WO2018142026A1

WO2018142026A1 - Insulated metal panel

Info

Publication number: WO2018142026A1
Application number: PCT/FI2018/050072
Authority: WO
Inventors: Marika LISKI
Original assignee: Foodmail Finland Oy
Priority date: 2017-02-01
Filing date: 2018-02-01
Publication date: 2018-08-09
Also published as: FI20175088A7; CA3050991A1; FI20175088L

Abstract

The invention relates to an insulated metal panel (1) and a method and an apparatus for manufacturing it. The method comprises at least the following steps: - the edges (4) of a metal sheet (3) are bent in the same direction whereby a panel body (2) with an insulation space (6) having a bottom (5) and edges (4) is formed, - an insulation board (8), such as a polyurethane sheet, which substantially covers the bottom (5) of the insulation space (6) is fastened to the insulation space (6).

Description

INSULATED METAL PANEL

TECHNICAL FIELD

The invention relates to an insulated metal panel and a method and an apparatus for its manufacture presented in the preambles of the independent claims presented below.

PRIOR ART

Insulated metal panels are used, for example, in buildings as facade material. Existing metal panels have problems, for example, with respect to their thermal insulation, structural load capacity and retaining evenness of large surfaces. Manufacturing of metal panels is often complicated and costly.

OBJECT OF THE INVENTION

The present invention aims to reduce or even eliminate the above-mentioned prior art problems.

One of the objects of the present invention is to achieve an insulated metal panel that is easy to manufacture and that has good thermal insulation and structural load capacity.

One object of the present invention is to achieve an insulated metal panel that retains its shape in different situations and environments. BRIEF DESCRIPTION OF THE INVENTION

For carrying out among others the above-mentioned objects, an insulated metal panel and method and apparatus according to the present invention as well as other embodiments of the invention are characterised by what is presented in the characterising parts of the independent claims.

The embodiments and benefits mentioned in this text apply, where applicable, to the insulated metal panel according to the invention as well as the method and the apparatus for its manufacture despite not always being mentioned separately. A typical method according to the invention for the manufacture of an insulated metal panel comprises at least the following steps

- bending the edges of a metal sheet in the same direction, forming a panel body with an insulation space having a bottom and edges,

- arranging insulation material in the insulation space by fastening in the insulation space an insulating board substantially covering its bottom.

A typical insulated metal panel according to the invention comprises a panel body bent from a metal sheet. The edges of the metal sheet are bent in the same direction whereby an insulation space framed by the edges and the bottom is formed. The metal panel also comprises an insulation material arranged in the insulation space. The insulating material covers substantially the bottom of the insulation space and is, for example, an insulation board glued to the bottom. The fixing of the insulation board can be arranged in different ways, for example, the insulation board can be formed by extruding into the insulation space some as such known foam material that hardens in the form of a board, such as polyurethane foam.

The dimensions and other characteristics of the insulation board may vary depending on the need in each case. For example, the thickness of the insulation board may be 20-60 mm or 40 mm.

The insulation board may be, for example, a polyurethane sheet. The polyurethane sheet is rigid, consists mainly of closed cells and is an effective thermal insulation material. A polyurethane sheet is easy to glue firmly to the metal sheet. The polyurethane sheet as such is a known building material and its features are not covered here in more detail.

The metal sheet may, for example, have a thickness of less than 1 .5 mm or less than 1 mm, or the metal sheet may, for example, have a thickness of 0.4-1 .5 mm or 0.5-1 mm, typically for example 0.7 mm. The material may be, for example, stainless steel or copper. Bending of a metal sheet is a technique known as such. Bending can be done, for example, using robots, such as so-called PSBB apparatus. In a PSBB apparatus punching, shearing, buffering and bending are done on the same line (P = Punching, S = Shearing, B = Buffering and B = Bending). Punching and shearing are operations needed before bending. Buffering means here an intermediate storage before bending.

