JP2008513247A - Equipment and process for producing extruded plastic foil hose - Google Patents

Abstract

  The equipment is arranged to be coaxial with the orifice H of the mold E for the extruder, and for the coolant stabilizing the unstabilized section M of the foil hose F expanded by the helical coolant flow 46, 48. Internal and / or external multi-stage cooling devices 40, 47 with multiple multi-level tangential outlets. The internal device 40 includes cooling units 41 to 44 that are arranged at positions axially separated from each other and surround the foil section M through the gap G1. Each cooling unit 41-44 is connected to a coolant supply 45 for supplying coolant with a selectively adjustable temperature. The external device 47 comprises at least two cooling units 47.1, 47.2, 47.3 which are arranged axially apart from each other and surround the foil section M through the gap G. Each cooling unit 41-44 has a tangential inlet 17, 18 and is connected to a coolant supply 60 that supplies coolant whose temperature and / or volume and / or pressure is selectively and individually adjustable. .

Description

  The present invention cools a plastic foil hose that has just emerged from a mold for an extruder in the process of integrated production of extruded plastic foil hose (tubular film) and extrusion of a thermoplastic foil, The invention relates to an equipment and process (method) for orienting.

  The proposed solution is to produce blown (expanded) foil hoses (tubular film) from various plastics such as low density polyethylene (LPDE) or high density polyethylene (HDPE) or even produce shrink foil Can also be used to Such a plastic foil hose can be used, for example, when packaging various products.

  U.S. Pat. No. 6,068,462 discloses an apparatus for integrated production of inflated foil hoses which includes internal and external cooling units adjacent to the drawer opening of an extruder mold. Is provided. The internal cooling unit is composed of a concentric disk provided with a groove-like radial air outlet along the outer periphery. An external cooling unit also consists of a disk provided with an annular radial air outlet along the inner periphery.

  For foil production, the temperature of the molten foil exiting the extruder mold is generally in the range of 150 ° C. to 180 ° C., so that the unstabilized foil must be cooled relatively quickly. Rather, in the first step, the solid is brought to a temperature of about 80 ° C. to 100 ° C., and then in the second step, the storage temperature is raised to about 20 ° C. to 25 ° C. This process must be done before winding. However, in the foil cooling described above, rapid and uniform foil cooling is not always guaranteed by the predominantly axial air flow exiting the radial outlet. In this situation, the time available for foil cooling is relatively short in such a case, and this raises a particular problem when the foil speed is increased. This means that at present foil cooling is a critical step in the overall foil production technology. The maximum foil speed applicable to conventional cooling technology is about 120 m / min, which is an obstacle to further increasing foil production.

  With respect to the above equipment, a portion of the cooling funnel having a minimum diameter of the cooling funnel surrounding the first unstabilized conical portion of the foil hose inflated through the cooling flow path with an external cooling device at the bottom only. Blowing into the cooling gap is a problem when the foil speed is relatively low and the aperture is small. As the foil hose progresses upwards, it extends approximately parallel to the conical funnel, its caliber increases continuously, its wall thickness decreases, but its speed of travel also increases.

  For this reason, the flow cross-section of the annular cooling gap between the foil hose and the conical funnel doubles as the diameter of the expanded foil hose (balloon) increases and the radial air flow entering from below The next problem is that as the vehicle decelerates greatly and warms up rapidly, the resulting cooling efficiency becomes extremely poor. This unfortunately occurs despite the fact that the size of the cooling gap between the foil hose and the conical funnel is reduced due to the lack of coolant, and therefore considers the increase in foil thickness. Must.

  In our experience, when using the above equipment, the foil is very unstable, but in fact it is intended to “stretch” the inflated foil hose that the foil and cone Cooling air flowing at high speed between the funnel.

  In conventional foil cooling equipment, the maximum applicable foil speed is about 120 m / min, which is a major obstacle to further increasing production.

  If we look closely at the above two drawbacks, it can be pointed out that the prior art has some inconsistencies as follows.

  The foil is accelerated and the air is decelerated and heated, but this reduces the difference between temperature and speed, and everything that affects cooling, that is, the heat transfer coefficient deteriorates, (Conversely) means to occur.

  The air flow that is supposed to support the foil in the upper section of the cooling funnel is blown into the bottom of the conical funnel, so that a small amount of low-speed warmed air flow reaching the top of the funnel is already for this purpose. Is no longer suitable.

  Cold air is blown into the bottom of the funnel, but the air is sufficient due to the large temperature difference even at ambient temperature, while the cooling air warms up as it goes up, but the temperature gradually decreases Cooled air is actually required in the upper section of the cooling funnel to further cool the trailing foil hose.

  The main object of the present invention is to eliminate the above-mentioned drawbacks, i.e. to cool and stabilize the foil hose exiting the extrusion orifice of the extruder faster, uniformly and efficiently compared to the prior art. It is to provide improved technology that can be done.

  Yet another object is to improve the quality of foil products by faster, uniform and efficient cooling. In this context, “quality improvement” mainly means reducing the foil thickness tolerance and orienting the texture of the thermoplastic material appropriately.

  Yet another object is to eliminate the shortage above the coolant during the cooling phase, to allow the coolant volume to be easily and selectively controlled in the longitudinal (axial) direction, and to expand the foil hose ( (Balloon) is held in a more stable state.

  Another objective is to increase the production efficiency of foil production, generally by improving the efficiency of cooling technology.

  The main objective is to provide equipment for the integrated production of extruded plastic foil hoses with an extruder mold suitable for forming foil hoses with annular drawer orifices, and / or said drawer orifices And a method of implementing an external cooling device that surrounds at least a portion of an expanded foil hose. The internal and / or external cooling device is connected to a coolant supply, an inlet for coolant, preferably cooling air, and an expanded foil hose to be cooled and an annular skirt of the internal and / or external cooling device At least one outlet for supplying coolant to the main annular gap between the two. The essence of the invention is that the internal and / or external cooling device is formed as a multi-stage device—coaxially with the drawer orifice, preferably directly arranged in the extruder mold, and with internal and / or external helical coolant In that it has multiple levels of tangential outlets for coolant to stabilize the first conical unstabilized section of the expanded foil hose by flow. The multi-stage internal cooling device comprises at least two annular cooling orientation units arranged axially away from each other and at least partially unstabilized in the foil hose internally through the main internal annular gap Enclose the section. Each of the internal annular cooling orientation units is connected to a coolant supply so as to supply a coolant whose temperature and / or volume and / or pressure can be adjusted selectively and individually. The multi-stage external cooling device comprises at least two annular external cooling units arranged axially away from each other, if any, and conical stabilization of the expanded foil hose through the main external annular gap Enclose at least partly external sections. Each outer annular cooling orientation unit comprises a second coolant supply so as to supply a coolant with at least one tangential inlet, the temperature and / or volume and / or pressure being selectively and individually adjustable. Connected to the source.

  In a preferred embodiment, the installation comprises at least one of the internal multi-stage cooling device and at least one of the external multi-stage cooling device.

  According to another feature of the invention, each of the external cooling units of the external multi-stage cooling device includes at least one coolant distribution ring having at least one conical mantle (baffle) surrounding the main external annular gap / flow path. Prepare. Further, the tangential outlet is formed in the conical mantle and is preferably formed as a slot that forms an inlet for the coolant around the foil hose.

  In another embodiment of the installation, each of the inner annular cooling orientation units comprises at least one coolant distribution ring and at least one conical mantle surrounding the main inner annular gap, and a tangential outlet, preferably a foil hose A slot is provided that forms a tangential coolant inlet therearound.

  In one preferred arrangement, the cooling orientation units and / or conical coolant directing mantles of adjacent cooling orientation units are arranged axially so as to overlap each other, thereby providing an annular gap between adjacent conical mantles. It is formed. The mutual axial position of the mantle and thereby the flow cross section of the annular gap can be adjusted.

  At least one conical mantle of the external cooling orientation unit comprises at least one conical extension (extension) mantle with a relatively small bore whose relative axial position is adjustable with respect to the corresponding directing mantle. Can do. Thereby, an annular gap is formed between the directing mantle and its extension mantle, and its flow cross section can be easily adjusted. Thus, part of the coolant already in use can be removed from the main external ring gap of the external multistage cooling device through the upper free end of the gap leading to the external open gap.

  Preferably, the flow cross section of the annular coolant inlet gap of the cooling unit is such that the cooling ring and / or its conical directing mantle is axially adjusted and / or at the lowest cooling unit-its cooling ring and its lower neck It is possible to adjust by adjusting the mutual axial direction.

  In another embodiment, the mutual axial positions of at least two of the internal cooling orientation units are fixed in an adjustable manner, so that their axial distance and the main internal annulus around the foil hose The flow cross section of the gap can be set.

  Such an arrangement is possible, in which case the cooling orientation unit of the internal multi-stage cooling device forms a common cooling ring with the common internal coolant distribution space. These units further comprise a conical mantle / baffle, in which a tangential outlet forms a conical skirt of the cooling ring. The coolant distribution space is further closed by a top cover and a bottom plate. A built-in fan / rotor is rotatably incorporated in the coolant distribution space and connected to a rotary drive device. In addition to the conical mantle of the cooling unit, the cover and the bottom plate cooperate to form one “fan housing”. The integrated cooling ring includes an inlet for supplying a coolant having a predetermined temperature.

  In order to produce foil hoses from high density plastic materials, mainly polyethylene (HDPE), the internal multi-stage cooling device can be arranged at a predetermined axial distance from the mold for the extruder.

