NL2023202B1

NL2023202B1 - Thermo-insulated multi-layered panel and method for producing such a thermo-insulated multi-layered panel

Info

Publication number: NL2023202B1
Application number: NL2023202A
Authority: NL
Inventors: Albert De Mol Henricus; Bernard Henry Baptist Van Der Wielen Paul
Original assignee: Tabb Interior Systems B V
Priority date: 2019-05-27
Filing date: 2019-05-27
Publication date: 2020-12-02
Also published as: WO2020242307A1

Abstract

The present invention relates to a multi-layered panel, having two opposite outer panel layers; a cell structured intermediate layer located between the outer panel layers; adhesive material connecting the intermediate layer with the outer panel layers, and a phenolic foam located in the cells of the cell structured intermediate layer. The invention also relates to a method for producing such a multi-layered paneL.

Description

Thermo-insulated multi-layered panel and method for producing such a thermo-insulated multi-layered panel The present invention relates to a thermo-insulated multi-layered panel and to a method for producing such a thermo-insulated multi-layered panel. Panels used in high-end applications may be engineered to fit the demands relating the specific panel application and/or use. Some examples of high-end panel applications are: interior panels used in mobile applications like means of transport (trains, airplanes, boats, busses, trucks, cars, etc.), furniture panels, interior and exterior construction panels, display panels, screening/partition/shielding panels, construction panels and so on. Demands in such high-end panel applications may be: flexibility in design (in relation to shape, size, thickness, material choices, look, feel and/or additional functionality integration), high strength, low weight, prepared fixation feasibilities; temperature resistancy, fire resistancy, chemical resistancy and/or carrying capacity. To provide many of such demands layered panels are applied in various structures and compositions, wherein different material layers are combined to meet — as much as possible — the demands.

The present invention has for its object to provide an improved type high-end multi- layered panel that combines the mechanical and physical properties of existing high-end multi-layered panels but that has enhanced thermo-insulating properties. lt is also an object of the invention to provide a method for producing such a thermo-insulated multi-layered panel produced that requires only limited amendment of the existing production methods.

To realise these objects the present invention provides a multi-layered panel, comprising: first and second opposite outer panel layers at specified shape and dimensions; a cell structured intermediate layer located between the internal sides of the outer panel layers; an adhesive material connecting the cell structured intermediate layer with the outer panel layers, and a phenolic foam located in the cells of the cell structured intermediate layer. The multi-layered panel according the present invention allows a large freedom of form/shape, a great stiffness and the possibility to assemble the multi-layered panel with other layer cooperating parts.

As the multi-layered panel is “glued” together the need to use mechanical fasteners is eliminated, and thus the drawbacks of mechanical fasteners may be avoided. One of the avoided drawbacks of the need for fasteners is that in their absence they may not act as thermo-bridges (heat or cold bridge). The e.g. smooth surfaced multi-layered panels have besides the requirement of fasteners however even further enhanced thermal insulating properties due to the phenolic foam located in the cells of the cell structured intermediate layer. Rigid phenolic insulation products offer very good thermal insulating properties due to the very low thermal conductivity of phenolic foam compared with rigid polyurethane or extruded polystyrene (extreme low A values of 0.018 W/m K, thus exceptionally low thermal conductivity). Its low thermal conductivity allows specified thermal performance targets to be achieved with minimal thickness of insulation. However use of phenolic foam in multi-layered panels was until the present invention not obvious for the skilled person as the mechanical properties of phenolic foam are very poor. Due to the incorporation of the phenolic foam in the cells of the intermediate layer located between the internal sides of the outer panel layers the mechanical strength of the multi-layered panel is not influenced by the inclusion of the phenolic foam; the mechanical strength of the structure is identical to the mechanical strength of such a multi-layered panel without the inclusion of phenolic foam as the first and second opposite outer panel layers are held together by the adhesive material and the cell structured intermediate layer. The presence or absence of phenolic foam is thus not influencing the mechanical strength of such a panel. However the thermo-insulating properties of the multi-layered panel are substantially improved by the phenolic foam located in the cells of the cell structured intermediate layer. This is particularly advantageous in situations where multi-layered panels with high thermo-insulating properties are required and where also space saving is important. In case space saving is less an issue also panels with lower thermo-insulating properties could be used with larger thickness (so to compensate their lower thermo-insulating properties).

