JPH04350055A - Carrying device - Google Patents

Abstract

PURPOSE:To obtain stable travelling without giving any limitations to the blowout air volume distribution by providing a different curvature of the side part of air blowout boxes in the advancing direction from that of the central part of air blowout boxes of a contact-free carrying device and the air blowout boxes are arranged alternately with the web surface therebetween to support a continuously travelling web. CONSTITUTION:There are provided air blowout slits or a number of holes on the surface of air blowout boxes 1, and a web 4 is carried in the space where the air blowout boxes 1 are arranged alternatively. The widthwise curvature on the side part of the air blowout boxes 1 is different from that on the central part, preventing contact of the web on the side part. The materials used for the web 4 are of flexible film type, and films of various kinds of plastics, resin-coated paper, metal web of aluminum plate or the like are included. The device is also used for carriage or drying of various kinds of coated films, e.g. silver halogenide photo-sensitive material.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stable running conveyance device, and more particularly to non-contact conveyance.

0002

BACKGROUND OF THE INVENTION The use of rollers for conveying or drying coated materials such as silver halide photographic light-sensitive materials and magnetic tapes that are coated on both sides or where surface scratches are extremely difficult to cause may cause scratches. It is preferable to avoid this as it may cause For this reason, a technique is known in which the web is conveyed by air flow without contact. That is, this is a device in which air blowing boxes are arranged alternately on both sides of the web, the web is floated by air flow, and the web is conveyed continuously in a non-contact manner.

In order to run the web stably in such an apparatus, it is necessary to equalize the amount of air blown out in the width direction and to equalize the amount of floating.

However, when considering the relationship between the amount of air blown from the air blowing box and the web in the width direction of the web, air escapes from the side portions compared to the center portion, so that the blowing pressure of air against the web decreases.

[0005] For this reason, there is a risk that the side portion of the web may come into contact with the balloon box. In particular, when coating is carried out using a web as a support and then transported or transported including drying, this tendency is exacerbated because there are uncoated areas on the sides, and contact between the coated layer and the balloon box can cause quality deterioration. Sometimes it brings. Such a local decrease in the floating amount of the web at the side portions is countered by a local increase in the air volume, but this results in problems such as increased vibration and increased running costs.

[0006]

OBJECTS OF THE INVENTION In order to solve the above-mentioned problems, an object of the present invention is to provide a non-contact conveying device that can provide stable running performance without restricting the distribution of the blown air volume.

[0007]

[Structure of the Invention] The above-mentioned object of the present invention is to support a continuously running web by blowing out air from a blow-off port, and to provide a non-contact conveyor in which air blow-off boxes are installed alternately across the web surface. This is achieved by a conveying device characterized in that the curvature of the air blowing box in the web traveling direction is different between the center and the sides.

The present invention will be explained in detail below.

[0009] In the present invention, the web refers to a flexible elongated support.

[0010] The shape of the air outlet in the present invention is as follows:
It may be a slit type, a perforated plate, or a porous plate, and can be appropriately selected depending on the shape and properties of the web to be conveyed.

The conveying device of the present invention can also be used as a drying device.

FIG. 1(a) is an example of a perspective view showing the arrangement of the air blowing box 1 of the present invention. In the figure, the web is conveyed between air blowing boxes 1 having air blowing slits or a large number of holes on their surfaces that are arranged alternately.

FIG. 1(b) shows these air blowing boxes 1.
FIG.

FIG. 2(a) is a sectional view showing the state of the web at the web width when the web 4 having the coating layer 3 is transported using a conventional air blowing box. In this case, since the floating amount of the side portion is small, the side of the web including the coating layer hangs down and is in contact with the air blowing box.

On the other hand, FIG. 2(b) is a sectional view of the air blowing box according to the present invention. The side parts of the drawstring have a different curvature from the center part, and the sides are tapered to prevent contact between the web and the side parts. In the same figure, Rs
is the radius of curvature of the side portion, and lt represents the position where the radius of curvature starts changing.