In an embodiment of the invention, the insulation board is glued to the bottom of the insulation space. The gluing of an insulation board to a metal sheet is prior art as such. It can be done manually or mechanically, for example, with a robot. Typically, in the gluing process an adhesive is first applied either to the metal surface or to the insulation board. Then the insulation board is pressed onto the metal i.e. to the panel body, the board is usually pressed against the metal for a few seconds, for example 3-10 seconds, then the adhesive is allowed to dry and strengthen, for example, for 1 -3 hours.

Many insulation boards, such as polyurethane boards (PU), are available dimensionally accurate. Many insulation boards do not get waterlogged in practice. For example, a polyurethane insulation board, such as a polyisocyanurate plate (PIR), does not get waterlogged, so the backside of the cartridge may not even require a separate surface plate even in outdoor use. Insulation boards, such as a polyurethane board, for example a PIR board, can be made extremely fire safe.

It has now been found that the manufacture of an insulated metal panel is remarkably easy and effective if an insulation board is glued to a panel frame with bent edges. The invention allows a metal panel production line to be implemented as at least almost fully automatic. According to the invention, the metal panel is bent accurately in the desired manner and to the desired size, an insulation board with suitable characteristics is used and the gluing is performed accurately. The result is a dimensionally accurate panel that can be installed without risks, for example as a facade element on the wall of a building. If the materials are suitably selected, a weatherproof and in desired conditions even almost completely rigid and very heat insulating panel is achieved. One advantage of the invention is that the glued composite structure provides structural rigidity, for example high rotational strength, to the metal panel. Yet the metal panel is relatively light. The invention allows for the manufacture of large elements, e.g. with surface areas greater than 3 m^A2, or more than 5 m^A2, or for example, the manufacture of metal panels with the dimensions of 1500x3000 mm. Due to the glued structure and suitably selected materials, the metal panel according to the invention has a high impact resistance and high compression resistance.

The invention enables even a large panel's surfaces to remain flat in different conditions. The metal panel is almost maintenance-free and easy to keep clean, it is easy to coat if desired and attach to its base, it is durable and its appearance is flawless. The panel according to the invention is fully recyclable if needed. The metal panel does not necessarily require surface treatment.

One of the advantages of the invention is that it is suitable for ceiling construction, for example as an additional heat insulation. The invention is suitable for building acoustics. An insulated metal panel according to the invention is well suited for facade construction and on top of all known building materials as additional heat insulation. The invention allows the use of different materials on inner surfaces or facades to be combined, for example, copper and steel can easily be used on the same surface. In the glued structure, there is typically no air gap between the insulation board and the metal sheet. The glued composite structure thus does not exhibit dewpoint problems, at least if an appropriate, for example PU or PIR insulation board, is selected as the insulation material. With some materials such as PU or PIR, the likelihood of mildew in the structure and undesired moisture's capillary action is minimized. For example when using PU or PIR board, the structure is easily made rigid and otherwise sturdy. Thus, deformations of the outer surface, for example when the temperature changes, are minimized. In one embodiment of the invention, substantially the entire insulation space is filled with an insulation board. In this case, the insulation board being used is substantially as thick as the height of the edges of the insulation space, whereby the insulation board that is of the same shape as the insulating space's bottom substantially fills the insulation space. An insulation board that completely fills the insulation space strengthens the panel and further reduces risks caused by moisture.

In one embodiment of the invention, prior to bending of the edges, the metal sheet is gripped firmly with one or more grippers, such as a magnetic gripper or vacuum gripper. After the edges have been bent, the grippers can be detached from the metal sheet. Grippers allow the metal sheet or panel to be easily moved and rotated to a desired place and position. With the grippers, the metal sheet can be conveniently and effectively held in place during the bending of the edges. Thus, the metal sheet and the metal panel to be manufactured from it will end up being exactly of desired shape and will remain in the desired shape during the manufacture and throughout its use.

