JPS6194739A - Cooling ring for inflation film - Google Patents

Abstract

PURPOSE:To produce a film at high speed by providing the first air blow of port composed of a bottom ring and a reflection ring, the second air blow off port composed of the reflecting ring and a guidance-reflection ring and the third air blow off port composed of the guidance-reflection ring and a guidance ring. CONSTITUTION:The molten tube 3 extruded from an extruding die 1 is cooled by an extruding shaft core 11 and the air ring body 2 of said shaft. The tube 3 is precooled by the cooling air from the first spouting port composed of a bottom ring 4 and a reflection ring 5, and further tube 3 is stretched radially and outward by Venturi effect of the cooling air-stream from the second air spouting port composed of the reflection ring 5 and a guidance-reflection ring 6 and the third air spouting port composed of the guidance-reflection ring 6 and a guidance ring 7, and simultaneously is cooled.

Description

[Detailed Description of the Invention] [Industrial Application Field] The invention relates to a cooling ring for producing a blown film of thermoplastic resin, and more particularly, to a cooling ring for producing a blown film of thermoplastic resin, and more particularly, to increase the speed of a bath melt tube extruded from an extrusion die. Even if the molten tube is caught on the inner wall of the cooling ring or becomes clogged and cut, the tube will not be cut due to the pressure This relates to a cooling ring for blown film that can produce films stably at high speed without the bath melting tube being crushed or swinging up, down, left or right.

[Prior art]

Blow cooling air onto the surface of the extruded bath melt tube, °C.
Using the negative pressure generated in the space formed by the ring and the tube, the double-stranded tube is pulled outward in the radial direction,
A so-called venturi type air ring for cooling the tube is, for example, as described in Japanese Patent Publication No. 57-25269, in which the diameters of the outer surface of the deflection ring and the inner surface of the B14filJ ring constituting the annular air discharge port are Examples include those that are gradually larger in size and are shaped so that the cooling air flowing through them is directed outward in the radial direction.

However, such known techniques are not completely satisfactory both technically and economically, and the current state is that they cannot produce films stably at a relatively high speed.

〔problem〕

In the cooling ring described in Japanese Patent Publication No. 59-25269, as shown in FIG. 12 and the gap 15 made up of the deflection ring 12 and the HA straightening ring 13.
The deflection ring 12 used for this is pulled radially outward and main cooled by the cooling air blown radially outward from the The upper part gradually decreases its wall thickness to form a concave side surface, and then (the upper part has a substantially uniform wall thickness and a side surface whose diameter becomes gradually narrower while maintaining the same slope f+). The structure that forms and the summer temperature.

Accordingly, [adjusting ring 1: l is moved up and down by °C with respect to the direction of the extrusion axis to change the flow velocity of the cooling air blown out from the gap 15 formed by the deflection ring 12 and the adjustment ring 13, When trying to maintain the Venturi effect that pulls the bath melting tube 3 radially outward in a proper range, the concave side surface formed on the lower part of the outer surface of the deflection ring 12 and the bottom end of the adjustment ring 13 In the case where a gap is formed by the concave side surface, the Venturi effect does not change linearly due to the influence of the concave side surface, which may cause problems in stable production of the film.

The inventors of the present invention have conducted intensive research to overcome the drawbacks of conventional devices, and have found that even if the speed of the tube extruded from the extrusion die increases, the tube does not ring in the air ring. If the inner wall gets caught or clogged and the melting tube does not cut, or if the velocity of the cooling air blown out from the air ring increases, the pressure may crush the bath melting tube or cause it to oscillate vertically and horizontally. The present invention has been achieved which allows film to be manufactured stably at high speed without any vibration or vibration.