Except for the poor mechanical properties of phenolic foam various other properties of phenolic foam are advantageous in the combination with the multi-layered panel according the present invention. Phenolic foam is a rigid cellular foam insulation material with a substantially closed cell structure, whose polymer structure is made primarily from the poly-condensation of phenol, its homologues and/or derivatives with aldehydes and ketones. A phenolic foam may be made by foaming and curing a foamable phenolic resin composition that comprises a phenolic resin. Rigid phenolic insulation is produced by mixing high solids and phenolic resin with a surface acting agent. The heat created by the reaction evaporates a volatile liquid blowing agent in the mixture which produces a network of small bubbles in the material. The fire performance of phenolic foam is exceptional. It combines zero or very low flame spread with negligible smoke emission and a very low level of toxic gas emission. Furthermore the phenolic foam is rodent/insect proof, low water absorbent, corrosion and chemical resistant, it resists organic solvents and chemicals, it is non-abrasive and hydrophobic and it does not corrode metal. Also the service temperature range of phenolic foam is wide (approximately -200°C - 130°C) and the poor mechanical strength has as in reverse the advantage that it is easy to apply it into the cells of the cell structured intermediate layer of the multi- layered panel.

To realise a maximum thermal insulation preferably substantially all open space between the first and second opposite outer panel layers is filled with phenolic foam, more specific located in the cells of the cell structured intermediate layer. In this respect substantially is defined as at least 80% of all space between the outer panel layers left free, over even more preferred at least 90%, or even at least 95%.

The open space between the two outer panel layers is the space left free by the cell structured intermediate layer and any other objects located in between the two outer panel layers, like for instance one or more spacer blocks which will be clarified later. To maximise the use of the thermal insulating effect of the phenolic foam it is useful to fill all open spaces. The open space included the cells of the intermediate layer but also any space - if present - left open between adjoining the cell structured intermediate layer.

The cells of the cell structured intermediate layer may be closed off by the internal sides of the first and second outer layers so the phenolic foam in the cells of the intermediate layer is locked up in the cells. As the mechanical strength of the phenolic foam is limited the closed off cells so “protect” or shield the phenolic foam and thus the phenolic foam is stabilised in the cells and shielded against any external loads.

Besides the cell structured intermediate layer also at least one spacer block may be located between the internal sides of the outer panel layers.

The presence of the one or more spacer blocks may provide additional functionality to the multi-layered panel.

Not only the distance between the outer layers may be controlled with the presence of at least one spacer block but also the sides of the layers panel may be shielded with one or more spacer blocks and/or the spacer blocks may be used as mechanical stable elements for attaching external objects to the layers panel, like for instance door handles, hinges, fasteners, frames, locks, rebates, slots, luminaires and so on.

A draw back of the inclusion of one or more spacer blocks could be that the spacer blocks have a negative influence on the thermal insulation value of the panel; a spacer block could (also referred to as an “insert”) act as a heat- or cold-bridge.

To counteract this effect, or at least reduce it, a spacer block may be designed such that its thermal conductivity is limited, for example by designing the spacer block as a layered element including at least one thermal insulating layer.

The adhesive material to be used for connecting the cell structured intermediate layer to the outer panel layers may also connect the at least one spacer block to the internal sides of the outer panel layers.

An adhesive material to be used in this application is for instance a polyurethane adhesive like 2KPU.

However additionally or as an alternative also a double sided adhesive tape, like for instance double- sided acrylic foam tapes as VHB-tape ™ may also be applied.

All the adhesive materials to be selected for use in the layered panel according the present invention have to be able to create quick and easy high-strength and long-lasting bonds that also may be resilient.

The adhesive material has to enable to join a variety of materials including aluminium, steel, glass, plastics and painted and powder-coated surfaces.

As an alternative or in combination with another adhesive also a double sided adhesive tape may be used.

