JP2003145605A - Extrusion molding machine and die for extrusion molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion molding machine which can continuously mold even a molten resin mixed with a waste material such as sawdust into a prescribed plate shape without defective molding and a die for extrusion molding. SOLUTION: The extrusion molding machine has an extruder main body 1 in which a freely rotatable screw 11 is set in a cylinder 4, an extrusion head 14 fitted to the tip part of the cylinder 4, and the die 15 connected to the extrusion head. The extrusion head 14 is fitted freely openably/closably to the tip part of the cylinder 4 through a hinge 16, and the die 15 which is a flat die with a channel 26 formed in the die expanded in a fan-shape toward a slit-shaped discharge opening 27 is divided into a freely openable/closable upper part die 28A and a lower part die 28B. A plurality of heat generation controllable heating elements 36 are fitted to each of the die 28A and the die 28B in a prescribed arrangement pattern, and a pair of lip plates 44 which can adjust the upper and lower clearances of the discharge opening 27 and a pair of width adjusting plates 45 which can adjust the opening width of the discharge opening 27 are fitted to tip parts of the die 28A and the die 28B. A choker 37, with channel resistance pieces 40 whose quantity of protrusion into the channel 26 can be adjusted arranged in the longitudinal direction of the discharge opening 27, is fitted to the upper part die 28A.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an extrusion molding machine and an extrusion molding die mainly used for shaping a molten resin into a plate shape.

[0002]

2. Description of the Related Art Generally, an extruder comprises a cylinder which can be heated and cooled and a screw or a plunger which is built in the cylinder, and a plasticized raw material such as a molten resin is formed into a predetermined shape at its tip. A die and an extrusion head to hold it in place. Of these, the cylinder that constitutes the extruder main body is generally called a barrel, an electric heater for temperature control and a jacket for passing a heat medium are provided on the outer peripheral portion, and the inner peripheral surface has wear resistance. Various linings such as nitriding treatment are applied to improve. Further, the screw is formed with a continuous thread from the feed side to the tip, and the surface thereof is plated with chrome, and the top of the thread is subjected to hardening treatment such as induction hardening. on the other hand,
The extrusion head is composed of an adapter, a breaker plate, a screen, a die plate and the like, and is connected to the extruder main body with a bolt or the like. The dies held by the dies are roughly classified into circular dies having an annular lip and straight dies having a linear shape, depending on their shapes. this house,
Flat dies are roughly classified into T dies, fish tail dies, and coat hanger dies depending on the shape of the flow path. With this type of flat dies, molten resin, etc. can be discharged from a linear slit-shaped discharge port. It can be extruded and shaped into a film or sheet.

[0003]

However, in the conventional screw type extrusion molding machine, the clearance between the inner peripheral surface of the cylinder and the screw is set to a minimum (about 0.1 mm) in order to obtain a large discharge pressure. The motor that drives the screw to rotate requires a minimum output of about 75 kW. For this reason, there is a problem that the drive system is complicated, the screw is significantly worn, and the maintenance costs a lot. Also, since the clearance between the screw and the cylinder is small, there is a risk that the screw may be damaged due to overload when foreign matter such as wood chips is mixed, or the gas generated inside the cylinder may become high pressure and explode. . Furthermore, most of the screws were machined, which was very expensive.

On the other hand, in the flat die used for this, molten resin or the like can be continuously molded into a sheet shape, but the molded product often has uneven thickness or deformation due to its structural failure or setting failure. In addition, uneven flow of the resin inside the die and uneven temperature may cause a striped pattern called a flow mark to be formed on the surface of the molded product.

The present invention has been made in view of the above circumstances, and an object thereof is to perform extrusion capable of continuously molding a molten resin containing a waste material such as sawdust into a predetermined plate shape without defective molding. An object is to provide a molding machine and an extrusion die.

[0006]

In order to achieve the above object, the present invention provides an extruder main body comprising a rotatable screw in a cylinder provided with a hopper for charging a raw material at one end thereof, and In an extruder comprising an extrusion head provided at the tip of a cylinder and a die connected to the extrusion head, the extrusion head is attached to the tip of the cylinder via a hinge so as to be openable and closable, while the die is The flow path formed inside is divided into an upper die and a lower die that can be opened and closed by forming a flat die that spreads in a fan shape toward the slit-shaped discharge port, and heat generation can be controlled individually for the upper die and the lower die. A plurality of heating elements are arranged in a predetermined arrangement pattern, and a pair of lip plates capable of adjusting the upper and lower gaps of the discharge port are provided at the tips of the upper die and the lower die. Is provided with a pair of width adjusting plates capable of adjusting the opening width, and the upper die has flow path resistance pieces arranged in the longitudinal direction of the discharge port, the projection amount of which can be adjusted into the flow path. It is characterized in that a choker made up of at least one is provided.

