JPS6238132B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a distributor for manufacturing a synthetic resin laminate that facilitates the manufacturing of various synthetic resin laminates.

More specifically, the present invention produces laminated sheets of thermoplastic resin or other layers by combining different materials together before extruding them through a forming die. Regarding the distributor for.

BACKGROUND OF THE INVENTION Conventionally, materials are generally introduced into the injection tube of a forming die in coaxial, or at least parallel, flow to combine materials while avoiding mixing of the materials. In this regard, for example, French patent no.
No. 1486660 and two supplementary patents to this patent, No. 92331 and No. 92986, respectively. With this method, by using coaxial cylindrical flow,
It is possible to produce a uniformly ordered sheet metal comprising an inner layer and at least a layer that is to cover this inner layer. Thus, sheets are made of sandwich material in which the other layers are arranged symmetrically or asymmetrically with respect to the inner layer. It has already been considered to further modify this method by arranging radial partitions in the path of the flow to separate the outer flow and allow injection of different materials on each side of the inner layer. Still other examples use parallel channels separated by partition walls. Into this path various materials are placed, which are to touch each other at the ends of the parallel paths, avoiding any risk of turbulence or mixing, as in the previous example. (French patent no. 1495368). It is thus possible to produce laminates containing several different layers.

(Problems to be Solved by the Invention) In the devices described in these, the sheet obtained from the die connected to its output side can have several overlapping layers, in which case the flow layer Their width is simply expanded in the die while their thickness is simultaneously reduced.

However, this process requires the presence of connecting parts that limit the number of different flow passages in a certain length and provide a guiding partition, i.e. a connecting part with a precise shape and therefore relatively difficult to realize. is absolutely essential. Therefore, when manufacturing a laminate by coextrusion, the entire distributor installed between the extruder that supplies the melt and the molding die can be replaced to change the composition of the laminate. I needed to. Therefore, replacement work is complicated, and it is also economically problematic to prepare spare distributors for each set, which are generally large. The main drawback of all these prior art is the difficulty in creating a block which allows a number of individual streams to be directed into a single stream. There is prior art described in an application filed by the applicant in 1972, but the block was so complex that it was almost impossible to make. Moreover, it was necessary to create special blocks when the size of the constituent streams was changed.

(Means for Solving the Problem) As a result of various studies conducted by the present inventors in order to eliminate the drawbacks of these conventional methods, the present inventors found that a main path for guiding the first molten material to a die for forming a laminate in each connected block;
In addition, in each block except for the downstream terminal block, there is a sub-path for each melt that runs parallel to the main path and leads to the second and subsequent melts, and a sub-path for directing the molten material from the sub-path to one of the joint surfaces of each block. It has now been discovered that a distributor having a connecting passageway that joins a connecting passageway is advantageous when manufacturing various synthetic resin laminates. This method is advantageous because when changing the configuration of the laminate, it is sufficient to partially replace the blocks constituting the distributor.

The structure of this distributor is very simple, and in practical use, the number of layers in the thin plate can be increased or the properties and locations of the layers in the thin plate can be changed with simple operations.

Each synthetic resin melt can be fed by an extruder. That is, this distributor is connected to at least two extruders of thermoplastic synthetic resin, in which several streams of material are combined into a main channel connecting with the inlet of the molding die. . This distributor consists of a set of ring-shaped blocks connected to define the aforementioned main passage, but an inlet block may be placed at the end of this set of blocks. In this distributor, sub-paths are created which are respectively connected to the extruder described above, and each block is connected to the above-mentioned main path and connected to one of the sub-paths in a radial or other shape. have at least one.

These properties allow each block of a set of articulated blocks to pass through one or more layers determined by the sausage melt inserted into the forming die. For this reason, it is easy to increase the number of laminate layers to be obtained, for example by increasing the number of blocks of the distributor. Furthermore, by changing the location where the radial or other communication channel of the block connects to the main channel, it is easy to change the location of the overlap within the sausage-shaped melt entering the forming die.

