JPH03106610A - Extrusion molding device for multi-layer parison - Google Patents

Abstract

PURPOSE:To form a multi-layer parison having a resin layer without unevenness all over, even if resin of comparatively high moisture absorbing properties is used, by setting variable extrusion pressure of an extruder based on the water absorbing rate of the resin sensed by a sensing means. CONSTITUTION:An extrusion molding device 10 is provided with a water absorbing rate sensor 110 for measuring the water absorbing rate of nylon as an auxiliary material in a material feeding system and an auxiliary material/ bonding agent control circuit 101 constituted for setting variably the target extrusion pressure of a second extruder 12 based on the water absorbing rate of nylon sensed by the water absorbing sensor 110. When the water absorbing rate of nylon is high and the melting viscosity of molten nylon in an accumulator 20 is low, the target extrusion pressure of the second extruder 12 is set low to control the action of a second electromagnetic proportional type pressure servo valve 107 and control the nylon not to be extruded in excess. On the other hand, when the water absorbing rate of nylon is low, the target extrusion pressure of the second extruder 12 is set high to control the action of the second electromagnetic proportional type pressure servo valve 107 to prevent the shortage of extrusion quantity of nylon.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an extrusion molding apparatus for a multilayer parison, and more specifically, a plurality of resins are supplied and the supplied resins are pressed at a predetermined pressure. A device for extruding or shaping a multilayer parison, including a plurality of extruders configured to extrude resin, and configured to merge resin extruded from each extruder to form a multilayer parison consisting of a predetermined resin layer. It is something.

Prior Art In a hollow or shaped container made of a resin as the main material, such as polyethylene, in order to prevent the contained substance contained inside the container from penetrating the wall of the container and being released to the outside, a blow molded container is used. A multilayer hollow sealed container is known in which a barrier layer for preventing permeation is provided between the main material layers constituting the wall, and is made of an auxiliary material such as polyamide resin.

For example, fuel tanks used in vehicles such as automobiles generally consist of a main material layer made of a main material such as high-density polyethylene, and an auxiliary material such as polyamide resin that is placed between the main material layers and prevents the permeation of gasoline, etc. The barrier layer becomes
and an adhesive layer interposed between the main material layer and the barrier resin layer in order to improve the adhesiveness between the main material layer and the barrier resin layer.

Such multilayer blow molded containers are generally manufactured by blow molding a multilayer parison in which the molten resin constituting each resin layer is arranged at a desired position. , an extruder configured to extrude each resin such as a main material, an auxiliary material, and an adhesive at a predetermined pressure, and a resin passageway that allows each resin extruded from each extruder to join in a desired arrangement. A multilayer parison extrusion apparatus is used which is configured to form a multilayer parison comprising a desired resin layer.

In such an extrusion molding device, in order to ensure the quality of the multilayer blow-molded container, each extruder extrudes each resin to a desired thickness and merges them, so that a uniform resin layer is formed throughout. It is necessary to form a multilayer parison, and in order to meet this need, for example, a timer is used to stagger the extrusion start timing of each extruder and to control the rise characteristics of the extrusion pressure of each extruder. A multilayer parison extrusion or forming apparatus is provided with a time constant generating control device configured to prevent irregular portions from occurring in the multilayer parison immediately after each extruder starts extruding resin. etc. have been proposed (for example, Japanese Patent Publication No. 59-23212, etc.).

Problems to be Solved by the Invention However, relatively highly hygroscopic resins such as polyamide resins absorb a relatively large amount of moisture from the external atmosphere while being stored as pellets or chips, so storage conditions etc. The water absorption rate of the resin varies greatly depending on the pressure, and the melt viscosity of the resin tends to fluctuate greatly when it is fed as a molten resin to an extruder. In the multi-layer parison extrusion molding apparatus configured, the amount of resin extruded changes due to fluctuations in the melt viscosity of the resin, resulting in variations in the thickness of the resin layer, and as a result, it is difficult to ensure a predetermined thickness of the resin layer. or if the resin layer exceeds the specified thickness,
In some cases, it was not possible to extrude a multilayer parison with the desired resin layer.