Using an double sided adhesive tape is especially advantageous for positioning a spacer block onto a first outer panel layer.

A further advantage of the use of a double sided adhesive tape is that such a tape automatically controls the layer thickness of adhesive material, as the adhesive quantity is dictated by the tape.

Quality loss due to using too much or too little adhesive will not easy occur when using a double sided adhesive tape and thus the quality of the panel is well controlled.

The double sided adhesive tape -

and more in particular a double-sided acrylic foam tape - may be pressure sensitive so that it requires substantive pressure (in the order of >5 N/cm? or >10 N/cm?) to realise a solid bonding. The present invention however, due to the fact that the adhesive material in the stack is heated to a temperature of at least 50°C, or preferably even a bit warmer to at least 55°C, 60°C or 65°C, makes it superfluous 5 to subject the adhesive material to a specific high level of pressure. The heat will enhance the fluidity of the adhesive material (it enables a flow of the adhesive material) so that is binds without the need of a substantial external binding force. The only pressure required during processing step F) to bring the stack layers in contact with each other may be substantive lower (in the order of <5 N/cm? , <3 N/cm?, or even <1N/cm?). The binding of the adhesive material will normally build strength over time. The cell structured intermediate layer may be a honeycomb structured layer, preferably a metal honeycomb structured layer or a phenol impregnated paper honeycomb structured layer, as such layers have positive characteristics in weight, strength and thermic insulation value. The cell structured intermediate layer may also be embodied as a fiberglass layer. Good strong panel constructions may be realised when an adhesive material like a polyurethane adhesive and/or a double sided adhesive acrylic foam tape, for instance a VHB-tape™, is used. Such adhesive materials are off the shelf available and thus easy and cheap to obtain. The layers panels according to the present invention may have various shapes and dimensions. In the more standard versions of the panels the first and second outer layer have identical shapes and/or dimensions. In a standard embodiment the first and second outer layer of the stack are parallel, normally flat. However the present invention also allows the panels to have any spatial structure desired, like for instance curved shapes.

At least one spacer block may be longitudinal and/or may coincide with the contour of at least the first or second outer layer. Any shape or size of a spacer block is allowable. If the circumference (outline, periphery) of a panel is partly or completely formed by one or more spacer blocks the interior of the panel is fully of partly shielded off from the outside world and thus also the phenolic foam is additionally shielded. if when more than one spacer block is integrated in the panel all spacer blocks have identical heights then the multi-layered panel will as a result normally be a flat panel, or in other words, the first and second outer layer are parallel in such situation.

As for one or both of the outer layers, these may be embodied as single metal layer, coated metal layer, glass layer, plastic layer, stone layer or multi-layered product containing plural of these material layers.

The present invention also provides a method for producing a multi-layered panel according to the present invention, comprising the processing steps: A) customising a first and a second outer layer at specified shape and dimensions; B) placing the first outer layer in a substantially horizontal position; C) placing a cell structured intermediate layer at the internal side of the first outer layer with an intermediate adhesive material between the first outer layer and the cell structured intermediate layer; D) bringing a phenolic foam in the cells of the cell structured intermediate layer; E) placing the internal side of the second outer layer on the phenolic foam filled cell structured intermediate layer with an intermediate adhesive material between the cell structured intermediate layer and the second outer layer; and F) exerting a pressure on a stack of the first outer layer, the adhesive material, the phenolic foam filled cell structured intermediate layer, the adhesive material and the second outer layer.

For the advantages of this method for producing a multi-layered panel reference is made to the advantages already mentioned above in relation to the multi-layered panel according to the present invention.

Before step D) at least one spacer block may be placed on the internal side of the first outer layer with an intermediate adhesive material, for instance a double sided adhesive tape, between at least the spacer block and the first outer layer.

The adhesive material may be attached at the internal side of the first and the second outer layer before the first and/or second outer layer is placed against the intermediate cell structured layer.

Preparing the first and/or second outer layer with the adhesive material before stacking the layers makes it possible to limit the lead time of the method for multi-layered panel producing and also allows to better control the fixation of the adhesive material onto the first and/or second outer layer.

