JPH06126807A - Thermoplastic rein extrusion device - Google Patents

Abstract

PURPOSE:To provide an extruding device of themoplastic resin which can feed easily a liquid additive within a cylinder and is capable of performing a high extrusion quantity and extrusion of resin having a low temperature even if resistance at an outlet of the cylinder is great and resin pressure in the cylinder is high. CONSTITUTION:This is an extrusion device of thermoplastic resin which melts the pelletlike thermoplastic resin 4 to be fed within a cylinder 3 through a falling port 2 of the lower end of a hopper 1 and sent out to an outlet 6 side of the cylinder 3 through a rotation of a screw 5, several pieces of tapered grooves 9 are formed along a longittudinal direction of an inner circumferential surface 8 of a feed part 7 out of the cylinder 3, to which the thermoplastic resin is fed through the hopper 1. Then the depth of the tapered groove 9 is constituted so that the groove becomes shallow gradually to the outlet 6 side of the cylinder 3 from the hopper 1 side and an outlet 12 of an additive of a feed pipe 11 feeding a liquid additive 10 to the cylinder 3 is introduced within the falling port 2 of the hopper 1 or the feed part 7 of the cylinder 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The thermoflexible resin extrusion apparatus of the present invention is used for extruding a thermoflexible resin such as crosslinked polyethylene onto the outside of the core wire of a power cable when the cable is manufactured. It is used.

[0002]

2. Description of the Related Art As shown in FIG. 5, a pellet-shaped thermo-flexible resin C supplied from a hopper A into a cylinder B is rotatably provided in the cylinder B together with heat applied to the cylinder B. Conventionally, there is a thermo-flexible resin extruding device which melts when the screw D is rotated by shearing and is sent out from the outlet E of the cylinder B.

In the case of using this thermoflexible resin extruder, conventionally, the additive F is injected from the midpoint of the cylinder B by the pump P while the thermoflexible resin C is being melted and conveyed. The heat-flexible molten resin mixed with the additive F is extruded from the outlet E of the cylinder B.

[0004]

The thermoflexible resin extrusion apparatus of FIG. 5 has an ultrafine screen mesh for the purpose of capturing foreign matter mixed in the thermoflexible resin C at the outlet E of the cylinder B. Pack G and breaker plate H are attached,
A die I for molding the molten resin into a predetermined shape is attached.

Therefore, when extruding the heat-flexible molten resin mixed with the additive F, they become a resistance. Moreover, when the resistance increases, the extrusion capacity of the screw D decreases, and the extrusion rate, that is, the production rate, remarkably decreases. Further, if this decrease in the extrusion amount is captured by increasing the rotation speed of the screw D, in addition to the rise in the resin temperature due to the resistance, the heat generation of the resin due to the shearing also becomes large, and the resin temperature considerably rises, resulting in extrusion molding. There is a problem in that the quality of the product obtained by this method is significantly deteriorated.

As one of the methods for solving the above problems, conventionally, a taper groove (not shown) is formed on the inner peripheral surface of the supply portion J of the cylinder B to which the thermo-flexible resin C is supplied from the hopper A. ) Is formed and the pelletized material supplied to the supply section J is forcibly sent to the outlet E side of the cylinder B.

According to this method, as compared with the case where there is no taper groove, even if the resistance of the outlet E is large, it is possible to extrude the resin having a high extrusion rate and a low temperature. However, the thermo-flexible resin C is forced by the taper groove. There is a new problem that the resin pressure in the cylinder B is increased by the amount of the feeding, and it becomes difficult or impossible to inject the additive F into the cylinder B, and desired quality cannot be obtained.

The object of the present invention is to enable the liquid additive to be easily supplied into the cylinder even if the resistance on the outlet side of the cylinder is large and the resin pressure inside the cylinder to be high. An object is to provide a flexible resin extrusion device.