OBJECTS OF THE INVENTION The present invention has been made in view of the above points, and includes a plurality of extruders each supplied with a plurality of resins and configured to extrude the supplied resins at a predetermined pressure, When a relatively highly hygroscopic resin is used in a multilayer parison extrusion forming device that is configured to combine the resins extruded from each extruder to form a multilayer parison consisting of a predetermined resin layer, The object of the present invention is to provide a multilayer parison extrusion forming device capable of forming a multilayer parison having a desired resin layer that is uniform throughout.

Structure of the Invention An object of the present invention is to provide a multilayer parison extrusion molding apparatus including a water absorption rate detection means for detecting the water absorption rate of the resin, and a water absorption rate detection means for detecting the water absorption rate of the resin detected by the detection means. This is achieved by including an extrusion pressure control means for variably setting the extrusion pressure of the extruder.

Effects of the Invention According to the present invention, the multilayer parison extrusion forming device detects the water absorption rate of the resin using the water absorption rate detection means, and extrudes the resin appropriately according to the water absorption rate of the resin using the extrusion pressure control means. Pressure can be set.

Therefore, when the viscosity of the molten resin in the extruder becomes low due to an increase in the water absorption rate of the resin, the extrusion molding device sets the extrusion pressure of the extruder low based on the detected water absorption rate to increase the resin. On the other hand, if the viscosity of the molten resin in the extruder increases due to a decrease in the water absorption rate of the resin, the extrusion pressure of the extruder can be set high based on the detected water absorption rate. Thus, the desired amount of resin to be extruded can be secured.

In this way, when the water absorption rate of the resin changes and its melt viscosity fluctuates, the extrusion shaping device can ensure the desired extrusion amount of each extruder without being affected by the fluctuation of the resin viscosity, and the overall It is possible to form a multilayer parison having a desired resin layer evenly throughout.

EXAMPLES Hereinafter, examples of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a schematic longitudinal cross-sectional view of a multilayer parison extrusion forming device constituting an automobile fuel tank manufacturing device according to an embodiment of the present invention. FIG. 2 is a schematic vertical cross-sectional view of the blow-forming device constituting the manufacturing apparatus, showing the fuel tank immediately after blow-forming.

As shown in FIG. 2, the fuel tank l for an automobile manufactured by the automobile fuel tank manufacturing apparatus according to the present embodiment has a wall portion that is sequentially formed from the inside.
An internal main resin layer 2 made of high-density polyethylene as the main material, an internal adhesive layer 3 made of modified polyethylene as an adhesive, and a secondary material made of nylon that forms a barrier layer that prevents gasoline from permeating. It is formed of five layers: a resin layer 4, an outer adhesive layer 5 made of Henkai polyethylene as an adhesive, and an outer main resin layer 6 made of high-density polyethylene as the main material. Polyethylene, nylon, and adhesive are supplied to the first extruder 11, the second extruder I2, and the third extruder 13 of the extrusion molding apparatus IO shown in FIG. 1, respectively.

As shown in FIG. 1, the l-th extruder 11 is disposed above the aquifer combulator head 14, and high-density polyethylene, which is the main resin, is transferred from the first extruder 11 to the aquicumulator head I4. The main material resin is supplied into the annular main material storage chamber l8 through an annular main material resin passage 17 formed between the cylinder 15 and the core 16 disposed inside the cylinder 15. , an annular annular piston l9 provided so as to be slidable in the vertical direction along its inner peripheral surface.
While pushing up, the resin is stored in the main resin storage chamber ls.

On the other hand, the second extruder l2 has an accumulator head l4
Nylon, which is placed at the lower part of the accumulator 20 and is an auxiliary resin, is supplied into the accumulator 20 by the second extruder l2, and is stored in the accumulator 20 while pushing up the plunger 2l of the accumulator 20.

Moreover, the third extruder 13 has an accumulator head! 4
is arranged at the bottom of the extruder 12 to face the second extruder 12,
The adhesive made of modified polyethylene is supplied into the accumulator 22 by the third extruder 13, and is stored in the accumulator 22 while pushing up the plunger 23 of the accumulator 22.