  For shrink foil production, the following arrangements can be used in the installation according to the invention. The first cooling device is arranged directly above the extruder mold to cool the first unstabilized conical section of the foil hose to a predetermined temperature, if desired. At a certain axial distance from the cooling device, a heating device is arranged to warm the foil material that has already been partially extended and oriented, thereby softening it again. A second multi-stage foil cooling and orientation device is placed directly above the heating device, which is arranged coaxially so as to finally cool and stabilize the foil hose.

  According to this process invented to produce plastic foil hoses, the following steps are performed.

  (A) By using the external multistage cooling device, thereby providing a main outer ring gap / flow path at a constant radial distance from the outer surface of the unstabilized expanded conical section of the foil hose. And / or using the internal multi-stage cooling device, thereby providing a main internal annular gap / flow path at a constant radial distance from the inner surface of the unstabilized expanded conical section of the foil hose Encloses at least a portion of the unstabilized expanded section of the foil hose that has just exited the drawer opening of the extruder mold.

  (B) through an axial multi-level tangential inlet, selectively with a predetermined temperature and / or pressure and / or volume of coolant, mainly cooling air, external (s) and / or internal main ring gaps. And tangential coolant flow is directed to the outer and / or inner surface of the unstabilized section of the foil hose so that the unstabilized section of the foil hose is externally and / or internally By using a centrifugal force that cools and thereby affects the helical coolant flow along the outer surface and / or inner surface of the unstabilized expanded conical section of the foil hose By using the density and pressure differences between the various parts of the coolant flow, multiple layers in the outer and / or inner main ring gap / flow path are used. To stabilize the structure using to generate at least one spiral coolant stream from Le tangential coolant flow.

  When flat foil strips are made from pre-produced foil hoses, the above process cuts the tubular foil hoses longitudinally at least two locations during the final stage of the cooling and stabilization process Alternatively, an additional step of forming a flat foil strip from the foil hose immediately thereafter can be included.

  In order to eliminate the conventional device for inflating the foil hose in the expansion process, the above process can be selectively controlled in a multi-stage internal cooling device that inflates the foil hose, thereby extending and orienting in the crossing direction. An additional step of using a tangential coolant flow provided by the coolant supply can be included.

  For shrink foil production, the process according to the invention can include the following steps. First, the unstabilized conical section of the foil hose is cooled to a predetermined temperature and only partially stabilized, and then the foil material is heated and thereby softened again. Immediately after the heating step, the foil hose is completely stabilized by using a second multi-stage foil cooling and orientation device according to the invention.

  The present invention is based on the recognition that one of the most important factors in terms of foil hose thickness tolerance is always the uniformity of the cooling temperature. When the temperature of the melted plastic material exits the extruder mold, that is, in the upper zone of the extruder mold, it is not uniform, as a result, even if it cools completely uniformly There is no appropriate thickness tolerance. On the other hand, the thickness tolerance is not appropriate if the molten plastic material of uniform temperature along the periphery exits the mold but is not cooled back uniformly.

  Our experimental results show a similar phenomenon for both of the above cases, which explains the non-uniform foil thickness of the prior art. At multiple locations, if the relatively cold molten plastic material exits the extruder mold and / or is cooled more strongly and / or the air flow is relatively cool, the foil material will be released sooner These are point parts or sections of the foil that quickly lose cooling and return to their original temperature as they cool down rapidly, so that these point parts or sections remain thick.

  On the other hand, if the hotter molten plastic material exits the extruder mold and / or the cooling is performed weaker and / or the cooling airflow is relatively warm, the molten foil material will later slowly Because they are cooled back to their original temperature, these are the foil spots or sections that later lose their elastic stretch capability, so that the foil spots and sections can continue to stretch. For this reason, the final product (final foil hose) is thinner than required in these locations, which also has a negative effect.

  The reason was that one of the main objectives of our experimental development was to produce completely homogeneous and efficient cooling around the periphery of the foil hose outlet. According to the present invention, two main preconditions can be formulated, which we believe is “ideal” for foil cooling, as follows.

  The selectively changing coolant volume requirement must be met when going up along the cooling funnel (within the main cooling gap).

  • Different temperature coolants must be guaranteed to be tangentially blown at different axial levels.

  According to our experiments, the amount of heat transferred per unit time depends on the heat transfer coefficient, the heat transfer surface, the temperature of the heating medium, and the temperature of the foil. However, in order to generate cooling air, since this air is always taken from the atmosphere and blown back into the atmosphere, a large capacity air cooling system is required. On the other hand, the heat transfer surface cannot be changed, for example in the process of foil production, because some geometrical conditions and proportionality must be met in order to obtain a high quality product, which means that the surface of the foil Means given (constant). Third, the heat transfer coefficient can be varied within limits. In the case of air, this can be mainly affected by the relative moisture content and flow rate of air (relative speed difference between foil and air).

The degree of heat transfer can be significantly affected by both factors. The heat transfer coefficient of still dry air is about 5 W / m ² k, while the heat transfer coefficient of moist, intensely flowing air is about 250 W / m ² K. Therefore, the amount of heat removed can increase by a factor of 50 depending on the heat transfer coefficient.

  Our experimental results show that the cooling gas velocity is limited by the strength of the foil hose. However, the speed difference between the foil and the coolant can be surprisingly further widened by supplying the coolant tangentially according to the present invention. Furthermore, the centrifugal force from the helical coolant flow-affecting the foil hose also has a positive influence on the stability of the foil hose, resulting in a surprising technical effect.

  According to our other experimental results, the coolant speed is limited by the strength of the foil hose. However, the coolant velocity can be effectively increased by introducing the coolant flow as a tangential turbulent (spiral) swirl (vortex). Furthermore, the centrifugal force of the coolant vortex rotating in the main cooling gap / flow path also has a beneficial effect on the stability of the foil hose and the foil hose.

  For the cooling process, the efficiency, i.e. the appropriate cooling capacity, is also very important. The melted plastic material of the inflated foil hose just emerging from the extruder mold is stretched (orientated) along the cooling section in two directions, transverse and longitudinal, while the mesh plastic There is a texture there.

  The foil balloon is inflated, that is, as a result of inflating, deviates from the transverse orientation. When the foil hose is inflated with the compressed air of the additional equipment using known methods, its diameter doubles and is therefore considerably stretched in the transverse direction. In the process of stretching, the plastic molecules are aligned in the stretching direction.

  The other orientation of the foil is in the longitudinal direction, which is the result of a fast lifting of the foil by known methods. In the process of pulling up, the foil is further stretched by a multiple thereof and the molecules are aligned longitudinally.

  When stretched in two directions (orientations) in this way, foils are fast enough that strong cooling is intended to stabilize (fix) the mesh texture by efficiently cooling. A convenient mesh-like texture of the hose is produced. Without cooling, the plastic molecules in the plastic material that are stationary but not stabilized lose their orientation after a while, resulting in disordered texture and the plastic material is not solidified.

  As a result of proper cooling, the plastic flux exiting the extruder head orifice begins to harden and almost solidifies at the end of the conical cooling channel, resulting in a final thickness and stabilized state. can get. Therefore, as mentioned earlier, a uniformly selectively controllable cooling of appropriate strength plays a major role in this regard.

  The invention will be disclosed in more detail on the basis of the accompanying drawings showing some embodiments of the solution according to the invention. The drawings will be explained later.

  As illustrated in FIG. 1, a first embodiment of a foil production facility according to the present invention is an extruder for continuous extrusion of foil hose F with pressurized coolant, mainly compressed cooling air. It is equipped with an external foil cooling device 1 for feeding the unstabilized conical section M of the inflated foil hose F just emerging from the drawing orifice H of the mold E.

  According to the present invention, the external cooling device 1 is formed as a multi-stage foil cooling device arranged directly on the mold E for an extruder so as to be coaxial with the drawing orifice H, and is a foil hose that is continuously extruded. At least two annular external cooling units arranged axially away from each other in the direction of travel X of F.

  In the first embodiment shown in FIG. 1, three external cooling units 2, 3, 4 are applied, which are arranged one after the other in concentric fashion with the foil hose F and see direction X. Are separated from each other by axial distances T1 and T2, respectively. The external cooling units 2, 3, and 4 are fixed in a predetermined axial position such that they can be adjusted relative to each other and / or to the framework structure of the apparatus (not separately illustrated).

  In the case of the present invention, the dimensions of the distances T1 and T2 are selected to be 100 mm and 200 mm, respectively, so that the inflated foil hose F stabilization and cooling conical section M is 600 mm as a whole. Selected.

  In FIG. 1, the lower cooling unit 2 is directly on the upper part of the mold E for the extruder of the foil production facility, only partly shown by the thin result line, having the circular outlet orifice H as described above. It is connected. The newly extruded foil hose F exits continuously through the withdrawal orifice H in a known manner, but the melted plastic material (eg polyethylene) is currently unstable plastic. Is in a state.

  The cooling units 2, 3, and 4 of the external foil cooling device 1 according to the present invention are of a substantially similar design, i.e. they are each an internal space or conveying channel system (shown in the figure) that distributes the coolant flow. And a cooling ring with a conical coolant directing mantle. Accordingly, the cooling unit 2 includes a cooling ring 5 and a conical orientation mantle 6, the cooling unit 3 includes a cooling ring 7 and a conical directing mantle 8, and the upper cooling unit 4 includes a cooling ring 9 and a conical shape. A directing mantle 10 is provided. An internal space is provided for each of the cooling units 2 to 4 so that coolant can be distributed to the cooling rings 5, 7 and 9.