[Structure of the invention]

That is, the present invention provides an air ring body that is installed coaxially with the extrusion center and has an opening that can form a bath melting tube passage inside, and an air ring body that is installed coaxially with the extrusion axis at the opening of the main body. a bottom ring, a reflective ring installed above the paper ring coaxially with the extrusion axis and whose outer surface is parallel to or radially inwardly inclined with respect to the extrusion axis; are mounted coaxially and the lower end of the ring extends below the upper end of the reflective ring, the outer surface of the ring is parallel or radially inwardly inclined with respect to the extrusion detail, and the inner surface of the ring is radially outward. A guide/reflection ring tilted toward the direction, an extrusion shaft 7LL above the guide/reflection ring? a guide ring mounted coaxially with the guide ring, the bottom end of the ring extending below the top end of the guide/reflector ring, and the inner surface of the ring sloping radially outward; The reflective ring constitutes a first air outlet, the reflective ring and the guide/reflection ring constitute a second air outlet, and the guide/reflector ring and the guide ring constitute a third air outlet. This is a cooling ring for blown film which has an air outlet.

In this invention, the cooling air blown out from the second air outlet configured with a reflective ring, a guide/reflector ring, and the third air outlet configured with a guide/reflector ring and a guide ring, Reflection ring and guide/reflection ring outside 1
The flow is deflected by the 11J plane and guided toward the guide/reflector ring and the inner m-plane of the guide ring, and rises along the slope of the guide/reflector ring and the inner surface of the guide ring, with respect to the extrusion axis direction. In order to flow radially outward, the outer surfaces of the reflection ring and the guide/reflection ring need to be parallel to the extrusion axis direction or inclined radially inward; It is preferably inclined radially inward from 6° to 15° with respect to the extrusion fineness, preferably from 5° to
A tilt of 10° is more preferred.

Additionally, the guide/reflector ring and the bottom end of the guide ring must extend below the bottom lip and the top end of the guide/reflector ring, respectively, and preferably at least 311%, depending on the dimensions of the ring. It is preferable that it extends below the bottom lip and the upper end of the guide/reflection ring to a range that does not impede the introduction of cooling air by more than 5 rttm.

In addition, the inner surfaces of the guide/reflection ring and the guide ring must be inclined outward in the radial direction, but this inclination is not limited to a straight line, but may be curved (or a combination of these). good.

Furthermore, the shape of the upper girder rope on the inner surface of the guide ring on the downstream side with respect to the running direction of the bath melting tube must be slanted outward in the radial direction and parallel to the direction of the extrusion axis. It may be.

The reflection ring and the guide/reflection ring may be structurally independent rings, or may be integrally structured rings.

Note that the second air outlet, which is composed of a reflective ring, a guide/reflection ring, and the third air outlet, which is composed of a guide/reflector ring, and a guide ring, are preferably within the normal range.

The air passage of the cooling ring is Q-3≧2 (Ql+Q2
), the bath melting tube has a second air outlet consisting of a reflecting ring and a guide/reflecting ring, and a third air outlet consisting of a guiding/reflecting ring and a guide ring. This is preferable because it is pulled radially outward by the negative pressure generated by the venturi throat and is strongly supported and fixed in the circumferential direction.

Here, Ql: Amount of cooling air blown out from the first air outlet m3
/m1nQ2: 2nd) ba 1 cooling air lid m''7m1nQ, 3: 3rd ゝρ air ψ〡 ro'+bom 9 ri cooling air amount is '/min.

In addition, in order to pull the bath melting tube outward in the radial direction by the negative pressure generated by using the second air outlet as the venturi throat, and to strongly support and fix it in the circumferential direction, the cooling must be performed so that Q + 2 and Q1. Preferably, the air passages of the ring are configured.

The cooling air blown out from the first air outlet, which is composed of a bottom ring and a reflective ring, is directed parallel to or radially inward with respect to the extrusion axis, preferably at an angle of 5 degrees from the outlet in the range of 0° to 20°. This is preferable because the tension in the melt tube near the exit of the extrusion die becomes large and the blowing speed of the cooling air can be increased.