[0009]

As shown in FIG. 1, the thermo-flexible resin extrusion apparatus of the present invention is a pellet-shaped thermo-flexible resin which is supplied into a cylinder 3 from a drop opening 2 at a lower end of a hopper 1. A thermo-flexible resin in which the resin 4 is melted by the heat given to the cylinder 3 and sheared by the rotation of the screw 5 rotatably provided in the cylinder 3 and sent to the outlet 6 side of the cylinder 3. In the extruder, a taper groove 9 is formed along the longitudinal direction on the inner peripheral surface 8 of the supply part 7 of the cylinder 3 to which the thermo-flexible resin 4 is supplied from the drop opening 2 of the hopper 1. Depth of taper groove 9 in hopper 1
Side to the outlet 6 side of the cylinder 3 is formed in a taper that gradually becomes shallower, and a supply pipe 11 for supplying the liquid additive 10 into the drop port 2 of the hopper 1 or the supply portion 7 of the cylinder 3 is provided. The additive outlet 12 is introduced.

[0010]

In the thermoflexible resin extrusion apparatus of the present invention, the cylinder 3 is used.
Since several taper grooves 9 are formed along the longitudinal direction on the inner peripheral surface 8 of the supply part 7, the friction coefficient between the cylinder 3 and the thermo-flexible resin 4 inside the cylinder 3 increases. The thermo-flexible resin 4 is forcibly sent to the outlet side of the cylinder 3. The resin pressure in the cylinder 3 at this time is as shown in FIG. That is, the resin pressure gradually increases from the deeper side to the shallower side of the taper groove 9, reaches the maximum near the terminal end of the taper groove 9, and then gradually decreases toward the outlet 6 side.

Further, in the present invention, since the additive agent outlet 12 of the supply pipe 11 is introduced into the drop opening 2 at the lower end of the hopper 1 or the supply portion 7 of the cylinder 3, the additive agent outlet 12 is sent out. The liquid additive 10 is directly supplied into the supply portion 7 having a lower resin pressure than that of the outlet 6 side of the cylinder 3 and stably enters the cylinder 3 reliably. Therefore, it is possible to obtain the molten resin in which the required amount of the liquid additive 10 is mixed in the cylinder 3.

[0012]

EXAMPLE An explanation will be given based on an example in which the thermo-flexible resin extruder of the present invention is applied to the crosslinked polyethylene insulated cable production line shown in FIG.

In the figure, 1 is a hopper, 2 is a drop opening formed at the lower end of the hopper 1, 3 is a cylinder, 4 is a thermo-flexible resin supplied from the hopper 1 to the cylinder 3, and 5 is inside the cylinder 3. It is a screw that is rotatably attached.

Reference numeral 9 in FIG. 1 denotes a taper groove. The taper groove 9 increases the friction coefficient between the pellet-shaped thermo-flexible resin 4 in the cylinder 3 and the cylinder 3 to increase the thermo-flexibility resin 4. Is forcibly sent in the direction of the outlet 6 of the cylinder 3. Therefore, as shown in FIGS. 1 and 2, the taper groove 9 has four grooves along the longitudinal direction on the inner peripheral surface 8 of the supply part 7 of the cylinder 3 to which the thermoflexible resin 4 is supplied. Further, the four tapered grooves 9 are formed at equal intervals in the circumferential direction of the inner peripheral surface 8 of the supply section 7. Further, the depth of the tapered grooves 9 is from the hopper 1 side to the outlet 6 of the cylinder 3. The taper gradually becomes shallower toward the side. The number of tapered grooves 9 may be other than four.

