned above, whereby it is possible to modify the construction the same to simplify and reduce the dimensions.

In the first instance, the invention provides a method of compression molding articles made of plastic material with a plurality of Components supplied, which comprises a first pressing phase, in which a mixing head, which is arranged according to a mold is fed with a first and a second component, both of which work together, and in which the remaining components are fed through the inlet and return devices for the components themselves to the corresponding containers j in which the material is left to harden in the form, while at the same time all other components run back through the devices mentioned above; where in the inflow and return lines of the said device and the mixing head, which serve the various components together, a cleaning fluid is introduced, as well as at least one second pressing process, in which the same mixing head with a third

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and a fourth component is fed, both of which work together, while the remaining run back, and from which at least one of the components added last should have properties that differ from those in the previous one To distinguish between the components fed to the pressing phase. Another purpose of the invention was to provide a "device supplied for feeding a single mixing head with more components to carry out the compression molding process mentioned above to be able to, which contains:

A first and a second main return line, together for multiple components; secondary supply and return lines for the individual components, each to the corresponding one mentioned Main supply or return line connected; the The device also contains a shut-off valve for each secondary inlet and return line and accordingly a return valve operated by common control elements; each of the main supply and return lines is also with an inlet and the corresponding drain for a cleaning fluid slide and among each other through a Control valve for the mixing head connected.

These and other characteristics of the method and apparatus of the present invention will be better understood from the following Description with reference to the examples of the accompanying drawings, in which - Fig. 1 shows a general diagram of a machine for molding shoe soles, of the rotating type

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And which the present invention includes

Fig. 2 is a view of the device according to the invention

- Fig. 3 shows a horizontal section of the device along the line 3-3 of Fig. 4j

- Fig. 4 shows a vertical section along the line 4-4 of Fig. 3j

- Fig. 5 is the complete flow diagram for two components. In Fig. 1 there is shown the scheme of a rotating table machine equipped with a compression molding device according to the invention. The machine mainly comprises a rotating table 1 which carries a number of molds 2, such as for molding shoe soles with a base sole of a different color or of material with a different hardness than that for the edge of the sole itself. This rotating table 1 moves step by step in the manner known per se, in order to bring the individual molds 2 into the position corresponding to a single fixed mixing head 3, which is located above the table 1 and the molds 2; 4, on the other hand, shows a device for the inflow and return of the individual components, which consist of a resin (or polyol) and an isocyanate, which - mixed with one another in a stoechiometrically suitable ratio - react and form a plastic material that is in a mold 2 can be injected or poured, which is located under the mixing head 3. Therefore, in the example shown, the feed device 4 is through the necessary feed lines 5, 6, 7 _} 8 and the ent-

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speaking return lines 9 j 10 * H ₃ 12 connected to the containers of the components Al, B1 and A2, B2 as shown. An example of a device for the inlet and the return of four components is shown in detail in Figs. 2-5, in which Fig. 3 indiscriminately shows a section in a horizontal plane along the line 3-3 or 3'-3 'of the Fig. 4 shows and Fig. 4 shows a section in a vertical plane according to the line 4-4 or 4'-4 'according to Fig. 3 * while Fig. 5 shows a complete flow diagram for the components A1 and A2, where the scheme for the remaining components B1 and B2 is completely identical.

As shown, the lines and control valves are located for reasons of simplicity in design and assembly for the individual components Al, A2, B1, B2 in individual plates that are attached to the holding plate 13 for the mixing head 3 In detail, the device contains a first 14 and a second 15 main inlet line for the individual Components as well as a first 16 and a second 16 'main return line of the components, of which only the line 16 is visible in the section shown in Fig. 4.

The feed line 14 and the return line 16 serve the components Al and A2, while the inlet line 15 and the corresponding Return line 16 'for the two components Bl and B2 are provided.