The cell structured intermediate layer may partly of fully come in contact with the adhesive material.

The first and/or second outer layer may also be covered over a full side with adhesive material.

In case the adhesive material contacts the full circumference of a cell wall in the cell structured intermediate layer the phenolic foam brought in that cells is safely stored in that cell.

The (limited) pressure to be exerted on the stack of the first outer layer, the adhesive material, the cell structured intermediate layer, the adhesive material and the second outer layer may be provided by moving the stack through a press.

As already mentioned before the pressure to bring the stack layers in contact with each other may be limited, as long as it ensures a good contact between the layers.

The press for bringing the stack layers in contact with each other may simultaneously with the pressing process be used for heating the stack; thus combining two processing steps.

During such double action pressing/heating the stack may be heated to a temperature of at least 50°C.

The phenolic foam may be brought in the cells of the cell structured intermediate layer by exerting a pressure on the phenolic foam with a pressure element having a flexible contact surface.

Normally the phenolic foam is (very) brittle and easy to press into a desired space.

Using a pressure element with a flexible contact surface enables to press the phenolic foam to below the edge of the cells of the cell structured intermediate layer, or at least so far into the cells that the ends of the cell walls are free from phenolic foam to enable a good contact with an outer panel layer and/or the adhesive material.

The present invention will be further elucidated on the basis of the non-limitative exemplary embodiments shown in the following figures.

Herein shows:

figure 1A a schematic perspective view on a multi-layered panel according to the present invention in a partially exploded state; figure 1B a schematic perspective view on the multi-layered panel according to figure 1A in more assembled but still partially exploded state;

figure 1C a cross section through the multi-layered panel according to figure 1A and 1B is a fully assembled state; figure 2 a schematic partially exploded perspective view on an alternative embodiment of a multi-layered panel according the present invention; figures 3A and 3B cross sections through two production steps of the method of producing a multi-layered panel according the present invention; figures 4A - 4F subsequent productions step of the method for producing a multi-layered panel according to the present invention; figure 5 a perspective view on a third alternative embodiment on a multi- layered panel according to the present invention; and figure 6 a perspective view on an fourth alternative embodiment on a multi- layered panel according to the present invention.

Figure 1 shows a multi-layered panel 1 in a partially exploded view with a lower outer layer 2 that is carrying a layer of adhesive material 3 that on the other side is in contact with the lower side of a cell structured intermediate layer 4. Above the cell structured intermediate layer 4 a phenolic foam block 5 is depicted that still has to be brought into cells 6 of the cell structured intermediate layer 4. Above the phenolic foam block 5 an upper outer layer 7 is shown that on the side directed towards the phenolic foam block 5 carries a further layer of adhesive material 8. In figure 1B the multi-layered panel 1 of figure 1A is further assembled in that the former phenolic foam block 5 is pushed into the cells 6 of the cell structured intermediate layer 4 so that the cells 6 comprise a phenolic foam filling 9. The upper outer layer 7 with the layer of adhesive material 8 is still not attached to the - now phenolic foam filled - cell structured intermediate layer 4. In figure 1C the cross section of the multi-layered panel 1 of figures 1A and 1C is completely assembled as compared to figure 1B now the upper outer layer 7 with the layer of adhesive material 8 is attached to the - phenolic foam filled - cell structured intermediate layer 4. Figure 2 shows a schematic partially exploded perspective view on an alternative embodiment of a multi-layered panel 10 according the present invention having upper and lower opposite outer panel layers 11, 12 and a cell structured intermediate layer 13 located between the internal sides of the outer panel layers 11, 12. The internal sides of the outer panel layers 11, 12 are both provided with layers of adhesive material 14, 15. Also depicted is a block phenolic foam 16 to be brought into cells 17 of a cell structured intermediate layer 13. Different from the multi-layered panel 1 as shown in figures 1A — 1C here also spacer blocks 18 are placed on the lower outer panel layer 12, or more correct they are placed onto the layer of adhesive material 15 - here applied as double sided adhesive tape 15 - that is attached to the lower outer panel layer 12.

