FR2532582A1 - ROTATING TOOL FOR BLOWING FILMS WITH A CENTRAL SUPPLY OF MOLTEN MATERIAL AND INTERNAL COOLING OF THE FILM - Google Patents

Abstract

A. ROTARY FILM BLOWING TOOLS WITH CENTRAL MELTED MATERIAL SUPPLY AND INTERNAL FILM COOLING. B. TOOLING CHARACTERIZED IN THAT THE ROTATING NOZZLE HEAD WITH AN ANNULAR SLOT IS CONSTITUTED BY A CHUCK 16 AND BY AN EXTERNAL RING 17 AND IS ARRANGED ON THE FIXED DISTRIBUTOR 1, AND THAT THE CENTRAL MELTED MATERIAL SUPPLY CHANNEL 15 IN THE FIXED DISTRIBUTOR 1 IS DIVIDED AT A RIGHT ANGLE INTO HOLES 2 EXTENDING RADIALLY IN THE SHAPE OF A STAR. C. THE INVENTION RELATES TO A MACHINE FOR THE PRODUCTION OF PLASTIC FILMS BY HEATING CENTRIFUGATION.

Description

Rotating tools for blowing films with a food supply

  central melting and cooling

internal of the film ".

  The invention relates to a rotary tool for blowing films, with a central inlet of the melt and an internal cooling of the film, a tool consisting of a fixed distributor of the melt comprising flow channels extending in form

  of star and with a rotating nozzle head with annular

  tube, having inside the tubes, axially arranged

  and concentric to each other, supply and discharge of air, and which are connected to tubes of

  radial connections arranged in the fixed splitter.

  We already know, by the document DD PS 137 553, a

  rotary film blowing equipment with a feed

  This film blowing tool consists of a connecting piece through which the melted material is brought to the center of a distributor. The splitter is fixed in this splitter box.

  the molten plastic is channeled through

  of star-shaped flow channels

  obliquely upwards, towards an interna-

  rotary ring This intermediate ring is connected to the annular slit nozzle head from which the flexible film tube exits and has a circular ring-shaped flow channel interrupted by bars.

link.

  The supply and discharge tubes for the internal cooling air extend into the fixed part of the tool between the melt-shaped distribution bores arranged in the form of a star. These bores open into the fixed tubes arranged concentrically in the melt distributor, in the mandrel and the intermediate ring of the annular slotted nozzle head and provided for the transport of the cooling air to the melt to be cooled or for the removal of the melt. cooling air heated out of the upper part of the tube blowing device Between the annular slot rotary nozzle head and the concentrically arranged fixed tubes, for the supply and discharge of the cooling air, are arranged sleeves

  with sliding rings for guiding.

  The rotating intermediate ring is sealed by means of

  In this solution, it has proved to be very disadvantageous that the sealing between the rotating intermediate ring and the fixed distributor is very difficult for the fixed melt distributor towards the outlet of the melt. expensive from the point of view

  construction and manufacture, because of the drilling

  When the diameter of the annular slit nozzle increases, this sealing becomes more complicated or even no longer possible. The reason is that with a larger nozzle diameter, the projected circular annular surface of

  parts to be sealed relative to each other, believes.

  But, because of this, the necessary force conditioned by the pressure of the molten plastic material to seal the fixed distributor relative to the intermediate ring

  rotary, also believes The rise of the application effort

  cation under pressure, then causes the appearance

  more friction, and therefore

  training session, a tight seal

  satisfying that is no longer guaranteed.

  Another drawback of this solution lies in the fact that traces of flow appear in the molten plastic material due to the perforated plate, these traces not being completely eliminated by the erasing thread placed in the following position. Homogeneity leads to quality defects for the flexible tube film thus produced. With this solution, it is furthermore not possible to evenly distribute on the periphery of the film, the vortexes of air originating at the time of the invention. because of manufacturing deviations, and the resulting differences in film thicknesses, because the air supply tubes and the blow lips do not rotate with the annular slot nozzle head On the roll of the film are born this

  what are called piston rings, which make beautiful

  more-difficult shot the subsequent processing of the film.

  In the case of two other rotary film blowing tools, which are technically almost identical and which are described in more detail in DE-GM 7 412 102 or in DE-OS 2 509 024, the plan separation between the rotating part and the fixed part of the tool is placed immediately

  in the central channel for feeding molten material.

  The advantage is that, because of the reduced diameter in the separation plane, no significant sealing problem

  for molten plastic material does not occur between.

  fixed part and the rotating part of the tooling -The molten plastic material is then regularly distributed

  by star-shaped holes which are

  wind in the rotating part of the tool and which leads to

  respectively in a propeller of the splitter at

2532-582

  propellers The supply of air inside the tooling takes place between the distribution bores extending

  in the form of a star in the rotating part of the tooling.