As shown in FIG. 2 (a), the inner diameter d of the drop port 2 at the lower end of the hopper 1 is about 1D to 2D in relation to the inner diameter D of the cylinder 3, and as shown in FIG. 2 (b). The width w of the tapered groove 9 is D / 10 to D in relation to the inner diameter D of the cylinder 3.
/ 5, and the maximum depth h of the taper groove 9 is the cylinder 3
It is desirable to set it to about D / 200 to D / 20 in relation to the inner diameter D of. By setting this degree, the friction coefficient between the pellet-shaped thermo-flexible resin 4 in the cylinder 3 and the cylinder 3 forcibly feeds the thermo-flexible resin 4 toward the outlet 6 of the cylinder 3. It is a value suitable for.

Reference numeral 11 in FIG. 1 is a supply pipe for supplying the liquid additive 10 in the tank into the cylinder 3 by the pump 13. This supply pipe 11 is introduced from the outside to the lower end of the hopper 1, and further the lower end thereof. The additive outlet 12 is introduced into the drop opening 2 of the hopper 1 so that the liquid additive 10 is directly supplied onto the screw 5 from the additive outlet 12. This outlet may be introduced below the supply part 7 of the cylinder 3 as shown by the phantom line in FIG.

In FIG. 1, 14 is an ultrafine mesh screen mesh pack provided at the outlet 6 of the cylinder 3, 15 is a breaker plate provided on the outside thereof, and these are mixed in the thermo-flexible resin 4. The purpose is to remove even minute foreign matter in the unit of several μm.

Reference numeral 17 in FIG. 1 denotes a crosshead for extrusion-coating the outer periphery of the cable conductor 18 with the resin extruded through the screen mesh pack 14 and the breaker plate 15.

[0019]

[Example 1 of use] In the thermo-flexible resin extruding apparatus of FIG. 1, when a pellet-shaped thermo-flexible resin 4 is put into the hopper 1, the thermo-flexible resin 4 is discharged from the drop port 2 at the lower end of the hopper 1. It falls into the cylinder 3. The dropped thermo-flexible resin 4 is forcibly sent toward the outlet 6 of the cylinder 3 by the taper groove 9 of the cylinder 3. Further, the thermo-flexible resin 4 is melted by the heat given to the cylinder 3 and the shear due to the rotation of the screw 5 in the cylinder 3, and is sent to the outlet 6 side of the cylinder 3.

At this time, the resin pressure of the thermo-flexible resin 4 forcedly sent out by the taper groove 9 increases. Further, since the screen mesh pack 14 and the breaker plate 15 are provided at the outlet 6 of the cylinder 3 and the crosshead 17 is provided outside the screen mesh pack 14, the thermoflexible resin 4 to be delivered becomes considerably high pressure due to their resistance.

For example, as the screen mesh pack 14, 60 mesh × 2 sheets, 150 mesh × 2 sheets, 10
When 00 mesh x 2 sheets and 2000 mesh x 1 sheet are set, the pressure becomes 500 to 600 kg / cm ² ,
The resistance is about twice as high as the normal cable extrusion of 200 to 300 kg / cm ² .

However, in the thermoflexible resin extrusion apparatus of FIG. 1, a liquid additive (for example, a cross-linking agent or a cross-linking agent or the like) is supplied from the additive outlet 12 of the supply pipe 11 introduced into the drop port 2 at the lower end of the hopper 1. Since the mixed solution 10 of the cross-linking agent and the anti-aging agent directly drops onto the screw 5, the thermo-flexible resin 4 is sufficiently mixed with the liquid additive 10 and is smoothly delivered. Therefore, even if the pressure is high as described above, the extruded thermo-flexible resin 4 does not reach a high temperature and the extrusion amount does not decrease, and the outer periphery of the cable conductor 18 is covered. The cable extruded and coated with the thermo-flexible resin 4 is sent to the cross-linking pipe 19 and cross-linked.

[0023]

[Embodiment 2] FIG. 4 is an embodiment in which the thermo-flexible resin extruder of the present invention is used for the first-stage extruder of a cross-linked polyethylene insulation cable production line by a multi-stage extrusion method.