In one embodiment of the invention, the edges of the metal sheet are bent one at a time. In one embodiment, several edges, for example, opposite edges or all edges, are bent simultaneously. The optimal manufacturing method for the best quality and production efficiency depends on, among others, the equipment used, the materials used and the size of the metal panel to be manufactured. Several folds can be made to the edges, for example a flange can be bent to the end of the edge for the purpose of mounting of finished panel.

It is thus possible that a metallic panel body is visible on the front side of the panel, but on the back side the insulation board glued to the insulation space of the body is visible. In one embodiment of the invention, another metal sheet, i.e. the back cover of the panel, is glued to the insulation board. This way the insulation board is easily and firmly protected under a metal sheet also on the back side of the panel. The structure of the metal panel is further strengthened this way. In one embodiment of the invention, panel body is sealed to the back cover of the panel so closely that the panel forms of a hermetically sealed insulated metal panel. Such a panel is even more weather-resistant, structurally sturdy and otherwise versatile.

In one embodiment of the invention, the edges of the back cover of the panel are bent in the same direction. This way the back cover of the panel forms an interior with edges and bottom. The bottom may have a surface area substantially equal to the dimensions of the panel's outer frame. In one embodiment of the invention, the panel body is mounted at least partially in the interior of the back cover of the panel. This way the back cover of the panel covers the insulation board and the edges of the back cover of the panel cover at least partially the edges of the panel body. The structure of the metal panel is further strengthened this way, the panel is even more weather-resistant and otherwise versatile.

In one embodiment of the invention, during bending of the edges of the metal sheet and/or during fastening of the insulation board, the metal sheet is stretched in at least one stretching direction parallel to its plane. The stretching is stopped for example after the edges have been bent and/or the insulation board has been fastened. At this point, the metal sheet can return at least almost to its original dimensions. Stretching can be done in many different ways, for different durations, in different directions or in several directions simultaneously. In one embodiment, the metal sheet is stretched in its longitudinal direction. Because of this stretch, the panel made of metal sheet can be made even more dimensionally accurate and it can tolerate changes in conditions better.

In one embodiment of the invention, the stretching is carried out in the area of the metal sheet that is intended to be flat, for example in the area between the bends of the edges. For example, when bending the panel body, where bends are formed near the edges of the metal sheet, the metal sheet may be stretched in its center area intended to be flat. For example the following can be done: with a suitable stretching device, gripping points near one or more bending points of the metal sheet are gripped, the sheet is stretched, and one or more bends are bent in the metal sheet. The stretching can be stopped for example when the bendings are complete.

Metal, such as steel, when stretched more and more usually has a sharp yield limit, whereby until that point elastically behaved metal suddenly starts to stretch in a plastic way. Once started, plastic stretching continues with smaller tension. The average tension required to start the yielding is referred to as an upper yield limit and the tension required to continue stretching is called lower yield limit. In the embodiment of the invention, the metal sheet is stretched so that it remains elastic, i.e. it returns at least approximately to its original dimensions. The stretching is thus done at maximum to the upper yield limit of the metal sheet or the stretching is stopped before the upper yield limit is reached. In one embodiment, the stretching is done at maximum to the lower yield limit or the stretching is stopped before the lower yield limit is reached. The metal sheet may be stretched in the stretching direction, for example at least 0.05% or at least 0.1 % or at least 0.5%. This way stretching will typically remain clearly below the upper and lower yields limits. The stretching depends on the characteristics, thickness and respective yield limit of the used metal. The yield limits vary with different metals and may vary between different metal coils. Optimal stretching is suitably chosen for each situation.

In one embodiment of the invention, the metal sheet is stretched with one or more grippers, such as a magnetic gripper or a vacuum gripper. In one embodiment, the grippers are the aforementioned grippers used during bending of the edges. Grippers can also be used during the gluing of the insulation board.