From Figs. 3, 4 and 5 it can also be seen how each of the Main supply lines 14 and 15 via corresponding control valves

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tile 17 and l8 for the mixing head 3 with the corresponding Main return lines 16 and 16 'can be connected to this connection is not only necessary for the circulation of the two components before each pressing phase, as is normally necessary is, but also for the circulation of the cleaning fluid in the common for different components Lines as described below. Therefore, each of the feed lines 14 that are common to more components and 15 via a channel 20 'with a valve 19 to a corresponding one Input for the cleaning fluid connected, while each of the return lines 16 and 16 'via one Channel 22 'with a valve 21 to a drain 22 for the called cleaning fluid is connected. There are also secondary supply and return lines for the individual components are provided, each of which is connected to the corresponding main inflow and return lines. It is emphasized that what is said below in relation to the component Al also applies to the remaining components Components is valid.

From Figs. 3, 4 and 5 it can be seen that a secondary inlet line 23 is provided for the component Al, which is connected to the inlet line 14 by a shut-off valve 24, which serves for the components A1 and A2 togetherj at the same time is a secondary return line for each component 25 are provided, which are provided with a return valve 26 is, which is to the side and parallel to the shut-off valve

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for the above component is located.

The secondary return line 25 is connected by a valve 26 'to the outlet line 25' of the component A1; at the same time said outlet line 25 'is further connected by a valve 24' to the main return line 16, as shown in FIG. The valves 24 'and 26 · are completely similar to the valves 24 and 26 and are arranged below them for reasons of common control; therefore the section of Fig. 3 corresponds to a section along the line 3-3 as well as one along the line 3'-3 'of Fig To isolate components from the supply and return lines common to the components when the cleaning fluid has to be supplied.

The valves responsible for the individual components can be operated individually in the appropriate operating sequence or together as shown; in the latter case, the closures of the valves 24 and 26 as well as 24 'and 26' are in pairs attached to slidable Bioecken 28 and 2 9, which are moved by an intermediate connecting rod 27 and its rotation about a vertical Axis by a pneumatic cylinder unit with rack 30 is controlled.

The function of the device described above for compression molding articles of plastic material in several colors or made of materials with mutually different properties It.

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Invention is made in the manner described below. Suppose you have to make shoe soles where the The base sole is a different color than the edge of the sole itself; suppose further that the first pressing phase is in each of the molds using, for example, the components A1 and B1 and their interaction takes place, while in the second or following pressing phase the other two components A2, B2 or one of the two is used in conjunction with one of the aforementioned will; As is known, the components must be which are fed to the mixing head 3 and are intended to work together, are circulated separately in order to obtain the necessary Preparation through thermal stabilization. For this reason, the valves 24 and 24 'for the two components remain open, while the secondary return valves 26 and 26 'remain closed. Since the valves 17 and 18 of the head 3 are in the position shown in Fig. 4, it results that the component Al through the feed lines 23, 14 and returned to their container through the valve 17 of the mixing head and the lines 16 and 25 '. to be led. The same thing happens with the second component B1. In contrast to the above, the corresponding valves 24 remain and 24 'closed for the remaining two components A2 and B2, while valves 26 and 26 'are open; consequently each of these latter two components is replaced by the secondary ones Valves and return lines to your own container returned without running through the mixing head 3.

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After the return of the components A1 and B1 has ended carried out the first pressing phase, the components mentioned are placed in the container of the mixing head, so that their mixing and the subsequent pouring or injection into the various molds 2 can take place, each under the head itself comes to an end ^ the other two components continue to circulate as before.

The material already poured into the mold must be used for the necessary Endure or solidify for a long time before performing a second press phase. Because the compression molding for shoe soles are provided with several molds carried by the movable table 1 which cycles them under the mixing head 3 brings, the consolidation of the material in a mold generally takes place during the pressing phase in the remaining molds of the Machine.