The blocks are packed together using copper plates or the like, and are fastened together using conventional means. If it is necessary to keep the molten material passing through the block warm, it is heated with electricity or the like and insulated.
The main path of melt passes through each block, but the secondary paths typically terminate at a point where they join the main path. However, according to the present invention, by extending the sub-path further, the same type of synthetic resin can be appropriately laminated again, so there is no need to additionally install an extruder, which is extremely convenient. When the molten material merges from the secondary path to the main path, a groove provided on either side of the joint surface of the block is used as a communication path.
The connecting path must have an inclined surface near where it joins the main path, and the shape of the connecting path must be selected appropriately, taking into account the melt viscosity of each synthetic resin to be laminated, the thickness of the lamination, etc. The melt discharge pressure and discharge rate should also be controlled.

Next, the present invention will be explained in more detail with reference to embodiments shown in the drawings.

FIG. 1 shows a schematic diagram of an installation for producing multilayer sheets of thermoplastic synthetic resin using a distributor according to the invention. The installation includes a molding die A, the inlet B of which is connected to a distributor 1 according to the invention. This distributor 1 receives via a collector C several extrudates of thermoplastic synthetic resin of different properties (for example with respect to composition and color).

In this case, the collector C is connected to four extruders D ₁ to D ₄ , each producing the extrudates mentioned above.

2 to 10 illustrate a distributor according to the present invention.
As can be seen in FIG. 2, the distributor of the present invention comprises a set of connected blocks, each of which consists of four blocks, numbered 2 to 5, as noted below. It is placed between and connected to the inlet block 6 and the outlet block 7 (both of which have the same axis as blocks 2 to 5 and are circular in shape).

Each block has a threaded rod 9 extending through the blocks to receive a locking nut 10.
Eight shaft holes 8 are carved through which the holes pass. Suspension ears 11 make the distributor easy to handle, and are provided at both ends of the distributor and fixed to two adjacent bars 9. Thus, the inlet block 6 and each block 2 to 5 each have a peripheral annular portion 12 which, when assembled, fits into a peripheral matching portion 13 made on the opposite side of the adjacent block. It is prepared in one of the aspects. Disc-shaped leakproof packings 14 are placed between adjacent sets of blocks, each packing 14 having an opening adapted to fit into the intervening block. Additionally, the entire block assembly provides a circumferential groove 15 for receiving the heating ring (see especially FIG. 3). Each heating ring includes an electrical heating resistor connected in a manner known per se via a socket 17 and a plug 18 to a current source (not shown), and the whole is connected to a temperature regulator (not shown). adjusted via. Upstream from D ₁
Four channels 19a to 19d are included in the inlet block 6, which are to be connected to respective extruders up to _D4 .

Blocks 2 to 5 each have a hole in the center, and their alignment determines the main path 20 of the distributor. The main passage 20 communicates with an outlet passage 21 formed in the outlet block 7 and which is to be connected to the injection port B of the molding die A.

On the side facing the inlet block 6, the block 2 has a communication channel 22 consisting of a radial groove that contacts the channel 19C of the inlet block 6. This block 2 also shows three axial sub-channels 23, 24, 25 passing through the block 2 and offset by 90 degrees from the axis of the block 2.

Block 3 is directly aligned with the secondary path 24 of block 2, and is directly aligned with the main path 20 of the distributor.
The main road 20 of this block, which forms part of
and an axial secondary channel 26 communicating via a radial connecting channel 27.

The block 4 includes an axial secondary channel 30 which connects to the main channel 20 of this block 4, which forms part of the main channel 20 in FIG. 8 via a connecting channel 31. As shown in particular in FIGS. 2 and 6, the connecting channel 31 is carved into one face of the block 4 and is also almost completely cut out by a radial straight section 32 emanating from the minor channel 30. It is composed of a groove consisting of an arcuate portion 33 that widens at 90 degrees and wide radial portions 34 and 35, and communicates with the main passage 20.

In addition, the block 4 has an axial secondary passage 36 connected to the axial secondary passages 23 and 29 of blocks 2 and 3.
Contains.

The block 5 is provided with a communication channel 37 consisting of a groove whose shape is the same as the communication channel 31 of the block 4. And this block 5 is compared to block 4.
It is understood that the position has been shifted by 180 degrees.
In particular, block 5 has an axial secondary passage 38 which connects with the axial secondary passages 36, 29, 23 of blocks 4, 3, 2. Since block 5 is the last in the set of blocks in the distributor, this block 5 does not contain any other subpaths.

