RU2407636C2 - Device and method of producing hollow cases made of two materials by multi-component injection moulding - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of hollow cases. The latter are produced from two materials by multi-component injection moulding. Proposed device comprises: cavities 1 to mould the base or sets of cavities 1 with their number making n, cores 3 or set of cores 3 with their number 2n arranged between cavities (2a, 2b) or sets of cavities (2a, 2b) with their number n+1. Said cores are attached to core holder plate (32) arranged to move in crosswise direction (DT) on support plate (30) moving in lengthwise direction (DL) to allow inserting in turn each core 3 in one cavity 1 to mould the base to mould first layer, and in one cavity (2a, 2b) to mould second layer. Device incorporates also moulded hollow case extractor (P) and valve device (21) to distribute materials between cavities. Proposed method comprises the following stages: inserting rods in appropriate cavity, injecting base material and multi-component moulding material therein, controlling material distribution and extracting finished cases.

EFFECT: alternating sequential moulding operations.

15 cl, 14 dwg

Description

FIELD OF THE INVENTION

The present invention generally relates to a device and method for manufacturing housings made of two materials by injection multicomponent molding, and more particularly to manufacture blanks made of two materials by injection multicomponent molding.

State of the art

The manufacture of plastic parts made of two materials has long been a widespread method. The scope of its application is very wide and covers technical details, for example, for automobiles, electronics, household appliances, etc., cosmetics, perfumes, personal hygiene, etc. Initial materials, i.e. plastic resins are also very diverse, and this method can be used for aesthetic purposes, for example, to create parts having several colors, for technical purposes, for example, to obtain various technical properties characteristic of different parts of a part, or for economic purposes, for example, for manufacturing important part of the part using cheap material, and other parts using high-quality material, for example, to ensure the required surface condition or to satisfy a given sled Arno-hygienic conditions.

It is known to manufacture hollow bodies made of plastic, such bodies are hereinafter referred to as "hollow bodies made of two materials" which are formed from a base layer and a coating layer of different plastics. These hollow bodies made of two materials include, for example, containers such as vessels, containers, cans, etc., lids and caps for containers, and parts for household appliances and vehicles.

There are several methods for the manufacture of plastic parts made of two materials, of which the main are the following methods.

Reforming over the base by moving the insert . Insert i.e. the part formed from the first layer of the base molding material is moved from the cavity for molding the base into which it was introduced into another cavity for multicomponent molding in which the coating layer is molded. This movement can be performed manually or using a robot. The cavities for molding the base and the cavities for multicomponent molding can be in two different molds installed in two different injection presses, or in the same double mold.

Reforming by rotation of the half-mold . This system provides for the reshaping of parts without first removing them from their original mold. The parts are held in a half-mold (usually on the extraction side), the half-mold rotates, usually 180 °, and the parts, which are then reshaped in the cavities for multi-component molding, unfold.

Reforming by displacement of the bar (also referred to as forming by a system based on the bar). The core acts as a valve for separating cavities for molding the base from the cavities for multicomponent molding. First, the base layer is molded into the cavity for molding the base, then the rod opens the passage into the cavity for multicomponent molding.

Joint injection . Two different materials are molded inside the same molding cavity. The system is based on allowing the second material to pass through the first material to form several layers of different materials.

A particularly important group of hollow bodies made of two materials is the group of blanks for making bottles and other containers. These blanks consist of hollow plastic housings in the form of a test tube containing an inlet and a neck, which optionally include an external thread and a perimeter annular edge. These blanks are intended for the subsequent manufacture of plastic bottles by blow molding a part in the form of a test tube inside a blow molding mold, in which the manufacturing process of the neck and inlet is unchanged. The manufacture of blanks made of two materials is carried out in several ways mentioned above, for example, by means of multicomponent molding by moving the insert, multicomponent molding by rotating the half-mold, multicomponent molding by displacement of the rod or joint injection. However, each of these methods has disadvantages and / or limitations.

In the multi-component molding method by moving the insert when the insert is removed from the cavity for forming the base, the newly formed base layer forming it is very hot and therefore is in a soft state, which is associated with the risk of deformation or other damage during movement into the cavity for multicomponent molding. In addition, the equipment for applying this method is complex and expensive and requires significant space, provided that it usually involves the use of two molds, two injection presses and a robot or other means of transportation.

In the method of multicomponent molding by rotating the half-mold, the cavities for forming the base and multicomponent molding are located symmetrically with respect to the axis of rotation of the mold. Therefore, both stages of the injection must fit into the surface of the injection press, limited to 4 press stands. Therefore, the dimensions of the press must be very large or the number of cavities of the mold must be very limited. In addition, the cooling fluid of the mold, which should be in excess in the method of injection of two materials, must pass through a rotating connection, which further limits the performance of the system. In addition, the workpieces must be pushed with displacement, and since it is very important to provide the necessary force, the pusher system tends to be decompensated.

In the co-injection method, which is currently widely used, the boundaries of the multicomponent molding material layer cannot be performed ideally, thus, the final geometry of the base layer and the coating layer formed from various materials cannot be controlled with high accuracy. This restriction, although it allows you to use this method for applying protective layers, makes it unsuitable for using reusable materials in combination with high-quality materials, as well as for creating aesthetic two-color elements by molding and multicomponent molding of two materials of different colors.

In another case, international patent application PCT 2006 / ES 00001, owned by one of the authors of this invention, describes a device for injection molding of blanks containing rows of cavities for molding in an amount of n, alternately inserted between rows of cavities for cooling in an amount of n + 1, and rows rods in an amount of 2n attached to the plate of the rods, adapted and driven to move above the support plate in the transverse direction between two positions in which the rods are aligned respectively enno the first and second sets of cavities. Each of said first and second sets of cavities is formed from said number of n rows of cavities for molding and the number n of rows of cavities for cooling, including one or the other of the end rows of cavities for cooling, respectively. The support plate is driven in such a way that it can be moved in the transverse direction between the closed position in which the rods are inserted into said first or second sets of cavities and the open position in which the rods are removed from the first or second sets of cavities. Each rod contains an ejection element associated therewith, configured to form part of the preform mold and set in motion to effect lateral movement along the rod and thereby remove the preform. Ejector elements are arranged in several rows, each associated with one of the rows of rods. The ejector elements of each row are connected to the ejector plate, and the various ejector plates are independently driven by the ejector elements to eject the workpieces only from those rows of rods that are removed from the rows of cooling cavities.

In this device, the periodically varying movement of the plate of the rods in combination with the movements of the support plate provides in one position of the rods relative to the cavities for molding and cavities for cooling injection of the molding material in the cavity for molding the preforms, while at the same time other, previously cast preforms are cooled in the cavities for cooling, and then changing the position of the rods relative to the cavities for molding and cavities for cooling after removing the cooled workpieces for ivki new pieces on the newly liberated rods and simultaneous cooling of the preforms, recently cast in the previous position, and so on cyclically.

Disclosure of invention

In accordance with a first aspect, the present invention describes a device according to claim 1. Other features of this device in accordance with this first aspect are defined in dependent clauses 2-5.

In accordance with the second aspect, the present invention describes a method according to claim 6, suitable for implementation by means of the device according to any one of paragraphs 1-5. Other features of this method in accordance with this second aspect are defined in dependent clause 7.

In accordance with a third aspect, the present invention describes a device according to claim 8. Other features of the device in accordance with this third aspect are defined in dependent clauses 9-12.

In accordance with a fourth aspect, the present invention describes a method according to claim 13, suitable for implementation by means of the device according to any one of paragraphs 9-12. Other features of the method in accordance with this fourth aspect are defined in dependent clauses 14 and 15.

The device in accordance with the first and third aspects of the present invention is based on the mechanical operation of the device described in the aforementioned international patent application PCT 2006 / ES 00001, with the inclusion of a number of modifications, whereby successive molding operations of the first layer of the base molding material and multi-component molding of the second layer of coating material for the formation of hollow bodies made of two materials, instead of the known alternating operations of molding and cooling. With this design, the devices of the present invention usually provide for the manufacture of hollow bodies made of two materials, and, in particular, blanks made of two materials, using one mold and one injection press. The devices operate with minimal movement of the rods, picking up the first layer of the base material from the cavities to form the base in the cavity for multi-component molding, which reduces or substantially eliminates the risk of damage in the said layer of the base material with the relatively small space required for a significant number of cavities in one and the same same mold, and at high performance.

