JPH03501712A - Injection molding equipment for semi-fluid materials - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Injection molding equipment for semi-fluid materials The present invention relates to an injection device as set forth in the preamble of claim 1. child An injection device such as It is publicly known.

Blown fill from semi-fluid (viscous) materials, especially plastic synthetic extruded materials Injection equipment (and blowing heads or spindle head) is used. The device has a ring-shaped gap at its axial end. have. The material passes through the gap and is shaped by blowing. Blowing At the outlet, the material is cooled by a cooling ring and changes from semi-fluid to solid. become However, the following difficulties exist.

In other words, in order to keep the wall strength of the final product within a narrow tolerance range, a ring-shaped gap is required. Within the material, the material must have as uniform a viscosity, temperature, and thickness as possible. It is necessary to spread with shear stress.

In the known structure of such an injection device (DE-GebrMS 1927405), , a small shaft is arranged in a hollow cylindrical outer box, and its axial end flange (cranium ) is screwed to the axial end of the outer box of the device. Lower axial direction of the device outer box A ring-shaped gap is formed between the end face of the small shaft and the outer box of the device. semi-liquid The supply of the reactive material is carried out by means of injection channels arranged radially in the end region of the upper axial outer box. It is further connected to a distribution passage provided on the outer surface of the small shaft. The distribution channel is injected first. There are two branches connected to the road. This branch occupies one quarter of the circumference of the minor axis. , followed by multiple axial branches. The ends of such a tree-like structure are It connects to a ring-shaped gap at its lower end. Such an axial distribution path The advantage of this is that the branch flow into each ring gap has its own length. That is. In any case the pressure loss along the distribution path amounts to, for example, 300 bar. . This loss is covered by a corresponding increase in pumping capacity of the injection pump. There must be. Pumping capacity by progressively increasing the temperature of the material in the axial direction The conversion corresponds to, for example, 12-15°C. Because the distribution channel extends in the axial direction, , in order to keep the temperature of the pipe wall the same over the entire distribution line length, the melted It must be ensured that the temperature difference between the material and the walls of the distribution channel increases in the axial direction . These localized temperature differences occur on the distribution channel wall of the molten liquid material. This causes a difference in the fluid velocity at the branching part of the distribution channel, Ultimately, this will result in variations in the thickness of the product. Furthermore, individual portions within the ring-shaped gap Insufficient flow superposition results in the final product being created by individual split streams. This produces clearly visible seams (streaks) between sub-areas. No regarding the distribution route. The use of the well-known helical distribution channel may be helpful in improving the overlap described above. However, at the same time, this method significantly increases the axial length of the minor shaft. Therefore, phosphorus Maintaining the uniform width of the gap may impair the rigidity of the device structure, which is a necessary condition. Become.

In contrast, the object of the present invention is to control the wall temperature of the distribution channel in the injection device of the method described above. Correspondingly, the aim is to match the temperature of the materials as precisely as possible.

The above problem is solved by the features stated in claim 1 of the invention.

Further improvements and structures of the injection device of the present invention are described in the dependent claims. It becomes clearer.

The present invention is based on the idea that the distribution path of the device is provided not in the axial plane but in the radial direction. ing. This has two advantages. Firstly, the radial distribution path is easily axially It is possible to connect with the distribution path of This reduces the length of the small axis to the length of the spiral. It is mostly controlled by the length of the line and can therefore be made sufficiently short and rigid. screw By installing the swirl path at the rear, the overlap caused by the shunting of material from the distribution path can be satisfied. This allows you to avoid sushi in the final product. As the next advantage , the distribution channels running in the radial plane, together with their channel walls, are directed outward from the interior of the material of the device. It is dominated by a decreasing temperature gradient. The materials in the molten and fluid state are as described above. Pump efficiency due to temperature increasing radially from outside to inside along the path As the conversion to The temperature at all locations is almost the same as that of the passage wall. This automatic temperature Adaptability is based on the same sliding, or in other words, frictional relationship and, with it, the same uniformity. Guarantee material fluid velocity. This significantly reduces the variation in thickness of the final product .