The material of the web used in the present invention is not particularly limited, and any flexible thin film material may be used. Examples include various plastic films, resin-coated paper, and metal webs such as aluminum plates. Further, they can be applied to various coated films using these as supports, such as conveying or drying silver halide photographic materials.

The shape of the air blowing box may be any shape as long as it can statically hold the web without contact, and it may have a curvature R in the web traveling direction or be flat. Further, the air blowing plate may be a porous plate with several holes or a plate having slit-like openings in the width direction, or may be a porous plate with the same level of pressure loss.

[0018]

[Example] The effects of the present invention will be illustrated below with reference to Examples.

Example 1 In the conventional non-contact conveying device shown in FIG. 2(a), the radius of curvature: 1500 mm, the aperture ratio of the air outlet: 1.5%, the length of the web in the traveling direction: 700 m, and the air When a web with a thickness of 75 μm, a width of 2.5 m, and a material of polyethylene terephthalate was conveyed under the following conditions: internal pressure of the balloon box: 50 mm Aq, tension: 5 Kg/m, the floating amount at the center was 10 mm, but the floating amount on both sides was 10 mm. The floating amount decreased to 5 mm, and even larger vibrations occurred, causing the web and the air blowing box to come into contact, making transport impossible.

Example 2 When an air blowing box as shown in Fig. 2(b) with the following three types of tapered radii of curvature was used, the vibration levels were as shown below and all were stable. Transport is now possible.

Type lt Rs
Vibration level 1 100
1300 ◎2
200 1400
○3 300 1400
○4 None
2000 ×lt: Position where the radius of curvature starts changing (mm) Rs: Radius of curvature at the side (mm) Evaluation of vibration level is as follows: ◎: Almost no vibration
○: There is vibration, but there is no practical problem ×: There is considerable vibration, and it is not practical Example 3 Width: 1 m, Thickness: 100 μm, Material: Polyethylene terephthalate, 150 μm in the center 95 cm of the web.
A web coated with a photosensitive material to a thickness of When the web was transported in a non-contact transport device using an air blowing box, the floating amount of the lateral side of the web decreased, and the web and the air blowing box came into contact.

Example 4 In Example 3, as shown in FIG. 2(b), the radius of curvature Rs at the side part of the air blowing box on the application surface side was 95.
0mm, the position lt where the radius of curvature starts changing is 50mm
When using an air blowing box, it was possible to transport the material stably without contact. Furthermore, in contrast to the above, the air blowing box has a radius of curvature Rs of 1030 mm at the side part of the air blowing box on the non-applied side as shown in FIG. 2(c), and a position lt at which the radius of curvature starts changing is 50 mm. Figure 2(d)
When used in the arrangement shown in Figure 1, vibration was extremely reduced and stable conveyance became possible.

[0023]

[Effects of the Invention] According to the present invention, it was possible to provide a non-contact conveying device that can provide stable running performance without restricting the distribution of the blown air volume.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view showing the arrangement of the air blowing box. FIG. 2B is a sectional view showing the state of the web being conveyed without contact by the air blown from the air blowing box. FIG. 2(a) is a sectional view showing a state in which a web having a coating layer is transported by a conventional air blowing box. Figure 2 (
b) is a sectional view showing the shape of the air blowing box according to the present invention. FIG. 2(c) is a sectional view showing the shape of the air blowing box used for the non-coated surface. FIG. 2(d) is a sectional view showing an example of the arrangement of air blowing boxes of the present invention.

[Explanation of symbols]

1, 2: Air blowing box 3: Coating layer
4: Web lt: Position where the radius of curvature starts changing Rs: Radius of curvature at the side R: Radius of curvature of the air blowing surface

Claims (1)

[Claims] Claim 1: In a non-contact conveying device in which a continuously running web is supported by blowing air out of a blow-off port, and air blow-off boxes are installed alternately across the web surface, the air blow-off boxes are A conveying device characterized in that the curvature in the web traveling direction is different between the center portion and the side portions.