The fine direction of extrusion here means the running direction of the molten tube, and refers to the state with respect to the extrusion axis 11.

In the apparatus of the present invention, the method of adjusting the gap between the cooling air outlets does not need to be particularly limited. For example, during film production, the guide ring, the guide/reflector ring, and the reflector ring may be individually moved steplessly to create a gap between the cooling air outlets. Even something that can adjust the
It may also be possible to adjust the gap by moving only the guide ring steplessly during film production.

Cooling air may be used as a mist to increase slow motion capability.

An overview of one embodiment of the present invention is shown in FIGS. 1 and 2.

Figure 1 is a cross-sectional view of a cooling ring in which each ring is structurally independent so that only the busy guide ring can be moved steplessly in the axial direction during film production to adjust the gap between them.
The bath molten tube 3 extruded from the bottom ring 4 is attached to the opening of the air ring body 2, which is attached coaxially to the extrusion axis 10, and the bottom ring 4 is attached coaxially to the extrusion center 10. The outer surface is pre-cooled by cooling air blown out from the air outlet of the shaft, which is constructed of a reflective ring 5 which is attached and whose outer surface is inclined radially outward in relation to the extrusion center, and which is pre-cooled by cooling air blown out from the air outlet of the shaft. A reflective ring 5 is attached coaxially with the center and whose outer surface is inclined inward in the radial direction with respect to the extrusion axis. A second air blowing ring 6 extends downwardly, the outer inch of the ring is inclined radially inwardly with respect to the extrusion, and the inner surface of the ring is inclined radially inwardly. Exit and guidance/
A guide ring 1 is mounted coaxially with the reflection ring 6 and the extrusion axis, the bottom end of the ring extends below the top end of the guide/reflection ring, and the inner surface of the ring is inclined radially outward. The air is pulled radially outward by the Venturi effect of the slow moving air flow blown out radially inward from the third air blowout port, and is fully cooled.

Figure 2 is an fIfr side view of a cooling ring in which a reflecting ring and a guide/reflecting ring are integrated, allowing only the film production neutralization guide ring to be moved steplessly in the axial direction to adjust the gap between them. The bath melt tube 3 extruded from the die 1 is attached to the same sVc as the extrusion shaft/u10 and coaxially with the bottom ring 4 which is attached coaxially to the fixed axis at the surrounding part of the air ring body 2. and a reflective ring 5 whose outer surface is inclined radially inward with respect to the extrusion fine and is precooled by cooling air blown out from a first air outlet, and which is coaxial with the extrusion fine. and the outer 111i1 surface is attached coaxially to the extrusion axis with a reflection ring 5 whose outer surface is inclined radially inward with respect to the extrusion axis, and whose bottom end extends below the upper end of the reflection ring. The outer surface of the ring extends and the outer surface of the ring is inclined radially inward with respect to the M-output axis, and the inner surface of the ring is inclined 111 radially outward. The outlet and the guide/reflector ring 6 are coaxially attached to the extrusion shaft IO, and the bottom end of the ring extends below the upper end of the guide/reflector ring, and the inner surface of the ring is inclined radially outward. Due to the Venturi effect of the slow-moving air flow blown radially outward from the third air outlet formed by the guide ring 7, the air is pulled radially outward and is fully cooled. .

[Function and effect of the invention]

