FR2487696A1 - CONTINUOUS VACUUM PROCESSING APPARATUS - Google Patents

Abstract

THE APPARATUS ACCORDING TO THE INVENTION INCLUDES A VACUUM TREATMENT CHAMBER 1 AND AT LEAST ONE AUXILIARY VACUUM CHAMBER 2, 3 ON EACH SIDE OF THE VACUUM TREATMENT CHAMBER. EACH AUXILIARY CHAMBER INCLUDES TWO SEALING ROLLS 21, 22 IN CONTACT, A DEVICE ENSURING THE SEALING BETWEEN THESE ROLLS AND THESE CASINGS ON THE AXIAL LENGTH OF THE ROLLS AND A DEVICE ENSURING THE SEALING BETWEEN THE END SURFACES AND THE CASINGS.

Description

The present invention relates to a

  continuous vacuum treatment apparatus for carrying out continuous vacuum plasma treatment of different

  plastics, for example ma-

  plastic, sheets of plastic and

  electric wires coated with plastic.

  A batch type processing device is already known comprising a vacuum processing chamber in which a flexible article such as a

  plastic film is treated, for improvement

r its surface properties.

  There is also an air-to-air treatment system for vacuum vaporization or ion plating of a hard material, such as a strip

  metallic, metallic wire or the like, in the-

  which hard material is introduced from then the side of the atmosphere into the vacuum processing chamber

  passing through a preparatory vacuum chamber available

  placed upstream of the vacuum treatment chamber, and, after the formation of a metallic film or an alloy on the article, the latter is entrained towards the side of the atmosphere by passing through an outlet vacuum chamber . In this air-air type system, the vacuum is maintained in the preparatory chamber and in the outlet chamber by means of a water seal or

a nozzle seal.

  In the first of these systems,

  say that of the batch type, it is comparatively easy to make the sealing device. But when the surface properties of the article are improved to some extent, it is

  necessary to break the vacuum in the vacuum chamber.

  In other words, the repeated establishment and breaking of the vacuum are necessary for the treatment of successive batches of articles. This not only disrupts mass production in chains, but degrades

  also the characteristics of the products treated.

  More particularly, in the case of articles which contain a volatile constituent such as a plas-

  tifier, for example a chlorine resin film

  vinyl rure, the properties of the article are degraded

  if it is left in a vacuum for a long time.

  It is therefore desirable to process a batch of articles in very short periods, of the order of a few tens of seconds. It is very difficult to carry out treatment in such a short period, in a

vacuum treatment chamber.

  The seoond of these systems can easily per-

  put the processing of hard items because it is rela-

  easily obtainable from the preparatory vacuum chamber and the outlet vacuum chamber, without risk of damaging the surfaces of the articles or

  to cut them. But this air-to-air system can be difficult-

  apply to the treatment of flexible articles, because it is extremely difficult to obtain an effective seal for the preparatory vacuum chamber and for the outlet vacuum chamber without risking damage or cutting

articles.

  An object of the invention is therefore to propose a continuous vacuum treatment device capable of maintaining a good seal of a preparatory vacuum chamber and of an outlet vacuum chamber, to ensure good modification characteristics.

  in surface treatment, as well as very good-

  our adaptations to mass production.

  Another object of the invention is to improve the longevity of different elements constituting the preparatory vacuum chamber and the vacuum chamber of

  outlet, for example sealing rollers, friction

tors and side pieces.

  To this end, the invention therefore relates to a continuous vacuum treatment apparatus comprising a chamber

  vacuum treatment, at least one vacuum chamber pre-

  paratory arranged on the upstream side of the vacuum treatment chamber and at least one vacuum chamber

  outlet arranged on the downstream side of the processing chamber

  vacuum vacuum, the preparatory vacuum chamber and the outlet vacuum chamber each consisting of two sealing rollers, a device which seals between each sealing roller and a

  casing in the axial direction of the roller and a provision

  sealant that seals between the two ends

of each roller and the housing.

  Other features and advantages of the

  vention will appear during the description which goes

  follow several examples of implementation and

  referring to the attached drawings in which:

  Figure 1 is a schematic section of an apparatus

  continuous processing, according to one embodiment

  tion of the invention, Figure 2 is a schematic plan view of the apparatus of Figure 1,

  Figure 3 is a schematic sectional elevation

  tion of a vacuum treatment chamber of the apparatus

reil of Figure 1,

  Figure 4 is a section of a sealing device

  adopted in an auxiliary vacuum chamber of the device of Figure 1, Figure 5 is a section along the line V-V of Figure 4, Figure 6 is an enlarged view

  of an essential part of the apparatus according to the invention

  tion, showing in particular the manner of fixing a pressure adjustment piece, Figure 7 is a section similar to that of Figure 5, showing another example of a sealing device adopted in the auxiliary vacuum chamber according to Invention, Figure 8 shows another example of a wiper incorporated in the sealing device of Figure 7 and Figure 9 illustrates how to fix the wipers.

