GB2109293A

GB2109293A - Corrugating apparatus

Info

Publication number: GB2109293A
Application number: GB08229395A
Authority: GB
Inventors: Bo Kennet Lindberg
Original assignee: ISOFLEX AB
Current assignee: ISOFLEX AB
Priority date: 1981-10-29
Filing date: 1982-10-14
Publication date: 1983-06-02
Also published as: DE3238181A1; FR2515575A1; SE425149B; JPS58132323A

Abstract

Apparatus for continuous corrugation of a web material such as a plastic, paper or metal foil in the longitudinal direction consists of a pair of cooperating corrugating rolls (7) which are provided with profiling rings (14) which are guided laterally but which are free to rotate around the rolls (7) for lowering the stress upon the corrugated material and for increasing the quality of the final corrugated material. The rings are located in grooves (15) in the roll surface, the grooves being lined with a low friction layer eg Teflon RTM, and the tips of the rings about rubber inserts (18) in the opposite roll. In an illustrated embodiment (see Figure 1), outer webs from reels (2 and 4) are transversely corrugated by conventional rollers (2.), 2.8 and 4.7, 4.8), and an inner web from reel (3) is longitudinally corrugated by pairs of rolls (7) of the above construction. The sheets so formed have adhesive applied to them by rolls (10) and one laminated by apparatus (11,12). <IMAGE>

Description

SPECIFICATION Corrugating apparatus The invention relates to the corrugating of web material and more particularly to an apparatus for continuously corrugating thin materials such as plastic foil or metal foil in rolls, whereby the corrugating is performed in the longitudinal direction of the web material and thus also in the feeding direction of the web material.

By the corrugating of cardboard or paper in order to manufacture corrugated cardboard or by the corrugating of thin foils for different purposes the corrugating has usually been performed at an angle, usually 90 , to the longitudinal or feeding direction of the material, and regarding the continuous corrugating of web material the corrugating has solely been performed in the described way. Corrugating at a straight angle relative to the feeding direction of the web material has in most cases, such as by the manufacturing of corrugated cardboard, been quite satisfactory and relatively simple to performe since the dimensional change of the material due to the corrugations in that case solely results in that the corrugated material will be somewhat shorter than the initial material.When it is desired to manufacture sheets consisting of several layers of the corrugated material, e.g. for use as insulating material or as material in certain kinds of heat exchangers, it is however in many cases not suitable to use web material that is only corrugated at a straight angle in relation to the longitudinal direction, since in such cases it is preferred that the corrugations of the adjacent layers run at an angle of usually 900 in relation to each other and thus the subsequent layers would have to be positioned in such a way that they cross each other.Due to this fact the dimensions of the finished sheets are restricted by the width of the web materials and this is especially inconvenient i.e. in connection with vindow insulations where it is not desired to have joints or by insulations for non-planar walls where the sheets will have to be bent in order to follow the wall surfaces.

Sheets of the above mentioned kind have also been produced by manufacturing the different layers of the sheets one by one. Hereby pre-cut foils or the like have been positioned on a table provided with corrugations and a roll provided with corresponding grooves has been used to provide permanent corrugations in the foils. Subsequently the foils have been positioned on top of each other and have been bonded or welded together. Such a method does not permit a continuous manufacturing of such sheets and will thus be very time consuming and inefficient and as a result of this it will be financially unsatisfactory.

Finally efforts have also been made to corrugate the web material in such a way that the corrugations run at an angle different from 900 and usually at an angle of 45 , in relation to the feeding direction of the web material. By the production of sheets of the kind described above, which consist of two or more layers of corrugated foils where the corrugation of adjacent layers run at an angle in relation to each other it is possible either to corrugate each layer with its corrugations running at the same angle in relation to the feeding direction of the web material, whereafter every other layer is turned in such a way that it runs upside down in such a way that the corrugations of the adjacent layers run at an angle in relation to each other, orto initially corrugate the adjacent layers at different angles in such a way that the corrugations thereof run at an angle in relation to each other from the start. One disadvantage with this procedure is that for each layer it is necessary to employ one such apparatus for corrugating at an angle in relation to the feeding direction of the web material and since each such apparatus is relatively complicated and expensive in relation to conventional corrugating rolls the investments costs will be comparatively high. Furthermore it is very difficult to obtain a satisfactory corrugation by means of such an apparatus and this is partly due to the fact that the web material tends to wander or become distorted.