One embodiment of the invention is an apparatus for manufacturing an insulated metal panel. The apparatus comprises at least a bending device, a fastening device and a stretching device. The bending device bends the edges of the metal sheet so that panel body is formed. At the same time, an insulation space is formed in the body. With the fastening device, the insulation board is fastened to the bottom of the panel body. The fastening device can be for example a gluing device. With the stretching device, the metal sheet is stretched during the bending of the edges of the metal sheet and/or the fastening of the insulation board. The stretching device is arranged to stretch the metal sheet in at least one stretching direction parallel to its plane at the most up to the yield limit of the metal sheet.

The insulated metal panel according to the invention may be used as a wall element or as part of a variety of wall elements, for example in refrigerators, freezers or other refrigeration appliances, buildings or room modules such as ship cabins. The metal panel can even function as a load-bearing structure of a wall element.

In a solution to which the solutions and advantages presented in this application are applicable where appropriate, a bent metal sheet is made without insulation being attached. For example, a panel body can be made, where by bending the edges of the metal sheet a space having a bottom and edges is formed. The method thus comprises at least the following steps

- bending folds to the metal sheet,

- during the bending of the metal sheet, the metal sheet is stretched in at least one stretching direction parallel to its plane at maximum to the yield limit of the metal sheet.

In this case, an apparatus is used which comprises

- a bending device for the metal sheet bending,

- a stretching device to stretch the metal sheet during the bending of the metal sheet, the stretching device being arranged to stretch the metal sheet at least in one of its stretching directions parallel to its plane at maximum to the yield limit of the metal sheet.

SHORT DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail below with reference to the accompanying schematic drawing in which

figure 1 shows a cross-section of the insulated metal panel according to the invention, and

figure 2 shows the manufacturing method according to the invention as a flowchart. DETAILED DESCRIPTION OF EXAMPLES IN THE DRAWINGS For clarity, same reference numbers are used for some corresponding parts in different figures and embodiments. For the sake of clarity, in some figures, some parts meant to be tight against each other are shown slightly disconnected from each other. Glue or insulating material that is in between parts is not shown.

Figure 1 shows the insulated metal panel 1 according to the invention, which metal panel 1 comprises a panel body 2 bent from a metal sheet 3. The metal sheet edges 4 are bent in the same direction whereby an insulation space 6 framed by the edges 4 and the bottom 5 of the insulation space is formed. The tips of the edges 4 are bent as mounting flanges 7, by which the panel 1 can be fastened to its installation site, such as a wall and other panels. The mounting flanges 7 also reinforce the structure of the panel 1 . Insulation board 8 is glued to the bottom 5 of the insulation space. The insulation board 8 covers the bottom 5 of the insulation space and its thickness equals the height of the edges 4. Thereby the insulation board 8 substantially fills the insulation space 6.

A second metal sheet has been used to form a back cover 9 for the panel. The edges 10 of the back cover 9 are bent in the same direction, whereby an interior 1 1 with edges 10 and a bottom 12 is created in the back cover 9 of the panel. The size of the surface area of the interior 1 1 is substantially equal to the outside dimensions of the panel body 2. The panel body 2 is partially mounted to the interior 1 1 of the back cover 9 of the panel. Thereby, the back cover 9 of the panel covers the insulation board 8 and the edges 10 of the back cover 9 of the panel cover the mounting flanges 7 at least partially. The bottom 12 of the back cover 9 of the panel is glued to the insulation board 8. The mounting flanges 7 and the back cover 9 edges 10 are sealed together with a sealing agent in an airtight manner.

An example of the production method according to the invention is illustrated in Figure 2. The metal sheet 3 comes from storage 21 , either from a coil or from a metal sheet storage. The material coming from the coil typically needs to be straightened by a straightening device (not shown). If needed, after the possible straightening, the raw material is cut using a possible cutting device (not shown) to fixed size, to pre-cut sheets suitable for making the panel 1 . It is possible that in the storage 21 there already are pre-cut sheets of a suitable size.

