NL2004513C2 - Pe sandwich laminate. - Google Patents

Description

\ r« PE sandwich laminate

TECHNICAL FIELD OF THE INVENTION

The present invention is in the field of panels suitable for insulation, 5 building purposes etc.. The present invention relates to a PE sandwich laminate, a panel thereof, a method of producing said laminate and use of said laminate.

BACKGROUND OF THE INVENTION

10 In the field of laminates panels are known. A laminate is a material that can be constructed by uniting two or more layers of material together. The process of creating a laminate is lamination, which in common parlance refers to the placing of something between layers of plastic and gluing them with heat and/or pressure, usually with an adhesive. The 15 materials used in laminates can be the same or different. An example of the type of laminate using different materials would be the application of a layer of plastic film — the "laminate" — on either side of a sheet of glass — the laminated subject. Vehicle windshields are commonly made by laminating a tough plastic film between two layers of glass. Plywood is a common 20 example of a laminate using the same material in each layer.

A sandwich structured composite is a special class of composite materials that is fabricated by attaching two thin but stiff skins to a lightweight but thick core. The core material is normally low strength material, but its higher thickness provides the sandwich composite with high 25 bending stiffness with overall low density. Open and closed cell structured foam, balsa wood and syntactic foam, and honeycomb are commonly used core materials. Glass or carbon fiber reinforced laminates are widely used as skin materials. Sheet metal is also used as skin materials in some cases. Metal composite material (MCM) is a type of sandwich formed from two thin 30 skins of metal bonded to a plastic core in a continuous process under controlled pressure, heat, and tension.

2004513 2

Panels for insulation are known in the field. Various types of panels exist.

Structural insulated panels (or structural insulating panels), SIPs, are a composite building material. They consist of a sandwich of two layers of 5 structural board with an insulating layer of foam in between. The board can be sheet metal or oriented strand board (OSB) and the foam either expanded polystyrene foam (EPS), extruded polystyrene foam (XPS) or polyurethane foam.

Rigid panel insulation is made from fibrous materials (fiberglass, rock 10 and slag wool) or from plastic foam.

For instance, sandwich panels of metal-foam-metal construction are known. Sometimes adhesive layers are present as well, in order to improve the adhesibility. Also further layers may be present, as required by a specific application. Examples of these documents are DE 31 25 839 A1, EP 1 770 15 227 A3, FR2 834 738A1, FR 2 904 015 A1,and WO 2008/054637 A1.

These types of panels have various disadvantages. For instance, they are difficult to manufacture, costly, e.g. due to use of metal, often not applicable for a given application, etc.

Also so-called twin-walled panels are known. These panels relate to 20 T-shaped panels welded together. Thereby hollow spaces (Hohlenkammer) are formed and enclosed. Typically the panels are made from polymers. Examples of documents disclosing such panels are DE 10 2007 055 257 A1, DE 10 2004 023 975, DE 20 2004 018 471 U1 and US 2003000172 A1. These types of panels have various disadvantages. For instance, they are 25 difficult to manufacture, limited in thickness in that only a few thicknesses can be made with existing processes, provide limited insulation with respect to heat and/or noise, etc.

Panels comprising foam and plastic are also known. Examples of documents disclosing such panels are DE 40 17 539 A1, EP 1 162 058 A1 , 30 JP 1997 0303011, NL 1 000 615 C2, US 5,135,806 A and WO 2010/013085 A1 .These documents relate in general to complex laminate structures, 3 typically having a foam layer, sometimes having an adhesive layer or foil, for various applications, such as skis.

Also anti-castor surface laminates are known. US 7,462,400 B2 discloses a caster-resistant surface laminate using plywood, a synthetic 5 resin and a flooring comprising the surface laminate. The surface laminate utilizes buffering properties of a synthetic resin layer, thus minimizing damage to the surface of the flooring. The surface laminate uses a resin selected from PVC, PE, PET, PETG, PCTG and PU in order to enhance the caster resistance, impact resistance and water resistance. WO 2007/042174 10 A1 discloses a cold-workable laminate consists of an aluminium foil whose two sides are coated with a plastic materials and which is used for producing blister bottom parts for blister packaging of pharmaceutical products lyophilised on the bottom. The laminate comprises the following layer sequence: a layer A / layer B/ aluminium foil/, layer C/ and a layer D, 15 wherein the layer (A) is embodied in the form of a film consisting of a COC/PE blend or co-extruded COC-PE and has the thickness ranging from 10 to 100 pm, the layers B and C are embodied in the form of oPA, oPP or PET foils whose thickness ranges from 10 to 50 pm, the layer D is a foil consisting of the COC/PE blend, co-extruded COC-PE or PVC whose 20 thickness ranges from 10 to 100 pm.