  Figures 1 and 2 therefore represent an apparatus

  reil for continuous vacuum treatment according to the invention,

  which has a vacuum chamber 1 in which an ar-

  flexible sheet F such as a plastic film

  that, for example vinyl chloride, is subjected to a continuous treatment with vacuum plasma. Several auxiliary vacuum chambers 2 are arranged on the upstream side of the vacuum treatment chamber 1, in the direction of movement of the article to be treated. Similarly, several auxiliary vacuum chambers

  3 are arranged on the downstream side of the processing chamber

  Vacuum 1. A vacuum pump 4 is connected by an evacuation tube 5 to the treatment chamber 1 to empty it to a level 10-2 Torr. As the

  shown in Figure 2, several vacuum pumps 6 are re-

  linked to successive auxiliary chambers 2, 3,

  each side of the treatment chamber 1, by tubes

  bes evacuation 7. The layout is such that the

  vacuum reaches gradually decreasing levels-

  in successive auxiliary vacuum chambers 2 on the upstream side, while the vacuum reaches

  gradually increasing levels in the rooms

  successive vacuum bres 3 on the downstream side. It is obvious that the vacuum levels established in these

  auxiliary chambers are intermediate between the pres-

  atmospheric pressure and the vacuum produced in the chamber

vacuum treatment 1.

  The article F to be treated is driven continuously-

  from an unwinder 8, in the processing chamber

  vacuum chamber 1, passing through the vacuum chambers

  successive auxiliaries 2, and it is subject to a

  vacuum plasma in the treatment chamber

  1. The article is then taken out of the milking chamber

  ment 1, and continuously wound by a reel 9 passing through the successive auxiliary vacuum chambers 3. The reference numeral 10 designates a motor

  that provides the driving force for the

  in vacuum 1, in auxiliary chambers 2, 3 and in the

  roller 9, via an intermediate shaft

  11 and progressive transmissions 12, 13, 14 and 15.

  Drive speeds in the milking chamber

  ment 1, in auxiliary chambers 2, 3 and in the

  roller 9 are adjustable by means of the transmissions

pectives 12, 13, 14 and 15.

  Figure 3 shows schematically the cham-

  vacuum treatment bre 1, which comprises a cathode 16 in the form of a drum, several anodes 17 arranged around the cathode 16, and a guide roller 18 which guides the article F to be treated. The cathode 16, the anodes 17 and the guide roller 18 are supported in

  overhang by one 19 of the side walls, tan-

  say that the other wall 20 constitutes a door which can

  be open to access the interior.

  Figures 4 and 5 show the embodiment of each of the auxiliary chambers 2 and 3, arranged upstream and downstream of the vacuum treatment chamber 1. As these figures show, each auxiliary vacuum chamber comprises several elements, namely upper and lower sealing rollers 21 and 22 in mutual contact, arranged in a pair, housings

  upper and lower 23, 24, wheel supports

  upper and lower parts 25, 26, side pieces

  left and right rails 27, 28 and so on.

  More particularly, and with reference to these Figures, the upper sealing roller 21 comprises a core made of a metal such as iron and an elastic surface layer 29 of rubber, for example nitrile rubber, fixed to the surface of the iron core, while the lower sealing roller

  22 has a core of metal such as iron and a layer

  hard che formed on the surface of the iron core, for example a layer 30 of chromium plated. The elastic surface layer of the upper roller 21 can be made of a layer of silicone rubber, or a layer of urethane rubber fixed to the iron core. It is also possible to use an alloy

  steel for the material of the lower sealing roller

  laughing 22. Although the lower sealing roller 22 is shown with two layers, that is to say the metal layer of the core and the hard surface layer, it is obvious that this roller 22 can be produced in

  a single hard metallic material.

  The upper and lower sealing rollers

  laughing 21, 22 are supported by their two ends

  to be able to turn, by the side pieces 27, 28.

  The driving force is transmitted from the lower sealing roller 22 to the upper sealing roller 21 by

pinions 31, 32 which mesh.

  The support 25 of the upper roller is made of a metallic material and it is fixed on the casing

  upper 23 so as to face the lateral surface

  outer rale of the upper sealing roller 21.