In the first-stage extrusion device (extrusion device of the present invention) 20 of FIG. 4, as in the case of FIG. 1, the heat-flexible resin 4 supplied from the hopper 1 is heated and melted in the cylinder 3. It is sheared by the screw 5 and sent to the outlet 6 side, and at that time, a liquid additive 10 such as an antioxidant is supplied into the cylinder 3 through the supply pipe 11 so that it can be mixed with the thermo-flexible resin by the screw 5. I am doing it.

As described above, the thermo-flexible resin mixed with the liquid additive 10 passes through the screen mesh pack 14 and the breaker plate 15 mounted for the purpose of removing foreign matters, and is then provided by the resin cooling device 21. After being cooled to an appropriate temperature, it is guided to the second stage extruder 30. At this time, the first
At the outlet of the extrusion device 20 of the first stage, the screen mesh pack 14 and the resin cooling device 21 generate a high pressure more than double the normal pressure. The amount does not decrease, and the resin temperature is suppressed from rising and the resin is extruded.

Further, as in the case of FIG. 1, a liquid additive 10 such as an antioxidant is stably supplied from an additive outlet 12 of a supply pipe 11 introduced into a drop opening 2 at the lower end of a hopper 1. Therefore, the resin of uniform quality is extruded from the outlet of the first-stage extrusion device 20 in a stable amount.

The resin introduced to the second-stage extrusion device 30 is mixed with the cross-linking agent 32 injected into the cylinder 31 of the device 30 from the middle of the cylinder 31 by the screw 33 of the device 30. It is pushed out and sent to the crosshead 35 through the screen mesh pack 34, and the outer periphery of the cable conductor 18 is extrusion-coated as an insulator by the crosshead 35.

[0028]

The thermoplastic resin extruder of the present invention has the following effects. ． Since the cylinder 3 has the tapered groove 9, the thermoplastic resin 4 supplied from the hopper 1 to the cylinder 3 is forcibly sent to the outlet 6 side of the cylinder 3. ． Since the additive outlet 12 of the supply pipe 11 is introduced into the drop opening 2 at the lower end of the hopper 1, the liquid additive 10 is reliably and stably supplied from the additive outlet 12 into the cylinder 3. ． For the above reason, even if the resistance on the outlet 6 side of the cylinder 3 is large, even if the resin pressure becomes high by forcibly sending the thermoplastic resin 4 in the cylinder 3 to the outlet 6 side, the thermoplastic resin 4 will be smooth. Is sent to the outlet 6 side of the cylinder 3, and it is possible to perform extrusion with a high extrusion rate and low resin temperature, and it is possible to perform extrusion molding with excellent quality.

[Brief description of drawings]

FIG. 1 is an explanatory view of a crosslinked polyethylene insulated cable manufacturing apparatus using a thermoflexible resin extrusion apparatus of the present invention.

FIG. 2 (a) is a side view showing the relationship between the inner diameter of the cylinder and the hopper drop port in the thermo-flexible resin extruder of the present invention, and FIG. 2 (b) shows the relationship between the inner diameter of the cylinder and the taper groove. FIG.

FIG. 3A is an explanatory view of a resin pressure distribution in a cylinder in the thermo-flexible resin extrusion device of the present invention, and FIG. 3B is a positional relationship between a screw and a tapered groove corresponding to the resin pressure distribution in FIG. 3A. FIG.

FIG. 4 is an explanatory view of a multistage crosslinked polyethylene insulated cable manufacturing apparatus using the thermoflexible resin extrusion apparatus of the present invention.

FIG. 5 is an explanatory view of a conventional thermoflexible resin extrusion device.

[Explanation of symbols]

 1 Hopper 2 Drop Port 3 Cylinder 4 Thermoflexible Resin 5 Screw 6 Cylinder Outlet 7 Supply Portion 8 Inner Surface 9 Tapered Groove 10 Supply Pipe 11 Additive Agent Outlet

[Procedure amendment]

[Submission date] January 19, 1993

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

[Title of Invention] Thermal friendly 塑 resin extruder

[Claims]

Detailed Description of the Invention

[0001]

Heat Allowed 塑 resin extrusion apparatus of the present invention relates, for example, in the production of power cables, to the heat-friendly 塑 resin outside crosslinked polyethylene or the like of the core wire by extrusion coating It is used.

