JPS5863431A - Resin extrusion molder - Google Patents

Abstract

PURPOSE:To provide a subject device which can extrude by applying an appropriate, even extruding pressure to resin in a manner to maintain resin at uniform temperature, by constituting a device such that a gear pump and a static mixer are located in series at a resin path between an extruder and a mouth ring. CONSTITUTION:Resin, heated and kneaded in an extruder 1, is fed to a static mixer 2, and is further fed to a gear pump 3. Resin, evenly heated on the whole, is obtained by the static mixer 2, a shortage in an extrusion pressure is appropriately compensated by the gear pump 3, and the resin can uniformly be fed to a mouth ring 4 by relieving pulsation. This enables to perform an easy molding of an excellent resin-extruded form having a large cross-section.

Description

[Detailed description of the invention] The present invention relates to a resin extrusion molding apparatus.

A resin extrusion molding device consists of an extruder with a die attached to the tip. 'Most extruders had a mechanism in which a screw was attached to the barrel and the material was continuously extruded by the rotation of the screw. As an extruder,
It was thought that a machine equipped with a plunger or gear pump instead of a screw could also be used, but in reality, extrusion molding machines with screws were exclusively used to make large molded objects such as pipes or plates. Ta.

It was not common practice to equip seven extruders with screws and plungers or gear pumps at the same time. It heats and kneads the resin enough with just the screw,
This is because it can be in a state ready for extrusion. In particular, by changing the length or structure of the screw, it was possible to plasticize most resins. However, when extruding a foam, it was proposed to add a foaming agent in the extruder and then add a one-gear pump to uniformly stir and propel the foaming agent-containing resin. That is the special public service of 1977/
- Described in Dako YGO Publication. According to the method described in this publication, when a gear pump is used in combination, the foaming agent t-
It is said that it is easy to incorporate M- into a foam and that it is possible to obtain a good foam. 'There was a drawback that foaming was uneven.

The inventor found the cause of the drawbacks in the method described in Japanese Patent Publication No. 1 to 1 as follows. In other words, in this method, after mixing the foaming agent, the resin is simply stirred with a gear pump, so it is not possible to maintain the resin at a uniform temperature in the center and periphery of the resin passage. Ta.

On the other hand, it is already known to use a static mixer to uniformly mix the resins. Furthermore, it has already been proposed to attach a static mixer to the end of a one-screw extruder in order to better mix the resin extruded from the extruder.

However, the static mixer i1 is constructed by inserting a passage dividing body into the short cylinder, and the passage dividing body has a large number of divided passages therein, and the divided passages have their traveling direction aligned with the axis of the short cylinder. On the other hand, the structure includes passages KK that are oriented obliquely and that are adjacent to each other and have different traveling directions. Therefore, the resin flowing through the static mixer is not only mixed by being guided by the passage dividing body and progressing diagonally and irregularly inside the cylinder, but also by moving from passage dividing body to passage dividing body. By repeating the aggregation and division, K1 is sufficiently combined. At the same time, the resin flow is subjected to great resistance.

Therefore, the addition of a static mixer requires a significant increase in extrusion pressure. Therefore, it was considered preferable to add a static mixer because it would unnecessarily reduce the amount of extrusion.

The inventor used a gear pump with a static mixer.
They found that the gear pump compensates for the reduction in extrusion rate caused by the static mixer, promotes stirring, generates little heat from stirring, and is sufficient to bring the resin into a suitable extrusion state. May I know that the combined use of a static mixer and a gear pump is suitable not only for producing foams containing a blowing agent, but also for extruding large, non-foamed shapes. I found it. This invention was made based on such knowledge.

The present invention relates to a resin extrusion molding apparatus characterized by having a one-gear pump and a static mixer arranged in series in a resin passageway between an extruder and a die.

The following is an explanation of Jin's invention using a drawing. FIGS. 1 and 1s2 are partially cut away longitudinal sectional views of the device according to the invention, respectively.

In these figures, /Fi is an extruder, 1.2t is a static mixer, J is a gear pump, and Da is a mouthpiece. Screenie/cot in extruder/barrel//
- It is rotatably attached. The static mixer is made by inserting a passage dividing body into a short cylinder. It is divided into a small board and a board, and has nine passages. The divided passages have their traveling directions directed obliquely to the axis of the cylinder, and adjacent passages have different traveling directions. A gear saw jFi, an interlocking gear saw and a gear saw JJt are rotatably attached in the housing Jl. The cap y has an inner mold 41 fixed inside the outer mold and a cylindrical resin passage provided therebetween.