In order to be able to produce corrugations of a satisfactory quality it is necessary to exerize extreme accuracy by the manufacturing and adjustment of such apparatuses, which makes them even more expensive.

The object of the present invention is thus to provide an effective and comparatively cheap apparatus for a continuous corrugation of web material in the feedin direction of the web material, by means of which apparatus the above mentioned disadvantages may be overcome.

These objections are achieved by means of an apparatus of the kind indicated in the enclosed claims. From the claims the special characteristics of the invention are also clear.

The invention is described more closely below in connection with the enclosed drawings on which: Figure 1 is a schematic side view of an apparatus in accordance with the invention included in a set-up for the manufacturing of three-layer insulating sheets, whereby only certain parts of the manufacturing line is shown, Figure 2 is a view of the apparatus according to the invention seen in the feeding direction, Figure 3 is a cross-sectional view through the arrangement along the line 3-3 in Figure 2, and Figure 4 schematically illustrates an enlarged portion of the apparatus according to Figure 3 in a cross-sectional view along the line 4-4 in Figure 3.

As is clear from Figure 1 the invention is herein described and illustrated included in a manufacturing line for the manufacturing of three-layer insulating sheets, but it should be obvious that the invention in no way is limited to be used in this environment but that it also may be used in itself or in combination with other set-ups.

In accordance with Figure 1 the corrugating apparatus 1 of the invention is included in a plant for the manufacturing of three-layer insulating sheets, in which plant upper, middle and lower supply rolls 2,3 and 4 respectively for the three layers of web material are provided in a frame 5.From the upper and lower supply rolls 2 and 4 respectively the web material is guided over guide rolls 2.1,2.2,2.3,2.4 and 4.1,4.2,4.3,4.4 respectively which are likewise mounted in the frame and over guide rolls 2.5,2.6 and 4.5,4.6 respectively which are mounted in a second frame 6 to pairs of conventional corrugating rolls 2.7,2.8 and 4.7,4.8 respectively which are likewise mounted in the frame 6 and which are provided with profiling means which are extended in the longitudinal direction of the rolls for performing the corrugation of the respective web material at a straight angle in relation to the feeding direction thereof.From the middle supply roll 3 the web material is guided over guide rolls 3.1,3.2,3.3,3.4, 3.5 and 3.6 which are mounted in the frame 5, and into the corrugating apparatus 1 according to the invention, which will be described more closely below, and which basicly consists of a pair of corrugating rolls 7 which are mounted in the frame 6 and which are provided with profiling means which are exteded parallel to each other around the periphery of the rolls for corrugating the web material in its feeding direction, which will be described more closely below. From the corrugating rolls 2.7, 2.8,7 and 4.7,4.8 at least two of the webs are guided through adhesive application means 10 and subsequently all three webs are brought together, over guide rolls 11, and into an agglutination section 12.Finally the material is brought to conventional stations for drying, cutting and so forth (not shown).

The basic problem existing in connection with corrugating a web material in its feeding direction lies in the fact that if a corrugating apparatus is used which is constructed in accordance with the principles laid down for the above described corrugation at a straight angle to the feeding direction of the material, i.e. comprising rolls having parallel fixed profiling rings extending around the periphery of the rolls, the material would be exposed to a greater amount of stress and most likely it would be torn to rags by the corrugating means. In all events it would not be possible to achive any uniform, high-quality corrugation in such an apparatus since the peripheral speed at the tip of the profiling means of the rolls would be higher than the peripheral speed at the bottom of these profiling means, which in turn leads to stress in the material.

With reference to Figures 1 and 2 this problem is in accordance with the invention overcome by means of a corrugating apparatus 1 comprising two corrugating rolls 7 which are journalled in the frame 6 and between which the material 9 is corrugated. Preferably one of the rolls, in the illustrated embodiment the lower corrugating roll 7, is driven by an electric motor 13.

In Figure 4 the particular construction of the corrugating rolls 7 is illustrated and with reference thereto it is thus clear that the profiling means of the rolls are provided in the shape of rings 14 which are positioned in recesses or grooves 15 in such a way that they are guided laterally but are free to slidingly rotate around the periphery of the rolls. In order to further decrease the friction between the rings 14 and the bottom of the grooves 15 the grooves and possibly also the rings may be provided with a teflon RTM layer 16. In their outer ends, which face the opposite roll, the rings 14 are shaped in a way suitable for the corrugation, i.e. as cogs or teeth.