The methods in accordance with the second and fourth aspects of the present invention describe in detail the steps for manufacturing hollow bodies made of two materials by means of such devices.

All this, when using the device and method of the present invention, makes it economically feasible to manufacture hollow bodies made of two materials for applications that have not been feasible to date using known methods. For example, preforms adapted for the manufacture of containers having protective properties against gas or light can be manufactured using a new device and method by molding the first base layer of a protective material having a suitable thickness and multicomponent molding of the outer coating layer from a material suitable for giving the appearance of the tank, which may be, for example, the original or restored polyethylene terephthalate.

In accordance with another application, using the device and method of the present invention, it is possible to produce preforms, including the use of recovered material, either reused or directly crushed into flakes. In this case, and assuming that the preform is intended for the manufacture of a container for food products, the inner surface of the preform, including the open end corresponding to the opening of the container, can be made with a main layer of high-quality material suitable for use with food products, for example, the starting polyethylene terephthalate, and the outer coating layer can be reshaped using a more economical material, for example recovered or reused polyethylene terephthalate. The percentage of each of the two components may vary, as an example, it may be 50%. Thus, it is guaranteed that the contents of the container are in contact only with suitable material, and the coating layer serves to ensure the configuration of the container. This application does not reduce the quality of the capacity, and it can significantly reduce the cost of the product, since the cost of the source material is the most significant part of the final cost of the workpiece. In addition to economic benefits, the use of reclaimed material offers a very great environmental advantage, since it provides for the reuse and recovery of waste materials.

Another application made possible by the device and method of the present invention is the manufacture of two-color blanks, designed primarily to give the aesthetic value of the container, since they can be used to produce containers with a base color and a second color in the form of lines, stripes or gradual color transitions . To this end, for example, the base layer forming the inner surface of the preform, including the open end corresponding to the opening of the container, is first formed using a material of the first color, and then the coating layer is formed using a material of the second color, creating the desired shape. The design and shapes of these color coatings can create many combinations, so you can provide a very wide area of use.

In all cases, as a result of the successive steps of forming the base and multicomponent molding, the base layer and the coating layer are precisely delimited, thereby preventing the inaccuracies existing in the co-injection method described above. In some cases, the choice of materials for molding and multicomponent molding, as well as the conditions for their injection, provides the manufacture of hollow bodies made of two materials, or containers obtained by blowing from blanks made of two materials, in which two layers tend to separate from when they undergo certain mechanical deformations, for example, compression, whereby it is easier to separately recover two materials at the end of the actual product life.

Brief Description of the Drawings

The previously mentioned and other advantages and features will be fully understood from the following detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

1 is a schematic longitudinal sectional view of an apparatus for manufacturing hollow bodies made of two materials by injection multi-component molding in accordance with an embodiment of the present invention;

2 is a schematic longitudinal sectional view of an apparatus for manufacturing hollow bodies made of two materials by injection multi-component molding in accordance with another embodiment of the present invention;

figure 3 depicts a view in longitudinal section of an example of a hollow body made of two materials obtained by means of the device illustrated in figure 1;

FIG. 4 is a longitudinal sectional view of an example of a hollow body made of two materials obtained by the device illustrated in FIG. 2;

FIG. 5 is a schematic longitudinal sectional view of a device in accordance with another embodiment of the present invention obtained from the embodiment illustrated in FIG. 1;

FIG. 6 is a schematic longitudinal sectional view of a fixed part of a device in accordance with another embodiment of the present invention obtained from the embodiment illustrated in FIG. 2, including an alternative valve means;

Fig.7 depicts a front view of the fixed part of the device in accordance with the embodiment illustrated in Fig.5;

Fig.8 depicts a front view of the movable part of the device illustrated in Fig.7;

Fig.9 depicts a view in longitudinal section of another hollow body made of two materials, which can be obtained by means of the device of the present invention;

10 is a schematic longitudinal sectional view of an apparatus for manufacturing hollow bodies made of two materials by injection multi-component molding in accordance with yet another embodiment of the present invention;

11 is a longitudinal sectional view of an example of a hollow body made of two materials obtained by the device illustrated in FIG. 10, which also shows the end of the rod and the associated ejection member;

Fig. 12 is a cross-sectional view of a cavity for forming a base in accordance with another embodiment of the device of the present invention with a rod inserted in the cavity for forming the base and a first layer of a hollow body formed in a mold formed therebetween;

FIG. 13 is a cross-sectional view of a multi-component molding cavity according to the embodiment illustrated in FIG. 12 with a rod inserted therein and a second layer formed on said first layer to form a finished hollow body;

Fig.14 depicts a perspective view in partial section of a hollow body made of two materials, which can be obtained using the device illustrated in Fig.12 and 13.

The implementation of the invention

Figure 1 shows a device for manufacturing hollow bodies made of two materials by injection multi-component molding in accordance with the simplest embodiment of the present invention. In the embodiment illustrated in FIG. 1, said hollow body is a first type P blank made of two materials, shown in longitudinal section in FIG. 3.

A blank made of two materials, illustrated in FIG. 3, comprises a hollow plastic housing in the form of a test tube containing an opening 62 and a neck 61 with an external thread and a perimeter annular edge 63. Such blanks P are intended for the subsequent manufacture of plastic bottles by blowing. During the blasting process, the tube-shaped part is inflated until it takes the form of a hollow vessel or container body, while the neck 61, the hole 62 and the perimeter annular edge 63 remain unchanged. A blank P made of two materials is formed from a first layer P1 of a base molding material, for example, an initial polyethylene terephthalate, and a second layer P2 of a coating material, for example, recovered or reused polyethylene terephthalate, superimposed by multicomponent molding on said first layer P1. In this example, illustrated in FIG. 3, the neck 61, the hole 62, and the perimeter annular edge 63 are formed from the first layer P1. This means that the product contained in the container or vessel made by blowing from a preform of this type P made of two materials, illustrated in FIG. 3, will never come into contact with the second layer P2, thus preventing the possibility of product contamination, for example , recovered or reused material forming the second layer P2.

The device in accordance with this embodiment includes a fixed part, shown in figure 1 on the right, and a movable part, shown in figure 1 on the left. In the fixed part there is a cavity 1 for molding the base and the first and second end cavities 2a, 2b for multicomponent molding located at the same distance on both sides of the said cavity 1 for molding the base in the transverse direction DT in the direction of the recess of their shape or in the longitudinal direction DL. The first hot channel 10 is configured to feed the base molding material into the cavity 1 for molding the base, and the second hot channel 20 is configured to supply the multi-component molding material to said end cavities 2a, 2b for the multi-component molding. In said second hot channel 20, a valve 21 is arranged, which is adapted to alternately ensure or interrupt the passage of the multicomponent molding material towards one and the other of the first and second end cavities 2a, 2b for multicomponent molding in accordance with the cycle, which will be explained below.

The movable part comprises a support plate 30 on which a rod holder plate 32 is mounted, comprising a system of two rods 3 spaced apart from each other at a distance equal to the distance between the cavity 1 for forming the base and each of the first and second end cavities 2a, 2b for the multi-component molding. Said rod holder plate 32 is driven by conventional drive means (not shown) for alternately driving said support plate 30 in said transverse direction DT between two positions. In the first position (illustrated in FIG. 1), the rods 3 are aligned with the first set of cavities formed from the cavity 1 for molding the base and the first end cavity 2a for multicomponent molding. In a second position (not illustrated), the rods 3 are aligned with a second set of cavities formed from a cavity 1 for forming a base and a second end cavity 2b for multi-component molding. The support plate 30, in turn, is driven to provide longitudinal movement DL between a closed position (not illustrated) in which the rods 3 are inserted into said first or second sets of cavities and an open position (illustrated in FIG. 1), in which rods 3 or groups of rods 3 are removed from the first or second sets of cavities. The movable part also includes ejection means adapted to eject the molded ones, i.e. finished, preforms P made of two materials, only from rods 3, which are removed from one of the first and second end cavities 2a, 2b for multicomponent molding. In the embodiment illustrated in FIG. 1, said ejection means comprise two ejection elements 4, each ejection element 4 being connected to one of the rods 3. These ejection elements 4 are connected to respective ejector plates 40 driven by a drive means (not shown ) so that they can move independently and alternately between the molding positions and the ejection positions.