  This results in a rotation of the entire supply and exhaust of cooling air and an optimum distribution of film thickness tolerances is achieved by the film roll.

  the supply and evacuation of the air presents -in

  It is advisable that, at the connection of the fixed air channels on the rotational tools, very large air distribution rings, subdivided, which are capable of rotating each other.

  compared to the others, sealed and arranged concentric-

  tools are necessary, the cost of

  cation is therefore very high from the constructive point of view,

  technological and mechanical This solution is relative-

  subject to breakdowns during operation,

  it entails a high maintenance expense and is

  duit by a relatively high noise level.

  This disadvantage of complex sealing by the supply and exhaust air does not intervene in the case of a film blowing tool fed laterally Such a solution is described in DE OS 2 508 930 The supply and the discharge of cooling air are carried out centrally, whereby the tooling occupies little space in width. In addition, the diameter for the plane of separation between the fixed part and the rotating part of the tooling can be maintained to a reduced size, whereby the sealing of these parts relative to each other

  does not pose a problem The lateral feeding of

  melted pot is above the racco-rds for food.

  However, this results in a very high construction height for all the film blowing equipment. The lateral feeding of molten material also has the disadvantage that shortages of homogeneity

  important occur in the molten plastic material.

  These lack of homogeneity give rise to different lengths of the flow paths, which result from the lateral feeding of the deflection and the distribution of the molten plastic material on the periphery, and which have very adverse effects on the the quality of the film. The object of the invention is to reduce the technical and economic expense of implementation, to improve the operability, to simplify the monitoring and maintenance and to guarantee a good quality of the film. the invention,

  the case of a rotary tool for blowing films, with-

  a central supply of molten material with an ame-

  born and a cooling air outlet for the

  internal cooling of the film, is to achieve the

  circular annular face to be sealed, between the part

  stationary part and the rotating part of the tooling,

  constant and reduced, irrespective of the diameter of the annular slit nozzle, and simultaneously create a connection of an operation on and of a construction

  simple, with regard to rotating

  cooling air outlet and exhaust system in the

  rotary nozzle head with annular slot.

  This problem is solved in accordance with the invention in that the ring-shaped rotating nozzle head is constituted by a mandrel and an outer ring, and is arranged on the fixed distributor, while in the separation plane is a channel annular which

  is sealed radially outwards and towards the inside

  The central melt feed channel in the fixed splitter box

  is divided at right angles into radially extending holes

  in the form of a star, and which, deviated by 90, extend parallel to the axis and then open into the annular channel: At the periphery of the annular channel,

  holes are distributed regularly which de-

  close after a new inflection at 900, each in a helix of a propeller splitter The mandrel is

  provided in the separation plan by a flange at the

  fixed motor, on which is fixed the outer ring.

  In the chuck of the rotating nozzle head at

  annular slot is placed, secured in rotation, a disc

  positive air supply which is connected directly to each other, the air supply tube and the upper and central section of the exhaust air tube

  transversely into three sections through

of a perforated disc.

  The air supply tube is movably disposed in

  rotation on a retaining disk, placed in the distribution

  fixed section, the central section of the exhaust air tube is fixed to the fixed distributor under the lower section

evacuation tube.

  The air discharge tube is preferably divided transversely into two parts on the central section

  the exhaust air tube is placed

  In prolongation, this upper section The fixed connection between the different parts connected to rotation, preferably comprises a connection by pin in bonding

and withdrawal.

  The invention will be explained in more detail with reference to an exemplary embodiment shown in the accompanying drawings in which

  FIG. 1 is a simplified longitudinal section

  of rotary film blowing equipment.

  centrally and with internal cooling

  2 of the film shows on a larger scale the detail X of FIG. 1 relating to the connection between the supply and exhaust tube and the use

rotary air ducts.

  FIG. 3 shows on a larger scale the detail Y of FIG. 1 relating to the connection locations of the fixed distributor and of the fixed air evacuation tube with the rotating mobile supply and exhaust tubes,

  FIG. 4 is a partial view of the disc

  Drilled seen in the direction of the arrow Z of Figure 2.

  The rotary film blowing tool with a

  central supply of molten material and a cooling

  the film is composed of the distributor

  stationary 1 and the annular rotating nozzle head

  20 with the mandrel 16 and the outer ring 17, which is provided with a drive 14 for generating the movement

  of rotation, as well as tubes 10 or 13 for feeding

  removal and evacuation of the cooling air.