An additional spacer block 19 is forming a boundary on one of the sides of the panel 10, thus partially confining the cell structured intermediate layer 13. In this picture the intermediate layer 13 is embodied as a single material piece, however it is also possible to embody the intermediate layer 13 from several separate parts. Clearly visible is that apertures 20 are left open in the intermediate layer 13 to accommodate the spacer blocks 18. The layer of adhesive material 15 that is stuck to the lower outer panel layer 12 will also connect to the cell structured intermediate layer 13. Alternatively also a larger part — or even the complete surface - of the lower outer panel layers 12 may be covered with the layer of adhesive material 15. Also on the side of the upper outer panel layers 11 that is facing to the cell structured intermediate layer 13 a layer of adhesive material 14 is provided. Figures 3A and 3B show how cross sections through two production steps of the method of producing a multi-layered panel according the present invention. In figure 3A a lower outer layer 20 carries a layer of adhesive material 21 that on the side facing away from the lower outer layer 20 is attached to the lower side of a cell structured intermediate layer 22. Above the cell structured intermediate layer 22 a phenolic foam block 23 is depicted that still has to be brought into cells 24 of the cell structured intermediate layer 22. Above the phenolic foam block 23 a pressure element 25 having a flexible contact surface 26 is shown that s not in contact yet with the phenolic foam block 23. In figure 3B the pressure element 25 is moved (according arrow P+) towards the assembly of the lower outer layer 20 and the cell structured intermediate layer 22. As the phenolic foam block 23 is very brittle the pressure element 25 pushes the phenolic foam into the cells 24 of the cell structured intermediate layer 22 and due to the flexible nature of the flexible contact surface 26 the phenolic foam is pushed into the cells 24 so that the ends of the cells 27 will be free of phenolic foam so that an upper outer layer (not depicted here) is easy to attach to the cell structured intermediate layer 22. In figures 4A - 4F subsequent productions step of the method for producing a multi- layered panel 30 according to the present invention are shown. In figure 4A a first outer layer 31 that has been brought in the desired shape and dimensions is shown and in figure 4B a layer of adhesive material 32 is brought onto this first outer layer

31. In the subsequent process step spacer blocks 33, 34 are placed on the first outer layer 31. In figure 4D also a cell structured intermediate layer 35 including a phenolic foam filling is placed on the first outer layer 31, filling the space left between the spacer blocks 33, 34. In figure 4E a second outer layer 36 - that is provided with a layer of adhesive material 37 on the side facing the spacer blocks 33, 34 and the cell structured intermediate layer 35 - is pressed (see arrows Py) onto the first outer layer 31 with the spacer blocks 33, 34 and the cell structured intermediate layer 35. In figure 4F the complete panel 30 is now heated 38 so that the layers adhesive material 32, 37 reach a temperature that enhances the fluidity of the adhesives 32, 37 so to create a substantial bounding between the various components of the panel 30 without the need of applying the substantial pressure normally required to realise such bonding.

Figure 5 shows a panel 40 according to the present invention, with an upper outer layer 41, various spacer blocks 42, an intermediate cell structured layer 43 including a phenolic foam filling 44 and a lower outer layer 45. Different form the panels 1, 30 shown in the previous figures this panel 40 has a curved shape.

In figure 6 a panel 50 is shown that is prepared as a door panel. The whole circumference of the door panel 50 is provided with spacer blocks 51, 52, 53, 54 (here thus spacer beams) as is represented also with a dashed line. At the location where a door handle has to applied a larger spacer block 55 is located and an opening 56 for the attachment of a door handle housing has already been provided (e.g. milled). The same applies for the locations where hinges will be attached. Also here wider spacer blocks 57, 58, 59 are located and also here apertures 60, 61, 62 for the hinge attachment are visible. More central in the door panel 50 a window opening 63 is left open of which the boundary is also fully covered with spacer blocks 64, 65. Again a dashed line represents the location where spacer blocks around the window opening 63 are located.