In the embodiment illustrated in FIG. 1, each ejector element 4 is in the form of a sleeve mounted on a corresponding rod 3, and has an annular surface 44 surrounding the rod 3. In said molding position (illustrated in FIG. 1 with respect to the rod 3, located opposite the first end cavity 2A for multicomponent molding), said end ring-shaped surface 44 of the ejector element 4 is located near the beginning of the molding surface of the rod 3, and in position of the pusher (illustrated in FIG. 1 with respect to the rod 3 opposite the molding cavity 1), the end annular surface 44 of the ejector element 4 is adjacent to or at a distance from the free end of the rod 3. When moving between the molding and ejection positions, the end annular surface 44 of the ejector element 4 is in contact with the workpiece P made of two materials, and pushes it from the rod 3. In addition, at least one part of the end annular surface 44 ka dogo ejecting element 4 is adapted to perform the function of the molding surface when the ejecting element 4 is in the molding position and the base plate 30 is in the closed position.

For forming an external thread neck 61 of a workpiece P made of two materials, the device comprises a half-mold holder plate 50 on which a pair of half-molds 5a, 5b is fixed, adapted and set in motion to ensure closure after opening the cavity 1 for forming the base and to ensure opening . The half-molds 5a, 5b contain corresponding inner surfaces forming part of the mold, which are configured to form the neck 61 of the workpiece P, made of two materials, with the corresponding thread. Thus, when the support plate 30 is in the closed position, the inner surface of the base molding cavity 1, the outer surface of the shaft 3, said end ring-shaped surface 44 of the ejector element 4, and the said inner surfaces of the half-molds 5a, 5b are adapted to form a mold for molding said the first layer P1 of the molding material of the base of the workpiece P made of two materials, including a neck with an external thread 61, formed by the inner surfaces of the half 5a, 5b. Injection of the molding material through the first channel 10 forms the first layer P1 on the rod 3 inserted into the cavity 1 for molding the base.

Then, the rod 3 on which the first layer P1 is molded is removed from the cavity 1 for forming the base and then introduced into one of the first or second end cavities 2a, 2b for multicomponent molding by a combination of movements of the support plate 30, the rod holder plate 32 and the holder plate 50 half-form. Suppose that the rod 3 is inserted into the first end cavity 2a for multicomponent molding, in this new position, the inner surface of the first end cavity 2a for multicomponent molding and the outer surface of the first layer P1 of the molding material of the base located on the rod 3 are adapted to form a mold for multicomponent molding of the second layer P2. The injection of the material for multicomponent molding into the first end cavity 2a for multicomponent molding through the second hot channel 20 provides the formation of a second layer P2 on the first layer P1 to obtain a finished workpiece P made of two materials. To this end, the valve 21 is pre-installed in the position (illustrated in figure 1), providing the passage of material for multicomponent molding only in the direction of the first end cavity 2A for multicomponent molding.

At the same time as the injection of the multicomponent molding material into the first end cavity 2a for multicomponent molding, the first layer P1 of the new blank P made of two materials is formed on another rod 3, which is simultaneously inserted into the cavity 1 for molding the base, by a new injection of the molding material of the substrate through the first hot channel 10. Then, the movement of the support plate 30 in the longitudinal direction DL towards the open position removes both rods 3 from the corresponding field spacers 1 for molding the base and the first end cavity 2a for multicomponent molding. Subsequent movement of the rod holder plate 32 in the transverse direction DT on the support plate 30 ensures alignment of the rod 3, recently removed from the first end cavity 2a for multicomponent molding, with the cavity 1 for forming the base and the rod 3, recently removed from the cavity 1 for forming the base, with second end cavity 2b for multicomponent molding. Then, the finished workpiece P, made of two materials, is pushed out of the rod 3, which was aligned with the cavity 1 for molding the base, by moving the corresponding ejector plate 40, and the valve 21 is set to the position (not illustrated), allowing the passage of material for multicomponent molding only towards the second end cavity 2b for multicomponent molding. Then, a new movement of the support plate 30 in the longitudinal direction DL towards the closed position introduces the rods 3 into the cavity 1 for molding the base and the second end cavity 2b for multi-component molding, respectively, and the half-molds 5a, 5b are closed and set to the molding position next to the opening of the cavity 1 for molding the basics. In this position, a new simultaneous injection of the base molding material into the cavity 1 for molding the base through the first hot channel 10 and the multi-component molding material into the second end cavity 2b for multi-component molding through the second hot channel 20 is carried out. New combinations of movements of the support plate 30, holder plate 32 the rods and the plate 50 of the holder of the half-mold removes the rods 3 from the corresponding cavity 1 for molding the base and the second end cavity 2b for multicomponent molding, and also combines them respectively with the first end cavity 2a for multicomponent molding and cavity 1 for molding the base. Then, the finished workpiece P made of two materials is pushed out of the rod 3, which is aligned with the cavity 1 for molding the base, by moving the corresponding ejector plate 40, and the valve 21 is again set to the position that the material for the multi-component molding passes only towards the first end cavity 2A for multicomponent molding, the position illustrated in figure 1. From this moment, the cycle can be repeated endlessly for the manufacture of a workpiece P made of two materials.

Preferably, if the ejection operation of the workpiece Q, made of two materials, is carried out when the corresponding rod is in a centered position relative to the support plate to prevent torque and to facilitate the collection of the ejected hollow bodies. In the embodiment illustrated in FIG. 1, an ejection operation is performed when the corresponding rod 3 is aligned with the cavity 1 to form the base, i.e. after removing the rods 3 and after moving them in the transverse direction DT.

The specialist in the field of injection molds and injection molding devices will understand that the device described previously in accordance with figure 1, provides many options and can be used for the manufacture of other types of blanks made of two materials, or hollow bodies made of two materials different from the workpiece P made of two materials.

FIG. 2 depicts another embodiment, which is an embodiment of the embodiment described in accordance with FIG. 1, and similar reference numbers are used to describe the same or equivalent elements. In the fixed part of the device illustrated in FIG. 2, the first and second end cavities 1a, 1b for forming the base are connected, connected to the first hot channel 10, between which there is a cavity 2 for multi-component molding, connected to the second hot channel 20. The valve 11 is installed in the first hot channel 10 to ensure alternately passing the molding material of the warp only towards one or the other of the first and second end cavities 1a, 1b for forming the warp. Here, the half-mold holder plate 5 with a pair of half-molds 5a, 5b is installed in accordance with one cavity 2 for multicomponent molding. The movable part has not changed compared to the movable part described in accordance with FIG. 1, and the injection and ejection cycle is also similar. However, in the first position (illustrated in FIG. 1), the rods 3 are aligned with the first set of cavities formed from the first end cavity 1a for forming the base and the cavity 2 for multi-component molding. In the second position (not illustrated), the rods 3 are aligned with the second set of cavities formed from the cavity 2 for multicomponent molding and the second end cavity 1b for forming the base. The hollow body made in this embodiment is a blank Q made of two materials, shown in longitudinal section in figure 4.

FIG. 4 depicts the aforementioned blank Q made of two materials, which, like the blank P made of two materials, illustrated in FIG. 3, is formed from a first layer Q1 of a base molding material and a second layer Q2 of a coating material. The difference here is that the external thread of the neck 61 and the perimeter annular edge 63 are formed from the material of the second layer Q2. This geometry can be used, for example, to create a container with a layer of protective material either inside (first layer Q1) or outside (second layer Q2), since in this example both layers cover the entire workpiece Q made of two materials, and the container, formed from them.

Thus, in the embodiment illustrated in FIG. 2, the inner surface of the base molding cavity 1a, 1b, the outer surface of the shaft 3 and the end annular surface 44 of the ejector element 4 are adapted to form a mold for molding the first layer Q1 of the base molding material, and the inner surface of the multicomponent molding cavity 2, the outer surface of the first layer Q1 of the base molding material and said inner surfaces of the half-molds 5a, 5b are adapted to form Ia mold for molding the outside of the second layer Q2 overmolding material, which here includes a neck 61 with external thread formed by the inner surfaces of the mold halves 5a, 5b.

The kinematic movement and stages of the injection and ejection cycle are similar to those described above in accordance with FIG. 1, the difference being that the valve 11 changes its position to allow the material for forming the substrate to pass through the first hot channel 10 towards one or the other of the first or second end cavities 1a, 1b for forming the base, and the workpiece Q made of two materials is ejected when the corresponding rod is in a centered position aligned with the Tew 2 for overmolding, i.e. after removing the rods 3 and before moving in the transverse direction DT.