When the first mold comes back under the mixing head 3, a cleaning process must be carried out before the second pressing phase is carried out of the lines, which are used for the passage of various components, i.e. the main inlet and -ruecklauflextungen 14? 15> 16, 16 ', already mentioned earlier became. Therefore all shut-off valves 24 and 24 'for the various components remain closed, while all secondary ones Valves 26 and 26 'are open for the return of the components themselves remain as shown for components A2 and B2 in Fig. 3. The cleaning fluid, generally a solvent, can now from inlet 20, along the two main inlet

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lines 20 ', 14, the valves 17 and 18 of the head 3 and the corresponding main return lines 16, 22 'f Hesse, to exit again through the outlet 22, since the valves 19 and 21 are open.

After cleaning is complete, the second pressing phase can now be carried out on the first in any form of the machine will. If, for example, the second pressing phase is to take place with components A2 and B2, the components corresponding to the two components are used Valves switched over, whereby the shut-off valves for the components themselves are opened so that they can be passed through the The mixing head can run, which means that the new pressing phase takes place in the individual molds until all molds are in the machine are filled.

In the specific case, two components A2 and B2 were used for the second pressing phase, which are assumed to be both different of the components Al and B2 are from the previous pressing phase; however, it is obvious that one of the two second components can be the same as one from the first phase. From the above description it will be understood that the The invention consists mainly of a method and an apparatus for realizing the same, whereby it is possible Carousel machines with more shapes can be programmed to produce pieces in different colors and made with a single mixing head Pressing materials with different hardnesses without emptying and cleaning the containers of the individual components

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the rivers, with time and material of a not inconsiderable Saving value while reducing the dimensions of the machine itself.

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Claims (4)

Patent attorneys BEETZ-LAMPRECHT-BEETZ 8000 Munich 22 - Steinsdorfstc 10 ol4o-29.8o2P (29.8o3H) June 26, 1979 OFPICINA MECCANICA GUSBI S.n.c. di Gusberti Emilio & Bianchi Terenzio, Vigevano, Pavia, Italy claims 1.) Method of compression molding articles from plastic Material with more components, characterized in that a first pressing phase is carried out, with a mixing head, which is attached in correspondence with a shape, with a first and a second component, which both work together, is fed, and that the remaining components as which run back to the corresponding containers via an inlet and return device for the components themselves that the material hardens in the form, at the same time all other components through the above Devices are in return; that the line sections for the inlet and return of the device mentioned 030024/0 5 68 ORIGINAL INSPECTED and the mixing head, which are common to the various components serve, to be filled with a cleaning fluid; that at least a second pressing phase is carried out, a third and a fourth through the same mixing head interacting components are supplied, of which at least one of these components should have properties, which should differ from those of the components supplied in the previous pressing phase. 2. Device for feeding a single mixing head of a machine for compression molding of articles made of plastic material with more components according to the method of claim 1, characterized by a first and a second main inlet line and first and second main return lines (16) serving a plurality of components; secondary feed— and return lines (23, 25, 25 ') for the individual components, each of them connected accordingly to said main lines (14j 16) for inflow and return; the device also includes for each supply and return line (14, 16) a shut-off valve (24, 24 ') and accordingly a return valve (26, 26') for the individual components with common control members (30), each main feed line (14) and the corresponding main return line (16) also with an inlet (20) and an outlet (22) for a cleaning fluid and are connected to one another by control valves (17i 18) for the mixing head (3). 0300 24/0568 3. Device according to claim 2, characterized in that the secondary lines for inlet (23) and Return (25, 25 ') of each component, together with the corresponding valves (24, 24 ', 26, 26') in the individual separate panels are located. 4. Device according to claim 2, characterized in that the shut-off valves (24, 24 ') and the return valves (26, 26 ') of each component are parallel to each other and the respective closures by an intermediate connecting rod (2 7) are moved, the rotation of which is controlled by a single pneumatic cylinder unit with rack. 030024 / 0KB8