[0002]

BACKGROUND OF THE INVENTION pelletized heat-friendly 塑 resin C supplied from the hopper A into the cylinder B as shown in FIG. 5, rotatably provided heat and the cylinder B given in the Shilling B melted by the shearing caused by the rotation of the screw D, heat Allowed 塑 resin extrusion apparatus that sends out the exit E of it the cylinder B is conventionally.

[0003] When using thermal-friendly 塑 resin extrusion apparatus, conventionally melted Netsuka 塑 resin C, and the course of conveying, the additive F in the middle of the cylinder B therein was injected by a pump P heat Allowed 塑 molten resin which addenda F from the outlet E of the cylinder B was mixed had to be extruded.

[0004]

For the purpose of trapping foreign matter mixed in the outlet E of the cylinder B in Netsuka 塑 resin C in hot friendly 塑 resin extrusion apparatus of FIG. 5 THE INVENTION An object you try solving], ultra fine screen mesh Pack G and breaker plate H are attached,
A die I for molding the molten resin into a predetermined shape is attached.

[0005] they become resistance Therefore additive F was mixed thermally-friendly 塑 molten resin when extruded. Moreover, when the resistance increases, the extrusion capacity of the screw D decreases, and the extrusion rate, that is, the production rate, remarkably decreases. Further, if this decrease in the extrusion amount is captured by increasing the rotation speed of the screw D, in addition to the rise in the resin temperature due to the resistance, the heat generation of the resin due to the shearing also becomes large, and the resin temperature considerably rises, resulting in extrusion molding. There is a problem in that the quality of the product obtained by this method is significantly deteriorated.

Conventional One way to solve the above problems, the heat-friendly 塑 resin C is not tapered groove (shown on the inner peripheral surface of the supply portion J which is supplied from a hopper A of the cylinder B ) Is formed and the pelletized material supplied to the supply section J is forcibly sent to the outlet E side of the cylinder B.

[0007] Force than if tapered groove is not According to this method, a high extrusion rate, even if the resistance is large exit E, it makes possible extrusion cold resin, the heat-friendly 塑 resin C by tapered grooves There is a new problem that the resin pressure in the cylinder B is increased by the amount of the feeding, and it becomes difficult or impossible to inject the additive F into the cylinder B, and desired quality cannot be obtained.

The object of the present invention is to easily supply the liquid additive into the cylinder even if the resistance on the outlet side of the cylinder is large and the resin pressure in the cylinder is high, and it is possible to extrude a high extrusion amount and a low temperature resin. It is to provide a heat-friendly 塑 resin extrusion apparatus.

[0009]

Thermal friendly 塑 resin extrusion apparatus of the present invention SUMMARY OF THE INVENTION As shown in FIG. 1, a pellet-shaped heat-friendly 塑 of being supplied from the fall opening 2 of the lower end of the hopper 1 into the cylinder 3 the resin 4, and melted by shear by rotatably rotation of the screw 5 provided in the heat and the cylinder 3 provided in the cylinder 3, the heat-friendly 塑 resin was set to send out to the outlet 6 of the cylinder 3 in the extrusion apparatus, the inner peripheral surface 8 of the supply unit 7 for heat-friendly 塑 resin 4 from the drop opening 2 of the hopper 1 of the cylinder 3 is supplied, a tapered groove 9 along its longitudinal direction, the Depth of taper groove 9 in hopper 1
Side to the outlet 6 side of the schilling 3 is formed in a taper that gradually becomes shallower, and a supply pipe 11 for supplying the liquid additive 10 into the drop port 2 of the hopper 1 or the supply part 7 of the cylinder 3 is provided. The additive outlet 12 is introduced.