The present invention provides a reflective ring which is mounted coaxially with the extrusion center above the paper part ring and whose outer surface is parallel to or radially inwardly inclined with respect to the extrusion center; and the bottom end of the ring extends below the top end of the reflective ring, the outer surface of the ring is parallel or radially inwardly inclined with respect to the extrusion axis, and the inner surface of the ring is radially outwardly inclined. The inclined guide/reflector ring is mounted coaxially with the upper end of the guide/reflector ring, and the bottom end of the ring extends below the upper end of the guide/reflector ring, and the inner surface of the ring is an air outlet consisting of a guide ring inclined outward in the radial direction, the reflecting ring and the guiding/reflecting ring; and an air outlet consisting of the guiding/reflecting ring and the guide ring. When cooling air is blown out from the cooling air, the flow of the cooling air is deflected by the outer surfaces of the reflecting ring and the guiding/reflecting ring, and is directed toward the guiding/reflecting ring and the inner surface of the guiding ring, The molten tube rises along the slope of the inner surface of the ring and flows outward in the middle diameter direction, and the molten tube is connected to the reflecting ring and the guide/reflecting ring.・The air outlet consisting of the reflection ring and the guide ring is pulled outward in the radial direction by the negative pressure generated as a venturi throat, is strongly supported and fixed in the circumferential direction, and is cooled to form a cross line. Therefore, even if the speed of the molten tube extruded from the extrusion die increases, the molten tube will not get caught on the inner wall of the air ring or become clogged, or the cooling air blown out from the air ring will not be cut. Even as the speed increases,
This cooling ring for blown film can provide a cooling ring that can stably produce films at high speed without the molten tube being crushed, vertically and horizontally rocking, or vibrating due to the influence of the pressure.

In addition, since the air outlet gap can be adjusted linearly, film manufacturing conditions can be varied considerably.

In addition, in cases where the outer surfaces of the reflective ring and the guide/reflector ring are directed outward in the radial direction, the gap can be covered by a slight vertical movement of the ring compared to a case where the outer surface of the ring is parallel. It has the characteristic that the height of the air ring can be lowered because it can be adjusted to a wide width.

In addition, the cooling airflow blown out from the second air outlet and the third air outlet can be pulled outward in the radial direction by the Pentier effect, and can be strongly supported in the circumferential direction by the second air outlet.
It also has the feature that it can be applied to the production of films having a smaller diameter than the guide ring diameter.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of one embodiment of the present invention, and FIG. 3 is a cross-sectional view of a conventional air ring in use. In the figure, 1 is an extrusion die, 2 is an air ring body, 3 is a melting tube, 4 is a bottom ring, 5 is a reflection ring, 6 is a guide/reflection ring, 7 is a guide ring, 8 is a first air outlet, 9 is the second air outlet, 10 is the third air outlet, 1
1 is an extrusion fine detail, 12 is a deflection ring, 13 is a PT adjustment ring, and 14 and 15 are gaps. Patent applicant Asahi Kasei Kogyo Co., Ltd. Procedural amendment (Originally dated November 27, 1980)

Claims (1)

[Claims] 1. An air ring body that is installed coaxially with the extrusion axis and has an opening that can form a molten tube passage therein, and an air ring body that is installed coaxially with the extrusion axis at the opening of the main body. a reflective ring mounted above the bottom ring coaxially with the extrusion axis and whose outer surface is parallel to or radially inwardly inclined with respect to the extrusion axis; and the bottom end of the ring extends below the top end of the reflective ring, the outer surface of the ring is parallel or inclined radially inwardly with respect to the extrusion axis, and the inner surface of the ring is radially inwardly inclined with respect to the extrusion axis. a guide/reflector ring inclined outwardly, mounted above the guide/reflector ring coaxially with the extrusion axis, the bottom end of the ring extending below the upper end of the guide/reflector ring; an inner surface of which comprises a radially outwardly inclined guide ring, the bottom lip and the reflective ring forming a first air outlet; the reflecting ring and the guiding/reflecting ring forming a first air outlet; A cooling ring 2 for blown film, characterized in that the guide/reflector ring and the guide ring constitute a third air outlet, Q_3≧2 (Q_1+Q_2
) Cooling ring Q_1 according to claim 1, characterized in that the air passage is configured so that: cooling air amount m blown out from the first air outlet;
^3/min Q_2: Amount of cooling air blown out from the second air outlet m
^3/min Q_3: Amount of cooling air blown out from the third air outlet m
＾3/min