The pre-cut sheets are transported in the example in the figure to the PSBB apparatus 22, in which the angles and perforations required for bending are done in step 23 to the pre-cut sheet and a shearing is performed in step 24, buffering in step 25 and bending in step 26. The shearer 24 is well suited for rectangular panels such as many facade panels. This way yield rate for a sheet is high and less waste is generated. If necessary, pre-cut sheets are stored intermediately, i.e. buffered in intermediate storage 25 before bending 26.

The metal sheet coming from the buffering is gripped firmly with one or more grippers (not shown). The grippers move the metal sheet to the bending machine 26. The edges 4 of the metal sheet 3 are bent, for example one edge at a time, typically all edges in the same manner. First, a mounting flange 7 is bent to the outer edge of the metal sheet 3 at a 90 degree positive angle to the plane of the metal sheet. The length of the flange 7 can be, for example, 10-15 mm. Thereafter, the same edge is bent, for example, at 40 mm length to a 90 degree negative angle. This creates a 40 mm high edge 4 to the insulating space 6 of the panel body 2. Subsequently, the pre-cut sheet is rotated using the grippers and the other edges are bent in exactly the same way. It is possible to create, for example, a tight overlapping joint in the corners between the edges. The result is a dimensionally accurate panel body 2, with precisely 90 degree angles. After bending, finished panel bodies 2 can be transported to another intermediate storage (not shown).

During bending, the metal sheet is stretched slightly in its longitudinal direction, for example 0.5%. Stretching can be done, for example, by pulling the grippers away from each other. When the stretching is stopped, the metal sheet returns at least almost to its original dimensions.

If the metal panel 1 will have a back cover 9, it is bent correspondingly, according to its own dimensions. The bent panel bodies 2 and the back covers 9 as well as the insulation boards 8 are brought to the assembly point 27. At the assembly point 27, glue is applied to the bottom 5 of the insulating space 6 of the panel body 2 and/or to the insulation board 8 by a gluing device (not shown). The insulation board 8 is placed in the insulation space 6. If the metal panel 1 will have a back cover 9, the glue is applied between it and the insulating board 8 and the back cover 9 is set in place. Filler, possibly the same adhesive used to glue the insulation board 8 to the panel body 2 and the back cover 9, can be applied to the connection points of the panel body 2 and the back cover 9. The insulation board 8 and the panel body 2 and/or back cover 9 can be pressed against each other for a good gluing result. The panel body 2 and/or the back cover 9 can be stretched for a period of time during the gluing. The stretching is done so that the yield limit of the metal is not exceeded, which means that at the end of the stretching the metal will return at least approximately back to its previous dimensions.

The gluings of the completed insulated metal panel 1 are allowed to dry for a required period of time in a suitable storage (not shown), for example, for a few hours. Thereafter, panel 1 is ready for further processing 28, for example, to be packaged for transportation to an installation site.

The examples in the drawings do not illustrate all possible features of the invention, such as support structures, storages, grippers, conveyors, robots. The invention is not intended to be limited to the examples shown but the scope of protection is determined by the independent claims. The dependent claims illustrate some beneficial embodiments of the invention.

Claims

1 . A method for manufacturing an insulated metal panel (1 ) comprising at least the following steps

- bending the edges (4) of a metal sheet (3) in the same direction to form a panel body (2) with an insulation space (6) having a bottom (5) and edges

(4),

- arranging insulation material into the insulating space (6),

characterized in that

- an insulation board (8), such as a polyurethane board, substantially covering the bottom (5) of the insulation space (6) is fastened to the insulation space (6).

2. The method according to claim 1 , characterized in that

- the insulation space (6) is substantially filled with an insulation board (8).

3. The method according to any of the preceding claims, characterized in that

- the insulation board (8) is glued to the bottom (5) of the insulation space (6).

4. The method according to any of the preceding claims, characterized in that

- before bending the edges (4), the metal sheet (3) is gripped firmly with one or more grippers, such as a magnetic gripper or vacuum gripper,

- after bending the edges (4), the grippers are detached from the metal sheet (3).