Obviously, in both the embodiment illustrated in FIG. 1 and the embodiment illustrated in FIG. 2, changing the position of the valve 11, 21 and ejecting the finished workpiece P, Q made of two materials can be performed the same before or after removing the rods 3 by moving the support plate 30 toward the open position and before or after moving the rods 3 towards their positions aligned with the cavities located adjacent to the cavities from which they are removed. It is obvious that both the valve 21 illustrated in FIG. 1 and the valve 11 illustrated in FIG. 2 are shown schematically and can be replaced by any other valve means adapted to perform the same functions. In addition, two half-holder plates 50 and two half-mold pairs 5a and 5b associated with end cavities, or end cavities 1a, 1b for forming the base, or end cavities 2 for multi-component molding, can be used instead of one central plate 50 of the half-mold holder, although this implies useless duplication of devices.

FIG. 5 depicts another embodiment, which is a more complex version of the embodiment described above in accordance with FIG. 1, and like reference numbers are used to describe the same or equivalent elements. The device in accordance with the embodiment illustrated in FIG. 5 is suitable for the manufacture of type P blanks shown in FIG. 3.

The device illustrated in FIG. 5 comprises a first hot channel 10 configured to supply base material in the cavity 1 for forming the base in an amount n (in the illustrated example three), and a second hot channel 20 configured to supply multi-component molding material in the cavity 2, 2a, 2b for multicomponent molding in an amount of n + 1 (four in the illustrated example). The said cavities 1 for molding the base and the said cavities 2, 2a, 2b for multicomponent molding are alternately arranged in the system along the transverse direction DT with such a feature that the cavities located at the two ends of the said system are, respectively, the first and second end cavities 2a, 2b for multicomponent molding. A rod holder plate 32 is fixed to the support plate 30, containing a similar system of rods 3 in an amount of 2n (six in the illustrated example). The rod holder plate 32 is driven to provide alternating movement on the support plate 30 in the transverse direction DT between two positions in which the rods 3 are aligned with the first and second set of cavities. Said first set of cavities is formed from said number n (in the illustrated example of three) cavities 1 for forming the base and the number n (in the illustrated example of three) cavities 2, 2a for multicomponent molding, including all cavities 2 for multicomponent molding located between the cavities 1 for molding the base and the first end cavity 2A for multicomponent molding. Said second set of cavities is formed from said number n (in the illustrated example of three) cavities 1 for forming the base and the number n (in the illustrated example of three) cavities 2, 2b for multicomponent molding, including all cavities 2 for multicomponent molding located between the cavities 1 for molding the base and the second end cavity 2b for multicomponent molding. The support plate 30 is driven to provide longitudinal movement DL between the closed position in which the rods 3 are inserted into said first or second sets of cavities and the open position in which the rods 3 are removed from the first or second sets of cavities.

The device also comprises valve means, represented by a valve 21, installed in said second hot channel 20 for alternately securing or interrupting the passage of the multicomponent molding material towards the first and second end cavities 2a, 2b for multicomponent molding in accordance with the positions of the support plate 30 and the plate 32 rod holder. In this case, the ejection means is adapted to eject the multicomponent molded hollow bodies P from only those rods 3 that are removed from the cavities 2, 2a, 2b for multicomponent molding. The pushing means comprises 2n pushing elements 4 (six in the illustrated example), similar to those described above in accordance with FIG. 1, each pushing element 4 being connected to one of the rods 3. The pushing elements 4 are connected to respective pushing plates 40 driven independently and alternately. Each ejector element 4 has the shape of a sleeve mounted on a respective rod 3. The device comprises plates 50 of half-mold holders on which pairs of half-forms 5a, 5b are fixed in the amount of n (three are illustrated in the illustrated example), each pair of half-forms 5a, 5b being adapted and brought into movement to ensure closure after opening the cavities 1 for forming the base and for opening. The half molds 5a, 5b of each pair contain corresponding inner surfaces forming part of said mold for forming a workpiece P made of two materials. More specifically, the half-molds 5a, 5b are adapted to form a male threaded neck 61.

In the device of FIG. 5, a mold for molding a first layer P1 of a base material of each billet P made of two materials is formed from the inner surface of the corresponding cavity 1 for forming the base, the inner surfaces of the respective half-forms 5a, 5b, the outer surface of the corresponding rod 3 and the end annular surface 44 of the corresponding ejector element 4. Therefore, the first layer P1 will include a male neck 61. A mold for multi-component molding of a second layer P2 of multi-component molding material of each billet P made of two materials is formed from the inner surface of the respective multi-component molding cavity 2, 2a, 2b and the outer surface of said first layer P1 of the base molding material formed on the corresponding core 3.

6 depicts a fixed part in accordance with another alternative embodiment similar to that described in accordance with FIG. 5, but this is a more complex version of the embodiment described above in accordance with FIG. 2 than the embodiment of the device described in in accordance with figure 1. In other words, this is a device similar to the device described in accordance with FIG. 5, but adapted to produce blanks Q made of two materials, such as that shown in FIG. 4. In this case, the device comprises a first hot channel 10 configured to supply the base molding material in the cavity 1, 1a, 1b for forming the base in an amount of n + 1, and a second hot channel 20 configured to supply the multi-component molding material in the cavity 2 for multicomponent molding in the amount of n, the feature being that the cavities 1, 1a, 1b for forming the base and the cavity 2 for multicomponent molding are arranged alternately in the system along the transverse direction, and that the cavity E located at the two ends of the said system are, respectively, first and second end of the cavity 1a, 1b forming the base. In this case, the valve means is represented by a pair of valves 11a, 11b installed in the first hot channel 10 to alternately ensure or interrupt the passage of material for forming the base towards the first and second end cavities 1a, 1b for forming the base in accordance with the provisions of the support plate 30 and plate 32 of the rod holder. The plates 50 of the rod holders, on which pairs of half-forms 5a, 5b are fixed in the amount n for forming the threads of the outer part of the neck 61 of the workpiece Q, made of two materials, are connected to the holes of the cavities 2 for multicomponent molding. The movable part (not shown) of this embodiment is not different from the movable part described above in accordance with FIG. 5.

It should be noted that the arrangement of the two valves 11a and 11b illustrated in FIG. 6 and the one valve 11, 21 illustrated in FIGS. 1, 2 and 5 are two different alternative valve means equally applicable in any embodiment of the present invention . The choice of one or the other will depend on such factors as the viscosity of the injected molten plastic, the ease of machining, the simplicity of the mold design, etc. It should also be noted that in both embodiments illustrated in FIGS. 5 and 6, it is preferable if the operation the ejections of the blanks P, Q made of two materials are carried out when the respective rods 3 are aligned respectively with the cavities 1 for forming the base or the cavities 2 for multicomponent molding, i.e. when the respective rods 3 are in symmetrical positions relative to the center of the support plate 30.

7 and 8 depict front views, respectively, of the fixed part and the movable part of the device in accordance with the embodiment illustrated in FIG. 5, the purpose of which is to increase productivity. The only difference is that if in FIG. 5 there is a cavity 1 for molding the base, a cavity 2, 2a, 2b for multi-component molding or a pair of half-forms 5a, 5b, then in the embodiment illustrated in FIG. 7, there are also a number of cavities 1 for molding the base, a series of cavities 2, 2a, 2b for multicomponent molding or a series of pairs of half-forms 5a, 5b, respectively; and if in FIG. 5 there is a rod 3 with an ejector element 4 associated with it, then in the embodiment illustrated in FIG. 8, there are a number of rods 3 and a series of ejector elements 4 associated with them. In other words, FIG. 5 may be a longitudinal sectional side view of the device according to the embodiment illustrated in FIGS. 7 and 8, where each row extends in a second transverse direction perpendicular to said transverse direction DT, and contains the same the number m of elements located at the same distance from each other. As a result, in the fixed part illustrated in Fig. 7, there is a system of cavities formed of n rows (in the illustrated example of three) of m (in the illustrated example of four) cavities 1 for forming the base and n + 1 (in the illustrated example four) rows of m (in the illustrated example of four) cavities 2, 2a, 2b for multicomponent molding. In the moving part illustrated in FIG. 8, there are 2n (six illustrated) rows of m (four illustrated) rods 3.