[0010]

[Action] In the heat-friendly 塑 resin extrusion apparatus of the present invention is the cylinder 3
Of the inner peripheral surface 8 of the supply unit 7, since the longitudinal direction several along the tapered grooves 9 are formed, the friction coefficient of the cylinder 3 and the heat-friendly 塑 resin 4 therein is increased, heat Allowed 塑 resin 4 is forcibly fed to the outlet side of the cylinder 3. The resin pressure in the cylinder 3 at this time is as shown in FIG. That is, the resin pressure gradually increases from the deeper side to the shallower side of the taper groove 9, reaches the maximum near the terminal end of the taper groove 9, and then gradually decreases toward the outlet 6 side.

Further, in the present invention, since the additive agent outlet 12 of the supply pipe 11 is introduced into the drop opening 2 at the lower end of the hopper 1 or the supply portion 7 of the cylinder 3, the additive agent outlet 12 is sent out. The liquid additive 10 is directly supplied into the supply portion 7 having a lower resin pressure than that of the outlet 6 side of the cylinder 3 and stably enters the cylinder 3 reliably. Therefore, it is possible to obtain the molten resin in which the required amount of the liquid additive 10 is mixed in the cylinder 3.

[0012]

It will be described with reference to an embodiment in which the heat-friendly 塑 resin extrusion apparatus of the embodiment of the present invention is applied to cross-linked polyethylene insulated cable production line shown in Figure 1.

[0013] 1 in the figure hopper 2 drop opening formed in the lower end of the hopper 1, 3 a cylinder, 4 is heat-friendly 塑 resin supplied from the hopper 1 to the cylinder 3, 5 into the cylinder 3 It is a screw that is rotatably attached.

[0014] 9 of FIG. 1 is a tapered groove, the tapered groove 9 thermally friendly 塑 resin 4 increases the coefficient of friction between the pellets of the heat-friendly 塑 resin 4 and the cylinder 3 in the cylinder 3 Is forcibly sent in the direction of the outlet 6 of the cylinder 3. Therefore the tapered groove 9 1, as shown in FIG. 2, four thermally Allowed 塑 resin 4 from the hopper 1 of the cylinder 3 along a longitudinal direction of the inner peripheral surface 8 of the supply portion 7 to be supplied Further, the four tapered grooves 9 are formed at equal intervals in the circumferential direction of the inner peripheral surface 8 of the supply section 7. Further, the depth of the tapered grooves 9 is from the hopper 1 side to the outlet 6 of the cylinder 3. The taper gradually becomes shallower toward the side. The number of tapered grooves 9 may be other than four.

As shown in FIG. 2 (a), the inner diameter d of the drop port 2 at the lower end of the hopper 1 is about 1D to 2D in relation to the inner diameter D of the cylinder 3, and as shown in FIG. 2 (b). The width w of the tapered groove 9 is D / 10 to D in relation to the inner diameter D of the cylinder 3.
/ 5, and the maximum depth h of the taper groove 9 is the cylinder 3
It is desirable to set it to about D / 200 to D / 20 in relation to the inner diameter D of. With this degree, the coefficient of friction between the pellets of the heat-friendly 塑 resin 4 and the cylinder 3 in the cylinder 3 is fed into the outlet 6 the direction of forcing cylinder 3 Donetsuka 塑 resin 4 It is a value suitable for.

Reference numeral 11 in FIG. 1 is a supply pipe for supplying the liquid additive 10 in the tank into the cylinder 3 by the pump 13. This supply pipe 11 is introduced from the outside to the lower end of the hopper 1, and further the lower end thereof. The additive outlet 12 is introduced into the drop opening 2 of the hopper 1 so that the liquid additive 10 is directly supplied onto the screw 5 from the additive outlet 12. This outlet may be introduced below the supply part 7 of the cylinder 3 as shown by the phantom line in FIG.