Between each of the grooves 15 recieving the rings 14 a channel 17 is furthermore provided in the surface of the roll, and into this channel a rubber ring 18 is inserted which will thus cooperate with the tip of a ring 14 in the opposite roll. The purpose of the rubber rings 18 is to facilitate the feeding of the web material 9 since the feeding thereof is also established by means of the corrugating rolls 7. Apart from promoting the feeding of the material the rubber inserts 18 do simultaneously also prevent the material from being damaged when it is engaged between the rolls. It should also be pointed out that in Figure 4 the construction of the corrugating rolls is, for purposes of clarity, only illustrated very schematically and as an example of this the distance between the rings is in reality substantially less.

From Figures 1, 2 and 3 it is also clear that the apparatus is provided with two rubber cylinders 19 of which each contacts one of the corrugating rolls 7 and the rubber cylinders contact the profiling rings 14 of the rolls along the entire length thereof.

Although teflon RTM layers are provided between the rings 14 and the grooves 15 it is not possible to guarantee that the friction between the different rings and grooves would be exactly the same this is due to manufacturing tolerances and the like and the purpose of the rubber cylinders 19 is thus to contact all ofthe rings 14 with a light pressure in order to guarantee that the rings 14 slide equally free in the grooves 15.

Suitable heating means 8 are furthermore provided directly adjacent the corrugating rolls 7 and in front of these, and by a preferred embodiment said heating means consist of infra-red heating means which are provided at a distance above the web material and which are directed towards the corrugating roils 7 in such a way that they heatthe rolls to a temperature which is suitable for the corrugation.

When the profiling means of the rolls have given the material its final shape the material is cooled through its contact with the ambient air and as a result of this the corrugations are fixed in their final shape.

Constructed as described above the corrugating rolls 7 will thus bring about that when the heated material is fed in between the heated rolls the difference in peripheral speed between the tip and the bottom of the profiling means, which difference is harmful to the corrugation, is compensated due to the fact that the profiling rings 14 are permitted to slide on the roll and may adjust themselves in such a way that the stress upon the material will not be too high and thereby it is possible to avoid tearing of the material or uneven feeding thereof. Experiments has shown that such an arrangement provides corrugations of very high quality and thus the objects set up in the introduction have been achieved by means of the apparatus according to the invention.

Although the invention has been described above with reference to a particular embodiment thereof it should be obvious to a man skilled in the artthat several modifications and alterations may be made thereto without departing from the scope of the invention such as this is stated in the enclosed

Claims

patent claims. CLAIMS

1. Apparatus for continuous corrugation of a web material, such as plastic, paper or metal foil, in the longitudinal direction of the material, by means of a pair of cooperating corrugating rolls, characterized by the fact that the corrugating rolls (7) are provided with parallel profiling means which are extended around the periphery thereof and by the fact that these profiling means consist of rings (14) which are guided laterally and are free to rotate upon the rolls.

2. Apparatus according to claim 1 characterized bythefactthatthe rings (14) areslidably mounted in grooves (15) in the rolls and by the fact that the rings and/or the grooves (15) are provided with a teflon RTM layer (16) which decreases the friction.

3. Apparatus according to claim 1 or 2 characterized by the fact that the web material is fed by means of the corrugating rolls (7) of which at least one for this purpose is driven by means of an electric motor (13).

4. Apparatus according to claim 3 characterized by the fact that the corrugating rolls (7) between their profiling rings (14) are provided with rubber inserts (18) for promoting the feeding.

5. Apparatus according to any of the preceding claims, characterized by the fact that the profiling rings (14) of the corrugating rolls (7) at their ends cooperating with the opposite rolls are shaped as teeth.

6. Apparatus according to any of the preceding claims, characterized by a pair of rubber cylinders (19) of which each contacts one of the corrugating rolls (7) along the entire length thereof providing the rings (14) with the same ability to rotate freely around the rolls (7).

7. Corrugated material produced by an apparatus according to any preceding claim.

8. Apparatus for continuously corrugating webbed material constructed and arranged substantially as hereinbefore described with reference to and as shown in the accompanying drawings.