  The molten plastic material arrives from the central melt feed 15 into the stationary distributor 1; whereof it is distributed in individual flow in the holes 2 extending in the form of star The holes 2 are arranged at right angles to the supply of molten material and extend first of all rectilinearly then they are then deflected by 90 and then extend parallel to the axis, opening into the annular channel 5. This annular channel is arranged in the plane of separation between the fixed distributor 1 and the annular slotted rotary nozzle head 20. sealing rings 3 and 4 which are preferably made of a bronze alloy, satisfactory sealing is

  inward and outward between the

  fixed titrator 1 and the rotary nozzle head with annular slit

  The annular channel 5 starts from the 6-point bores.

  distributed peripherally in the annular slot rotary nozzle head 20, these holes opening, after a new deflection of 90 outwards, in each of the helix propeller propellers 7 La

  molten plastic material is homogenised intensively

  sive in this distributor by an axial and radial flow superimposed before it comes out of the tooling under

  form of flexible tubes of films at the orifice 8 of the nozzle.

  The mandrel 16 is provided in the separation plane with the fixed distributor 1 of a flange 19 on which

is screwed the outer ring 17.

  The cooling air enters through the

  radially disposed tubes 10 at the periphery of the distributor 1 in an air distribution chamber 24

  in the form of a blind bore and which is in

  In this connection, a discharge tube for the heated cooling air is arranged in the distributor and in the mandrel, the tube through which the heated cooling air is cooled. sucked out

  the upper part of the blowing device.

movies.

  The exhaust air tube is transversely

  divided into two parts and consists of an eva-

  fixed 12 air cuation disposed in the distributor 1, and

  which is connected with the fixed tubes 13 arranged radially

  in this distributor 1 On the exhaust pipe

  12, is fixed a retaining disk 22 -don't the diameter-

  outer diameter is smaller than that of the bore of the

  air distribution chamber 24 (Figure 3) A second disc

  that * retaining 23 is fixed above the retaining disk

  22 against the wall of the air distribution chamber 24.

  On the fixed evacuation tube 12, is arranged, rotatable, the portion 12 'of the evacuation tube

  of air which is surrounded by a thermal insulation 12 ".

  * But the air exhaust tube 12 'can also be

  rotatably disposed on the retaining disk 22.

  The drilling in the retaining disk 23 is greater than

  diameter of the 12 ", 12", but less

  the outer diameter of the retaining disk 22.

  On the retaining disc 23 is disposed, rotatable, the air supply tube 9 It is connected to a lining of air ducts 27 disposed in the mandrel 16 which it is secured The air duct lining- 27 and the air supply tube 9, are at the same time secured to their location

  connected by a perforated disc 21 which, in turn, is

  made integral with the extension of the exhaust tube 12 "'press-fitted on the evacuation tube

  air 12 '(Figure 2) The junction -rigid between the garnish

  air duct 27 with the mandrel 16 and the air supply tube 9, as well as the perforated disk 21 and the air outlet tube 12 "and 12" 'can, given the reduced forces to support, be carried out in the form of a connection by pins and / or by gluing or by withdrawal On the air outlet tube 12 "'is placed, being secured to this tube, a rigid liner

  of air orientation 28 which is adapted to the geometrical contour

  27 Between the bore in the mandrel and the feed tube

  air 9, is a hollow space 30 playing the role of iso-

  between the flow of the melt into the

  propeller distributor 7 and the flow of air

  In the air chamber 26 between the retaining disk 23 and the rotating air supply tube 9, as well as between the retaining disk 22 and the air evacuation tube 12 'are located joints

sealing 31 and 32.

  The operating mode of the blower tooling

  The film according to the invention is as follows: From a non-extruded extrudate, the molten plastic material flows through the melt feed centrally to the bores 2 extending in the form of a star and arranged radially in the distributor 1, and which after a

  900 deviation open into the annular channel 5.

  From there, the molten plastic material arrives via the bores 6 in the helix distributor 7 or a homogenization of the melt flow takes place at the orifice 8 of the nozzle, the flexible tube of

film comes out of the tooling.

  With the drive 14, a rotational movement

  is communicated to the outer ring 17 and the mandrel 16.

  In the plane of separation between the rotating nozzle head

  with annular slot 20 and the fixed splitter 2, a watertight

  satisfactory against an outlet of the melt 1-5 inwards and outwards is obtained by the rings

3 and 4.

  The air supplied via the tube 10 provoked

  that the formation of a flexible film tube, which is simul-

  cooled, from the plastics material

  due outgoing in a circular annular form The air supply tubes 10 arranged opposite each other

  others, open into the air chamber 24.

  In the air chamber 24 delimited by the disks

  22, 23, an accumulation pressure is generated

  dreaus causing a homogenization of the air flow

  over the entire flow cross-section.

  The cooling air stream, which then flows through the annular slot 25 into the

  air chamber 26, is approximately laminar.

  The air supply and discharge tubes dis-

  placed concentrically 9, 12 ", 12" 'are rotated, thanks to the rigid connection between them, through the perforated disk 21 and with the rotating nozzle head to

annular slot 20.