  A film 33 with a low coefficient of friction, for example a fluorinated resin, is formed by baking on the surface of the support of the upper roller. In addition, a film of fluorine resin 34 or ceramic resin of low friction coefficient is formed by baking on parts of the side pieces 27, 28 facing the axial ends of the rollers.

  upper and lower sealing 21, 22-

  Figure 6 is an enlarged view of an essential part of the vacuum treatment apparatus showing in particular a pressure regulator for regulating the pressure with

  which the side piece 27 is clamped against the ex-

  axial hoppers of the upper and lower sealing rollers 21, 22 and the upper and lower casings 23, 24. The pressure adjustment device comprises different parts, such as an elastic part such as a helical spring 35 disposed in the lateral part 27 and a clamping piece such as a bolt 36 for clamping the side piece 27 against the ends of the upper and lower sealing rollers 21, 22

  and the upper and lower casings 23, 24.

  The pressing force of the side piece 27

  is limited by the interval H between this side piece

  rale 27 and the bolt 26. In the case where the pressure adjustment device is arranged only on one side

  sealing rollers and housings, the side piece

  rale 28 arranged on the other side of the sealing rollers

  tee and housings is directly fixed on the housings

upper and lower 23, 24.

  In the auxiliary vacuum chambers 2, 3

  read in the manner described above, the seal between the upper roller 21 and the lower sealing roller 22 over which the material F to be treated passes,

  is obtained by tightening the rubber layer 29 of the roller

  the upper water 21 against the lower sealing roller

  laughing 22, via the article F to be treated,

  so as to deform the rubber 29 of the upper roller

laughing 21.

  Similarly, the seal between the rollers

  upper and lower seals and the crankcases

  lower and lower 23, 24 is obtained by bringing the upper and lower roller supports 25,

  26 in contact with the rollers 21, 22.

  The seal between the upper and lower sealing rollers 21, 22 and the side pieces 27, 28 is obtained by tightening the side pieces 27, 28 on the upper and lower casings 23, 24 to the

  by means of the pressure adjusting device.

  Thanks to this arrangement, the force of rubbing

  between the upper sealing rollers

  eur and lower as well as the sliding resistance, is reduced to improve not only the longevity of the upper and lower sealing rollers 21, 22 but also to improve the characteristics

  sealing between these two rollers.

  In addition, since the sealing rollers

  upper and lower tee 21, 22 are in contact with the upper and lower supports 25, 26, the friction force exerted between the lower roller 22 and the lower support 26 is reduced and the slip resistance is reduced to obtain a remarkable improvement in the longevity of the lower support 26, without taking into account the improvement in the longevity of the

  upper sealing roller 21 and the roller support

upper water 25.

  In addition, since the pressure force of the side piece 27 is adjusted by the bolt 36 of the pressure adjusting device, by means of the helical spring 35, as a function of a very slight axial movement of the rollers. upper and lower seals 21, 22, these are correctly positioned in the axial direction and longevity

  side pieces 27, 28 is improved, while ob--

  holding a higher sealing effect between the ex-

  axial hoppers of the sealing rollers 21, 22 and

  the side pieces 27, 28 facing them.

  The upper and lower sealing rollers 21, 22 are coupled together by means of the

  pinions 31, 32 fixed to the ends of the shafts which

  carry these rollers. Therefore, any unwanted free rotation or slipping of the upper sealing roller 21 is avoided and the loss of power is reduced, even if the friction resistance between the

  upper sealing roller 21 and the roller support

  upper water 25 or between the sealing roller

  upper 21 and side pieces 27, 28 is increased

  tee. Although in the present embodiment the pressure adjustment device is only provided at one axial end of the sealing roller, this arrangement is not the only possible and a device

  pressure adjustment can be arranged at each end

  axial mity of the sealing rollers.

  Figure 7 illustrates another example of a dis-

  positive intended to ensure sealing in the direction

  axial tion between the sealing roller and the casing;

  the same reference numbers are used to

  sign documents or items similar to those of

Figures 4 and 5.

  The reference numerals 39, 40 designate wipers fixed on the upper and lower casings

  23, 24, and directed in the axial direction of the wheels

  upper and lower sealing waters 21, 22 of ma-

  to be in linear contact with the lateral surfaces

  rales of these rollers. The wipers 39, 40 are made

  made of an elastic material, for example rubber

  nitrile, and their surfaces are coated with a material

  low friction coefficient, for example

  a fluorinated resin formed by baking.

  Thanks to the arrangement of the wipers 39, 40

  in linear contact with part of the lateral surface

  outer rale of each roller 21, 22 over its entire

  axial length, it is possible to obtain a sealing

  effective tee between the sealing roller and the casing over the entire axial length of the roller. In addition,

  since the frictional force between the wheels

  the upper and lower sealing waters 21, 22 and the wipers 39, 40 is remarkably reduced, the durability of the sealing rollers is considerably

increased.