  FIG. 1 shows that the external conical annular coolant channels 11, 12, and 13 are formed between the inner surface of the foil hose F and the outer mantle surface for coolant, for example air. And 4 are arranged concentrically with the theoretical midline K of the withdrawal orifice H from which the foil hose F is discharged, and they are united, spiraling along the height of the stabilization of the foil hose F and the cooling section M The formation of a continuous external main cooling ring gap G for a coolant flow (supported by arrows 22) swirling is shown.

  FIG. 1 further shows that adjacent directing mantles 6 and 8, as well as mantles and 10, are arranged in an axial overlap, and in these overlapping sections, the tangential coolant inlet gaps 14 and 15 are connected to the cooling ring 5. And 7 and the directing mantles 6 and 8, respectively.

  The lower external cooling unit 2 has a central neck N that is coaxial with the conical directing mantle 6 and an annular coolant inlet gap 16 between the conical surface extending upward and the inner surface of the directing mantle 6.

  According to the present invention, the cross section of the coolant inlet gap 16 can be controlled, for example, by adjusting the relative axial position of the neck N and the directing mantle 6 of the lower external cooling unit 2. Similarly, the flow through section of the coolant inlet gaps 14 and 15 is controlled at the cooling units 3 and 4 by adjusting, for example, the relative axial position of the coolant rings 6 and 9 and the associated directing mantles 8 and 10, respectively. can do. In FIG. 1, the axial sizes of the external directing mantles 6, 8, and 10 that overlap each other are designated by L1, L2, and L3, respectively.

  2 shows in detail the structural design of the uppermost cooling unit 4, it should be noted that other units have a similar structure. In the case of the present invention, the cooling ring 9 of the cooling unit 4 has a trapezoidal cross section welded from a sheet material. In order to introduce pressurized tempering coolant (eg cooling air) into the interior space of the cooling ring 9, it comprises two opposing tangential inlet studs 17 and 18. The conical directing mantle 10 is a continuous body that extends obliquely above the inner wall 19 of the cooling ring 9. The bevel angle of the orientation mantle 10 that constitutes the inner wall 19 and the extent of the inner wall, for example 60 °, is approximately the same as the angle of the conical unstabilized section of the inflated foil hose F.

  The inner wall 19 of the cooling ring 9 is provided with perforations 20 arranged at equal intervals along the circumference, which in the case of the present invention is from the U-shaped cuts of the inner wall 19 and the tongues so produced. It is formed by the bent part. Thereby, a special side surface outlet gap 21 for guiding the coolant in the tangential direction of the foil hose F is formed. The tangential side outlet gap 21 reaches into the annular coolant inlet gap 13 (FIG. 1).

  The middle cooling unit 3 is also of similar design (see FIG. 1), with the tangential side outlet gap 21 leading to the annular coolant inlet gap 14.

  The side wall of the cooling ring 5 of the lower cooling unit 2 is similarly provided with a tangential side exit gap 21 (FIG. 1). In addition, a cutting part (similar to the cutting part constituting the outlet gap 21) is provided on the bottom side 23 of the cooling ring 5, which constitutes a lower tangential outlet gap 24, the latter inside the annular gap 16. To.

  The helical air flow through them effectively cools the foil hose F that continuously exits from the withdrawal orifice H immediately after its outlet. In order for the surface of the melted plastic flux to harden first and the inflated foil hose F to be pulled up, the bottom spiral air flow thus generated is necessary. The cooling ring 5 of the lower cooling unit 2 includes a cover 25 under the perforated bottom side 23.

  Pressurized coolant introduced through the tangential inlets 17 and 18 of the external cooling units 2, 3 and 4 is supplied to the gaps 14, 15 and 16 through the side outlet gap 21 and the lower outlet gap 24, thereby The coolant is placed in a spiral coolant swirl-up motion in the main outer ring gap G along the outer mantle of the foil hose F (as indicated by the thin arrows 22 in FIGS. 1 and 2). By using the joint directing mantles 6, 8, and 10, the external cooling units 2, 3, and 4 are in a cooperating connection, i.e., the cooling air flow that progressively spirals up is a foil hose. The portion corresponding to the total height M of the section to be stabilized of F is effectively cooled.

  Thus, the air not only passes through the side outlet gaps of the external cooling units 2, 3, and 4, but also passes through the gap 16 that intersects the lower outlet gap 24 of the lower cooling unit 2, and each of the overlapping directing mantles 6. And through the gaps 14 and 15 between 8 and 8 and 10.

  The helical tempering coolant flow in the intermediate cooling unit 3 and the upper cooling unit 4—slowly conical upwards—is intended to meet the continuously increasing requirements of air and conditioning. The side exit gap of the cooling ring 7 of the intermediate cooling unit 3 and the side exit gap of the cooling ring 5 of the lower cooling unit 2 are further indicated by 21 in FIG.

  This arrangement solves the previously unavoidable problem of conventional equipment, i.e. the cooling air blown into the bottom slows down and warms with a conical expanse, thus the foil hose F and the conical shape. The ring gap with the mantle that spreads out decreases. According to the invention, “fresh” cooling air is supplied to the cooling units 2, 3 and 4 in a selectively controllable manner. Therefore, the size of the main outer ring gap G between the foil hose F and the externally oriented mantles 6, 8, and 10 spreading in a conical shape is always almost constant, which is very important for product quality. is there.

  As another important additional effect of the present invention, the coolant supply of the cooling units 2, 3 and 4 of the external foil cooling device 1 is transferred to separate, individually controllable coolant supplies HK 1, HK 2 and HK 3. It is pointed out that it emits (FIG. 1). With this measure, it is possible to selectively change the coolant code and / or pressure and / or quantity at the cooling units 2, 3 and 4 according to the current technical requirements.

  For example, at the upper cooling unit 4, the amount and temperature of the injected coolant is changed so that it is not changed at other places, for example at the lower cooling unit 2 and / or the intermediate cooling unit 3. Can do. This makes it much easier to control the effect of the intervention and also increases the separability of the effect.

  From our experimental results, the accelerating foil and hose F are completely cooled and rapidly cooled down to the original temperature while moving upward along the conical main outer ring gap G. It turns out that it is necessary to increase. Thus, the installation according to the invention supplies air on the outer surface of the foil hose F with individually regulated amounts and / or temperatures of air at various height levels of the cooling units 2, 3 and 4 of the external cooling device 1. be able to. Therefore, in the present invention, the temperature and speed differences required to provide adequate strength cooling are gradually cooled by a predetermined method so as to be the most even distribution possible as a result of the helical coolant flow. By blowing in while increasing the amount of air that increases the depth, it is ensured.

  Another advantage of this arrangement of the external cooling device 1 according to the present invention is that different amounts and / or pressures and / or temperatures of the coolant emanating from the individually controlled coolants HK1, HK2 and HK3 (FIG. 1) further It is also possible to blow based on the parameters of the coolant already inside the device 1. This is because the temperature of the helical coolant stream arriving from below is measured, for example, in the main outer conical ring gap G in front of the cooling units 3 and 4, and then the temperature of the coolant fed into it is It is determined as the function. In this way, the temperature difference required for proper heat transfer can be safely maintained in the system.

  The feasibility of other controls that make controlled heating even easier is closely related to the temperature measurement described above. Prior to introducing new coolant, it is possible to remove the incoming heated air from below, an example being shown with respect to FIG.

  FIG. 3 shows a modification of the external foil cooling device 1 of the installation according to the invention, which also comprises three external cooling units 2, 3 and 4, arranged in the axial direction with a distance between T 1 and T 2. Yes.

  The structural design and arrangement correspond substantially to those according to FIGS. The only difference here is that in the lower cooling unit 2, the conical orientation mantle 6 of the cooling ring 5 comprises a conical extension mantle 6A with a relatively small bore as its continuation, and its relative height The position can be adjusted with respect to the orientation mantle 6. For this reason, the cross-section of the annular gap 26 between the directing mantle 6 and the extension mantle 6A is adjustable, the latter actually leading to an external open gap. Therefore, a part of the coolant that has already been used can be taken out from the main outer ring gap G of the cooling device 1 through the outlet gap 26.

  In certain cases, the heated air arriving from below is measured by, for example, a heat sensor and cannot be mixed with sufficiently cold air using the next cooling unit to reach the desired coolant temperature. If this is the case, the heated air is drawn from the ring gap (and the cooling unit 2) through the gap 26 before reaching the intermediate cooling unit 3.

  The intermediate cooling unit 3 is designed in the same way. Here, a conical extension mantle 8A having a relatively small diameter is provided as a continuous body of the conical directing mantle 8, and an outlet gap 27 thus prepared is prepared, through which a part of the coolant is supplied. Similarly, it can be led to the external gap as needed.

  Based on the above, the external foil cooling (tempering) device 1 of the installation according to the invention can be used to create a foil cooling “map” tailored to the current product. This is because the amount, speed, and temperature of the coolant can be selectively selected as required at any height of the external cooling units 2 to 4, i.e. the axial section of the blow section, i.e. the tangential inlet gap 14,15, And 16 can be adjusted. In this way, an arbitrary cooling state can be created with knowledge of the plastic flux and taking into account the characteristics of the foil hose F that are intended to be achieved.

  This is extremely important, because the mesh-like texture of the plastic material produced by inflating, pulling up and rotating the rotating core-in the case of an extruder mold with a rotating core- This is because it must be fixed, i.e. it must be stabilized at a height M in this cooling section so that it is perfectly uniform along the circumference and length.