The invention will be elucidated by the drawings of the following examples. That is, Fig. 1: A vertical sectional view of the first embodiment of the injection device of the present invention, Fig. 2: Injection according to Fig. 1 A cross-sectional view of the distribution path along the line ■-■ of the output device, Figure 3 Details of an embodiment of the injection device of the present invention similar to Figure 1 but slightly modified cross section, Figure 3a: A plan view of the transition area between the distribution path and the collection path of the injection device in Figure 3; FIG. 4 A vertical cross-sectional view of another embodiment of the injection device of the present invention having a multilayer structure, A viscous fluid material, such as a plastic synthetic material (plastj fizierte Kunstsoffextrudat) (P VC1C1 The injection molding used to make blown membranes, tubes, and other similar products from polyethylene (1) The extraction device is a hollow cylindrical device with a flange-like attachment 10a at the upper shaft end. I have an outer box 10. The cylindrical inner hole 10b of the device outer box 10 has a head at the upper shaft end. A cylindrical small shaft 20 with a lid 21 is inserted. The cranium 21 is the device outer box 1 It is installed on the flange-like appendage 10a of 0, and equally divides the periphery of this skull. It is screwed by a plurality of bolts 13 located at the same positions. The diameter of the small shaft 20 is The diameter is set to be somewhat smaller than the diameter of the inner hole 10b. This is more details of small axis 20 A ring-shaped and screw-shaped groove is formed between the outer surface and the smooth cylindrical inner hole 10b. In the region of the rotationally symmetrical concentrating passage 22 and the thread groove 23 of the spiral distributing passage forming an outflow gap. C), in order to form a ring-shaped gap 30 that further extends to the lower end of the shaft. be. A narrow injection gap 31 existing at the lower end of the ring-shaped gap 30 has a hose-shaped or reveals a semi-fluid material formed into a tube, followed by air cooling (not shown). It is solidified by a ring or other cooling means. In the production of synthetic material foil, ring-shaped The convergence of the gap 30 is 3 mm, but the width of the -1 jet port 31 is 0.8 mm. . The inlet for the semi-fluid material is provided in the upper axial end region and is located in the flange of the device outer box 10. A radial injection channel is formed extending in the orange-shaped appendage 10a. injection The channel 11 continues through a radially extending segment 11a and a 90° angle change section 11b. The axially extending segment 11C1 further communicates with the distribution channel 12.

In the present invention, the distribution channel 12 runs exclusively in the radial plane of the device, and in the example of FIGS. As shown, on the surface between the cranium 21 and the flange-like appendage 10a of the device outer box 10, A distributor @ 12 formed as shown in the cutaway view of FIG. 2 and with its circular cross section. The cross section of the canal is shaped by half each in the cranial part 21 and in the appendix 10a. will be accomplished. Furthermore, the above distribution channel configuration divides the material flow into multiple equal-length branch streams. The purpose of this is to uniformly distribute the divided flow around the small axis. this This means that even though there is only one material injection port around the device, This is essential for uniformly distributing the material into the annular gap 30. This thing is manufactured This is also a prerequisite for obtaining a uniform wall thickness for hoses or pipes made of synthetic material.

In the distribution channel 12, the individual sub-streams are distributed successively.

The cross section of the conduit on each side of the source becomes smaller as the number of branched streams increases. explain individually First of all, the distribution path 12 becomes two branches 12a and 12b, each with a It spreads over a 45° range on the circumference, and the common source is the axial direction of the injection path 11. It is connected to an end portion 11c running in the direction. Axial end! Radiated from IC Due to the presence of 906 transitions to the shunts 12a and 12b in the direction, the accuracy of the material flow is The flow relationship for half-division is as follows unless this angle changing part and the end part 11c are provided. This is more convenient than the conventional fluid supply. Both shunts 12a, 12b ends are at both ends of the diameter and branch into two branches 12aL12a2 and 12bl, 12b2. do. These are shunt 12 &.

12b and extends in the opposite direction.

Such branching is repeated. That is, the shunt 12a1 is the shunt 12ala, 12alb, shunt 12a2, shunt 12a2a, 12a2b, shunt 12 bl is connected to the shunt 12bla, 12blb, and the shunt 12b2 is connected to the shunt 12b2a, It branches like 12b2b.

Approximately proportional scale of the shunt 12a, 12a2.12a2a illustrated in FIG. As can be seen in the cross section, as the number of diversions increases, the cross section becomes smaller. increases, and the pressure in the shunt decreases at the same time for the same flow rate. Diversion pressure At the same time, a decrease in the temperature of the divided flow means an increase in the temperature of the divided flow.

This means that the capacity of the pump (not shown) placed in front of the injection path 11 is This is clear from the fact that it has been converted into The above branch flow is radial direction from outside to inside. At the same time, as the temperature increases towards This corresponds to The result shows a degree drop. This temperature drop is counteracted by controlled heating of the outer walls of the device. can be treated. Accurately measure equipment dimensions, shunt diameter and pump capacity. By doing so, we have achieved a more advanced temperature change history for materials that can respond to temperature changes on the pipe wall. This makes it possible to respond in a way that

The first two branches 12a and 12b from the injection path 11 are injected in the region The change in direction, i.e. between radial and axial material flow, is To enable as uniform a distribution of material as possible around the minor axis (not shown) However, it also applies to all or at least the subsequent individual branches of the distribution channel 12. can be used.