In this way, high-density polyethylene is stored in the main resin storage chamber 18, nylon is stored in the accumulator 20, and adhesive is stored in the accumulator 22. When the storage amount reaches a predetermined amount, the first Single working hydraulic cylinder 2
4 operates to push down the plunger 25 and the annular piston 19 that is in contact with the lower surface of the plunger 25, and transfer the high-density polyethylene stored in the main resin storage chamber l8 to the cylinder 15 and the lower end of the cylinder 15. The resin is fed under a predetermined pressure into an annular resin passage 32 formed between the die 30 provided at the core 16, the core l6, and the core support 31 provided at the lower end of the core 16.

In synchronization with this, the second single-acting hydraulic cylinder 26 is operated, the plunger 2l of the accumulator 20 is pushed down, and the nylon stored in the accumulator 20 is arranged in an annular shape concentrically with the annular resin passage 32. is,
The third single-acting hydraulic cylinder 27 is actuated, and the plunger 23 of the accumulator 22 is pushed down, so that the adhesive stored in the accumulator 22 is sent to the annular extrusion member 40 having a substantially hexagonal cross section. , to the annular extrusion member 40.

3rd f! I is a schematic vertical cross-sectional view of the annular extrusion member 40,
As shown in FIG. 3, the annular extrusion member 40 includes an auxiliary resin passage 41 that communicates with the accumulator 20, an adhesive passage 42 that communicates with the accumulator 22, and two branch adhesive passages 43a that branch from this. ．． 43b, an auxiliary resin passage 41, and branch adhesive passages 43a, 43b.
are in communication with concentric annular nozzles 47, 4B, 49 opening at the lower surface of the annular extrusion member 40 via annular slits 44, 45, 46, respectively. Third
In the figure, a slit 44 communicating with the secondary material resin passage 41
is between the slits 45 and 460 which communicate with the branch adhesive passages 43a and 43b, and the annular nozzle 47 which communicates with the slit 44 communicates with the slits 45 and 46 in the radial direction of the resin extrusion device. It is arranged between annular nozzles 48 and 49 which are arranged in the same direction. Therefore, in synchronization with the pressure feeding of high-density polyethylene into the annular resin passage 32, the nylon sent to the annular extrusion member 40 passes through the auxiliary material resin passage 41, the slit 44, and the annular nozzle 47, and enters the annular resin passage 32. , the adhesive is pumped at a predetermined pressure and sent to the annular extrusion member 40 through an adhesive passage 42,
Branch adhesive passages 43a, 43b and slits 45, 4
6, annular nozzles 48 and 49 are arranged on both sides of the annular nozzle 47 in the radial direction of the resin extrusion device.
From there, the resin is pumped into the annular resin passage 32 at a predetermined pressure.

Although not shown, the annular extrusion member 40 is supported by four support members 50 spaced apart from each other by approximately 90 degrees.
In the portion supported by the cylinder l5 and not provided with the support member 50, the flow of high-density polyethylene pumped through the annular resin passage 32 is caused to flow inside the annular extrusion member 40 by the circular extrusion member 40. It will be divided into a flow and a flow flowing outside. Here, since the annular extrusion member 40 has a substantially hexagonal cross section, the flow of high-density polyethylene is smoothly divided into an inner flow and an outer flow by the annular extrusion member 40.

In this way, the flow of high-density polyethylene is split into an inner stream and an outer stream by the annular extrusion member 40, which is located at the annular nozzle 47 of the annular extrusion member 40 and on either side of the annular nozzle 47. Annular nozzle 4B, 4.
9, nylon and adhesive are extruded by the annular extrusion member 40 at a predetermined pressure, so that on the downstream side of the annular extrusion member 40, an adhesive layer is interposed between the high-density polyethylene layers. A cylindrical resin flow sandwiching the nylon layer is formed. Thus, in the annular resin passage 32 on the downstream side of the annular extrusion member 40, the high-density polyethylene layer 2 and the adhesive layer 3 are placed in order from the inside.
, a cylindrical resin flow consisting of five layers: a nylon layer 4, an adhesive layer 5, and a high-density polyethylene layer 6.