Respect theoretical explanation of velocity vector triangle as illustrated in Figure 4, the flow rate of the cooling air is indicated by v _L, the driving speed of the foil hose F is indicated by v _F, between them The angle is indicated by “α” (alpha), and the velocity difference vector is indicated by Δv.

First, let us examine the arrangement in which the coolant is driven parallel to the direction of the foil hose. In this case, the speed difference Δv ₁ is the same as the difference between the absolute values of the speed vectors (Δv ₁ = v _L1 −v _F ). In other words, this means that, for example, if the air velocity v _L1 is 100 m / min and the foil velocity v _F is 50 m / min, the velocity difference Δv ₁ is about 50 m / min.

However, if the coolant is supplied at an angle α relative to the foil, the speed difference is already a speed vector difference, which is certainly greater than the absolute speed value difference (see corresponding values in FIG. 4). V _L2 and Δv ₂ , v _L3 and Δv ₃ , v _L4 and Δv ₄ , v _L5 and Δv ₅ , and v _L6 and Δv _{6 The} wheel speed v _F was selected to be constant at 50 m / min. ).

The maximum speed difference v _Δ6 can occur when coolant is supplied in the opposite direction to the foil (see v _L6 and v _F ). In this case, the absolute values are only summed. In our view, in fact, the verticality (α = 90 °) of the two velocity vectors (v _L4 and v _F ) seems to be the maximum feasible (Δv _{4 in} FIG. ₄ ), and therefore , Δv ₄ can be relatively high, about 111 m / min, in the case of the above data.

  As another important advantage of the above embodiment, the pressurized coolant introduced tangentially into the external cooling units 2 to 4 preserves the angular momentum along the outer surface of the foil hose F, ie the cooling air Means that even when it reaches the foil, it travels tangentially and spirally. This is substantially the case with the conventional cooling technology described at the beginning of the text, because the air introduced in the radial direction already travels parallel to the foil when it reaches the foil due to the bypass effect of the distribution channel. Differences and advantages.

  In the proposed arrangement according to the invention, the importance of the air traveling tangentially or at an oblique angle compared to the foil lies in its influence on the heat transfer coefficient. When introduced tangentially, air can significantly increase the value of the heat transfer coefficient, thereby increasing the efficiency of heat transfer. This is a very important additional effect, but it is today that, as already mentioned above, the overall productivity of the foil production and the speed of the applicable foil track are actually This is because it is limited by efficiency and speed.

  In the course of our experiments, it has been discovered that the heat transfer coefficient can be effectively increased by introducing coolant tangentially into the main ring gap G. This background is described below.

The following known formulas can be used to calculate the amount of heat transferred per unit time.
Q = α · A ( _TF − _TL ), where α−heat transfer coefficient,
A-Heat transfer surface,
T _F -foil temperature,
T _L -Coolant temperature.

  From this formula, it can be seen that there are actually three factors that can modify the amount of heat transferred.

a) The temperature difference (T _F −T _L ) between the coolant and the foil wall. For example, the foil temperature (T _F ) is set to 200 ° C., and the temperature (T _L ) of cooling air from the environment is set to 25 ° C. Cooling the air from the environment to 5 ° C increases the temperature difference, but the change from 175 ° C to 195 ° C results in a 10% efficiency improvement, but it is expensive to generate cooled air Large capacity air cooling system is required. However, according to our experimental results, even this 10% efficiency increase induced by cooling and air was recognized in foil quality.

  b) In order to ensure the specified quality in the course of foil production, given geometric conditions and proportions must be observed, so that the surface of the foil is specified. Therefore, the value of the heat transfer surface is virtually unchangeable.

c) However, the heat transfer coefficient (α) can be varied within a wide range. In the case of air, this can be influenced primarily by the air flow rate (speed difference between foil and cooling air) as well as the relative humidity of the air. Both factors can have a significant effect on the degree of heat transfer. The heat transfer coefficient of still dry air is about 5 W / m ² k, but the heat transfer coefficient of moist and blown air can be as high as about 250 W / m ² K. From this it can be said that the amount of heat removed can also be increased by a factor of 50 due to the heat transfer coefficient.

  Of course, the air velocity is limited by the strength of the foil hose F. However, the cooling efficiency can be further increased when the speed is increased by introducing and flowing air in a spiral shape. Furthermore, the centrifugal force of the air vortex (spiral coolant flow) affecting the foil / hose also helps the foil / hose stability.

  Knowing the heat transfer coefficient and solution results of the present invention, it is easy to compare a conventional cooling ring with a solution adjusted at various levels according to the present invention. As mentioned above, temperature differences and relative speed differences are the most important factors in terms of heat exchange, ie foil tempering, because they affect the heat transfer coefficient in a modifiable manner. Because it is one factor.

  For comparison, in FIGS. 5A to 5C and 6A to 6C, the cooling and stability of both the conventional structure (FIGS. 5A-5C) and the multi-level adjusted external foil cooling structure (FIGS. 6A-6C) according to the present invention. The change in these factors in the figure, which proceeds upwardly along the outer conical annular gap G, throughout the height of the generalized section M is illustrated.

  FIG. 5A shows a conventional solution using the outer cooling cone HG, the foil hose F, and the height of the cooling stabilization section M of the foil hose F. 5B, the horizontal axis indicates the speed difference (Δv) obtained with the conventional solution, the vertical axis indicates the cooling section height M, and for the diagram of FIG. 5C, the horizontal axis indicates The temperature difference (ΔT) is shown, and the vertical axis shows the height M of the cooling section.

6A shows a cross section of an external foil cooling device 1 relating to the installation according to the invention (see FIG. 3) comprising external cooling units 2, 3 and 4, and FIGS. 6B and 6C show the speed and temperature differences. It is shown as a function of the height M of the cooling stabilization section of the foil hose F. 6B and 6C along with FIGS. 5B and 5C also show ideal speed and temperature differences (Δv _i , ΔT _i ) that are considered ideal from a cooling standpoint, so the substantial difference between the two designs is obvious It is.

The diagram in FIG. 5B shows that the velocity difference (Δv) between the air velocity (v _L ) and the foil velocity (v _F ) disappears at about 2/3 of the height M, and The foil hose F travels faster than the cooling air travels parallel to it before exiting the cooling cone HG. On the other hand, it will be apparent to those skilled in the art that a specific speed is absolutely necessary from a heat transfer perspective. The flux exits slowly through the extruder orifice of the extruder mold, but the cooling air velocity is high here (v _L ). While the foil travels upwards and accelerates considerably (V _F ), the cooling air is slowed down (v _L ) due to funnel spreading.

  On the contrary, by applying the multistage external foil cooling device 1 according to the present invention (FIGS. 6A to 6C), the cooling air blown at different levels continuously compensates for the shortage resulting from the expansion of the main external ring space G, Only a certain decrease in the speed difference (Δv) is observed between the two respective cooling units.

In the external foil cooling device 1 (see FIG. 6A), three individually and selectively controllable cooling units 2-4 were shown as an example (as in FIG. 1), but in theory Can apply any number of cooling units, ie tempering levels. The more annular cooling units above each other, the more uniform the speed difference (see FIG. 6B) and the closer to the ideal state (Δv _i , ΔT _i ).

The description on the drawing regarding the speed difference applies almost completely to the temperature difference (FIGS. 5C and 6C). According to FIG. 5C, the temperature of the foil (T _F ) remains very high even when the foil comes out and there is a large temperature difference (ΔT) compared to newly blown cooled air. This significant temperature difference disappears as it goes upwards, so it is very unlikely that the foil hose will be cooled and fully restored to its original temperature, if only by chance.

On the other hand, in the case of the solution according to the invention (see FIG. 6C), not only the lack of air due to the expansion of the space is compensated, but also the temperature difference (ΔT) is maintained above a desired level. If the temperature (T _L ) of the cooling air that reaches the next cooling unit in the line from the bottom, that is, the blowing level, is already too high, it can be led from the cooling unit to the environment just before blowing. . Of course, this method has to supplement a large amount of cooling air, but for a given case, it is an efficient solution that is effective in obtaining a properly and selectively controlled foil cooling / tempering effect. That is certain.

  The main advantages afforded by the test using the prototype of the above embodiment of the external foil cooling / tempering device 1 according to the invention are as follows.

  The foil balloon cools faster and more safely than conventional methods in that the cooling air is blown tangentially through the multi-level cooling unit and forced to flow spirally.

  As a result of the continuous supplementation of the cooling air at each level, the air in the conical outer main ring gap G will not be overheated and its cooling effect can be stabilized.

  The distribution of the cooling air is absolutely uniform along the circumference of the foil hose F in the conical main ring gap G over the entire height M;

  -When going upward along the axial direction, the size of the main ring gap G can be maintained at a permanent value.

  The foil hose is maintained in a highly stable state by cooling air flowing relatively tangentially in the outer main ring gap G between the foil hose F and the cooling unit, It can also be observed from the fact that when a conventional cooling ring is applied, the foil hose is very sensitive to external influences (eg drafts) in the system and easily torn. However, with the solution according to the invention, the foil hose does not become unstable, does not begin to “sway” and cannot be broken even in the case of intentional external effects (eg draft).

  Air has been shown as one example of the coolant disclosed above, but in certain cases it can be other gaseous agents such as nitrogen, neon, helium, or argon.