All pairs of half-molds 5a, 5b of each row are mounted on a common half-plate holder plate 50, so that there are n half-plate holder plates 50, as illustrated in FIG. All rows of rods 3 are mounted on one rod holder plate 32, and the ejector elements 4 of each row are connected to a common ejector plate 40, so that 2n ejector plates 40 are available, as illustrated in FIG. Next to the support plate 30 is a drive plate 43 in the form of a frame in which the first selector elements 41 are installed in positions corresponding to the positions of the rows of cavities 1 for forming the base, and the second selector elements 42 are fixed in the support plate 30 in positions corresponding to the positions of the cavities 2, 2a, 2b for multi-component molding. The ejector plates 40 have configurations 45 adapted to alternately connect with said first and second picking elements 41, 42 in accordance with the first and second positions received by the rod holder plate 32 relative to the support plate 30 as a result of its movements in the transverse direction DT. Thus, the first selector elements 41 connect the ejector plates 40 to said drive plate 43, which is driven to provide movement in the longitudinal direction, driving the respective ejector plates 40 and the rows of ejector elements 4 associated therewith towards the ejection position during each pushing stage. The second selector elements 42 connect the respective ejector plates 40 and the rows of ejector elements 4 associated with them to the support plate 30, holding them in the molding position during each ejection step.

One skilled in the art will understand that an alternative embodiment (not illustrated) is possible right there, similar to the embodiment described in accordance with FIGS. 7 and 8, but obtained from the embodiment described above in accordance with FIG. 6, instead a variant of the device described in figure 5. In other words, a device similar to the device described in accordance with FIGS. 7 and 8, but adapted to produce blanks Q made of two materials, such as the device illustrated in FIG. 4. In this embodiment, the fixed part is not subjected to changes in relative to that shown in Fig. 8 in order to perform ejection operations when the respective rods 3 are in symmetrical positions relative to the support plate 30. This creates an additional advantage of providing a device for manufacturing workpieces made of two materials, type P, illustrated in figure 3, or type Q, illustrated in figure 4, by simply rearranging the cavities 1 to form the base and cavities 2 for multicomponent molding.

According to the embodiment described in accordance with FIGS. 7 and 8, the apparatus of the present invention includes a plurality of cavities and rods grouped into systems other than rows. For example, each row of cavities or rods can be replaced by a group of cavities or rods arranged in accordance with a matrix formed of several columns and several rows, however, other types of systems are possible, for example in a checkerboard pattern. Thus, where in Fig. 7 there is a series of cavities 1 for molding the base, a series of cavities 2, 2a, 2b for multicomponent molding, or a series of pairs of half-forms 5a, 5b, in this embodiment there is, respectively, a group of cavities 1 for forming the base, a group of cavities 2, 2a, 2b for multicomponent molding or a group of pairs of half-forms 5a, 5b. Similarly, where in Fig. 8 there is a row of rods 3 and a row of ejector elements 4 associated with them, in this embodiment there is a group of rods 3 and a group of ejector elements 4 associated with them.

All pairs of half-molds 5a, 5b of each group are mounted on a common half-plate holder plate 50, so that there are n half-mold holder plates 50, and all groups of rods 3 are mounted on one core-holder plate 32. The ejector elements 4 of each group are connected to a common ejector plate 40, so that there are 2n ejector plates 40 that are selectively driven by the drive plate in cooperation with the first and second ejection elements 41, 42, similar to that described above in in accordance with Fig.

Obviously, such an option is possible as described above, which includes groups of different row elements, but obtained from the embodiment illustrated in FIG. 2, for manufacturing a type Q blank made of two materials, illustrated in FIG. 4, instead of from the embodiment illustrated in FIG. 1, for manufacturing a blank of type P made of two materials, illustrated in FIG. 3. It is also obvious that any of the embodiments described above are applicable for the manufacture of other types of hollow bodies made of two materials, from blanks, such as, for example, covers, caps, glasses, containers, etc.

As an example, FIG. 9 depicts a vessel made of two materials, in the form of a cup V, suitable for manufacture by a device in accordance with any of the above embodiments. A cup V made of two materials is formed from a first layer V1 of a base molding material and a second layer V2 of coating material. Given that the shapes of the first and second layers V1, V2 of the cup V made of two materials provide for their direct removal from the mold without the need for half-molds adapted for opening and closing, half-molds 5a, 5b and the plate 50 of the half-mold holders can be eliminated.

Figure 10 depicts another embodiment of the device of the present invention, applicable for the manufacture of caps T made of two materials. 11 is a cross-sectional view of one of said caps T made of two materials, which is formed from a first layer T1 of a base molding material and a second layer T2 of a multi-component molding material. The device illustrated in FIG. 10 comprises a fixed part with a cavity 1 for molding the base, located between the first and second end cavities 2a for multicomponent molding. The first hot channel 10 is configured to feed the base molding material into the cavity 1 for molding the base, and the second hot channel 20 is configured to supply the multi-component molding material to the first and second end cavities 2a, 2b for the multi-component molding. Valve means, such as valve 21, are configured to alternately pass the multicomponent molding material into both first and second end cavities 2a, 2b for multicomponent molding. The movable part comprises a support plate 30, driven to provide longitudinal movement DL, a rod holder plate 32 mounted on the support plate 30 and driven to provide lateral movement DT in accordance with it, a pair of rods 3 attached to a rod holder plate 32, a pair of ejector elements 4, each connected to one of the rods 3, and one ejector plate 40 connected to the ejector elements 4 and driven to provide one temporary movement of the ejecting element 4 relative to the plate 32 of the holder rods in the longitudinal direction DL. The kinematics of the support plate 30 and the rod holder plate 32 are the same as described above in accordance with FIG.

The cap T, made of two materials, does not contain any external thread or other external configuration that requires half-molds adapted to close and open after opening the cavities 1 for molding the base or the cavities 2a, 2b for multicomponent molding, therefore, such half-molds are not used. However, as illustrated in FIG. 11, the first layer T1 of the cap T, made of two materials, forms an internal thread 64. The same figure 11 shows a rod 3 forming a mold part for the inner surface of the first layer T1, including the configuration of the press -forms 33 for said internal thread 64. The ejector element 4 is adapted to eject a cap T made of two materials, removing the internal thread 64 from the configurations of the mold 33 of the rod 3 by plastic deformation of the cap T made of two x materials. In the device illustrated in FIG. 10, the mold for the first layer T1 is formed from the inner surface of the cavity 1 for forming the base, the outer surface of the shaft 3 and the annular surface described in step 31 (FIG. 11) formed in the base of the shaft 3. The mold for the second layer T2 is formed from the inner surface of the first or second end cavity 2a, 2b for multicomponent molding, the outer surface of the first layer T1, placed on the rod 3, and the end annular surface 44 of the corresponding extruder element 4. As a result, the ejector element 4 can move towards its ejection position (shown in dashed lines in FIG. 11) without collision with the first layer T1 when it is on the rod 3. FIG. 11 shows the first layer T1 in dashed lines, when it is on the rod 3. However, when the ejector element 4 moves towards its ejection position, the end annular surface 44 collides with the second layer T2 of the cap T made of two materials formed on terzhne 3 for its ejection from the rod 3.

For this reason, in the embodiment illustrated in FIG. 10, two ejector elements are connected to the same ejector plate 40 and shown in their ejection positions. The ejector element 4 connected to the rod 3, located opposite the first end cavity 2a for multi-component molding, moves in the longitudinal direction DL without encountering the first layer T1 located on the rod 3. However, the ejector element 4 connected with the rod 3 located opposite the cavity 1 for molding, it moves in the longitudinal direction DL, colliding with the second layer T2, adhered to the first layer T1, thereby pushing the finished cap T made of two materials from the rod 3.

During injection molding of hollow bodies made of two materials, the wall thickness of the part is distributed between two layers of plastic. When the total wall thickness of the casing made of two materials is relatively small and the injected molten plastic has a relatively high viscosity, a negative moment may arise due to the fact that each of the two layers may be too thin to allow its injection within the respective parameters. With this negative aspect in mind, FIGS. 12 and 13 depict another embodiment of the apparatus of the present invention adapted for manufacturing hollow W-type housings made of two materials, such as the housing shown in cross section in FIG. 14. The feature of the embodiment illustrated in FIGS. 12 and 13 affects only the configuration of the cavities 1, 1a, 1b for forming the base and is compatible with any of the previously described embodiments of the device of the present invention.