Further, in the extruder as described above, the screw is composed of a hollow rotary shaft extending along the cylinder and a spiral blade attached to the outer periphery of the rotary shaft, and the screw and the cylinder are It is characterized in that the clearance with the inner peripheral surface is set to 1 mm to 10 mm.

Further, the present invention is an extrusion molding die, which is divided into an upper die and a lower die which can be opened and closed by forming a flat die in which a flow path formed inside expands in a fan shape toward a slit-shaped discharge port. A die main body, a plurality of heating elements that are controlled by the upper die and the lower die in a predetermined arrangement pattern and can individually control heat generation, and a pair of lip plates that can adjust the upper and lower gaps of the discharge ports. A pair of width adjusting plates that can adjust the opening width of the discharge port, and a choker that is formed by arranging flow path resistance pieces that can adjust the amount of protrusion into the flow path in the longitudinal direction of the discharge port. It is characterized by having.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, application examples of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partially cutaway plan view of an extrusion molding machine according to the present invention, FIG. 2 is a side view of the molding machine, and FIG. 3 shows an enlarged cross section taken along line XX of FIG. .

In FIGS. 1 and 2, reference numeral 1 denotes an extruder main body, which is a pedestal 2 formed by joining structural steels and the like, and is horizontally installed on the pedestal 2 via a support 3. The cylinder 4 is formed of a cylindrical cylinder 4 (barrel) or the like, and the cylinder 4 is provided with a vent port 5 for degassing and a hopper 6 for introducing a forming raw material therein.

The hopper 6 is located on one end of the cylinder 4 and has an opening / closing lid 7 attached to its upper end opening.
A peep window 8 for inspecting the inside of the hopper 6 is provided in the. Further, a check opening 9 that can be opened and closed is provided under the hopper 6, and the inside of the cylinder 4 can be checked from the check opening 9.

Further, the cylinder 4 is provided with a heater 10 for heating and melting a thermoplastic resin or the like introduced from the hopper 6 as a forming raw material on the outer peripheral portion thereof, and moving such a forming raw material to the tip side. A rotatable screw 11 for allowing the rotation is built in. The screw 11 includes a hollow rotating shaft 11A and a spiral blade 1 attached to the outer periphery thereof.
1B, one end of the rotating shaft 11A has a coupling 12
Is connected to the output shaft of the drive motor 13 via. In this example, the drive motor 13 is an electric motor with a speed reducer,
The output is 7.5 kw and the maximum speed is 30 rpm.

Further, as shown in FIG. 3, the screw 11 and the inner peripheral surface of the cylinder 4 (more specifically, the blade 11B of the screw).
The clearance C between the tip edge of the cylinder and the inner peripheral surface of the cylinder 4) is set to 1 mm to 10 mm.

On the other hand, a die 15 is connected to the tip of the cylinder 4 via an extrusion head 14. In particular, the extrusion head 14 is attached to the tip of the cylinder 4 via a hinge 16 so as to open and close in the horizontal direction, and a heater 17 is provided on the outer peripheral portion thereof. Further, the die 15 is a flat-shaped flat die and is horizontally attached to the tip end portion of the extruder main body 1 via the extrusion head 14. In addition, in FIG.
Is a supporting leg for supporting the die 15, and a caster 19 is attached to the lower end thereof.

Next, FIG. 4 is a plan view showing the die.
FIG. 5 shows a cross section taken along line XX in FIG. In these figures, 20 and 21 are fixed flanges attached to the tip of the cylinder 4, and the extrusion head 14 is fixed flange 21.
And the movable flange 22 that closely adheres to the movable flange 22.
And a nozzle plate 25 connected to the extrusion head body 24 with bolts or the like, of which the movable flange 22 is the fixed flange 21 and the hinge 16. And the die 15 is connected to the opening of the nozzle plate 25.

As shown in FIG. 4, the die 15 belongs to a fish tail type of which the end is wide, and a flow passage 26 continuous from the inside of the cylinder 4 is formed inside the die 15 as shown in FIG. The discharge port 27 is opened to the outside. The flow path 26 has a discharge port 27 similar to the outer shape of the die body.
Fan-shaped toward. In particular, the die 15 is configured by equipping a fish-tail type die main body 28 having a fan-shaped flow path 26 therein with a heating element described later.

The die body 28 is composed of an upper die 28A and a lower die 28B which are divided into upper and lower parts, of which the lower die 28B is fixed to the nozzle plate 25, and the lower die 28B is fixed to the nozzle plate 25.
On the other hand, the upper die 28A is detachable. still,
The upper die 28A and the lower die 28B are fastened by bolts 29 provided at predetermined intervals along the side edges and lock bolts 30 penetrating the flow path 26.