[0017] 14 in FIG. 1 ultrafine eye screen mesh pack is provided at the outlet 6 of the cylinder 3, 15 is a breaker plate provided on the outside, it is mixed in the heat-friendly 塑 resin 4 The purpose is to remove even minute foreign matter in the unit of several μm.

Reference numeral 17 in FIG. 1 denotes a crosshead for extrusion-coating the outer periphery of the cable conductor 18 with the resin extruded through the screen mesh pack 14 and the breaker plate 15.

[0019]

[Example 1] In the heat-friendly 塑 resin extrusion apparatus of Figure 1, when turning on the heat-friendly 塑 resin 4 Perretto shaped hopper 1, Donetsuka 塑 resin 4 from dropping opening 2 of the lower end of the hopper 1 It falls into the cylinder 3. It dropped thermally Allowed 塑 resin 4 is fed to forcibly exit 6 direction of the cylinder 3 by the tapered groove 9 of the cylinder 3. Further, Donetsuka 塑 resin 4 is fed is melted by the shearing caused by the rotation of the screw 5 in the heat and the cylinder 3 provided in the cylinder 3 to the outlet 6 of the cylinder 3.

[0020] At this time, heat Allowed 塑 resin 4 increases the resin pressure fed forcibly by tapered grooves 9. The screen mesh pack 14 to the outlet 6 of the cylinder 3, there is a breaker plate 15, further because of the cross head 17 to the outside, the heat-friendly 塑 resin 4 is fed a considerably higher pressure at their resistance.

For example, as the screen mesh pack 14, 60 mesh × 2 sheets, 150 mesh × 2 sheets, 10
When 00 mesh x 2 sheets and 2000 mesh x 1 sheet are set, the pressure becomes 500 to 600 kg / cm ² ,
The resistance is about twice as high as the normal cable extrusion of 200 to 300 kg / cm ² .

[0022] However, in the heat-friendly 塑 resin extrusion apparatus of Figure 1, the hopper 1 of the lower end of the addenda outlet 12 from the liquid addenda of the supply tube 11 which has been introduced into chute in 2 (e.g. cross-linking agent or since mixture) 10 crosslinking agent and antioxidant from falling directly onto the screw 5, the heat-friendly 塑 resin 4 is fed smoothly is well mixed with an equal liquid addenda 10. Therefore, heat Allowed 塑 resin 4 to be extruded even when the high pressure as not so much to a high temperature, also extruded amount not lowered, is coated on the outer periphery of the cable conductor 18. Incidentally, the cable heat friendly 塑 resin 4 is extruded coating is crosslinked sent into the cross-linked pipe 19.

[0023]

Embodiment 2 FIG. 4 shows an embodiment in which the heat-friendly 塑 resin extruder was used to extrusion apparatus of the first stage of the cross-linked polyethylene insulated cable production line according to the multi-stage extrusion method of the present invention.

[0024] As in the case of 20 in FIG. 1 (extrusion apparatus of the present invention) Extrusion apparatus of the first stage of FIG. 4, the heat-friendly 塑 resin 4 supplied from the hopper 1 heated and melted in a cylinder 3 feeding 6 side outlet shears screw 5, then the liquid addenda 10 such antioxidant is fed through the supply pipe 11 into the cylinder 3, the heat-friendly 塑 <br/> resin it with screws 5 It can be mixed with.

[0025] pass through the screen mesh pack 14, a breaker plate 15 liquid addenda 10 mixed thermal <br/> friendly 塑 resin mounted purposes of the foreign matter removal as described above, then the resin cooling After being cooled to a suitable temperature by the device 21, it is guided to the second-stage extrusion device 30. At this time, the first
At the outlet of the extrusion device 20 of the first stage, the screen mesh pack 14 and the resin cooling device 21 generate a high pressure more than double the normal pressure, but the extrusion is performed by the effect of the taper groove 9 provided in the cylinder 3 of the extrusion device 20 of the first stage. The amount does not decrease, and the resin temperature is suppressed from rising and the resin is extruded.