  FIG. 8 represents a modification of the wipers of FIG. 7. These wipers 41, 42 have a cross section having a curved end

  resiliently in contact with each sealing roll

  cheity 21, 22. As shown in Figure 9, the fractions

  tors 41, 42 are arranged under specific orientations

  poured into the auxiliary vacuum chamber 2, on the upstream side of the vacuum treatment chamber 1, and into the auxiliary vacuum chamber 3 on the downstream side of this treatment chamber, so that

  elastic end parts of the wipers

  tifs are tightened against the associated sealing rollers under the effect of the pressure difference between the side connected to the atmosphere and the vacuum side. More

  particularly if we represent the atmospheric pressure

  spherical by A, the pressure in the vacuum side by B, and the intermediate pressure by C, the wipers 41, 42 shown in FIG. 9 are pressed against the upper and lower sealing rollers 21, 22 in the opposite direction to the direction of rotation of these rollers 21, 22 on the side at atmospheric pressure of the

  auxiliary vacuum chamber 2, because the pressure A is

  higher than pressure C. Similarly, the

  wipers 41, 42 are pressed against the sealing rollers

  respective dimensions 21, 22 in the opposite direction to that of rotation of these rollers, also on the vacuum side of the auxiliary vacuum chamber 2, since the pressure C is higher than the pressure B. The same is also true for the chamber with auxiliary vacuum 3, because the wipers in this auxiliary chamber 3 are oriented in the opposite direction to that of the wipers in

the auxiliary room 2-

  It thus appears that a better effect of

  is obtained between the upper sealing rollers

  lower and lower 21, 22 and the associated wipers 41, 42 by the application of a pressure force on these wipers 41, 42 under the effect of the pressure difference between the side with the atmosphere and the side under empty. The continuous vacuum processing device

  according to the invention, carried out in the manner described above

  above works as explained below. When the vacuum pumps 4 and 6 are started, the vacuum treatment chamber 1 and the auxiliary vacuum chambers 2, 3 are emptied to the desired vacuum level. In other words, in the bedroom

  vacuum treatment 1 a higher vacuum, i.e.

  say a lower absolute pressure is established than in the auxiliary vacuum chambers 2, 3. Next, the cathode drum driving devices 16, upper and lower sealing rollers 21, 22 of the auxiliary vacuum chambers 2 , 3 and the reel

  9 are started by means of the motor 10 and by the

  term of the respective transmissions 12, 13, 14 and 15. Under these conditions, article F to be treated, by

  example a vinyl chloride film is conti-

  nualy driven from the unwinder 8, from the side to the atmos-

  sphere, in the vacuum treatment chamber 1, in

  passing in the interval between the rollers at the sealing

  upper and lower tee 21, 22 of the auxiliary chamber

  re 2 In the vacuum treatment chamber, a

  plasma is carried out on the article F to be treated

  by means of a plasma discharge produced between the

  thode 16 and anode 17. The article F thus treated by the plasma is then entrained outside the chamber

  vacuum treatment 1 and it is wound on the

  roller 9, on the atmosphere side, passing through the interior

  between the upper sealing rollers and

  lower 21, 22 of the auxiliary chamber 3 under vacuum.

  Thus, article F is treated with plasma in a very short period of stay in the

  vacuum treatment 1, so that the evacuation inde

  sirable volatile content, for example a plasticizer,

  in vinyl chloride resin is avoided assu-

  thus transforming good properties of the sur-

opposite of item F.

  The table below shows examples of the ni-

  vacuum calves measured in vacuum chamber 1 and in auxiliary vacuum chambers a, b, c in Figure 1,

  in the case of continuous advance of article F treated,

  confirming the sealing effects in the processing device

  continuously under vacuum according to the invention

Board

  Elapsed time 5 min. 10 minutes. 15 min. 20 min. measuring point auxiliary chamber 20.0 10.5 10.0 10.0 bond (a) Torr Torr Torr Torr auxiliary chamber 700x10-3 140xlo3 127xlO3 125xlO-3 bond (b) auxiliary chamber 500x103 130x103 127xlO3 125x10 3

liar (c) - 3-

  150x103 chamber 25xlO3 23 x 10 22 x 10 treatment It appears from the table above that the vacuum levels in the vacuum treatment chamber 1 and the

  respective 2 auxiliary vacuum chambers increase pro-

  gressively, that is to say that the pressure levels

  absolute decreases as time goes by.