  Although not illustrated separately, for those skilled in the art, from the above description, each of the external cooling units 2 to 4 is assigned to a central control panel (not illustrated) according to current technical parameters and / or producer acceptance. It is obvious that it can be connected to a coolant source (for example a fan unit associated with a heat exchanger) with individually controllable pressure and supply volume that can be selectively controlled, for example in response to a control signal of a heat sensor It is.

  According to the invention, at least two or more such external cooling units can be provided. Obviously, the cooling units 2 to 4 of the external foil tempering device 1 according to the invention must be arranged in a section of height M along the trace of the newly inflated foil hose. In the given case, the lowermost cooling unit 2 can be cooled by air from the environment. Furthermore, it is possible to provide an embodiment in which warm tempering agent is pumped into at least one of the cooling units.

  FIGS. 7 to 10 show a third embodiment of the installation according to the invention for the production of plastic foil F, whose mold E for the extruder—shown only as contour—is A foil hose F is formed together with the drawing orifice H. The foil hose F just emerging from the withdrawal orifice H extends conically with a height M and still passes over the cylindrical section at the top after the unstabilized section. The stationary melted plastic is actually stabilized along this conical section M. The direction of travel drawn above the foil hose F is indicated by “x”, and the midline of the withdrawal orifice H is indicated by K, which is substantially the theoretical longitudinal midline of the foil hose F. Match.

  FIG. 7 shows an embodiment of the device according to the invention designed as a multi-level foil cooling orientation device 40 with only internal cooling function. In the case of the present invention, the internal foil cooling and orienting device 40 is arranged in a region adjacent to the extraction orifice H.

  According to the invention, the internal cooling orientation device 40 comprises at least two internal annular cooling units arranged in alignment with the unstabilized conical section M of the foil hose F through the cooling main ring gap G. . The internal cooling units are arranged axially away from each other and are in the direction of travel x of the continuously extruded foil hose F.

According to FIG. 7, the multistage internal cooling orientation apparatus 40 comprises four internal cooling units arranged coaxially with each other, from which the cooling unit 41 is arranged directly on the mold E for the extruder. On top of this, a second cooling unit 42 is arranged with an axial distance T ₃ , on which a third cooling unit 43 is arranged with an axial distance T ₄ , on which an axial distance is fourth cooling unit 44 of the top is a T ₅ is arranged.

  FIG. 7 shows that the internal cooling units 41 to 44 are only increasing in diameter as they travel upward, so that they have a main ring gap G having substantially the same gap size. Through the unstabilized conical section M of the foil hose F. Each of the cooling units 41 to 44 is separately connected to an integral coolant supply 45 that conveys coolant for each cooling unit 41 to 44 of individually controlled or pressure and / or temperature and / or quantity. Is done.

  According to the invention, the cooling units 41 to 44 comprise at least one coolant distributor, i.e. a cooling ring arranged transverse to the direction of travel x of the foil hose F. In the embodiment according to FIG. 7, each of the cooling units 41 to 44 comprises a separate cooling ring 41A, 42A, 43A and 44A, respectively, and has at least one coolant directing mantle 41B, 42B, 43B and 44B. Each comprises and constitutes the outer surface of the cooling unit, thereby surrounding the main ring gap G from the inside.

  Each of the internal cooling units 41 to 44 comprises two inlets that are offset from each other by 180 °, which are respectively indicated by reference signs 41C, 42C, 43C, and 44C and are common in the present case. Are connected to an individually controllable coolant supply 45. Accordingly, the temperature and / or pressure and / or amount of coolant supplied therethrough can be selectively controlled individually for each cooling unit 41 to 44 according to the technical requirements of the solid lines.

  In the case of the present invention, each of the cooling rings 41A to 44A of the cooling units 41 to 44 includes circular coolant distribution spaces 41E, 42E, 43E, and 44E, respectively, and corresponding outlets 41D, 42D, 43D, and Compared with the foil hose F, the coolant flow in the tangential direction is assured. In the present case, the outlets 41D, 42D, 43D, and 44D are formed as elongated slots.

  Through the tangential outlets 41D to 44D, a common internal helical coolant flow 46 is formed in the internal main ring gap G1, and from bottom to top along the inner surface of the unstabilized conical section M of the foil hose F. A traveling (see FIGS. 7 and 10) tangential coolant flow is generated, which provides uniform and effective cooling.

  In the embodiment according to FIG. 7, the adjacent cooling units 41 to 44 overlap each other and are fixed concentrically so as to be adjustable in the axial direction relative to each other. Thereby, annular gaps g1, g2, and g3 with adjustable flow cross-sections are formed along the overlapping portion between adjacent conical directing mantles 41B to 44B, through which a controllable tangential coolant flow is achieved. However, it exits through exits 41D to 44D, as illustrated by the thin result line arrows.

In the arrangement according to FIG. 7, the cooling units 41 to 44 are fixed in an axial mutual position of adjustable distances T ₃ to T ₅ so that the flow cross section of the main inner ring gap G1 and the gaps g1, g2, and g3. Can be adjusted to a predetermined value. Therefore, the cooling efficiency can be further improved.

  FIG. 7 illustrates only a single coolant source 45, but with a plurality of individually controllable outlet channels, but in the given case, each of the cooling units 41-44 has a separate coolant. A source can be provided. In such cases, each of these coolant sources can transmit individually controllable pressure and / or temperature and / or amount of coolant to a corresponding cooling unit according to the present invention.

  FIG. 8 illustrates a cross section of the structural design of the cooling unit 42. Here, it can be clearly observed that the outlet 42D, which ensures a tangential air flow, is cut out of the conical orientation mantle 42B and formed from a bent part in the case of the present invention. Therefore, the outlets 42D that ensure the tangential flow of the coolant are provided at the same distance from each other along the circumference. Note that the outlet 42D, which ensures tangential coolant flow, can also be formed in other ways. In the cooling units 43 and 44, the structural design is similar.

  However, in the case of the lowermost internal cooling unit 41, FIG. 7 shows that the tangential outlet 41D is provided in the lower part along the circumference of the cooling ring 41, so that the foil just emerged from the extraction orifice H It shows that it receives an effective internal cooling flow during and after exiting the hose.

  The foil hose F can be inflated simultaneously with cooling and orientation by the multi-level internal foil cooling orienting device 40, that is, by the coolant flow until the required expansion shape is obtained. It should be emphasized that the fact that it is not necessary for the device is another feature of the embodiment according to the invention as shown in FIGS. By inflating the foil hose F, the material of the foil hose F is stretched and guided laterally to the speed required by the tangential coolant flow exiting the cooling units 41-44. Therefore, the necessary conventional foil blowing device can be discarded and the equipment can be simplified.

  In the inner foil cooling and orienting device 40, the coolant directing mantles 41B to 44B of the cooling units 41 to 44 are conical and funnel-shaped elements, and the bevel angle in the present invention is, for example, 60 °. Although selected, in the given case, the adjacent directing mantles 41B to 44B are further selected as different values for the lateral stretching and orientation of the unstabilized conical section M of the foil hose F. You can also

  The fixing method of the cooling units 41 to 44 applied in FIG. 7 is not shown in detail, and the relative axial position thereof can be adjusted, and therefore any fixing method can be applied. I'll just keep saying. The cooling units 41 to 44 can be fixed to, for example, a mold E for an extruder or a central frame (not shown) of the equipment.

  FIG. 7 shows the knowledge of the installation intended to pull the foil hose F already destabilized in the direction of travel x for the known rolling and other processing of the stabilized foil hose F. It does not exemplify at least a pair of pinch rollers.

  From the arrangement according to FIG. 7, it can be observed that the cooling units 41 to 44 can supply the inner surface of the foil hose F with a tangential coolant flow of the amount, pressure and temperature already adjusted by the height level. Of course, the more cooling units applied on top of each other in the foil cooling and orientation device 40, the stronger the cooling.

  With regard to the installation according to FIGS. 7 to 10, the importance of the multi-level internal cooling and orientation device 40 is actually that the device is in the range where the lateral and longitudinal orientation is carried out, ie the outgoing flux stage. Lies in the fact that the foil hose F is effectively cooled until the end of the stabilization section M. This arrangement is particularly advantageous, i.e. the strength of the cooling is continuous from the initial melt flux stage of the plastic material to the fully stabilized and cooled state of the foil, i.e. the stabilized state of the foil hose. It can be raised to.

  The conical surfaces from the coolant directing mantles 41B to 44B properly guide the tangential coolant flow from the inside, direct the flow to the inner surface of the foil hose F, and are common in the main inner main ring gap G1 (FIG. 9). An internal helical coolant flow 46 is generated, and therefore the coolant flows only when clearly needed for cooling, so that the cooling stabilization process is more intensive and controlled.

  Another substantial advantage of the helical internal coolant flow 46 resulting from the tangential air flow is that it drives the foil hose F, so that the foil hose F is " It can be “supported” and oriented. Another substantial advantage is the occurrence of coolant depletion in the unstabilized conical section M of the foil hose F due to multi-level coolant blowing (which is unavoidable with conventional solutions and results in weak cooling) It can be eliminated.

  For better understanding, FIGS. 9 and 10 show a cross-sectional view and a front view, respectively, of the solution according to FIG. FIG. 10 shows the internal spiral coolant flow 46 traveling from bottom to top generated by the internal foil cooling and orientation device 40 in the internal main ring gap G1 along the inner surface of the foil hose F.

  Before showing another embodiment, the internal cooling method according to the present invention will be described in detail below.