As is clear from Fig. 3 and Fig. 3a, from the shunt 12ala to the shunt 12b2b. The distal end of the terminal has a rotationally symmetrical ring shape through a direction change area 12c like a fish's tail. It moves to the collection path 22 in the periphery of the small shaft, that is, the small shaft cover. The gathering road 22 is A plurality of small shaft covers corresponding to the number of shunts from 12ala to 12b2b are screwed. It is connected to an axial helical distributor consisting of a helical channel 23 of helically designed shape. the The narrow ring-shaped gathering path 22 is a small path 22 provided in the small shaft cover between the spiral path 23 and the spiral path 23. separated by a. The passage 22a extends, for example, in a radius to the inner surface of the container inner hole 10b. Maintaining a distance of 1.5mm. When each branch flow flows into the spiral path 23, this gap is Consideration has been given to ensuring uniformity. Path 2 provided between individual spiral paths 23 3a maintains a distance of, for example, 0.5tnm to 1.0+nm between the inner wall of the container and the inner wall of the container. There is. In this case, the material overflows from the spiral path in the gap between the narrow path 23a and the inner wall of the inner hole. This helps improve the overlapping of shunts.

In the case of Figures 1 and 3, the spiral distributor (spiral path 23) is one-third of the long axis of the filament 20. occupies one-half of the gap and connects to the ring-shaped gap 30. In the case of Figure 3, this gap is The seed injection gap is also curved to fit standard equipment dimensions with diameter.

Here, the device outer box lO and the small shaft 20 have an attachment part 10 that can be screwed onto their lower area. 1 and 201 are shown.

The embodiment of FIG. 4 is different from that of FIG. The difference is that it has a multilayer structure consisting of arranged joint sleeves 40.50. . This type of multilayer structure is created by manufacturing a so-called synthetic membrane, which is made by overlapping multiple thin film layers. used for making. Each individual membrane layer is made of a different material. If The shaft sleeve 40.50 has a radial flange portion 41 corresponding to the small shaft cranial portion 21. ．． 51 are provided. Each flange 41.51 has an additional injection channel 42. 52 is provided in a similar structure to the injection path 11 in the embodiment of FIG. addition The injection channels 41.51 each lead to a distribution channel 43.53 extending in the radial direction. The structure is similar to the distribution path 12 shown in FIG. Each 6 axis sleeve 40.5 The same applies to the convergent paths and spiral paths 44.45 and 54.55 formed on the outer surface of 0. It's like that. The ring-shaped gap following the spiral path 45.55 is connected to the device as shown in FIG. The injection gap 31 is obliquely connected to the injection gap 31 at the lower end in the axial direction. Therefore, the injection gap 31 formed by each level of the device (small shaft 20 and 6 shaft sleeve 40.50) All the ring-shaped material flows will come together.

international search report , , , , PCT/EP 90100490

Claims (1)

[Claims] 1. Molding of semi-fluid materials, especially from plastic synthetic extruded materials, An injection device for forming sheet films, tubes and the like, A hollow cylindrical outer box (10) in which a cylindrical core shaft (20) is arranged, and itself multiple times. , between the outer box (10) and the core shaft (20) via a continuously branching distribution path (12). injection of radially provided semi-fluid material connected to the ring-shaped gap (30) of path (11), The distribution path (12) is connected to the device outer box (10) and/or the device outer box (10). the device within the wall region formed by the cranial part (21) of the axillary shaft which radially covers the A semi-fluid material characterized by being provided only in a plane extending in the radial direction of Material injection molding equipment. 2. The injection device according to claim 1, wherein the radial distribution channel (12) is followed by a mandrel. A gathering path (22) is provided around the , and a ring-shaped gap ( 30). 3. The injection device according to claim 1 or 2, wherein the device outer box (10) and the mandrel (2 0), one or more coaxial core sleeves (40 and 50) are arranged between the each mandrel sleeve (40, 50) has a radial shape corresponding to the cranial part (21) of the mandrel. flanges (41 and 51), each of which has a radially extending Additional inlet channels (42 and 52) are arranged, each additional inlet channel (42 and 52) 2) respectively connect to the ring-shaped gap (30) via additional distribution channels (43 and 53). Furthermore, each additional distribution channel (43 and 53) is connected to a flange (41, 52). A wall formed by the skull part (21) of the axle and/or the outer box (10) of the device A device characterized in that it is provided only in a plane in a radial direction of the device within a region of the device. Place. 4. The injection device according to claim 3, wherein each mandrel sleeve (40, 50) has a radiation The concentration path (44 and 54) which receives the supply from the shaped distribution path (43 and 53) is connected to the surrounding area. is provided in the ring-shaped gap (30) through additional spiral paths (45 and 55). A device characterized by being connected. 5. The injection device according to any one of claims 1 to 4, wherein each injection path (11, 42, 52) in the axial direction in the process of transitioning to the subsequent distribution path (12, 43, 53). A device characterized by changing the direction angle. 6. In the injection device according to any one of claims 1 to 5, the distribution path (12, 4 3, 53) A device characterized in that the angle in the axial direction changes at each branch point. 7. The injection device according to any one of claims 1 to 6, wherein the axial cranial part (21 ) and, in some cases, the flanges (41, 51) can be heated. device to do. 8. The injection device according to any one of claims 1 to 7, wherein the ring-shaped gap ( 30) has a funnel-shaped cross-sectional shape in the axial direction, and the width of the gap is a ring-shaped gap (30). ) tapering towards the exit.