  It also appears that a pressure gradient suitable for reducing the absolute value, step by step towards the treatment chamber 1, is established in the successive auxiliary vacuum chambers (a), (b), and (c). This clearly shows that the desired sealing effect is obtained in the continuous vacuum processing apparatus according to

the invention.

  It thus appears next to the description

  made above that the invention provides an apparatus for

  continuous air-air type vacuum treatment, allows

  both to get a tight sealing effect in them

  auxiliary vacuum chambers, while allowing

  nir a good characteristic of transformation at 2487g95 during the surface treatment of the plastics treated, as well as a remarkable improvement of the

  productivity. These effects are particularly remarkable-

  ment when the article to be treated is a flexible article, for example a film of vinyl chloride resin.

Claims (17)

  1 - Continuous vacuum treatment device,   characterized in that it comprises a milking chamber   vacuum (1), and at least one vacuum chamber   bond (2, 3) disposed on each of the upstream and downstream sides of said vacuum processing chamber, said auxiliary vacuum chamber comprising two sealing rollers (21, 22) in mutual contact, a device ensuring sealing between said rollers and them   casings (23) along the axial lengths of said wheels   water, and a device ensuring the sealing between the   two surfaces at the end of said sealing rollers tee and housings.   2 - Apparatus according to claim 1, character-   rised in that a first (22) of said sealing rollers   is made entirely of metal while the other (21) has a metal core and an elastic piece   (29) on the surface of said metallic core.   3 - Apparatus according to claim 2, character-   laughed in that said first (22) of said rollers   sealing is made of iron or carbon steel.   4 - Apparatus according to claim 2, character-   laughed in that a hard layer is formed on said pre-   mier (22) of said sealing rollers.   - Apparatus according to claim 2, character-   laughed in that the other (21) of said sealing rollers tee is made of rubber.   6 - Apparatus according to claim 1, character-   laughed in that said sealing device between said sealing rollers (21, 22) and said housings (23) comprises roller supports (25, 26) arranged to be in contact with said sealing rollers.   7 - Apparatus according to claim 6, character-   laughed in that said roller holder (25, 26) is   consisting of an elastic piece coated with a film 2487 96   cule (33) of a material with a low coefficient of friction is lying.   8 - Apparatus according to claim 7, character-   in that the film (33) of material with a low coefficient of friction is a fluorinated resin.   9 - Apparatus according to claim 1, character-   laughed in that said device sealing between said sealing rollers (21, 22) and said housings (23) along the axial lengths of said   rollers has wipers (39, 40, 41, 42) available   laid in the axial direction of said sealing rollers   cheeness and in linear contact with parts of these sealing rollers.   - Apparatus according to claim 9, charac-   characterized in that said wipers (41, 42) are available   seated so as to be tightened against the sealing rollers   respective pressure due to the pressure difference between the atmosphere side and the vacuum side,   11 - Apparatus according to claim 9, charac-   characterized in that said wipers (39, 40, 41, 42) consist of elastic parts coated with   films of a material with a low coefficient of friction seriously.   12 - Apparatus according to claim 11, charac-   terized in that said film of a material with low   The coefficient of friction is made of a fluorinated resin.   13 - Apparatus according to claim 1, character-   laughed in that said device sealing between the two end surfaces of said rollers   sealing (21, 22) and said casings (23) comprise   you. side pieces (27, 28) in contact with the two ends of said sealing rollers and at least one pressure adjusting device (35, 36) intended to clamp one of said side pieces against the associated end surfaces of said sealing rollers.   14 - Apparatus according to claim 13, ca-   characterized in that said sealing part (27, 28) is coated, in its part in contact with said   sealing rolls, of a film (34) of a material   low friction coefficient.   - Apparatus according to claim 14, charac-   terized in that said film (34) of a material   low coefficient of friction is made in a re- fluorine.   16 - Apparatus according to claim 13, charac-   terized in that said sealing rollers (21, 22) are positioned axially by means of said parts side (22, 28).   17 - Apparatus according to claim 13, charac-   terized in that said pressure adjusting device   comprises an elastic piece (35) and a clamping piece rage (36).   18 - Apparatus according to claim 17, charac-   terized in that said elastic piece (35) consists of a spring.   19 - Apparatus according to claim 13, characterized in that it comprises a single pressure adjusting device (35, 36) for clamping one (27) of said side pieces on the end surfaces   associated with said sealing rollers.   - Apparatus according to claim 13, charac-   characterized in that it includes pressure adjustment devices (35, 36) intended to clamp the two parts   lateral (27, 28) on the respective end surfaces   tives of said sealing rollers.   21 - Apparatus according to claim 1, charac-   characterized in that the two sealing rollers (21, 22)   are driven by a source of motive force (10).