In this way, the cylindrical resin sent to the annular resin passage 32 passes through the annular die slit 34 formed between the die 30 and the core 33 fitted concentrically with the die 30 into the core sabot 31. , a mold 60 of the blow-forming machine shown in FIG.
Extruded during 60 minutes. In this state, the molds 60, 60
In FIG. 2, they are separated from each other in the left-right direction and held at separate positions. The thickness of the cylindrical resin can be adjusted by moving a rod 35 fitted into the core 16 in the vertical direction using a hydraulic cylinder (not shown) and adjusting the gap between the annular die slits 34. .

When a predetermined amount of cylindrical resin is extruded from the extrusion/forming device 10,
The pressing down of the plungers 25, 21, 23 by the first to third single-acting hydraulic cylinders 24, 26, 27 is stopped, and the pumping of the high density polyethylene, nylon and adhesive is stopped, and thus the extrusion forming device is stopped. The desired multilayer parison is formed below.

Thereafter, the mold 60.60 is closed so that the upper resin cut 61 formed in the upper part of each and the lower resin cut 962 formed in the lower part of each are brought into contact with each other, and a cylindrical shape is formed. Air is blown into the hollow part of the resin and the multilayer parison is blown or shaped as shown in FIG.

FIG. 2 shows the state of the fuel tank 1 immediately after blow molding. As shown in FIG. 2, after blowing and shaping, the lower resin cutting portion 62 of the molds 60, 60
A lower burr 70 is formed on the lower side of , 62, and an upper burr 71 is formed on the upper side of the upper resin cut portions 61, 61 of the molds 60, 60.

When the blow molding is completed as described above, the fuel tank 1 is taken out from the molding device together with the upper burr 71 and the lower burr 70, and then the upper burr 71 and the lower burr 70 are separated, and the fuel tank 1 as a product is produced. 1 is obtained.

Note that the upper burr 71 and lower burr 70 separated from the fuel tank 1 in this manner are collected and reused as recycled materials.

Next, control of the extrusion molding apparatus 10 will be explained.

FIG. 4 is a schematic configuration diagram of the control device of the extrusion shaping device 10, and FIG. 5 is a block circuit diagram partially showing the structure of the sub-material/adhesive control circuit shown in FIG. 4. .

As shown in FIG. 4, first to third single-acting hydraulic cylinders 24 are connected to plungers 25, 21, and 23, respectively;
26, 27 are those pistons 2 4 as 2 6
Hydraulic chamber 24b partitioned by as27a,
26b and 27b. Hydraulic chambers 24b, 26b,
27b is a hydraulic supply device 104 such as a hydraulic pump that supplies hydraulic oil to the hydraulic chambers 24b126b and 27b, and a first hydraulic pressure supply device that controls the hydraulic pressure in the hydraulic chambers 24b126b and 27b, respectively.
to third electromagnetic proportional pressure servo valves 106, 107, 1
It is connected to a hydraulic circuit with 08.

The extrusion molding machine 10 includes a first electromagnetic proportional pressure servo valve 10
6, a main control circuit 101 is provided, and second and third electromagnetic proportional pressure servo valves 107 are provided.
, 108, an auxiliary material/adhesive control circuit 102 is provided.

The main control circuit l01 includes a first single-acting hydraulic cylinder 2.
An output signal from a piston position detection sensor 103 that detects the position of the piston 24a of No. 4 is input. When a predetermined amount of high-density polyethylene is stored in the main material resin storage chamber l8 and the position detection sensor 103 detects the upper end position of the piston 24a, the main material control circuit 101 causes the first single-acting hydraulic cylinder 24 to The first electromagnetic proportional pressure servo valve 106 is actuated so as to push down the annular piston l9, and the high-density polyethylene stored in the main resin storage chamber 18 is delivered to the annular resin passage 32 at a predetermined pressure. Pressure feed.