12 is a cross-sectional view of one of the cavities 1 for forming a base in accordance with this embodiment. On the surface of the base molding cavity 1, grooves 65 are made extending in the longitudinal direction DL or the direction of extraction from the mold. These grooves 65 are located next to each other and distributed around the perimeter of the cavity 1 for forming the base. In the illustrated example, said grooves 65 have rounded edges and are laterally connected to each other by also rounded edges, together forming a wavy cross-sectional profile. Obviously, other profiles are possible, other than the profiles shown in Figs. 12 and 13. Inside the cavity 1 for forming the base, an inserted corresponding rod 3 is shown having an outer profile surface corresponding to the shape of the inner surface of the hollow body W made of two materials . Thus, between said inner surface of the base molding cavity 1 and said outer surface of the shaft 3, a series of channels formed by said grooves 65 are formed. When the base molding material is injected into the base cavity 1, it is preferable if molten plastic flows along said channels, and also flows laterally from one channel to another, while easily connecting to form the first layer W1, the outer surface of which reproduces negative grooves 66 corresponding to said cavity grooves 65. The grooves 65 are configured and made in the cavity 1 for forming the base with the possibility of forming the aforementioned corresponding negative grooves 66 in the area of the first layer W1, located opposite the inner profile surface of the cavity 2 for multicomponent molding.

13 is a cross-sectional view of one of the multi-component molding cavities 2 in accordance with this embodiment comprising a conventional inner surface. Inside the multi-component molding cavity 2, an inserted corresponding rod 3 is shown with a first layer W1 that has previously been formed in the cavity 1 for forming the substrate. Thus, between the said inner surface of the multicomponent molding cavity 2 and the outer surface of the first layer W1, a series of channels are formed formed by said negative grooves 66. When the multicomponent molding material is injected into the multicomponent molding cavity 2, it is preferable if the molten plastic flows along the said channels and also flows laterally from one channel to another, while the outer surface is easily connected to form a second layer W2 which reproduces the usual form determined by the inner surface of the cavity 2 for multicomponent molding.

Fig.14 depicts a hollow body W made of two materials obtained by the cavity 1 for forming the base in accordance with the embodiment illustrated in Fig.12 and 13. The hollow body is a workpiece W made of two materials, in which the first layer W1 it forms a neck 61 and a perimeter edge 63, and the second layer W2 is superimposed on the first layer W1 only in the part made in the form of a test tube adapted for molding as a container body by means of blasting. The first and second layers W1 and W2 contain thicker longitudinal sections and thinner longitudinal sections, alternating in the perimeter direction. The contact area of the first and second layers W1 and W2 is clearly delimited by the surface of the negative grooves 66 formed initially on the first layer W1.

One skilled in the art will understand that the cavity 1 for forming the base with the grooves 65 described in accordance with FIGS. 12 and 13 is applicable to any device for manufacturing hollow bodies made of two materials by injection multi-component molding, provided that this device comprises at least one of said cavities 1 for forming a base and at least one rod 3 inserted into it for forming a base of a first layer W1 of said hollow body W made of two materials, and at least one cavity 2 for multicomponent molding and at least one rod 3 inserted into it, said first layer W1 being located on the rod 3 for multicomponent molding of the second layer W2 of the hollow body W made of two materials, on the first layer W1.

A method for manufacturing hollow bodies made of two materials by injection multicomponent molding using the device in accordance with the embodiment illustrated in FIG. 1 or any of the embodiments and options obtained from the embodiment illustrated in FIG. 1 includes The following cyclic steps:

a) inserting a system of rods 3 with a first layer of base molding material molded on the first half of the rods 3 into said second set of cavities, said first layer of base molding material being formed on said second half of the rods 3 in the previous molding cycle;

b) installing said valve means 21 to permit the passage of the base molding material toward the second end cavity 2b for multi-component molding or the second end group of cavities 2b for multi-component molding;

c) simultaneously injecting the base molding material through said first hot channel 10 in the cavity 1 for molding the base and the multi-component molding material through the second hot channel 20 in the multi-component molding cavity 2, 2b;

d) removing the system of rods 3 from the second set of cavities with a first layer of base molding material formed on the second half of the rods 3 and finished with hollow bodies P, Q, T, V, W made of two materials formed from the first layer of the base molding material and a second layer of multicomponent molding material molded on said first half of the rods 3;

e) moving the rod system 3 until it is aligned with the first set of cavities;

f) expelling the hollow body P, Q, T, V, W or the hollow body P, Q, T, V, W from the first half of the rods 3;

g) inserting the configuration of the rods 3 with the first layer of the base molding material formed on said second half of the rods 3 into the first set of cavities;

i) installing said valve means 21 to allow the passage of the multi-component molding material toward the first end cavity 2a for multi-component molding or the first end group of cavities 2a for multi-component molding;

j) simultaneously injecting the base molding material through the first hot channel 10 in the cavity 1 for molding the base and the multi-component molding material through said second hot channel 20 in the multi-component molding cavity 2, 2a;

k) removing the system of rods 3 from the first set of cavities with a first layer of base molding material molded on the first half of the rods 3 and hollow bodies made of two materials P, Q, T, V, W formed from the first layer of the base molding material and a second layer of multicomponent molding material molded on the second half of the rods 3;

l) moving the system of rods 3 until it is combined with the second set of cavities;

m) expelling the hollow body P, Q, T, V, W or the hollow body P, Q, T, V, W from the second half of the rods 3.

A method of manufacturing hollow bodies made of two materials by injection multicomponent molding using the device in accordance with the embodiment illustrated in FIG. 2, or any of the embodiments obtained from the embodiment illustrated in FIG. 2, includes The following steps:

a) inserting a system of rods 3 with a first layer of base molding material formed on the first half of the rods 3 into said second set of cavities, said first layer of base molding material being formed on said first half of the rods 3 in the previous molding cycle;

b) installing said valve means 11, 11a, 11b to allow the passage of the base molding material toward the second end cavity 1b for forming the base or the second end group of cavities 1b for forming the base;

c) simultaneously injecting the base molding material through the first hot channel 10 in the cavity 1, 1b to mold the base and the multi-component molding material through the second hot channel 20 in the multi-component cavity 2;

d) removing the system of rods 3 from the second set of cavities with a first layer of base molding material formed on the second half of the rods 3 and finished with hollow bodies P, Q, T, V, W made of two materials formed from the first layer of the base molding material and a second layer of multicomponent molding material molded on the first half of the rods 3;

e) expelling the hollow body P, Q, T, V, W or the hollow body P, Q, T, V, W from the first half of the rods 3;

f) moving the rod system 3 until it is aligned with the first set of cavities;

g) inserting a system of rods 3 with a first layer of base molding material formed on said second half of rods 3 into the first set of cavities;

i) installing said valve means 11, 11a, 11b to allow the passage of the base molding material toward the first end cavity 1a for forming the base or the first end group of cavities 1a for forming the base;

j) simultaneously injecting the base molding material through the first hot channel 10 in the cavity 1, 1a for molding the base and the multi-component molding material through said second hot channel 20 in the multi-component molding cavity 2;

k) removing the system of rods 3 from the first set of cavities with a first layer of base molding material molded on the first half of the rods 3 and hollow bodies made of two materials P, Q, T, V, W formed from the first layer of the base molding material and a second layer of multicomponent molding material molded on the second half of the rods 3;

l) expelling the hollow body P, Q, T, V, W or the hollow body P, Q, T, V, W from the first half of the rods 3;

m) moving the system of rods 3 to combine it with a second set of cavities.

You must understand that in both versions of the method, some steps can be performed in an order different from the order described above. For example, the steps of pushing out the hollow bodies and / or the steps of controlling the distribution of the molding material or multicomponent molding into the end cavities by means of the valve means can be performed the same way before or after the steps of moving the rod system in the transverse direction DT to align it with the next first or second sets of cavities.

In any of the embodiments of the present invention, the cavity for molding the base, the cavity for multicomponent molding and the rods are equipped with cooling fluid circuits of the usual type, which are not described and which provide adequate cooling of the layers of the molding material and the multicomponent molding material.

One skilled in the art will be able to make changes and modifications to the illustrated and described embodiments without departing from the scope of the claims of the present invention as defined in the appended claims.