The constructions known thus have various disadvantages, such as limited applicability, lack of ease of further processing, costs, limitation to dimensions, difficult to manufacture, susceptible to UV damage and solvents, flammable and producing toxic fumes when they burn, susceptible 25 to termites, having R-values higher than that of still air, etc.

Thus there still is a need for an improved sandwich laminate, which sandwich laminate overcomes one or more of the above disadvantages, while at the same time not jeopardizing other favourable aspects of 30 laminates.

SUMMARY OF THE INVENTION

4

The present invention relates to a sandwich laminate for insulating comprising a. a first layer (111) of PE, b. a first layer (121) of textile laminated to the first PE-layer, 5 c. a suitable foam layer (130) attached to the first textile layer, d. a second layer (122) of textile laminated to the foam, and e. a second layer (112) of PE laminated to the second layer of textile, a method of producing the same and use thereof.

With respect to PE it is however known that PE is very difficult or 10 almost impossible to laminate. So despite advantages of the PE material, no laminates have been formed or produced, at least on a large scale, to date.

The present sandwich laminate has various advantages over the prior art.

15 Various elements of the present invention as well as advantages will be discussed below in detail.

Further advantages are mentioned below.

DETAILED DESCRIPTION OF THE INVENTION 20 In a first aspect the present invention relates to a sandwich laminate for construction comprising a. a first layer (111) of PE, b. a first layer (121) of textile laminated to the first PE-layer, c. a first adhesive layer (141), 25 d. a suitable foam layer (130) attached to the first textile layer, e. a second adhesive layer (142), f. a second layer (122) of textile laminated to the foam, and a. a second layer (112) of PE laminated to the second layer of textile, a method of producing the same and use thereof.

30 Relating to the term “layer” with respect to PE or foam, the term relates to a layer of certain thickness, having a suitable integrity, stiffness, 5 manufacturability, etc. In this respect the term does not relate to a foil or film, or to an adhesive layer.

Relating to the term “layer” with respect to the textile layer, this layer is relatively thin, typically less than 1 mm, and in itself not having a suitable 5 integrity, stiffness, etc..

Relating to the term "layer” with respect to the adhesive layer, this layer is relatively thin, typically less than 0.5 mm, and in itself not having a suitable integrity, stiffness, etc..

Relating to the term “PE” various types of PE are included, such as 10 HDPE, LDPE, PE, etc.

The sandwich laminate need not be symmetrical, i.e. a thickness of the first PE-layer need not be similar or the same as a thickness of the second PE-layer, etc. In an example the sandwich laminate is symmetrical, for instance as such a panel is easier to manufacture.

15 Relating to the term “solid foam ” it relates to an important class of lightweight cellular engineering materials. These foams can be classified into two types based on their pore structure: open cell structured foams and closed cell foams.

Open cell structured foams contain pores that are connected to each 20 other and form an interconnected network which is relatively soft. Open cell foam which will fill with whatever it is surrounded with. If filled with air this could be a relatively good insulator, but if the open cells fill with water, insulation properties would be reduced. Foam rubber is a type of open cell foam.

25 Closed cell foams do not have interconnected pores. Normally the closed cell foams have higher compressive strength due to their structures. However, closed cell foams are also generally denser, require more material, and consequentially are more expensive to produce. The closed cells can be filled with a specialized gas to provide improved insulation. The 30 closed cell structure foams have higher dimensional stability, low moisture absorption coefficients and higher strength compared to open cell structured 6 foams. All types of foam are widely used as core material in sandwich structured composite materials.

In an example the closed cell foams are preferred.

