GB2348212A

GB2348212A - Treatment installation for flat substrates

Info

Publication number: GB2348212A
Application number: GB0006605A
Authority: GB
Inventors: Karl-Heinrich Wenk
Original assignee: Leybold Systems GmbH
Current assignee: Leybold Systems GmbH
Priority date: 1999-03-20
Filing date: 2000-03-17
Publication date: 2000-09-27
Anticipated expiration: 2020-03-17
Also published as: DE19912707A1; DE19912707B4; IT1316806B1; ITMI20000564A0; GB2348212B; GB0006605D0; ITMI20000564A1

Abstract

Moving through a casing (1) are two circulating webs, a section of each of which is in contact with the other in the area of an opening (9) on the entry side and an opening (10) on the exit side. Between these sections of the webs (13, 14), which are in contact with each other, a substrate (6) is taken into and out of a chamber (1). Within the chamber (1), deflecting rollers (21, 22, 23, 24) ensure that the web (14) is separated from the substrate (6), so that the substrate (6) can be treated, more particularly vapour-deposited, by a treatment unit (5). The sections (13, 14) are two strips which move substantially syndronously with regard to each other from the exterior of the chamber into its interior. The substrate is positioned between the strips (13, 14), with the side of each strip that faces away from the substrate (6) being in contact with a casing surface (15, 16) so as to form a seal. Both strips (13, 14) may be continuous bands arranged to circulate about deflecting rollers (17 -24).

Description

2348212 Treatment Installation for Flat Substrates The present invention

relates to a treatment installation for flat substrates, more particularly films, the installation having a chamber with at least one opening for transporting the substrate between the exterior of the chamber and its interior.

Treatment installations of the above type are well known and are used for many different purposes. An important application is the coating of films or paper strips with a thin metal layer through condensing a metal vapour onto the substrate in a vacuum chamber. Also widespread is the treatment of substrates with fluorine to change their surface properties.

As the substrate is most commonly a film made of plastic or paper, the substrate should not touch the chamber whilst being transported into or out of the chamber, as otherwise the substrate could be scratched. For this reason openings to and/or from such chambers are often seen with relatively large gaps. However, this has the disadvantage that the chamber's vacuum pumps have to be undesirably large so that, despite the losses resulting from the size of the gap, a sufficiently high vacuum can be maintained. If there is a gas in the chamber which must not escape, the substrate can be brought into the chamber and taken out of it again between two rollers, in a similar manner to a washing mangle. However, in practice with such rollers only an incomplete vacuum can be achieved because only a line of contact is formed between the rollers and the substrate and also because the lateral sealing of the rollers presents difficulties.

The present invention is based on the problem of designing a treatment installation of the type described above in such a way that the chamber opening for the substrate is sealed as reliably as possible, without fear of scratching the substrate.

This problem is solved in accordance with the present invention in that the chamber opening is formed of two strips that are moved synchronously with each other from outside the chamber into its interior and are positioned such that the substrate squeezes between the strips, the side of each of the strips that faces away from the substrate forming a tight seal against the casing surface.

In such a treatment installation there is no relative movement between the substrate and the components in contact with the substrate during the transportation of the substrate between the exterior and the interior of the chamber. Rather, the substrate squeezes between the two strips and moves synchronously with the strips into the chamber or out of it. In this way scratching of the substrate is avoided. Relative movement only arises between the opposite side of each strip and the casing surface. However, this does not necessarily lead to undesirably high wear or high friction losses, as the material for the strips and the casing surface can be freely chosen, and it is possible, for example, to select a wearresistant material for the strips and to provide the casing surfaces with a light coating that allows slight sliding. With such measures it is possible to prevent abrasion, that might otherwise result in contaminants entering the chamber.

In the direction of movement of the strips, the casing surfaces can extend over a relatively large surface area of the strips, producing particularly good sealing, if, in accordance with another advantageous embodiment of the invention, the casing surfaces are provided on two chamber flanges positioned a small distance from each other and projecting outwardly with regard to the chamber. In one such embodiment, good sealing can be achieved even without the casing surfaces and the strips touching, if the flanges are sufficiently long and provide a labyrinth effect.

To transport the substrate, the two strips can each be unrolled from one roll and rolled onto another one. However, the chamber can be very simply designed if, in accordance with a further embodiment of the present invention, the two strips are each continuous bands and are arranged to circulate about deflecting rollers.

For the continuous treatment of webs of film, the chamber is particularly advantageously designed if it has an opening on two opposite sides, if the strips each travel a path with one section located externally to the chamber and with a second section extending from one opening to the other opposite opening through the entire chamber, and if inside the chamber a strip is re-directed by deflecting rollers, away from the web or substrate, around the outside of the treatment device and by further deflecting rollers back into contact with the substrate. In such a chamber a film or paper web can run in from one side and out at the other. Therefore it is not necessary for the supply roll and winding roll for the film or paper web to be arranged within an evacuated winding chamber.

The treatment installation is designed in a particularly simple manner if two deflecting rollers are arranged adjacent each side of the chamber and the strip is moved from a first opening via a deflecting roller to the side of the treatment unit and then back to the side of the chamber having the first opening and from there to two opposing deflecting rollers having a similar orientation to a second opening.

When coating films through vapour-deposition, the metal is applied to the film through condensation. The film must therefore be at a considerably lower temperature than the other areas of the chamber and usually has to be cooled. Good cooling of the film is achieved at low cost if at least the strip on the side of the film, which is facing away from the treatment unit, is made of metal, because such a metal strip is able to quickly remove heat reaching the film to be coated.

The treatment unit within the chamber is easily accessible for cleaning or monitoring purposes if the chamber has a cover which can be removed from a lower section of the casing that houses the treatment unit and this cover has one deflecting roller on each side of the chamber for moving the strip.