On the other hand, the secondary material/adhesive control circuit 102 includes a water absorption rate sensor 1 installed in a material supply system (not shown) that melts a nylon beleft as a secondary material and supplies it to the second extruder l2.
10, a signal indicating the water absorption rate of the nylon supplied to the second extruder (hereinafter simply referred to as water absorption rate signal) is input. The water absorption rate sensor 110 is an optical water absorption rate detection device configured to irradiate a measuring beam onto a nylon bereft, detect the reflected beam from the pellet, and convert it into an electrical signal. In addition, auxiliary material/adhesive control circuit 1
02, an activation or stop signal for extruding the main material is input from the main material control circuit 101, and the sub material/adhesive control circuit 1G2 controls the second and third electromagnetic proportional pressure servo valves 10.
7, 108 based on this activation or deactivation signal.
It is operated in synchronization with the electromagnetic proportional pressure servo valve 106.

The auxiliary material/adhesive control circuit 102, as shown in FIG.
A water absorption rate calculation circuit 111 calculates the water absorption rate based on the water absorption rate signal from the water absorption rate sensor 110, converts the calculated water absorption rate into an extrusion pressure correction signal, and outputs the extrusion pressure correction signal. Sub-material resin layers 2 and 4 having a thickness
An extrusion pressure setting device 112 that outputs an extrusion pressure signal to form A function generator 114 outputs a target extrusion pressure based on the output of the function generator 114, and a servo amplifier 115 controls the second electromagnetic proportional pressure servo valve 107 based on the output of the function generator 114.

When the sub-material/adhesive control circuit 102 receives an activation signal for the extrusion operation of the main material from the main material control circuit 101, the sub-material/adhesive control circuit 102 calculates the extrusion pressure signal output from the extrusion pressure setting device 112.
The extrusion pressure correction signal output by the water absorption rate sensor 110 is subtracted by the subtractor 113, the target extrusion pressure is calculated by the function generator 114, and the second single-acting hydraulic pressure is calculated based on this target extrusion pressure. The cylinder 26 is the second extruder 1
The operation of the second electromagnetic proportional pressure servo valve 107 is controlled so as to push down the second plunger 20. Therefore, when the water absorption rate of nylon is high, the target extrusion pressure is set low, and on the other hand, when the water absorption rate of nylon is low, the target extrusion pressure is set relatively high, and the plunger 26 is pushed out. The nylon stored in the accumulator 20 is pumped into the annular resin passage 32 at an extrusion pressure depending on the water absorption rate.

Further, the secondary material/adhesive control circuit 102 is connected to the main material control circuit 1
01, when the above-mentioned actuation signal is input, a control circuit (not shown) causes the plunger 23 to be pushed out by the 30th single-acting hydraulic cylinder 27 after a predetermined period of time has elapsed, and the adhesive stored in the accumulator 22 is released. Third extruder 1
The operation of the third electromagnetic proportional pressure servo valve 108 is controlled so that the resin is pumped from 3 to the annular resin passageway 32 at a predetermined pressure.

In addition, by causing the third extruder l3 to start extruding the adhesive a predetermined time later than the first and second extruders 11 and 12 in this way, the lower burr 70 can be removed from the high-density polyethylene layer 2, 6 and the nylon layer 4, it is easy to separate the high-density polyethylene and the nylon layer in the process of recycling the lower burr 70, and the lower burr 70 can be easily separated.
The reuse process is simplified.

When a predetermined period of time has elapsed since the third extruder 13 started extruding the adhesive and the multilayer parison excluding the upper parison 71 has been extruded from the annular extrusion member 40, the sub-material/adhesive control circuit 102 The third electromagnetic proportional pressure servo valve 108 is controlled to stop extrusion of the adhesive by the extruder 13, and after a predetermined period of time has elapsed, the entire multilayer parison including the upper parison 7l is transferred to the extrusion molding device. When the material is extruded from the l-th extruder 10, the main material control circuit 101 controls the first electromagnetic proportional pressure servo valve 107 to stop the single-acting hydraulic cylinder 24 from pressing down the plunger 25. 1
The pressure feeding of high-density polyethylene to the cyclic resin filling 32 by step 1 is stopped.