The lock bolt 30 serves to prevent thermal deformation of the die body 28. The lock bolt 30 penetrates a plurality of points of the die body 28 and has a nut 31 screwed to the tip thereof to form the upper die 28A. It serves to clamp the central region of the lower die 28B in opposite directions. The lock bolt 30 makes it possible to make the die main body 28 thin and lightweight and prevent thermal deformation thereof. A collar 32 is formed on a side edge of the die body 28, and U-shaped notches 33 for passing the bolt 29 through the collar 32 are formed at predetermined intervals. In particular, as shown in FIG. 6, each bolt 29 has a cutout 33.
Nut 3 that is swingably attached to the block 34 provided on the lower die 28B at the position
It is designed to come off from the notch 33 when 5 is loosened.

A plurality of heating elements 36, which are linear electric heaters, are installed in a predetermined array pattern on the upper and lower surfaces of the die body 28 as a heating means for controlling the temperature of the entire area. The upper die 28A forming the upper surface is provided with a choker 37 for locally narrowing the flow path 26 formed between the upper die 28A and the lower die 28B.

In this example, the heating element 36 is the upper die 28.
The A and the lower die 28B are opposed to each other at 16 locations, and heat generation is controlled individually by a control unit (not shown). Reference numeral 38 is a groove portion formed in the upper die 28A and the lower die 28B to embed the heating element 36,
A fixing plate 39, to which a temperature sensor (not shown) is attached, is provided on the groove 38. Then, the detection signal of the temperature sensor is transmitted to the control unit and compared with a set value to control the energization amount to each heating element 36.

On the other hand, in the choker 37, the flow path resistance pieces 40 (15 pieces in this example) whose projection amount into the flow path 26 can be adjusted from the outside are arranged in series along the longitudinal direction of the discharge port 27. It is arranged and arranged. An adjusting bolt 41 is connected to the upper portion of each flow path resistance piece 40, and the adjusting bolt 41 is movably supported by a receiving seat 42 fixed to the upper die 28A. Therefore, by turning the adjusting bolt 41, the flow path resistance piece 40 corresponding to this can be moved up and down, and the tip end thereof can be advanced into the flow path 26.
As a result, the molding material can be uniformly discharged from the discharge port 27 over its entire length, but in this example, the flow passage 26 inside the die is gradually thinned toward the discharge port 27, and the flow passage 26 is further reduced. As shown in FIG. 7, guide grooves 43 are formed on both sides of the groove so as to prevent uneven flow of the molding material concentrated in the central portion. Although the lower die 28B is shown in FIG. 7, similar guide grooves are formed on the inner surface of the upper die 28A.

As shown in FIGS. 4 and 5, the die body 2
A pair of lip plates 44 that can adjust the upper and lower gaps of the discharge port 27 and a pair of width adjustment plates 45 that can adjust the opening width of the discharge port 27 are provided at the tip of 8.

As shown in FIG. 8, screw holes 46 for attaching the lip plates 44 are formed at the tip surfaces of the upper die 28A and the lower die 28B at predetermined intervals, and screw holes are formed in the lip plates 44. Long holes 47 extending vertically are formed at the same intervals as 46. Then, a pair of upper and lower lip plates 44
As shown in FIG. 9, the upper die 28A and the lower die 28A are screwed by screws 48 screwed into the screw holes 46 through the long holes 47.
It is fixed in parallel with the front end surface of B, and each has a long hole 47.
The distance between them can be adjusted by the length of, and the gap above and below the discharge port 27 can be adjusted.

On the other hand, the pair of left and right width adjusting plates 45 have horizontal grooves 49 at the top and bottom, and are attached to both sides of the lip plate 44 in the longitudinal direction. In FIG. 9, 50 is a width adjusting plate 45.
Is a screw for fixing the upper die 28A and the lower die 2 from the horizontal groove 49 through the long hole 47 of the lip plate.
It is screwed into the screw hole 46 of 8B. The mounting position of the width adjusting plate 45 is variable in the left-right direction by the length of the horizontal groove 49, whereby the opening width of the discharge port 27 can be adjusted.

As is apparent from FIG. 8, the upper die 28
The A and the lower die 28B have a seal cage structure in which the convex portion 51 and the concave portion 52 formed on both sides of the inner surface of the mold A and the lower die 28B are fitted to each other so that the raw material does not leak. Further, in FIGS. 4 and 6, reference numeral 53 denotes side plates fixed to both end surfaces of the lip plate 44, which serves to prevent the molding raw material from leaking out from both ends of the lip plate 44.