As the panel 50 is internally comprising a cells structured layer including a phenolic foam (not visible here) the panel 50 (door) is suited to be used in situations where a thermos insulation is required, like for instance at cold stores, in heated rooms, at fire doors and so on.

Claims

Conclusions

A multi-layer panel, comprising: - first and second opposed panel outer layers of a specific shape and dimension; - an intermediate layer with a cellular structure, present between the inner sides of the panel outer layers; - an adhesive material connecting the cellular interlayer with the panel outer layers, and - a phenol-containing foam present in the cells of the cellular interlayer.

A multi-layer panel according to claim 1, characterized in that substantially all of the space left between the first and second opposing panel outer layers is filled with phenolic foam, more specifically present in the cells of the interlayer with a cellular structure.

A multi-layer panel according to claim 1 or 2, characterized in that the cells of the cellular interlayer are closed off by the inner sides of the first and second outer layers and phenolic foam is enclosed in the cells of the cellular interlayer.

Multi-layer panel according to any one of the preceding claims, characterized in that at least one spacer block is present between the inner sides of the panel outer layers.

Multilayer panel according to claim 4, characterized in that the adhesive material also connects the at least one spacer block to the inner sides of the panel outer layers.

Multilayer panel according to any one of the preceding claims, characterized in that the interlayer with a cellular structure is a layer with a honeycomb structure, preferably a metal layer with a honeycomb structure or a layer with a honeycomb structure of phenol-impregnated paper.

Multi-layer panel according to any one of the preceding claims, characterized in that the interlayer with a cellular structure is a layer of glass fiber.

Multi-layer panel according to any one of the preceding claims, characterized in that the adhesive material used in the multi-layer panel is an adhesive, for example a polyurethane adhesive, and / or a double-sided adhesive tape of acrylic foam, for example a VHB tape. ™.

Multilayer panel according to any of the preceding claims, characterized in that the first and second outer layers have identical shapes and / or dimensions.

Multi-layer panel according to any one of the preceding claims, characterized in that the at least one spacer block coincides with the contour of at least the first or second outer layer.

Multi-layer panel according to any of the preceding claims, characterized in that, if more than one spacer block is included in the panel, all spacer blocks have identical heights.

12. Multi-layer panel according to any one of the preceding claims, characterized in that the first and second outer layers are parallel.

Multi-layer panel according to any one of the preceding claims, characterized in that the first and / or second outer layer is a single metal layer, a coated metal layer, a gas layer, a plastic layer, a stone layer, or a multi-layer product containing a multiplicity of these material layers.

A method for producing a multi-layer panel according to any of the preceding claims, comprising the process steps of: A) adapting a first and second outer layer to a specified shape and dimensions; B) Placing the first outer layer in a substantially horizontal position;

C) Placing an interlayer with a cellular structure on the inside of the first outer layer with an adhesive intermediate material between the first outer layer and the interlayer with a cellular structure; D) Introducing a phenolic foam into the cells of the cellular interlayer; E) Placing the inner side of the second outer layer on the interlayer with a cellular structure filled with phenolic foam, with an adhesive intermediate material between the interlayer with a cellular structure and the second outer layer; F) Pressing a stack of the first outer layer, the adhesive material, the interlayer with a cellular structure filled with phenolic foam, the adhesive material and the second outer layer.

A method for producing a multi-layer panel according to claim 14, characterized in that prior to step D), at least one spacer block is placed on the inside of the first outer layer with an adhesive intermediate material, for example a double-sided adhesive tape, between the at least one spacer block and the first outer layer.

A method for producing a multi-layer panel according to claim 14 or 15, characterized in that the adhesive material is applied to the inside of the first and second outer layers before the first and second outer layers are placed against the interlayer with a cellular structure.

A method for producing a multi-layer panel according to claims 14-16, characterized in that pressure on the stack of the first outer layer, the adhesive material, the interlayer with a cellular structure, the adhesive material and the second outer layer is provided by the moving the stack through a press.

A method for producing a multilayer panel according to claims 14-17, characterized in that the phenolic foam is introduced into the cells of the cellular interlayer by applying a pressure to the phenolic foam with a pressure element which has a flexible contact surface.