It should be noted that the distributor according to the present invention flows in continuous layers that never mix, even for completely compatible products, which is caused by the heat of the molten state. This is because the plastic synthetic resin is treated in the same way as a heated viscous fluid flowing through a flow path, and is based on the principle of laminar flux flow. From the outlet block 7 of the distributor the different layers of synthetic resin material are moved at the same speed and the sausage-like melt produced by these layers is usually subjected to several pressurizations in order to obtain a multilayer laminate from this. Before the roll is used, it enters a conventional T-die for forming thin sheets. Each of these pressure rolls is then supplied with a laminate prior to finishing the resulting laminate together with the other layers.

By means of the distributor according to the invention, the thickness of the respective layer appears in the final product as a result of the selection of the throughput of the respective extruder D ₁ to D ₄ . The uniformity and regularity of the sausage melt fed to the forming die depends on the uniformity and regularity of the extruder. It also depends on the melt viscosity of the synthetic resin material used and the dimensions of the main passage, secondary passage and communication passage of the distributor according to the invention.

Looking at FIG. 8, the flow coming out of the extruder _D1 first passes through the channel 19C of the inlet block 6, and
Main path 2 limited by the connection of blocks 2 to 5 via radial communication paths 22 made in block 2
It is connected to 0.

The flow coming out of the extruders D ₂ to _{D 4} flows from the inlet block 6 to the side channels 23, 24, 25 of block 2.
advance through. The flow in the secondary channel 24 subsequently joins the flow in the main channel 20 via an axial secondary channel 26 and a radial communication channel 27 made in the block 3. Secondary channel 25 passes the flow exiting extruder _D3 .

In block 4, the flow exiting extruder _D3 is guided and combined with the flow of main channel 20 via a communication channel 31 made in block 4. It can be seen that the sausage-like melt flowing in the main channel 20 then comprises three stacked layers. The fourth layer is formed by the flow coming out of extruder D ₄ joining the sausage-like melt in block 5 via communication channel 37 . Finally, the sausage-like melt from outlet block 7 will contain four stacked layers, the distribution of which has already been mentioned:
Determined by various factors. That is, the thickness of each layer of sausage-shaped melt from the outlet block 7 can be selected in advance by appropriate dimensioning of the main, secondary and connecting channels. It must be noted that the profile of each main channel, minor channels and connecting channels determines to a significant extent the amount of feed of each material that will be added to the sausage melt flowing through the main channel 20 per unit time. .

An important feature of the present invention is that the radial communication channel of the block is created by a groove carved in one of its faces, and the groove is one element that determines the flow path of the material flowing into the groove. It lies in the fact that it has become. The grooves are then shaped so that the distributor can be adapted to a defined group of synthetic resin material fed by the extruder to produce a sausage-like melt from the outlet block 7. This means that each block can be adapted. Furthermore, the following can be added to this. Thus, the distributor according to the invention can be easily assembled and disassembled due to the presence of the rod 9 and nut 10. On the one hand, the heating ring 16 can be easily separated by removing the plug 18 from the socket 17,
It is also possible to replace other previously prepared distributors, depending on the composition of the sheet that we wish to obtain. Furthermore, the distributor of the present invention is made easier to handle due to the presence of ears 11 bolted to two adjacent rods 9. In addition, when assembling the distributor, it is possible to assemble various blocks using the leak-proof packing provided, so that there is no need to prepare thick wedges in advance, and there is no risk of changing the sections of the main and secondary roads. It is also worth noting that this can be achieved with a simple concatenation of .
This is because changes in the sections of the main passage and the secondary passage may lead to a change in the pressure of the flow and a change in the distribution of each material in the sausage-shaped melt from the outlet block 7.

FIG. 9 shows another embodiment of a distributor according to the invention. In this case, instead of using the distributor blocks 3 and 5 in FIG. 8, blocks 3A and 5A are used, which are provided with connecting passages 39 and 40 each consisting of a semicircular groove. The communication path 39 leads to radial communication paths 41 and 42 located at opposite positions, and is connected to the main path 20 of the distributor.
In the block 5A, a semicircular communication passage 40 is connected to the main passage 20 via radial communication passages 43, 44 located at opposite positions.

It can be seen that a sausage-shaped melt consisting of seven stacked layers is obtained from the outlet block 7 by means of a distributor having a block configuration according to FIG.