Various types of adhesive are considered. Example of natural 5 adhesives are made from inorganic mineral sources, or biological sources such as vegetable matter, starch (dextrin), natural resins or from animals e.g. casein or animal glue. Examples of synthetic adhesives are elastomers, thermoplastics, emulsion, and thermosetting adhesives based on polyvinyl acetate, epoxy, polyurethane, cyanoacrylate polymers are examples of 10 synthetic adhesives. Examples of drying adhesives are white glue and rubber cements. Examples of contact adhesives are natural rubber and polychloroprene (Neoprene). Examples of hot adhesives are simply thermoplastics applied in molten form (in the 65-180 C range) which solidify on cooling to form strong bonds between a wide range of materials. 15 Examples of emulsion adhesives are dispersions often based on polyvinyl acetate. Examples of UV and light curing adhesives can cure in as little as a second and many formulations can bond dissimilar substrates (materials) and withstand harsh temperatures. Examples of pressure sensitive adhesives are safety labels for power equipment, foil tape for HVAC duct 20 work, automotive interior trim assembly, and sound/vibration damping films. Major raw material for PSA's are acrylate based polymers.

In an example the present sandwich laminate comprises a foam which is sufficiently stiff for construction purposes, preferably having a density of 15 kg/m3 - 100 kg/m3, more preferably of 25 kg/m3 - 50 kg/m3, 25 such as 35 kg/m3. If the density is too low the stiffness is too low. If the density is too high, the sandwich laminates become too heavy. Preferably the density is such that the sandwich laminate is self supporting.

In an example the present sandwich laminate comprises a foam which is selected from the group comprising PUR and polystyrene. PUR and 30 polystyrene are well known foams which can easily be adjusted to required characteristics, such as density.

7

In an example the present sandwich laminate comprises PE layers have a thickness of 0.1 mm - 30 mm, preferably from 0.5 mm - 20 mm, more preferably from 1.0 mm - 5 mm, such as 3 mm. Depending on requirements of a specific application PE layers may be thicker or thinner. A 5 too thin PE-layer does not provide sufficient protection, e.g. for impact, for chemicals, etc. A too thick layer does not provide further advantages and costs will increase.

The PE layer may have any suitable colour. It may further comprise further constituents, such as fillers, UV-blockers, etc.

10 In an example the present sandwich laminate comprises a foam layer which has a thickness of 1.0 mm - 200 mm, preferably from 5 mm - 100 mm, more preferably from 10 mm - 80 mm, such as from 20 mm - 60 mm. The thickness of the foam layer, often in combination with the density thereof, will determine what characteristics are obtained. As such the 15 present laminate, or panel thereof, is very suitable for construction, as its properties, e.g. thickness, can be varied without much problem.

In an example the present sandwich laminate comprises a foam layer which comprises two or more layers of foam.

20 In a second aspect the present invention relates to a method of manufacturing the present sandwich laminate comprising the steps of a. providing a first PE-layer of suitable thickness with a first textile layer laminated on said first PE-layer on a first side thereof, b. applying a first adhesive layer on said first side of the PE-layer, 25 c. applying a foam layer to said first adhesive layer, d. applying a second adhesive layer on said foam layer, e. applying a second PE-layer of suitable thickness with a second textile layer laminated on said second PE-layer on a first side thereof, with said first side on the second adhesive layer, and 30 f. optionally applying a vacuum.

In an example a first HDPE layer having a thickness of for instance 5 mm is provided. The first HDPE layer is preferably provided with a textile 8 layer by a supplier of said HDPE layer. The HDPE layer obtained is placed on a vacuum table of suitable size, placed with the textile layer facing upwards. Subsequently a suitable adhesive is provided, for instance by spraying or rolling. Then a PUR foam layer is placed on the adhesive, having 5 a thickness of 30 mm. Further a suitable adhesive is provided, for instance by spraying or rolling, this time on the foam. Subsequently a second HDPE layer having a thickness of for instance 5 mm is provided and placed with the textile layer facing downwards on the foam layer and adhesive thereon. The second HDPE layer is preferably provided with a textile layer by a 10 supplier of said HDPE layer. Subsequently the sandwich laminate obtained is placed under vacuum, thereby allowing the adhesive to cure under relatively large pressure, during a sufficient time. The laminate is then ready for use.

Laminating PE with a textile is a technique known per se.