  For comparison, FIGS. 11-13 and 14-16 show the cooling of the foil hose F for both the conventional device (FIGS. 11-13) and the multi-level internal cooling device according to the present invention (FIGS. 14-16). And the changes in temperature and velocity as advancing along the ring gap throughout the height of the stabilization section M are shown as a front view and a diagram.

  FIG. 11 shows conventional internal cooling using cooling ring HG, foil hose F, and cooling section height M. FIG. 12, the horizontal axis indicates the speed difference (Δv) obtained by the conventional solution, and the vertical axis indicates the height of the cooling section M. In the diagram of FIG. 13, the horizontal axis indicates the temperature difference (ΔT), and the vertical axis indicates the height M of the cooling section.

FIG. 14 shows a facility cooling and orientation device 40 according to the invention (similar to FIG. 7). 15 and 16 show the speed and temperature difference (Δv, ΔT) as a function of the cooling section M. FIGS. 12, 13 and 15, 16 also show the speed and temperature differences (Δv _i , ΔTi) that are considered ideal from a cooling standpoint, so the substantial difference between the two designs is obvious.

The diagram of FIG. 12 shows that the velocity difference (Δv) between the air velocity (v _L ) and the foil velocity (v _F ) disappears at about 2/3 of the height M. The foil hose F travels faster than the cooling air travels parallel to it before exiting the cooling ring H. However, from the viewpoint of heat transfer, a specific speed is absolutely necessary. The molten plastic flux of the foil exits slowly through the mold draw orifice, but the cooling air velocity (v _L ) is high here. The foil accelerates considerably while moving upward, but the cooling air (v _L ) is slowed down due to the funnel spreading.

On the other hand, in the present invention, the adjusted tangential coolant flow injected at different levels continuously satisfies the coolant requirement resulting from the expansion of the inner main ring space G1, and is ideally nominal (Δv _i , ΔT Any decrease in the speed difference (Δv) (FIG. 16) and the temperature difference (ΔT) (FIG. 16) when compared to _i ) is only observed between the two by the two respective cooling units of the device 40. It is.

  In the above embodiment of the multi-level internal foil cooling and guidance device 40 of the installation according to the invention, four individually and selectively controllable cooling units 41 to 44 are shown as an example, Above, any number of cooling units, ie tempering levels, can be applied. The more annular cooling units above each other, the more uniform the speed difference and the closer to the ideal state.

The description on the drawing relating to the speed difference applies almost completely to the temperature difference (FIGS. 13 and 16). According to FIG. 13, the foil temperature (T _F) remains very high even when came out foil, compared with the temperature of the blown new cooling air, a large temperature difference ([Delta] T) is Can be measured. This significant temperature difference (ΔT) quickly disappears as it goes upwards, so the foil hose F is very unlikely to be cooled and fully restored to its original temperature. It is only a coincidence.

In contrast, according to the present invention, the newly blown air not only compensates for the lack of air due to expansion of the space, but also maintains the temperature difference (ΔT) above the desired level (FIG. 16). . If the temperature (T _L ) of the cooling air that reaches the next cooling unit in the line from the bottom (T _L ) (ie the blowing level) is already too high, it can be led from the cooling unit to the environment just before blowing. (For example, through any of the gaps g1 to g3, see FIG. 7. In such a case, some of the gaps g1 to g3 are applied as coolant blowing and others as coolant extraction gaps). Of course, this method has to make up for a large amount of cooling air, but for a given case it is certainly an effective and efficient solution to get a properly and selectively controlled cooling effect. is there.

  The main advantages brought about by the testing of the installation according to the invention with the prototype according to FIGS. 7 to 10 are as follows.

  The foil hose F cools faster and more safely than conventional methods in that coolant is blown tangentially through the multi-level internal cooling unit and forced to flow spirally.

  As a result of continuously supplementing the cooling air, the air in the inner main ring gap G1 is not excessively warmed, and the cooling effect can be stabilized.

  The coolant distribution is absolutely uniform along the circumference of the foil hose F in the inner main ring gap G1.

  • When traveling upward along the cone generator, the size of the inner main ring gap G1 can be maintained at a permanent value.

  The foil hose F is kept in a highly stable state by the coolant flowing in the tangential direction at a relatively high speed in the inner main ring gap G1 between the foil hose F and the cooling unit. Does not become unstable, does not begin to “shake”, and cannot be broken even in the case of intentional external effects (eg drafts).

  It should be noted that the internal cooling orientation device according to the invention can also be combined with an external cooling device in a given case, thereby improving the cooling efficiency, examples of which are described below.

  FIG. 17 shows a preferred embodiment of a foil production facility in which the internal foil cooling and orientation device 40 according to FIG. 7 is combined with a simple external cooling device 47 '. This external cooling device 47 'is arranged right above the mold E for the extruder, and is fixed at that position. The structural design theoretically corresponds to the structural design of the internal cooling units 41 to 44, ie two tangential inlets 47C connected to a regulated coolant supply (not shown). A cooling ring 47A surrounding the distribution ring space is provided.

  The external cooling device 47 'includes a conical coolant directing mantle 47B that approaches the outer surface of the foil hose F from the outside together with the outer main ring gap G in the section immediately after the foil comes out. FIG. 17 shows that the outer cooling ring 47A includes a coolant directing mantle 47B, an inlet 47C, and a tangential outlet 47D along its side and bottom perimeter, the design of which is described with respect to FIG. It corresponds to the design of the cooling unit.

  Thus, the coolant flow exiting through outlet 47D begins to move in the form of a tangential vortex along the outer mantle of foil hose F and travels upward in a spiral to generate external coolant flow 48. .

  The efficiency and uniformity of foil cooling can be significantly improved by combining the inner helical cooling flow 46 and the outer helical cooling flow 48 (FIG. 17).

  It should be noted that the internal multi-stage cooling device 40 according to the present invention can be associated with any known external cooling device.

  FIG. 18 shows another embodiment of the installation according to the invention in which the design of the internal foil cooling and orientation device differs from that described above, which further comprises a simple external cooling device 47 ′ (of FIG. 17). Like).

  The inner foil cooling and orientation device 40 'consists of cooling units 41 to 44 arranged axially away from each other, so that the conical mantle is indicated by the reference symbols 41B, 42B, 43B and 44B. And its tangential exit is indicated by 41D, 42B, and 43D, respectively. However, from the above embodiment, here all the cooling units 41 to 44 have a single common internal distribution space 49, which is covered by the mantles 41B to 44B and the cover 51 at the top and the bottom plate at the bottom. 52 is closed laterally.

  A built-in fan / rotor 53 is embedded in the coolant distribution space 49 so as to rotate, and the coolant is sucked and distributed uniformly. The cover and bottom plate 52 as well as the directing mantles 41B to 44B from the cooling units 41 to 44 cooperate to form one fan cabinet and an integrated cooling ring (50).

  In the case of the present invention, this fan cabinet / house is provided with an axial inlet 54 for introducing temperature-controlled coolant. Besides the tangential outlets 41D to 43D communicating with the space 49, the bottom plate 52 is provided with an additional tangential outlet 55, the latter being tangential air for cooling the inside of the foil hose F just emerging. Send the flow down (indicated by arrows). The shaft 56 of the fan rotor 53 is connected to a rotary drive device 57 that is an electric motor capable of controlling the number of rotations.

  Thus, in FIG. 18, the internal fan is used as an internal coolant source and distributes the coolant completely evenly along the perimeter, so that only the external conditioning air source is at its inlet 54 (not shown). Must be connected.

  FIG. 19 shows a version of the embodiment according to FIG. 18, where the fan rotor 53 is driven at the bottom through a shaft 56 by means of a rotary drive 57. Another difference is that the upper fan inlet 54 'is applied to this coolant. Otherwise, the embodiment according to FIG. 19 substantially corresponds to the embodiment of FIG.

  When applying the solution according to FIG. 19, the already stabilized foil hose F can be divided into two or more strips at the top. Other possible applications can be provided for coolant in foil hoses (not separately illustrated).

  In particular, in the embodiments according to FIGS. 7, 18 and 19, it may be advantageous to arrange the conical coolant directing mantles 41D to 44D in a replaceable manner, and various bevels that can be replaced according to current manufacturing technology requirements. An angle orientation mantle can be applied.

  FIG. 20 shows another embodiment of the installation according to the invention, suitable for producing foil hoses from high density polyethylene (HDPE). The property of this material is that the material of the foil hose F coming out of the mold E for the extruder is still too strong to expand and orient by inflating. In this production method, a multi-level internal foil cooling and orienting device 40 (as shown in FIG. 7) according to the present invention is arranged on an extruder E at an axial distance L, and first with a drawing orifice H After exiting, the foil hose F is stretched to the required length and then the foil hose F is cooled along the stabilization section M using the foil cooling and orientation device 40 to fully stabilize.

  The value of the distance L is chosen as 4 to 5 times the diameter of the foil hose F exiting through the withdrawal orifice H, which is about 400 to 500 mm (for a foil hose with a diameter of 100 mm) ).

  By using this equipment, there is virtually no stabilization along the distance L. This newly extruded foil hose F is first stretched or elongated only by a known pair of upper foil pulling cylinders (not shown) and then the foil cooling and orientation device according to the invention 40 is activated (in the given case, with an external cooling device). Thereby, the cooled, oriented and inflated foil hose F is finally stabilized along a stabilizing section M having a final caliber.