Claims (15)

1. A device for the manufacture of hollow housings made of two materials by injection multicomponent molding, containing
the first hot channel (10), configured to feed the base molding material into the cavity (1) for forming the base or a group of cavities (1) for forming the base, the number of which is n;
the second hot channel (20), configured to supply multicomponent molding material in the cavity (2, 2a, 2b) for multicomponent molding or a group of cavities (2, 2a, 2b) for multicomponent molding, the number of which is n + 1,
wherein said cavities (1) for molding a base or group of cavities (1) for molding a base and said cavities (2, 2a, 2b) for multicomponent molding or a group of cavities (2, 2a, 2b) for multicomponent molding are placed alternately in the system along the transverse directions (DT), while the cavities or group of cavities located at the two ends of the said system are the first and second end cavities (2a, 2b) for multi-component molding, respectively, or the first and second end groups of cavities (2a, 2b) for multi-component entnogo molding;
a support plate (30) on which a rod holder plate (32) is installed, containing a similar system of rods (3) or groups of rods (3), the number of which is 2n,
wherein said rod-holder plate (32) is driven to provide alternating movement on the support plate (30) in said transverse direction (DT) between two positions in which the rods (3) or groups of rods (3) are aligned with the first and second sets of cavities, each of which is formed from the aforementioned number of n cavities (1) for molding a base or group of cavities (1) for molding a base and the number of n cavities (2, 2a, 2b) for multicomponent molding or groups of cavities (2, 2a, 20 ) for many component molding, including one or the other of the first and second end cavities (2a, 2b) for multicomponent molding or the first and second end groups of cavities (2a, 2b) for multicomponent molding, respectively, and wherein said support plate (30) is provided in movement in such a way that it can move in the longitudinal direction (DT) between the closed position in which the rods (3) or groups of rods (3) are inserted into the aforementioned first or second sets of cavities, and the open position in which the rod and (3) or groups of cores (3) are extracted from the first or second sets of cavities;
valve means (21) installed in said second hot channel (20) for alternately providing or interrupting the passage of the multicomponent molding material towards the first and second end cavities (2a, 2b) for multicomponent molding or the first and second end groups of cavities (2a, 2b) for multicomponent molding in accordance with the provisions of the support plate (30) and the plate (32) of the rod holder; and
ejector means configured to eject finished hollow bodies (P, Q, T, V, W) only from those rods (3) or groups of rods (3) that are removed from the cavities (2, 2a, 2b) for multicomponent molding or cavity groups (2, 2a, 2b) for multicomponent molding. 2. The device according to claim 1, characterized in that said ejector means comprises ejection elements (4) or groups of ejection elements (4) in an amount of 2n, each ejection element (4) connected to one of the rods (3), said ejection elements (4) or groups of ejector elements (4) are connected to the corresponding ejector plates (40), driven independently and alternately. 3. The device according to claim 2, characterized in that each ejector element (4) has the shape of a sleeve mounted on the corresponding rod (3), each mold for molding the base of the hollow body (P, Q, T, V, W) formed at least partially from the inner surface of one of the cavities (1) for molding the base, the outer surface of the rod inserted into it (3) and the end annular surface (44) of the corresponding ejector element (4), and each mold is for a multi-component molding a hollow body (P, Q, T, V, W) is formed, p at least partially from the inner surface of one of the cavities (2, 2a, 2b) for multicomponent molding and the outer surface of the first layer of the base molding material formed on the inserted rod (3), said first layer of the base molding material being preformed into one of the cavities (1) for forming the base. 4. The device according to claim 3, characterized in that it contains one or more plates (50) of holders of the half-molds, on which pairs of half-forms (5a, 5b) or groups of pairs of half-forms (5a, 5b) are installed in the amount of n, each pair the half-molds (5a, 5b) are adapted and set in motion to ensure closure after opening the cavities (1) for molding the base and for opening, while the half-molds (5a, 5b) of each pair contain corresponding inner surfaces forming part of said molding mold hollow body (P, Q, T, V, W), said hollow body (P, Q, T, V, W) is a preform (P) made of two materials, said inner surface of a cavity (1) for forming a base, said outer surface of a shaft (3), said end ring-shaped surface (44) of an ejector element (4) and the said inner surfaces of the half-molds (5a, 5b) are configured to mold for molding the first layer (P1) of the molding material of the base of said blank (P) made of two materials, including a neck (61) with external thread formed by the inner surfaces of the half-molds (5a, 5b), and said inner surface of the cavity (2, 2a, 2b) for multi-component molding and said outer surface of said first layer (P1) of the base molding material are configured to form a mold for multi-component molding the second layer (P2) of the material of multicomponent molding of a preform (P) made of two materials. 5. The device according to claim 1, characterized in that said number of n groups of cavities (1) for forming the base is the number n of rows of cavities (1) for forming the base, said number of n + 1 groups of cavities (2, 2a, 2b) for multicomponent molding is the number of n + 1 rows of cavities (2, 2a, 2b) for multicomponent molding, and the mentioned number of 2n groups of rods (3) is the number of 2n rows of rods (3). 6. A method of manufacturing hollow bodies made of two materials by injection multi-component molding using a device with placement of cavities (1) for molding, cavities (2, 2a, 2b) for multi-component molding, rods (3), valve means (21) and ejecting means (4, 40), described in claim 1, characterized in that it contains the steps:
alternately inserting the rods (3) into the corresponding first and second sets of cavities;
simultaneous injection of the base molding material in the cavity (1) for molding the base and the multi-component molding material in the cavity (2, 2a, 2b) for the multi-component molding of the corresponding first and second sets of cavities;
selective control of the alternate distribution of multicomponent molding material in the end cavities (2a, 2b) for multicomponent molding of the first or second set of cavities into which the rods are inserted (3);
extracting the rods (3) from the corresponding first or second set of cavities after each injection operation with the first layer of molding material formed on the first half of the rods (3) and the finished hollow body (P, Q, T, V, W) formed from the above a first layer of molding material and a second layer of multicomponent molding material formed on the second half of the rods (3); and
pushing the finished hollow bodies (P, Q, T, V, W) from the rods (3) of said second half of the rods (3). 7. The method according to claim 6, containing the initial stages:
inserting said rod system (3) or rod groups (3) into said first set of cavities;
injection of the base molding material through the first hot channel (10) in the cavity (1) to form the base;
extracting a system of rods (3) from said first set of cavities with a first layer of base molding material formed on the first half of the rods (3); and
moving the rod system (3) until it is combined with the second set of cavities;
and then the cyclic steps:
a) inserting a system of rods (3) with a first layer of base molding material molded on the first half of the rods (3) into said second set of cavities;
b) installing said valve means (21) to allow the passage of the multi-component molding material toward the second end cavity (2b) for multi-component molding or the second end group of cavities (2b) for multi-component molding;
c) simultaneously injecting the base molding material through said first hot channel (10) in the cavity (1) for molding the base and the multi-component molding material through the second hot channel (20) in the cavity (2, 2b) for multi-component molding;
d) removing the system of rods (3) from the second set of cavities with the first layer of the base molding material formed on the second half of the rods (3) and finished hollow bodies (P, Q, T, V, W) made of two materials formed from the first layer of the base molding material and the second layer of multicomponent molding material molded on the first half of the rods (3);
e) moving the rod system (3) until it is aligned with the first set of cavities;
f) pushing out the hollow body (P, Q, T, V, W) or the hollow body (P, Q, T, V, W) from the first half of the rods (3);
g) inserting a system of rods (3) with a first layer of base molding material molded on the second half of the rods (3) into the first set of cavities;
i) installing said valve means (21) to allow the passage of the multi-component molding material towards the first end cavity (2a) for multi-component molding or the first end group of cavities (2a) for multi-component molding;
j) simultaneously injecting the base molding material through the first hot channel (10) in the cavity (1) for molding the base and the multi-component molding material through the second hot channel (20) in the cavity (2, 2a) for multi-component molding;
k) removing the system of rods (3) from the first set of cavities with the first layer of the base molding material formed on the first half of the rods (3) and finished with hollow bodies (P, Q, T, V, W) made of two materials formed from the first layer of the base molding material and the second layer of multicomponent molding material molded on the second half of the rods (3);
l) moving the rod system (3) until it is combined with the second set of cavities; and
m) pushing out the hollow body (P, Q, T, V, W) or the hollow body (P, Q, T, V, W) from the second half of the rods (3). 8. A device for the manufacture of hollow bodies made of two materials by injection multicomponent molding, containing
the first hot channel (10), configured to supply the base molding material in the cavity (1, 1a, 1b) for forming the base or a group of cavities (1, 1a, 1b) for forming the base, the number of which is n + 1;