  In the plane of rotation formed by the disks of

2532582-

  It retains 22, 23 or the air discharge tube 12, the air supply tube 9 and the air discharge tube 12 'are sealed relative to the fixed connection in the distributor 1 by joints sealing means 31, 32 The air supply to the film blowing device is circular ring-shaped through

  the perforated disc 21 and the existing annular slot

  be the air line fittings 27 and 28.

  To obtain maximum permeability to air, the holes formed on the perforated disc 21 are covered by

  buttonhole shape 29 (FIG. 4).

  The air heated by heat transmission against the film, is sucked from the upper part of the

  device for blowing films through the evacuation tubes

  airflow 12 "'and 12" which rotate and are discharged to

  outside via fixed evacuation tubes

12 and 13.

  After proper cooling by the exchange

  of air continuing in the interior of the dis-

  positive blowing ,, and by external cooling

  by means of a cooling ring

  external dyeing 18, the flexible film tube is laid flat and developed The heated cooling air is

  evacuated to the outside via the tube of

12 and the tube 10.

  This embodiment according to the invention of a

  Rotary film blowing tooling allows a large

  reduced and constant sealing of the sealing in the plane of separation between the fixed distributor 1 and the annular slotted nozzle rotating head 20 Thus, a satisfactory and simple independent sealing is obtained

  the size of the diameter of the annular slit nozzle.

  Depending on the widths of films required, the holes 6 or circulating the melt may be extended as well.

  far we want to go outside and extend

  followed by a propeller distributor 7 of an appropriate diameter

  required, without the expense of sealing the rotating part in relation to the fixed part of the

film blowing, be modified.

  Other advantages of this solution lie in this

  that the expenditure of construction and manufacturing technology

  cation for the coupling connection between the fixed and rotary tubes of supply and exhaust air,

  is very small, while a secure seal is obtained.

  Thanks to the supply and exhaust air tubes

  Together, the air vortices originating in the air supply system due to manufacturing deviations, and the resulting tolerances on film thickness, can move around the periphery of the tube. that the fluctuations in the thickness of the film are uniformly distributed over the periphery of the film and that a film suitable for its subsequent processing is thus obtained. The construction height of the film blowing equipment in the

  the case of a supply of molten material and of a food

  tation and air evacuation, placed centrally

  in the fixed part, is very small The expenditure of realization in terms of construction and

  -technology is very small for the entire tool-

  and no special maintenance is required.

Claims (1)

R E V E N D I C A T IO N S   1) Rotating tools for blowing films with   a central arrival of the molten material and a cooling   internal dyeing of the film, tools consisting of a   fixed titrator with de-s star-shaped flow channels and with an annular slotted nozzle head, and which are sealed with respect to   the other and which contain inside the tubes   axially and concentric to each other for the supply and the evacuation of the air, and which are connected   to radial connecting tubes arranged in the distribution   stationary and placed between the flow channels   star-shaped tool, characterized in that the annular slotted nozzle head is constituted by a mandrel (16) and an outer ring (17) and is arranged on the fixed distributor (1), while that in the plane of separation is an annular channel (5) which   is sealed radially outwards and towards the inside   by the sealing rings (3) and (4), and that the central material supply channel (15) in the fixed distributor (1) is divided at right angles into bores (2) extending radially in the form of a star, and which, deviated by 90, extend parallel to the axis and then open into the annular channel (5), from which in the direction of the flow bores (6) distributed over the periphery and deviated from 90 towards   outside, lead to each of the propellers of the   propeller titter (7), while dan, s the chuck (16) is   disposed in rotation with a packing of canalisa-   (27) to which the air supply tube (9) and the air discharge tubes (12 ', 12 ") are connected directly via a perforated disc (21). ) rotatably connected to each other, the air supply tube (9) being rotatably mounted on a retaining disc (23) disposed in the fixed distributor (1) while the evacuation tube of air (12 ') is rotatably mounted on the air outlet tube   (12) arranged in a fixed position on the fixed distributor (1).   ) Rotary film blowing tool according to claim 1, characterized in that the mandrel (16) is provided in the separation plane to the fixed distributor (1) of a flange (19) on which is fixed the outer ring (17).   ) Rotating film blowing tool according to   Claim 1, characterized in that the evaluation tube   air cuation is preferably divided transversely into two parts, while on the central section (12 ') movable in rotation in the guide, an extension (12 "') is likely to be liftable integrally, the connection solidarity between the different parties   connected by being mobile in rotation, consists, preferably   a pin and / or bond by bonding and removal. Rotary film blowing tool according to claim 1, characterized in that the bores   in the perforated disk (21) take the form of   (29) offset from each other.