  FIG. 21 shows a further embodiment of the installation according to the invention which is suitable for producing shrink foil with a high shrink capacity. In the above description, since the coolant can only exit through the specified flow cross-section of a given main ring gap G1, the internal foil cooling and orientation device 40 of the installation according to the invention is a foil hose F ("balloon"). That is, it indicates that the inflated foil hose F is substantially “split” into a plurality of inner sections.

  In practice, due to the same “section division”, in the case of the arrangement shown in FIG. 21 and similar to the solution according to FIG. Arranged above, thereby cooling the first section M1 of the foil hose F to the extent necessary for partial stabilization. At a predetermined axial distance L1 from the upper edge, the annular heating device 58 is arranged coaxially, warming the foil hose F partially extended and oriented, thereby softening it again. Arranged immediately above the heating device 58 is a second cooling and orientation device 40 ″, which corresponds substantially structurally to the first foil cooling and orientation device 40.

  The softened and repeatedly inflated foil hose F is spread into the second stabilization section M2 and reaches the final caliber in the secondary foil cooling and orientation device 40 ". At the same time, by effective cooling, Ultimately stabilized along section M2, so a shrinking foil with a high shrinking capacity can be produced without the foil hose F being closed at the top and repeatedly inflated at a high production rate, good Such a shrink foil can be applied as a high value-added shrink foil, for example as a bulk packaging or shrink foil for bundling beverage bottles.

  In the installation according to FIG. 21, any of the internal foil cooling and orienting devices 40 and / or 40 ″ may be a conventional external cooling solution comprising a cooling ring, a cooling cone, or preferably an external foil cooling device 1, 47 according to the invention. They can be combined in various ways, but can also be used individually.

  Finally, FIG. 22 shows a preferred embodiment of a foil production facility according to the invention in which an internal multilevel cooling and orientation device 40 (according to FIG. 7) is combined with an external multilevel foil cooling device 1 (such as in FIGS. 1 to 3). An example is shown. The internal cooling units 41 to 44 of the internal foil cooling and orienting device 40 are fixed in a concentrically overlapping manner in an adjustable manner relative to each other and connected to a common coolant supply 45 (with reference to FIG. 7). As explained). Thereby, an annular gap—adjustable flow cross section—is formed between the conical directing mantles (see FIG. 7), through which the flow of controllable tangential coolant is indicated by thin arrows. Come out like you are. Together, they form a helical internal coolant flow 46 within the internal ring gap G1.

  The external multi-stage foil cooling 47 is composed of cooling units 47.1, 47.2 and 47.3 arranged axially away from each other, corresponding mainly to the cooling units 2 to 4 according to FIG. ) Are connected to the common coolant supply 60 in an individually controllable manner. (The structural design of the bottom cooling unit 47.1 substantially corresponds to the cooling device shown in FIG. 17).

  Each of the other external cooling units 47.2 to 47.3 has a conical orientation mantle 47.2B and 47 as well as a coolant distribution ring 47.2A and a cooling ring 47.3A arranged in an overlapping manner. . B is provided. Each of the cooling units 47.1, 47.2, and 47.3 is provided from an inlet 47.1C for directing a regulated tangential coolant flow to the outer surface of the foil hose F, for example to the main outer ring gap G. With 47.3C and outlets 47.1D to 47.3D. The tangential coolant flow collectively forms an external spiral air flow 48 and travels from below to above along the external main ring gap G. The multi-level external foil cooling device 47 is not shown in detail because it is identical to that shown in FIG.

  The efficiency of foil cooling can be dramatically improved by the combined effects of external and internal helical coolant flows 46 and 48, respectively.

  Another advantage of the facility's internal foil cooling and orientation device 40 according to the present invention is that it essentially closes the outer space of the foil hose F. This means that the foil hose F does not necessarily have to be flat, i.e. need to be closed, since the coolant cannot "escape" through the regulated flow cross section of the inner main ring gap G1 anyway. Is guaranteed in the conventional case by a pair of raised cylinders. More specifically, only an amount of air equal to the amount blown for cooling is removed through the main ring gap G1, while the foil hose F remains stable at all times. One advantage of this is that the foil hose F can be divided into two or more parts without closing with the already stabilized cylindrical section, as this procedure depends on the open foil hose. Is a point.

  An open foil hose is also required for another very important procedure, namely shrink foil production, as already described with respect to FIG.

  Thus, in the installation and process according to the present invention, the internal foil cooling and orientation device 40 ensures multiple levels of blowing in the direction of travel x of the foil hose F, so that the continuously increasing coolant demand is: It is completely filled as it travels upward along the conical unstabilized section M. This solves the long-standing problem of the prior art, where the air blown into the bottom is warmed at a slower rate due to spreading, and the gap between the balloon and the cone is filled with “fresh” air. Since it is exchanged and / or supplemented in multiple stages, it decreases, so the size of the inner main ring gap G1 remains the same at any time.

  It is also an important advantage that the air of the cooling units 41 to 44 is supplied from an independent controlled coolant supply 45 so that the amount and temperature of the injected coolant does not change elsewhere. It can be changed at each level. This makes it much easier to control the impact of the intervention and also increases the separability of the impact.

  In accordance with the present invention, the accelerating foil hose F cools up gradually along the conical section M, in order to fully and rapidly cool down to the original temperature in order to gradually increase the cooling air. There is a need. This is feasible with the present invention because coolant can be supplied to the foil hose F at individually adjusted amounts, temperatures, and pressures at various height levels of the cooling device 40. Thus, the temperature and speed differences required to provide adequate strength cooling are actually the main ring gap G and G, while increasing the amount of air that gradually cools, for example, to provide the most even distribution possible. By blowing into G1, it is ensured.

  Another advantage of the present invention—as described above—is that different amounts and temperatures of air originating from a controlled source can also be blown in based on the parameters of the air already inside the foil hose F. Is a point. This means that, in a given case, the temperature of the air arriving from below is measured, for example, before the blowing level in the cooling unit 42, and then the temperature of the air supplied therein is determined as a function thereof. . In this way, the temperature difference necessary for proper heat transfer is maintained.

  Based on the above, it is readily appreciated that an “arbitrary cooling map” can be created using the technique according to the present invention. This means that the amount, speed and temperature of the coolant can be adjusted selectively as needed at any height of the cooling unit, i.e. by the axial section of the blow section, i.e. by the section of the blow section. To do. In this way, any cooling condition can be created with knowledge of the plastic flux and taking into account the foil properties that are intended to be achieved. This is very important because the mesh texture produced by inflating, lifting and rotating the rotating core-in the case of an extruder head with a rotating core- This is because it must be fixed in this cooling section to be completely uniform along the length.

  The main advantages of the present invention are as follows.

  -As a result of the tangential coolant flow being blown from the outlets or channels arranged at various levels, the oil hose F is cooled more rapidly and returned to its original temperature.

  As a result of the continuous coolant supplement, the helical coolant flow 48, 49 does not warm in the main ring gaps G and G1, and its cooling effect can be maintained at a permanent value.

  The coolant distribution is completely uniform, which can also be seen from the circular ring gap.

  Along the generator of the unstabilized conical section M of the foil hose F, the size of the main ring gaps G and G1 is permanent.

  · Coolant flowing relatively tangentially in the main ring gap G or G1 between the foil hose F and the conical orienting mantle stabilizes and guides the oil hose F to a high degree. Let

  -When the external cooling and orientation device 40 "closes" the foil hose through the main ring gap G1 that occurs along the periphery, the foil hose can be divided into multiple strips within the stabilized cylindrical hose portion It is.

  The foil hose F is cooled at the location of orientation.

  The conical orientation mantle helps guide the coolant accurately and the foil hose is “supported” by the regulated coolant flow.

  ・ Applicable when there is a wide range of basic materials.

  -Can also be used to produce shrink foil.

  Multi-level internal cooling and orientation devices can be applied individually or in combination with external cooling devices.

  While the detailed description discloses only a few embodiments of the present invention, it will be understood that the invention is not so limited. Many modifications, variations and combinations thereof will be apparent to those skilled in the art within the scope of protection claims.

1 is a vertical sectional view of a first embodiment of the installation according to the invention. It is sectional drawing along the straight line II-II of FIG. FIG. 3 is a vertical cross-sectional view of a second embodiment of a foil installation according to the invention. It is a figure which shows the difference of the velocity vector of various arrangement | sequences. FIG. 4 shows a simplified arrangement of the known cooling device described in the introduction and the cooling device of the present invention, as illustrated in FIG. 3, illustrating speed and temperature differences, respectively. FIG. 4 shows a simplified arrangement of the known cooling device described in the introduction and the cooling device of the present invention, as illustrated in FIG. 3, illustrating speed and temperature differences, respectively. FIG. 4 shows a simplified arrangement of the known cooling device described in the introduction and the cooling device of the present invention, as illustrated in FIG. 3, illustrating speed and temperature differences, respectively. FIG. 4 shows a simplified arrangement of the known cooling device described in the introduction and the cooling device of the present invention, as illustrated in FIG. 3, illustrating speed and temperature differences, respectively. FIG. 4 shows a simplified arrangement of the known cooling device described in the introduction and the cooling device of the present invention, as illustrated in FIG. 3, illustrating speed and temperature differences, respectively. FIG. 4 shows a simplified arrangement of the known cooling device described in the introduction and the cooling device of the present invention, as illustrated in FIG. 3, illustrating speed and temperature differences, respectively. FIG. 6 is a cross-sectional view of details of a third embodiment of the installation according to the invention. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. FIG. 8 is a cross-sectional view of the details of FIG. 7, ie, the internal foil cooling and orientation device. FIG. 10 is a side view of the solution shown in FIG. 9. It is an external view of the side of the conventional foil production apparatus with an internal cooling function. It is a figure which illustrates the speed and altitude difference of the installation by FIG. It is a figure which illustrates the speed and altitude difference of the installation by FIG. FIG. 8 is a simplified side view of an embodiment of the installation according to the invention as shown in FIG. 7. It is a figure which illustrates the speed and altitude difference in the solution by FIG. It is a figure which illustrates the speed and altitude difference in the solution by FIG. Fig. 8 is a vertical sectional view of the version of the device according to Fig. 7 also equipped with an external cooling device. FIG. 8 is a vertical sectional view of another embodiment of the installation according to FIG. 7, wherein the internal cooling orientation device comprises a bottom feed internal fan. FIG. 19 shows a version of the solution according to FIG. 18 to which the upper coolant feed is added. FIG. 2 shows a special embodiment of the installation according to the invention for the production of high density polyethylene foil hose. FIG. 6 is a vertical sectional view of another special embodiment of the installation according to the invention, intended for producing shrink foil. FIG. 2 is a vertical cross-sectional view of a preferred combined embodiment of an installation according to the present invention equipped with both a multi-level internal foil cooling orientation device and a multi-level external cooling device.