15 Applying a foam is however discouraged in the prior art. The inventors have now found that a PE layer laminated with textile can be combined with a foam layer by applying a suitable adhesive. Such a step is repeated in order to apply a second PE layer.

Specific dimensions and advantages of the sandwich laminate 20 obtained by the present method are indicated throughout the description.

In a third aspect the present invention relates to a panel comprising the present laminate.

In a fourth aspect the present invention relates to use of the present sandwich laminate as a construction panel, as an air duct, as a container for 25 chemicals, as a process bath, as a self supporting construction, as a thermal insulation, as a sound insulation, as a decorative panel, as a chemically inert panel, and combinations thereof. As such the present laminate offers a wide field of in some cases novel applications. Further more, various existing applications can now be provided in an easier, cheaper, more adjustable 30 manner. For instance, present insulation panels are typically limited to one (or a few) thicknesses. With the present panel virtually any thickness can be provided.

9

The invention is further detailed by the accompanying figures, which are exemplary and explanatory of nature and are not limiting the scope of the invention.

5 DESCRIPTION OF THE DRAWINGS / FIGURES

The invention although described in detailed explanatory context may be best understood in conjunction with the accompanying figures and photographs.

Fig. 1 shows a schematic cross-section of an example of the present 10 invention.

In detail figure 1 shows a schematic cross-section of a sandwich laminate, wherein a first PE layer (111) is provided. A first layer (121) of textile is laminated to the first PE-layer. Further a suitable foam layer (130) 15 is attached to the first textile layer by applying a first adhesive layer (140). Next a second layer (122) of textile is laminated to the foam by applying a second adhesive layer (141), and further a second layer (112) of PE is laminated to the second layer of textile. As such a sandwich laminate is provided, typically forming a panel. A panel typically has a size in the order 20 of 10 cm - 2 meter width and 30 cm - 5 meter length. A panel is thereby suited to be handled by an individual person, possibly assisted by one or more further persons, that is not too large in size and not too heavy in weight. For specific applications, however, panels may be much larger.

2 0 0 ^51 3

Claims (8)

A sandwich laminate for construction purposes comprising a. A first layer (111) of PE, 5 b. a first layer (121) of textile laminated to the first PE layer, c. a first adhesive layer (141), d. a suitable foam layer (130) connected to the first layer of textile, 10 e. a second adhesive layer (142), f. a second layer (122) of textile laminated to the foam, and g. a second layer (121) of PE laminated to the second layer of textile. 2. Sandwich laminate according to claim 1, wherein the foam is sufficiently rigid for construction purposes, preferably with a density of 15 kg / m3 -100 kg / m3, more preferably 25 kg / m3 - 50 kg / m3, such as 35 kg / m \ Sandwich laminate according to one or more of claims 1-2, wherein the foam is selected from the group comprising PUR and polystyrene. Sandwich laminate according to one or more of claims 1-3, wherein the PE layers have a thickness of 0.1 mm - 30 mm, more preferably of 0.5 mm - 20 mm, even more preferably of 1.0 mm - 5 mm , such as 3 mm. Sandwich laminate according to one or more of claims 1-3, wherein the foam layer has a thickness of 1.0 mm - 200 mm, more preferably of 5 mm - 100 mm, even more preferably of 10 mm - 80 mm, such as of 20 mm - 60 mm has. 6. A method for producing a sandwich laminate comprising the step of a. Providing a first PE layer of suitable thickness with a first layer of textile laminated on the first PE layer on a first side thereof, b. applying a first adhesive layer to the first side of the PE layer, c. applying a foam layer to the first adhesive layer, d. applying a second adhesive layer to the foam layer, 2004513 e. applying a second PE layer of suitable thickness with a second layer of textile on the second PE layer on a first side thereof, with the first side of the second adhesive layer, and f. possibly applying a vacuum. A panel comprising a sandwich laminate according to one or more of claims 1-5. 8. Use of a sandwich laminate according to one or more of claims 1-5 or panel according to claim 7, as a building panel, as an air passage, as a chemical container, as a process bath, as a self-supporting structure, as a thermal insulation, as sound insulation, as a decorative panel, as a chemical inert panel, and combinations thereof. 2 ao 4 51-3 '