In FIG. 10, each block 51, 5 consists of five blocks.
2, 53, 54, and 55 are separated, and four kinds of synthetic resins, E, F, G, and H, are supplied by respective extruders. The synthetic resin E is connected to the main path 56 (correctly, each block 51, 52, 53, 5
4,55, but for convenience, in the figure,
Guide numbers are attached to the dotted lines. The same applies to side roads. ) and other synthetic resins F, G,
H are introduced into corresponding sub-paths 57, 58, and 59, respectively. Synthetic resin F is in the secondary path 57 in the block 51.
It passes through a vertical communication path 60 provided on the joint surface of the block 51, merges with the upper side of the synthetic resin E, and forms the upper layer of the synthetic resin E. The synthetic resin G passes through the sub-paths 58 in the blocks 51 and 52, and then passes through the communication path 61, which connects to the upper part of the main path 56 from the horizontal position bored on the joint surface of the block 52 with the block 53, to the synthetic resin. It merges with the upper side of F and constitutes the upper layer of synthetic resin F. Further, the synthetic resin F passes through the sub-paths 57 in the blocks 52 and 53, passes through the vertical communication path 62 bored in the joint surface of the block 53 with the block 54, and merges with the upper side of the synthetic resin G. It constitutes the upper layer of synthetic resin G. Finally, synthetic resin H is block 51,5
2, 53, and 54, passing through the subroad 59,
A semicircular communication path 63 bored in the joint surface of the block 54 with the block 55 connects the synthetic resin F and the synthetic resin E located at the upper and lower ends of the main path 56 to the upper and lower sides, respectively. The flow is divided into a flow that directly descends from below through an arc-shaped portion upwards, and a flow that flows directly above from below. The sausage-shaped melt exiting the main passage 56 of the block 55, the cross section of which is shown in FIG. 11, passes through a T-die and is guided to a calender roll to form a laminated sheet of a predetermined thickness. At this time, if necessary, it is also possible to laminate this onto a ready-made sheet. In recent years, synthetic resin laminates have been used in a wide range of fields such as food packaging by devising the structure according to the purpose and making use of the characteristics of each component, so the manufacturing method of the present invention is of great industrial value. It is something that has.

As is clear from the three examples mentioned so far,
The invention makes it possible to provide a distributor which can supply a molding die with a sausage-like melt having a certain composition in which the layer thicknesses can be varied within a wide range.

It should also be noted that the number of layers of sausage-like melt can be arbitrarily increased depending on the distributor used and the number of extruders feeding. It can therefore be seen that the present invention provides a distributor which is very simple in construction and can be manufactured at low cost. Among other things, the simple interlocking of the blocks simplifies the use and eliminates the need for special equipment each time.

[Brief explanation of the drawing]

FIG. 1 is a schematic representation of a multilayer sheet production facility of thermoplastic material incorporating a distributor according to the invention. FIG. 2 is an axial cross-sectional view of a distributor providing a four-layer superimposed sausage melt in accordance with the present invention. Third
Figures 7 through 7 are front views of various blocks that make up the distributor shown in Figure 2.
These figures are shown in Figure 2 -, -, -,
- and -, respectively. FIG. 8 shows a schematic perspective view of the distributor of FIG. 2. This diagram makes it possible in particular to consider how the sausage-shaped melt entering the die is stacked up. FIG. 9 is a schematic perspective view similar to FIG. 8 of another embodiment of the device according to the invention. FIG. 10 is a schematic perspective view similar to FIGS. 8 and 9 of a distributor showing another example of the present invention used in manufacturing a six-layer synthetic resin laminate. FIG. 11 shows a cross section of the sausage-shaped melt obtained in FIG.

Claims (1)

[Claims] 1. An injection block removably fixed between a molding die and a collector having a plurality of melt flow paths connected to as many extruders as the types of different resins to be laminated; , one or more intermediate blocks, and an outlet block for producing a synthetic resin laminate, wherein the injection block has a main passage aligned to connect with each outlet of the melt passage of the collector. and a secondary path, each intermediate block having a main path and, for each intermediate block, a secondary path aligned with a secondary path that does not merge with the main path of the upstream block and/or merging into the main path of the upstream block. It has a communication path formed by the joint surface with the upstream block to join the secondary path that is not connected to the main path, and if each intermediate block has a secondary path, the secondary path merges with the main path. The outlet block has only a main channel, and all secondary channels are connected from the outlet block by connecting channels in intermediate blocks. A distributor that merges with the main road at the front, and that each of the above blocks can be disassembled from each other.