The main material control circuit 101 also outputs a signal to stop the extrusion operation of the main material to the sub-material/adhesive control circuit 102 at the same time as the pumping of the high-density polyethylene is stopped.

The sub-material/adhesive control circuit 102 stops the extrusion of nylon from the second extruder 12, and as a result, the control device of the extrusion control device 10 causes all extruders 11, 12, and 13 to stop extruding the resin. Stop to complete one cycle of extrusion. Note that since extrusion of the adhesive from the third extruder 13 is stopped relatively early, the upper burr 71 is also formed only of the high-density polyethylene layers 2 and 6 and the nylon layer 4, and the upper burr 71 is not re-formed. The usage process becomes easier.

As described above, according to the present embodiment, the extrusion forming device 10 includes a water absorption rate sensor 110 that measures the water absorption rate of nylon as an auxiliary material in the material supply system, and a water absorption rate of the nylon detected by the water absorption rate sensor 110. Based on the second extruder l
The secondary material/adhesive control circuit 101 is configured to variably set the target extrusion pressure of nylon.
When the melt viscosity of the molten nylon in the accumulator 20 is low, the target extrusion pressure of the second extruder 12 is set low to control the operation of the second electromagnetic proportional pressure servo valve 107, thereby causing the nylon to be excessively extruded. On the other hand, when the water absorption rate of nylon is low and the melt viscosity of nylon in the accumulator 20 is high, the target extrusion pressure of the second extruder 12 is set high and the second electromagnetic proportional pressure servo is The operation of the valve 107 is controlled, thereby preventing the amount of nylon extruded from being insufficient.

Therefore, the extrusion/forming device 10 can always maintain the desired extrusion amount of nylon regardless of fluctuations in the water absorption rate of nylon, extrude the secondary material resin layer 4 to a desired thickness, and extrude the main material resin layer 4 to a desired thickness. The material resin layers 2, 6 and the adhesive layers 3, 5 can be combined to extrude a multilayer parison having a uniform barrier layer throughout.

The multi-layer parison extruded in this way has a constant thickness of nylon, which is an auxiliary material that forms the barrier layer, from the start of resin extrusion to the end, so it is not a molded product. To surely prevent the thickness of the main resin layer from being insufficient due to the formation of parts where the barrier layer is not formed or the barrier layer formed to be thicker than necessary in a Fucoel tank 1. Thus, the Fucoel tank 1 can reliably prevent gasoline from passing through its walls and being released to the outside.

The present invention is not limited to the above-mentioned examples, but various modifications can be made within the scope of the invention described in the claims, and these are also included within the scope of the present invention. Needless to say.

For example, the water absorption sensor 11G may be a water absorption sensor that detects the dielectric loss and temperature of the resin and outputs the detected values as electrical signals.

In the second embodiment, the sub-material/adhesive control circuit is provided with a water absorption rate calculation circuit, but a water absorption rate measuring device having a calculation circuit for calculating the water absorption rate may be used.

Furthermore, in the above embodiment, both the inner main resin layer 2 and the outer main resin layer 6 are formed of high-density polyethylene layers, and the inner adhesive layer 3 and the outer adhesive layer 5 are
are both made of modified polyethylene; however, different materials may be used as the main material for forming the inner main resin layer 2 and the outer main resin layer 6. Different materials may be used as the adhesive forming the outer adhesive layer 5. For example, the base material may be a material that, when formed as a layer, imparts rigidity, drop strength, and water resistance to the multilayer hollow or shaped container, such as low density polyethylene, polystyrene, polybutene, ethylene-vinyl acetate copolymer, Resins such as polypropylene, polycarbonate, and polyester can be used, and the adhesive can be a material that can bond the main resin layer made of the main material and the barrier resin layer made of the secondary material, such as ionomer resin,
Resins such as ethylene-vinyl acetate copolymer, acrylic resin, vinyl chloride-vinyl acetate copolymer, and polyolefin modified resin can be used. Here, polyolefin modified resin refers to polyolefin, kraft reaction,
It is chemically modified by alcoholysis reaction, copolymerization, etc. Specifically, it is made by crafting polyolefin with unsaturated carboxylic acid such as maleic anhydride or its anhydride, and after partially saponifying EVA, Examples include those made by partial esterification reaction with carboxylic acid anhydride, and those made by copolymerizing alpha-olefin and olefin.