a second hot channel (20), configured to feed the multicomponent molding material into the cavity (2) for multicomponent molding or a group of cavities (2) for multicomponent molding, the number of which is n;
wherein said cavities (1, 1a, 1b) for forming a base or group of cavities (1, 1a, 1b) for forming a base and said cavities (2) for multi-component molding or a group of cavities (2) for multi-component molding are arranged alternately in the system along the transverse directions (DT), and in this case, the cavities or groups of cavities located at the two ends of the said system are, respectively, the first and second end cavities (1a, 1b) for forming the base or the first and second end groups of cavities (1a, 1b) for forming the base ;
a support plate (30) on which a rod holder plate (32) is installed, containing a similar system of rods (3) or groups of rods (3), the number of which is 2n,
wherein said rod-holder plate (32) is driven to provide alternating movement on the support plate (30) in said transverse direction (DT) between two positions in which the rods (3) or groups of rods (3) are aligned with the first and second sets of cavities, each of which is formed from the above number of n cavities (2) for multicomponent molding or groups of cavities (2) for multicomponent molding and the number of n cavities (1, 1a, 1b) for molding the base or groups of cavities (1, 1a, 1b) for forming the base, including, respectively, one or the other of the first and second end cavities (1a, 1b) for forming the base or the first and second end groups of cavities (1a, 1b) for forming the base, and wherein said support plate (30 ) is set in motion to allow movement in the longitudinal direction (DL) between the closed position in which the rods (3) or groups of rods (3) are inserted into said first or second sets of cavities and the open position in which the rods (3) or groups rods (3) removed from ervogo or second sets of cavities;
valve means (11, 11a, 11b) installed in said first hot channel (10) for alternately securing or interrupting the passage of the base molding material towards the first and second end cavities (1a, 1b) for forming the base or the first and second end groups cavities (1a, 1b) for forming the base in accordance with the provisions of the support plate (30) and the plate (32) of the rod holder; and
ejector means configured to eject finished hollow bodies (P, Q, T, V, W) only from those rods (3) or groups of rods (3) that are removed from the cavities (2) for multicomponent molding or groups of cavities (2 ) for multicomponent molding. 9. The device according to claim 8, characterized in that said ejector means comprises ejection elements (4) or groups of ejection elements (4) in an amount of 2n, wherein each ejection element (4) is connected to one of the rods (3), said ejector elements (4) or groups of ejector elements (4) are connected to the corresponding ejector plates (40), driven independently and alternately. 10. The device according to claim 9, characterized in that each ejector element (4) has the shape of a sleeve mounted on the corresponding rod (3), each mold for molding the base of the hollow body (P, Q, T, V, W) formed at least partially from the inner surface of one of the cavities (1, 1a, 1b) for forming the base, the outer surface of the rod inserted into it (3), and the end annular surface (44) of the corresponding ejector element (4), and each mold for multicomponent molding of a hollow body (P, Q, T, V, W) at least partially from the inner surface of one of the cavities (2) for multicomponent molding and the outer surface of the first layer of the molding material of the base formed on the inserted rod (3), said first layer of the molding material of the base being preformed in one of cavities (1, 1a, 1b) for forming the base. 11. The device according to claim 10, characterized in that it contains one or more plates (50) of holders of the half-molds, on which pairs of half-forms (5a, 5b) or groups of pairs of half-forms (5a, 5b) are installed in the amount of n, each pair the half-molds (5a, 5b) are adapted and driven to provide closure after opening the cavities (2) for multi-component molding and for opening, the half-molds (5a, 5b) of each pair contain corresponding inner surfaces forming part of said mold for molding the hollow body (P, Q, T, V, W) referred to by hollow co the blank (P, Q, T, V, W) is a blank (Q) made of two materials, said inner surface of the cavity (1, 1a, 1b) for forming the base, said outer surface of the rod (3) and said ring-shaped end the surface (44) of the ejector element (4) is configured to form a mold for molding said first layer (Q1) of a molding material of a base of said blank (Q) made of two materials, and said inner surface of a cavity (2) for multicomponent molding, mentioned the outer surface of said first layer (Q1) of the base molding material and said inner surfaces of the half-molds (5a, 5b) are configured to mold for multi-component molding of a second layer (Q2) of multi-component molding material of a preform (Q) made of two materials, including the outer part of the neck (61) with an external thread formed by the inner surfaces of the half-molds (5a, 5b). 12. The device according to claim 8, characterized in that the said number n + 1 groups of cavities (1, 1a, 1b) for forming the base is the number n + 1 rows of cavities (1, 1a, 1b) for forming the base, said number n the number of cavity groups (2) for multicomponent molding is the number of n rows of cavities (2) for multicomponent molding, and the mentioned number of 2n groups of rods (3) is the number of 2n rows of rods (3). 13. A method of manufacturing hollow bodies made of two materials by injection multicomponent molding using a device with placement of cavities (1, 1a, 1b) for molding the base, cavities (2) for multicomponent molding, rods (3), valve means (11 11a, 11b) and ejecting means (4, 40) described in claim 8, characterized in that it includes the steps of:
alternately inserting the rods (3) into the corresponding first and second sets of cavities;
simultaneous injection of the base molding material in the cavity (1) for molding the base and the multi-component molding material in the cavity (2, 2a; 2, 2b) for the multi-component molding of the corresponding first and second sets of cavities;
selective control of the alternate distribution of multicomponent molding material in the end cavities (1a, 1b) to form the base of the first or second set of cavities into which the rods (3) are inserted;
extracting the rods (3) from the corresponding first or second set of cavities after each injection operation with the first layer of molding material formed on the first half of the rods (3) and the finished hollow body (P, Q, T, V, W) formed from the above a first layer of molding material and a second layer of multicomponent molding material formed on the second half of the rods (3); and
pushing the finished hollow bodies (P, Q, T, V, W) from the rods (3) of said second half. 14. The method according to item 13, containing the initial stages:
inserting said rod system (3) or rod groups (3) into said first set of cavities;
installing said valve means (11, 11a, 11b) to allow the passage of the base molding material toward the first end cavity (1a) for forming the base or the first end group of cavities (1a) for forming the base;
injection of the base molding material through the first hot channel (10) in the cavity (1, 1a) to form the base;
extracting a system of rods (3) from said first set of cavities with a first layer of base molding material formed on the first half of the rods (3); and
moving the rod system (3) until it is combined with the second set of cavities;
and then the cyclic steps:
a) inserting a system of rods (3) with a first layer of base molding material molded on the first half of the rods (3) in said second set of cavities;
b) installing said valve means (11, 11a, 11b) to allow the passage of the base molding material toward the second end cavity (1b) for forming the base or the second end group of cavities (1b) for forming the base;
c) simultaneously injecting the base molding material through said first hot channel (10) in the cavity (1, 1b) to mold the base and the multi-component molding material through the second hot channel (20) in the cavity (2) for multi-component molding;
d) removing the system of rods (3) from the second set of cavities with the first layer of the base molding material formed on the second half of the rods (3) and finished hollow bodies (P, Q, T, V, W) made of two materials formed from the first layer of the base molding material and the second layer of multicomponent molding material molded on the first half of the rods (3);
e) pushing the hollow body (P, Q, T, V, W) or hollow body (P, Q, T, V, W) from the first half of the rods (3);
f) moving the rod system (3) until it is combined with the first set of cavities;
g) inserting a system of rods (3) with a first layer of base molding material molded on the second half of the rods (3) into the first set of cavities;
i) installing said valve means (11, 11a, 11b) to allow passage of the base molding material toward the first end cavity (1a) for forming the base or the first end group of cavities (1a) for forming the base;
j) simultaneously injecting the base molding material through the first hot channel (10) in the cavity (1, 1a) to mold the base and the multi-component molding material through the second hot channel (20) in the cavity (2) for multi-component molding;
k) removing the system of rods (3) from the first set of cavities with the first layer of the base molding material formed on the first half of the rods (3) and finished with hollow bodies (P, Q, T, V, W) made of two materials formed from the first layer of the base molding material and the second layer of multicomponent molding material molded on the second half of the rods (3);
l) expelling the hollow body (P, Q, T, V, W) or the hollow body (P, Q, T, V, W) from the second half of the rods (3); and
m) moving the rod system (3) until it is combined with the second set of cavities. 15. The method according to claim 6 or 13, characterized in that it comprises the step of selecting a base molding material or multicomponent molding material from the group including recovered plastic material and a plastic protective material, and the step of configuring the cavities (1, 1a, 1b) for molding bases, cavities (2) for multicomponent molding and rods (3) in such a way that each of the first and second layers covers a well-defined area of the hollow body (P, Q, T, V, W).

Images