#I1 When using the device shown in Figure 1, the resin heated and uniformly mixed in the extruder enters the static mixer and is then extruded from the mouth via the gear pump Jt. . In this case, a part of the resin is made to advance diagonally downward along the small plate JK in the static mixer, and after colliding with the cylinder JK, is made to proceed diagonally upward along the small plate JK.

In addition, another part of the resin is made to advance obliquely upward along the small plate, and after colliding with the cylinder
It is made to advance diagonally downward along. In this way, the intersecting small plates cause the resin to travel diagonally downward and diagonally upward, respectively, thereby thoroughly mixing the resin as a whole.

In the static mixer, while traveling along the small plate 241, the resin is mixed with the small plate 241. and received resistance from Kono. For this reason, when the resin leaves the static mixer, the extrusion pressure is low, resulting in a decrease in the amount of extrusion. Therefore, the resin is introduced into the gear pump J, and necessary pressure is applied therein by a gear saw and a JJK to increase the extrusion pressure and the amount of extrusion. At the same time, the resin is kneaded between the gear saw and the JJ to make it suitable for extrusion. After that, the resin enters the metal die and is formed into a cylindrical shape to become a molded body. When the apparatus shown in Figure 1 is operated, the resin is heated in the extruder and uniformly kneaded with Kfl. The mixture first enters the gear pump J, where it is kneaded and the extrusion pressure is increased, and then enters the static mixing IL' and is then extruded from the mouthpiece. Therefore, in the case of Fig. 2, the resin is i
This is the same as the case using the apparatus shown in Fig. 1 in that the extrusion pressure is first reinforced and then the Ka combination is carried out, but the pressure reinforcement and mixing are carried out to the necessary extent as a whole. It is.

As the passage dividing body used in the static mixer 2 in the apparatus of the present invention, the one shown in Fig. IIi can be used. In Fig. 3, the passage dividing body Coco' consists of a large number of small plates Coco/, Cococo, etc., made of corrugated metal plates, which are stacked together so that the bent parts of the corrugated plates intersect with each other in the same direction. KrII was determined as follows. Specifically, for example, if a corrugated sheet Coco/ is arranged with its valleys and peaks extending in the direction of arrow a, the metal corrugated sheet Cococo located directly below it will be placed with its valleys and peaks extending in the direction of arrow a. The corrugated plates are arranged so that the extending direction faces in the direction of arrow 1, and the contact points of these corrugated plates are welded to form a cross shape. The corrugated sheet Kokono is made by arranging the grooves so that the valleys and peaks extend in the direction of arrow a, and welding them in the same way to form a cross-shaped Il!
It is fixed at .

In the same way, a small plate Kokoda made of corrugated plate, Kokoj1
These small plates are stacked and welded together to form the passage dividing body.

Inside the passage dividing body here, divided resin passages are formed between the small plates, but the passages F1am1s are oriented in different directions and the thickness of the passages varies. The passage dividing body here is placed in one cylinder K[
determined. In other words, it is inserted into the cylinder and fixed so that the direction indicated by arrow X in FIG. 3 is the axial direction. In a static mixer, such passage dividing bodies are arranged in series one after another with their ends close to each other, and housed in a cylinder. At this time, the ends of the passage dividing bodies 1111I are arranged so that the extending directions of the corrugated plates intersect with each other. ◎This type of mixer is an example of a static mixer.

In addition, the passage dividing body 5 of the static mixer may have a structure as shown in FIG. The passage dividing body 5 is made by combining the cross pieces 5/, j and 31. Specifically, the -set of small plates 5/, 5
Here, 5 pieces j, J pieces are lined up in parallel at equal intervals on one plane], and another set of small plates 52g1j pieces 2,j
The plates 11 and 2 are placed parallel to each other at equal intervals on another plane, and the latter pair is inserted between the former pairs and welded together at their intersections, so that the intersections of the small plates are formed. configured. Similarly, - group of small plates 61/1. fj ko, 61, f etc. are arranged at equal intervals, small plates 316.617, j
An intersection j2 is constructed by intersecting ll, etc. Furthermore, KL: similarly constitutes 5 intersections. Then, these intersections j/, s and 5 are further intersected, for example, the small plates 6j& of the intersection 5 are intersected by the small plates 5/ and j of the intersection 5/.
, and the intersections are welded together to form the passage dividing body 5. In this case, the ends of each intersection are aligned so that each intersection is on a straight line.