Furthermore, in the above embodiments, an explanation has been added regarding the case where the fuel tank 1 for an automobile containing gasoline is manufactured. Needless to say, the present invention can also be applied to the production of shaped containers and multilayer blow-molded containers for containing chemicals.

Furthermore, although nylon is used as the molding resin in the above embodiments, those skilled in the art will appreciate that the extrusion molding device according to the present invention can be used not only with polyamide resins such as nylon, but also with relatively high hygroscopic resins. It will be appreciated that it is also useful in extruding other types of multilayer parisons using resins where changes in water absorption can affect melt viscosity and thus vary extrusion rate.

Effects of the Invention According to the present invention, a plurality of extruders are provided, each of which is configured to extrude the supplied resin at a predetermined pressure. In a multilayer parison extrusion-forming device configured to form a multilayer parison consisting of predetermined resin layers by merging them together, when a resin with relatively high hygroscopicity is used, it is possible to form a desired uniform layer over the entire layer. It becomes possible to provide a multilayer parison extrusion shaping device that can shape a multilayer parison having a resin layer.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal cross-sectional view of a multilayer parison extrusion molding device that constitutes an automotive Fucoel tank manufacturing device according to an embodiment of the present invention, and FIG. 2 is a schematic longitudinal sectional view of a blow-forming device that constitutes the manufacturing device. 3 is a schematic vertical sectional view of the roar-shaped extrusion member shown in FIG. 1, FIG. 4 is a schematic configuration diagram of the control device of the extrusion molding device, and FIG. 5 is the schematic diagram of the control device shown in FIG. FIG. 2 is a block circuit diagram partially showing the configuration of an auxiliary material/adhesive material control circuit. l...Fuel tank, 2...Inner main resin layer, 3...Inner adhesive layer, 4...Sub-material resin layer, 5... ... External adhesive layer, 6... External main resin layer, 10... Resin extrusion shaping device, 11... Lth extruder, 12... ...Second extruder, 13...Third extruder, 14...Accumulation head, 15...
... Cylinder, 16 ... Core, 17
...... Annular main material resin passage, 18... Main material resin storage chamber, 19... Annular piston, 20, 22... Accumulator, 21, 23... Plunger, 24, 26, 27... Single acting hydraulic cylinder, 2
4 a s 2 6 a s 2 7 g...
...Piston, 24b, 26b, 27b...
Hydraulic chamber, 25...During plunging, 30...Die, 31...
Core support 32... annular resin passage, 33.
... Core, 34 ... Die slit,
35... Rod, 40... Annular extrusion member, 4l... Sub-material resin passage, 42... Adhesive passage, 43a, 43b...・Branch adhesive passage, 44, 4
5, 46...slit, 47, 48, 49...
... annular nozzle, 50 ... support member,
60... Mold, 6l... Upper resin cutting part, 62... Lower resin cutting part, 70... Lower part, 71... ...Upper part, 101... Main material control circuit, 102... Sub-material/adhesive control circuit, 103...
...Piston position detection sensor, 104...
Hydraulic supply device, 106, 107, 108... Electromagnetic proportional pressure servo valve, O... Water absorption rate sensor, 1... Water absorption rate calculation circuit, 2... ...Extrusion pressure setting device, 3...Subtractor, 4...Function generator, 5...Servo amplifier. Figure 3

Claims (1)

[Claims] A multi-layer product that includes a plurality of extruders each configured to be supplied with a plurality of resins and extrude the supplied resins at a predetermined pressure, and that the resins extruded from each extruder are combined to form a predetermined resin layer. In a multilayer parison extrusion molding apparatus configured to form a parison, a water absorption rate detection means for detecting the water absorption rate of the resin, and a water absorption rate detection means for detecting the water absorption rate of the resin detected by the detection means, the extruder 1. An extrusion molding apparatus for a multilayer parison, comprising: extrusion pressure control means for variably setting the extrusion pressure.