Here, according to the extruder configured as described above, the thermoplastic resin is put into the hopper 5 and melted, and waste materials such as sawdust and waste paper are added to the melt and mixed. However, this can be extruded from the discharge port 27 of the die 15 and shaped into a plate. However, it goes without saying that the present invention does not require the use of such a waste material as a molding raw material and can be applied to continuous molding of only a resin.

[0027]

As is apparent from the above description, according to the extrusion molding machine of the present invention, the extrusion head is attached to the tip of the cylinder so as to be openable and closable via the hinge, so that the internal cleaning is easy. Moreover, since the screw has a structure in which a spiral blade is attached to a hollow rotating shaft, it can be manufactured at a low weight and at low cost, and the clearance with the inner peripheral surface of the cylinder is set to 1 to 10 mm. Since the drive system can be simplified by using a small drive motor, the screw itself is not worn and maintenance costs are low, and there is little risk of damage to the screw due to overload even if foreign matter is mixed in. Even if a large amount of gas is generated due to the melting of the raw materials, this does not become trapped and there is no danger of explosion.

Further, since the die is made into a flat die having a flow path that spreads in a fan shape toward the slit-shaped discharge port, the die is divided into an upper die and a lower die that can be opened and closed, and therefore the internal cleaning is easy. Moreover, since the upper die and the lower die are temperature-controlled for each device area of the heating element, it is possible to prevent molding defects such as bending of the molded product due to non-uniform temperature.

Further, a pair of lip plates capable of adjusting the upper and lower gaps of the discharge port and a pair of width adjusting plates capable of adjusting the opening width of the discharge port are provided at the tips of the upper die and the lower die. Therefore, it is possible to form boards of various sizes, reduce trimming loss, and arrange flow path resistance pieces that can adjust the amount of protrusion into the flow path along the longitudinal direction of the discharge port. It is possible to prevent uneven flow of the forming raw material inside.

[Brief description of drawings]

FIG. 1 is a plan view showing an extruder according to the present invention.

[Fig. 2] Side view of the molding machine

FIG. 3 is a sectional view taken along line XX in FIG.

FIG. 4 is a plan view of the die.

5 is a sectional view taken along line XX in FIG.

FIG. 6 is a side view showing the tip of the die.

FIG. 7 is a plan view showing the inside of the die.

FIG. 8 is an end view showing a state where the die is separated.

FIG. 9 is a front view of the die.

[Explanation of symbols]

1 Extruder body 4 cylinders 6 hoppers 11 screw 11A rotating shaft 11B feather 13 Drive motor 14 Extrusion head 15 dies 16 hinges 26 channels 27 outlet 28 Die body 28A upper die 28B Lower die 36 heating element 37 Choker 40 flow path resistance piece 44 lip board 45 width adjustment plate

Claims (4)

[Claims] 1. An extruder main body having a rotatable screw in a cylinder having a hopper for charging a raw material at one end, an extrusion head provided at the tip of the cylinder, and the extrusion head. In an extruder including a die to be connected, the extrusion head is attached to the tip of a cylinder so as to be openable and closable via a hinge, while the die has a flow path formed inside the slit-shaped discharge port. It is divided into an upper die and a lower die that can be opened and closed in a flat die that spreads in a fan shape toward each other, and a plurality of heating elements that can individually control heat generation are installed in the upper die and the lower die in a predetermined array pattern. A pair of lip plates capable of adjusting the upper and lower gaps of the discharge port and a pair of width adjusting plates capable of adjusting the opening width of the discharge port are provided at the tip portions of the die and the lower die. In addition, the upper die is provided with a choker formed by arranging flow path resistance pieces whose amount of protrusion into the flow path is arranged in the longitudinal direction of the discharge port. . 2. The extruder according to claim 1, wherein the screw comprises a hollow rotary shaft extending along the cylinder, and a spiral blade attached to the outer periphery of the rotary shaft. 3. The extruder according to claim 1, wherein the clearance between the screw and the inner peripheral surface of the cylinder is set to 1 mm to 10 mm. 4. A die body divided into an upper die and a lower die that are opened and closed by forming a flat die in which a flow path formed inside is fan-shaped toward a slit-shaped discharge port, and the upper die and the lower die. A plurality of heating elements that are installed in a die in a predetermined arrangement pattern and that can individually control heat generation, a pair of lip plates that can adjust the upper and lower gaps of the ejection port, and the opening width of the ejection port For extrusion molding, which includes a pair of possible width adjusting plates and a choker formed by arranging flow path resistance pieces whose projection amount into the flow path can be adjusted in the longitudinal direction of the discharge port. Die.