In this way, the force 1 of the passage dividing body is created. The static mixer 2 may include such a passage dividing body j.

As already mentioned, the gear pump J has two gears meshed together within one housing to make it rotatable, but even if the gears rotate inward, they also rotate outward. Even if it's FC@, it's OK. In addition, it is desirable that the housing of the gear pump has a structure in which the heating medium can be circulated through the gear pump to control the temperature. It can be introduced into a static mixer and mixed well. To be more specific, in the extruder, although it is possible to mix well locally (by means of a screw saw), there is no difference between the part in contact with the outer surface of the screw saw and the part in contact with the inner surface of the barrel. Therefore, it is difficult to mix wires. However, if this resin is guided into the static mixer and allowed to pass through it, the resin that was in contact with the screw saw can be thoroughly mixed with the resin that was in contact with the barrel. Therefore, according to the apparatus of the present invention, it is possible to obtain resin that is uniformly heated as a whole. Also,
The resin that has passed through the static mixer is subjected to flow resistance by the passage dividing body, and if the extrusion pressure is insufficient, it is better, but it is better to guide it to the gear pump J and set the extrusion pressure to an appropriate level. can be fulfilled. Furthermore, since gear pumps generally generate less heat, the extrusion pressure can be mainly replenished without significantly increasing the resin temperature. In addition, since a gear pump was used, there was little pulsation in the pressure and the resin could be fed uniformly. Therefore, according to the apparatus of the present invention, it is possible to extrude the resin while maintaining the resin at a uniform temperature while applying an appropriate and uniform extrusion pressure to the resin. Therefore, according to the apparatus of the present invention, a good resin molded body having a large cross-sectional area can be easily produced. (K, by including a foaming agent in the resin, a large-sized foam t that is uniformly foamed)
& Can create shapes. In this respect, the inventive device exhibits remarkable effects.

Of the two methods shown in Figures 1 and 2, the first
The device shown in the figure, in which the resin passes through a static mixer first, is suitable when the resin exiting the extruder exhibits a high extrusion pressure. Suitable for exhibiting low extrusion pressure.

[Brief explanation of the drawing]

1 and 2 are partially cut away vertical sectional views of the device of the present invention. 1 and 2 are perspective views of a passage divider in a static mixer used in the apparatus according to the present invention. In the figure, /#i is an extruder, C is a static mixer, J is a gear dump, and y is a spinneret. // is barrel, /ko is screw, ko/ is cylinder, here is passage dividing body, 2 and koda are small plates, J/ is housing, saw and JJ gear, da/
The outside type is l-i, and the octopus is inside. Figure 1 Figure 4

Claims (1)

[Claims] / A IIJII extrusion molding apparatus, characterized in that a gear dump and a static mixer are arranged and placed in series in a resin passage between an extruder and a die. 2. The static mixer does not include a passage dividing body inserted into a short cylinder, and the passage dividing body has a large number of divided passages therein,
The divided passages have their traveling direction diagonally directed to the axis of the short tube, and the passages that are in contact with each other by 1 m have different traveling directions, and the ends of the divided passages face the cap. , Claim I! Apparatus as described in paragraph 1. The J9 aisle dividing body has a large number of small plates with different orientations at intervals and
The platelets are fixed in a crosswise manner at the same angle, and a passage is formed between the platelets, and the surface of the platelets extends at least partially obliquely to the axis of the short tube, and is attached to the inside of the tube. The device according to claim 1, wherein the direction of travel is upward between the passages. The small plates are made of corrugated plates, and a large number of corrugated plates are stacked one after another in the direction in which the peaks or valleys extend, and are fixed at points where they touch each other. 2. The device according to claim 2, wherein the device comprises: J2 The small plates form sets spread out in a plane, and the small plates of other sets are arranged intersectingly between the adjacent small plates of the seven sets, and are fixed at the points where they touch each other to form an intersection object. - configure;
The apparatus according to claim 1, wherein the intersecting objects are further fixed in a mutually intersecting manner to form a multi-passage dividing body.