Claims (15)

  Equipment for the integrated production of extruded plastic foil hoses, an extruder using a mold suitable for forming the foil hoses with an annular drawer orifice, the drawer orifice and the expanded An internal and / or external cooling device surrounding at least a part of the foil hose, said internal and / or external cooling device being connected to a coolant supply, an inlet for coolant, preferably cooling air, and cooling At least one outlet for supplying coolant into an annular gap between the inflated foil hose and the internal and / or annular skirt of the external cooling device, the external and / or external cooling device being an extrusion Preferably arranged directly on the mold (E) for the molding machine, coaxially with the drawing orifice (H), and inside and Or multi-level tangential direction for coolant to stabilize the first conical unstabilized section (M) of the expanded foil hose (F) by external helical coolant flow (46, 48) Characterized in that it is formed as a multi-stage device with outlets (41D to 44D, 14 to 16), the multi-stage internal cooling devices (40, 40 ', 40 ") being axially spaced from each other (T3, The unstabilized section (M) of the foil hose (F) through an internal main annular gap (G1) with at least two annular cooling orientation units (41-44) arranged in T4, T5) Are internally and at least partially enclosed, the internal annular cooling orientation units (41-44) are each selectively and individually temperature and / or volume and / or pressure. Connected to the coolant supply source (45) in such a way as to supply the coolant that is adjustable to the multi-stage external cooling device (1, 47) axially separated from each other (T1, T2) At least two annular outer cooling units (2-4, 47.1, 47.2, 47.3), and through the outer main annular gap (G), the expanded foil hose (F) Externally at least partially enclosing said conical unstabilized section (M), each outer annular cooling orientation unit (41-44) having at least one tangential inlet (17, 18) And connected to a second coolant supply (HK1, HK2, HK3) to supply coolant whose temperature and / or volume and / or pressure are selectively and individually adjustable. Equipment.   The at least one of the internal multi-stage cooling devices (40, 40 ', 40 ") and at least one of the external multi-stage cooling devices (1, 47). Facility.   Each of the external cooling units (2-4) of the external multi-stage cooling device (1) has at least one conical mantle (6, 8, 10) surrounding the external main annular gap (G). With coolant distribution rings (5, 7, 9), said tangential outlets (21, 24) being preferably formed as slots in said baffles (6, 8, 10) of the foil hose (F) 3. Equipment according to claim 1 or 2, characterized in that it forms a tangential inlet gap (14, 15, 16) of surrounding coolant sulfur.   Each of the inner annular cooling orientation units (41-44) comprises at least one coolant distribution ring (41A-44A) and at least one conical baffle (41B-44B) surrounding the inner main annular gap (G1). 3. An inlet (41C) and a tangential outlet (41D-44D), preferably comprising a slot forming a tangential coolant inlet around the foil hose (F). The equipment described.   The conical coolant directing mantles (6, 8, 10, 41B-44B) of the cooling orientation unit (2-4, 41-44) and / or the adjacent cooling orientation unit (2-4, 41-44) are , Arranged in an axial direction so as to overlap each other, thereby forming an annular gap between the adjacent conical mantles (6, 8, 10, 41B to 44B), preferably, the mantles (6, 8, 10. Equipment according to claim 3 or 4, characterized in that the mutual axial position of 10, 41B to 44B) and thereby the flow cross section (g1, g2, g3) of the annular gap can be adjusted.   At least one of the conical mantles (6, 8) of the external cooling orienting unit (2, 3) comprises a conical extension mantle (6A, 8A) having a relatively small aperture, the relative axial position of which is , The corresponding directing mantle (6, 8) can be adjusted so that the annular gap (26, 27) can be adjusted with the directing mantle (6, 8) and its extension mantle (6A, 8A). And the flow cross section thereof can be adjusted, preferably through the upper free end of the gap (26, 27) leading to the external open gap, to pass the part of the already used coolant to the external Equipment according to claim 3, characterized in that it can be removed from the outer main ring gap (G) of the multi-stage cooling device (1).   The flow cross-section of the annular coolant inlet gap (14, 15, 16) of the cooling unit (3, 4) is relative to the cooling ring (7, 9) and / or its conical orientation mantle (8, 10). 4. The axial adjustment and / or the lowest cooling unit (2) can be adjusted by mutual axial adjustment of its cooling ring (5) and its lower neck (N). The equipment described.   The mutual axial positions of at least two of the internal cooling orientation units (41-44) are fixed in an adjustable manner, whereby their axial distances (T3, T4, T5), and Equipment according to claim 4, characterized in that the flow cross section of the inner main ring gap (G1) around the foil hose (F) can be set.   The cooling orientation units (41-44) of the internal multi-stage cooling device (40 ′) form a common cooling ring (50) together with a common internal coolant distribution space (49), and a conical mantle (41B to 44B) and a tangent line. The units (41-44) having directional outlets (41D, 42D, 43D) form a conical mantle of the cooling ring (50) therefrom, and the coolant distribution space (49) further comprises an upper cover (51 ) And a bottom plate (52), and in the coolant distribution space (49), a built-in fan rotor (53) is rotatably embedded, connected to an external rotary drive device (57), and the cooling The cover (51) and the bottom plate (52) together with the mantle (41B to 44B) of the unit (41 to 44) cooperate with each other in the fan housing. Configure ing, the cooling ring (50), Installation according to claim 1 or 4, characterized in that it comprises an inlet (54) for supplying a coolant of a predetermined temperature.   In order to produce foils and hoses from high-density plastic materials, mainly polyethylene (HDPE), the internal multi-stage cooling device (40) has a predetermined axial distance (L) from the mold for the extruder (E). The equipment according to claim 1, wherein the equipment is arranged at a location.   For shrink foil production, the foil cooler (40) cools the first unstabilized conical section (M1) of the foil hose (F) to the required predetermined temperature. Arranged directly above the mold (E) for the extruder, and partially extended and oriented at a certain axial distance (L1) from the upper edge of the cooling device (40). A heating device (58) is arranged to warm the foil hose (F) and thereby soften it again, and a second multi-stage foil cooling and orientation device (40 ″) is directly above the heating device (58). The installation according to claim 1, characterized in that the foil hose (F) is arranged coaxially so as to finally stabilize. A process for producing plastic foil hoses,
By using an external multistage cooling device (1), thereby providing an outer main ring gap (G) at a certain radial distance from the outer surface of the foil hose (F) and / or an internal multistage cooling device (40), thereby providing an inner main ring gap (G1) at a certain radial distance from the inner surface of the foil hose (F) to draw out the mold (E) for the extruder Enclosing at least a portion of an unstabilized expanded section (M) of the foil hose (F) that has just exited the orifice (H);
Through an axial multi-level tangential inlet, selectively a predetermined temperature and / or pressure and / or volume of coolant, mainly cooling air, is introduced into the external and / or internal main ring gap (G). , G1) and sending the tangential coolant flow to the outer surface and / or inner surface of the unstabilized section (M) of the foil hose (F), Cooling the unstabilized section (M) externally and / or internally, so that the coolant along the outer surface (s) and / or inner surface of the expanded foil hose (F) By using the centrifugal forces that affect the flow, and by using the density and pressure differences between the various parts of the coolant flow (48, 49), Stabilizing the structure using generating at least one helical coolant flow (48, 46) from the multi-level tangential coolant flow in the outer and / or inner main ring gap (G and G1); Including processes.   Cut the tubular foil hose (F) longitudinally in at least two places to form a flat foil strip from the foil hose (F) during or immediately after the final stage of the cooling and stabilization process The process according to claim 12, characterized by an additional step.   Supplied by the selectively controllable coolant supply (45) of the internal multi-stage internal cooling device (40) for inflating the foil hose (F) and thereby extending and orienting in the crossing direction. 14. Process according to claim 12 or 13, characterized in that it has an additional step of using tangential coolant flow.   For shrink foil production, the unstabilized conical section (M1) of the foil hose (F) is first cooled to a predetermined temperature and only partially stabilized, and then the foil material is heated. And then softening again, and immediately after the heating step, the foil hose (F) is completely stabilized by using a second multi-stage foil cooling and orientation device (40 ″). The process of claim 12.

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