The opening and closing of the cover is particularly easily carried out if, in accordance with a further embodiment of the invention, the cover is arranged in a pivoting manner about an axis running co-axially with one deflecting roller.

The present invention permits various forms of embodiment. To explain its basic principle in more detail, one embodiment is shown in the accompanying drawings, by way of example, and is described below. In the drawings:

Fig. I is a longitudinal section through a treatment installation in accordance with the present invention; Fig. 2 is a cross-section through the treatment installation along line H-II in fig. 1; and Fig. 3 is a section through a sealing area of the treatment installation.

4- The treatment installation shown in fig. I has a chamber I which has a trough-shaped lower casing section 2 and a cover 3, which can be moved from the closed position, shown by continuous lines, about an axis 4 into an open position, shown in dot-dashed line. In the lower casing section 2 there is a treatment unit 5, which in this embodiment is an evaporator. The treatment unit 5 is for coating a web-shaped substrate 6, which is continuously unrolled from a supply roll 7, moved through the chamber I above the treatment unit 5 and thereafter emerges from the chamber I onto a winding roll 8.

Openings 9, 10 are provided for entry into the chamber I and emergence from the chamber 1 respectively. These two openings are each formed of two flanges 11, 12 lying parallel to each other but separated a short distance from one another, between which the substrate 6 is guided. This substrate 6 does not run directly between the flanges 11, 12, its surfaces are covered, on top and underneath, by sheet steel strips or webs 13, 14 which move in a circulating manner synchronously with the substrate. In the area of the flanges 11, 12, each one of the strips 13, 14 contacts a casing surface 15, 16 with their side that faces away from the substrate 6 and are in contact with each other.

To guide the two circulating strips 13, 14 there are, on each side of the chamber 1, two deflecting rollers 17,18 and 19, 20 arranged in parallel to each other, between which the substrate 6 and each of the strips 13, 14 are moved. The upper strip 13 moves in a straight line from deflecting roller 17 to deflecting roller 19, whereby one section of the path of the strip 13 passes underneath the cover 3 and the other section above the cover 3. The axis 4 of the cover 3 also forms the axis for the deflecting roller 17. The cover 3 can therefore be opened without changing the tension of the strip 13.

Inside the chamber 1, strip 14 is first diverted away from the substrate 6 by deflecting roller 21 to the side of the treatment unit and is then guided via a further deflecting roller 22 to the side of the chamber having opening 9. The strip then moves underneath the treatment unit 5 to two deflecting rollers 23, 24 before it reaches deflecting roller 20 via the opening 10.

I Fig. 2 shows the lower casing section 2 with the flange 12 and lying on top of it flange I I of the cover 3. This cover has the deflecting roller 17 at one end. Within the lower casing section 2, the deflecting roller 22 can be seen. Further to fig. 1, at one side of the lower casing section 2, a vacuum pump 25 can be seen which serves to evacuate the chamber 1. The strips 13, 14 and the substrate 6 are moved between the flanges 11, 12.

The detailed drawing in accordance with fig. 3 shows the strips 13, 14 and the substrate 6 squeezed between them. A seal 26 is also shown, by means of which the substrate 6 and the strips 13, 14 are sealed at the transverse sides.

Claims

1. A treatment installation for flat substrates, suitable for vapourdeposition on films, comprising a chamber with at least one opening for transporting a substrate between the exterior of the chamber and its interior, characterised in that the opening (9, 10) is formed of two strips (13, 14) which move substantially synchronously with regard to each other from the exterior of the chamber (1) into its interior, and in that the substrate (6) is positioned between the strips (13, 14), with the side of each strip that faces away from the substrate (6) being in contact with a casing surface (15, 16) so as to form a seal.

2. A treatment installation in accordance with claim 1, characterised in that casing surfaces (15, 16) are provided on two flanges (11, 12) of the casing (1) which are located a small distance apart from each other and project outwards with regard to the chamber (1).

3. A treatment installation in accordance with claims I or 2, characerised in that both strips (13, 14) are continuous bands arranged to circulate about deflecting rollers (17-24).

4. A treatment installation in accordance with at least one of the preceding claims, characterised in that opposed openings (9, 10), are provided, and in that the strips (13, 14) move in a path with one section outside the chamber (1) and with a second section extending from one opening (9) to the other opposite opening (10) through the chamber (1), the strip (14) being guided within the chamber (1) by deflecting rollers (21, 22) away from the substrate (6) around the outside of a treatment device (5) and back against the substrate (6) by further deflecting rollers (23, 24).

5. A treatment installation in accordance with at least one of the preceding claims, characterised in that on each side of the chamber (1) two deflecting rollers (21, 22; 23, 24) are provided and strip (14) is guided from one opening (9) via a deflecting roller (21) to the side of the treatment device (5) and then back to the side of the chamber having opening (9) via the other deflecting roller (22) and from there to the two opposing deflecting rollers (23, 24).

6. A treatment installation in accordance with at least one of the preceding claims, characterised in that at least the strip (13) on the side of the substrate (6), which faces away from the treatment dev ice (5) is made of metal.

7. A treatment installation in accordance with at least one of the preceding claims, characterised in that the chamber (1) has a cover (3) which can be removed from a lower casing section (2) which houses the treatment device (5), the cover (3) having one deflecting roller (17, 19) on each end of the chamber (1) for guiding the strip (13).

8. A treatment installation in accordance with claim 7, characterised in that the cover (3) is arranged in a pivoting manner about an axis (4) running co-axially with respect to the deflecting roller (17).

9. A treatment installation substantially as hereinbefore described with reference to and as shown in the accompanying drawings.