5. The method according to any of the preceding claims, characterized in that

- during bending of the edges (4) of the metal sheet (3) and/or fastening of the insulation board (8), the metal sheet (3) is stretched in at least one stretching direction parallel to its plane at maximum to the yield limit of the metal sheet (3).

6. The method according to claim 5, characterized in that - the metal sheet (3) is stretched in at least one stretching direction parallel to its plane at least 0.05% or at least 0.1 %.

The method according to claim 5 or 6, characterized in that

- the stretching of the metal sheet (3) is stopped after bending the edges (4) of the metal sheet (3) or after fastening the insulation board (8).

8. The method according to any of the claims 4 to 7, characterized in that - the metal sheet (3) is stretched using one or more mentioned grippers.

The method according to any of the preceding claims, characterized in that

- a second metal sheet, i.e. the back cover (9) of the panel, is glued to the insulation board (8),

- the panel body (2) is sealed to the back cover (9) of the panel so tightly that a hermetically sealed insulated metal panel (1 ) is formed.

The method according to claim 9, characterized in that

- the edges (10) of the back cover (9) of the panel are bent in the same direction, forming an interior (1 1 ) in the back panel (9), with edges (10) and a bottom (12), which to its surface area is substantially equal to the outer dimensions of the panel body (2),

- the panel body (2) is inserted into the interior (1 1 ) of the back cover (9) of the panel so that the back cover

(9) of the panel covers the insulation board (8), and the edges

(10) of the back cover of the panel cover the edges (4) of the panel body (2) at least partially.

1 1 . An insulated metal panel (1 ) comprising

- a panel body (2) bent from a metal sheet (3) so that the edges (4) of the metal sheet (3) are bent in the same direction, whereby an insulation space (6) limited by the edges (4) and the bottom (5) is formed in between the edges (4), and

- an insulation material arranged in the insulation space (6), characterized in that the insulation material is an insulation board (8), such as a polyurethane board, that is fastened to and substantially covers the bottom (5) of the insulation space (6).

12. The metal panel according to claim 1 1 , characterized in that the insulation board (8) is glued to the bottom (5) of the insulation space (6).

13. The metal panel according to claim 1 1 or 12, characterized in that the thickness of the insulation board (8) is substantially equal to the height of the edges (4), whereby the insulation board (8) substantially fills the insulation space (6).

14. The metal panel according to any of the preceding claims 1 1 to 13, characterized in that a second metal sheet, i.e. the back cover (9) of the panel, is glued to the insulation board (8) and the panel body (2) is sealed to the back cover (9) so tight that the insulated metal panel (1 ) is hermetically sealed.

15. The metal panel according to claim 14, characterized in that

- the back cover's (9) edges (10) are bent in the same direction, whereby an interior (1 1 ) having edges (10) and a bottom (12) and having a surface area substantially equal to the outer dimensions of the panel body (2) is formed in the back cover (9) of the panel, and

- the panel body (2) is at least partially mounted to the interior (1 1 ) of the back cover (9) of the panel so that the back cover (9) of the panel covers the insulation board (8), and the edges (10) of the back cover (9) of the panel cover at least partially the panel body's (2) edges (4).

16. A wall element, characterized in that its load bearing structure is a metal panel according to any one of preceding claims 1 1 to 15.

17. An apparatus for manufacturing an insulated metal panel (1 ) comprising:

- a bending device (26) to bend the edges (4) of a metal sheet (3) and thereby to manufacture a panel body (2) and to form an insulation space (6) in the panel body (2), - a fastening device to fasten an insulation board (8) to the bottom (5) of the insulation space (6) of the panel body (2),

characterized in that the apparatus also comprises

- a stretching device to stretch the metal sheet (3) during the bending of the edges (4) of the metal sheet (3) and/or fastening of the insulation board

(8), the stretching device being arranged to stretch the metal sheet (3) in at least one stretching direction parallel to its plane at maximum to the yield limit of the metal sheet (3).