Further, as in the case of FIG. 1, a liquid additive 10 such as an antioxidant is stably supplied from an additive outlet 12 of a supply pipe 11 introduced into a drop opening 2 at a lower end of a hopper 1. Therefore, the resin of uniform quality is extruded in a stable amount from the outlet of the first-stage extrusion device 20.

The resin introduced to the second-stage extrusion device 30 is mixed with the cross-linking agent 32 injected into the cylinder 31 of the device 30 from the middle of the cylinder 31 by the screw 33 of the device 30. It is pushed out and sent to the crosshead 35 through the screen mesh pack 34, and the outer periphery of the cable conductor 18 is extrusion-coated as an insulator by the crosshead 35.

[0028]

The thermoplastic resin extruder of the present invention has the following effects. ． Since the cylinder 3 has the tapered groove 9, the thermoplastic resin 4 supplied from the hopper 1 to the cylinder 3 is forcibly sent to the outlet 6 side of the cylinder 3. ． Since the additive outlet 12 of the supply pipe 11 is introduced into the drop opening 2 at the lower end of the hopper 1, the liquid additive 10 is reliably and stably supplied from the additive outlet 12 into the cylinder 3. ． For the above reason, even if the resistance on the outlet 6 side of the cylinder 3 is large, even if the resin pressure becomes high by forcibly sending the thermoplastic resin 4 in the cylinder 3 to the outlet 6 side, the thermoplastic resin 4 will be smooth. Is sent to the outlet 6 side of the cylinder 3, and it is possible to perform extrusion with a high extrusion rate and low resin temperature, and it is possible to perform extrusion molding with excellent quality.

[Brief description of drawings]

Illustration of cross-linked polyethylene insulated cable manufacturing apparatus using thermal friendly 塑 resin extrusion apparatus of the present invention; FIG.

2 (a) is a side explanatory view showing the relationship between the inner diameter and the hopper chute cylinder in the heat-friendly 塑 resin extrusion apparatus of the present invention, the relationship between (b) is of the same cylinder bore and the tapered groove FIG.

[3] Distribution explanatory view of a resin pressure inside the cylinder in the heat-friendly 塑 resin extrusion apparatus of the present invention.

Illustration of a multi-stage cross-linked polyethylene insulated cable manufacturing apparatus using thermal friendly 塑 resin extrusion apparatus of the present invention; FIG.

Figure 5 is an explanatory view of a conventional heat-friendly 塑 resin extrusion apparatus.

[Reference Numerals] 1 hopper 2 chute 3 cylinders 4 heat friendly 塑 resin 5 screw 6 outlet 7 inside the supply section 8 circumferential surface of the cylinder 9 the tapered grooves 10 feed pipe 11 addenda outlet

Claims (1)

[Claims] 1. A pellet-shaped thermo-flexible resin 4 supplied into a cylinder 3 from a drop opening 2 at a lower end of a hopper 1 is rotatably provided in the cylinder 3 together with heat applied to the cylinder 3. In a thermo-flexible resin extrusion device that is melted by shearing due to rotation of the screw 5 and sent out to the outlet 6 side of the cylinder 3, the thermo-flexible resin 4 from the drop port 2 of the hopper 1 of the cylinder 3 A taper groove 9 is formed along the longitudinal direction of the inner peripheral surface 8 of the supply portion 7 to which is supplied, and the depth of the taper groove 9 is gradually reduced from the hopper 1 side to the outlet 6 side of the cylinder 3. And a supply pipe 11 for supplying the liquid additive 10 into the drop opening 2 of the hopper 1 or the supply portion 7 of the cylinder 3.
The thermoflexible resin extrusion device is characterized in that the additive outlet 12 is introduced.