Composite material for a thermal and acoustic insulation made from recycled material mix

Abstract

The invention relates to a composite material (10) for providing a thermal and / or acoustic insulation, in particular in vehicles, buildings, or machinery installations, having a generally planar, plate-like, or strip-shaped basic shape and comprising at least one first insulation material (1) based on PU foam or other foam materials and at least one nonwoven material (2) which is made of a fiber material, in particular polyester fibers, and is connected to or mixed with the insulation material (1), wherein the nonwoven material (2) and the insulation material (1) are combined by a thermal and / or shaping process involving compression of the starting material such that a solidly connected uniform mixed product with a defined thickness D is formed, the insulation material (1) consists of recycling residues based on a PU foam material with an adhesive finish (3) bonded thereto, and the insulation material (1) is provided in the form of flakes as recycling material, including adhesive finish (3) residues, mixed with the nonwoven material (2) in the composite material (10).

Description

[0001] Composite material for thermal and acoustic insulation made from a mix of recycled materials

[0002] The present invention relates to a composite material for achieving thermal and / or acoustic insulation in various applications, such as in vehicles, buildings, or machinery, wherein the composite material is based on a recycled material or several different materials from residues of other manufacturing processes. When recycling insulating materials based on foams, such as polyurethane foam, or other plastic materials, a common problem is that the starting materials of the residues contain a mixture of different components. Separating the various materials bonded together in such foam residues is problematic for recycling these residues, as the different material components often cannot be separated from each other—or only with great difficulty.For example, foam remnants with adhesive backing are usually disposed of without any possibility of further use or meaningful recycling. Firstly, it is difficult to cut such remnants of foam mats or foam insulation elements into small pieces, as the adhesive residue makes further handling difficult.

[0003] On the other hand, with crushed flakes of foam material, there is often the problem that for further use and recycling in new products, an extra binding layer or adhesive must be used so that the individual foam flakes stick together in a compact form.

[0004] Against this background, the object of the present invention is to provide a composite material based on a high proportion of recycled materials, which exhibits good acoustic and thermal insulation properties and can be produced from multi-material residues at a reasonable cost, preferably without additional binder or adhesive layers. This object is achieved with a composite material having the features according to claim 1. Advantageous embodiments and further developments of the invention are the subject of the dependent claims.

[0005] According to the invention, a composite material as defined in claim 1 is provided, which is suitable for realizing thermal and / or acoustic insulation, in particular for insulation in vehicles, buildings or machinery, with an overall planar, plate-like or strip-shaped basic form comprising at least a first insulation material based on PU foam (polyurethane foam) or other foam materials and at least one nonwoven material made of a fiber material, in particular polyester fibers, connected to and mixed with the insulation material, wherein the nonwoven material and the insulation material are brought together via a heat and / or forming process with compaction of the starting material to form a firmly bonded, uniform mixture product of a defined thickness D, wherein the composite material is characterized in thatthat the insulation material consists of recycled residues based on a PU foam with an associated adhesive finish, and that the insulation material in the form of flakes is intended to be mixed with the nonwoven material in the composite material as a recycled material including residues of the adhesive finish.

[0006] In the composite material for manufacturing insulating layers in vehicles or buildings, a mixture of recycled foam material, including its original adhesive properties, is blended with a nonwoven material and provided as a new product or composite material. According to the invention, the bonding is achieved through simple compaction or compression using gentle heat application, without the need for additional fusion or intermediate layers of bonding agents such as added new adhesives. The inventors have surprisingly discovered that, after producing flakes from this blended material with the nonwoven, the original adhesive properties, which still adhere to the recycled PU foam, ensure a good bond simply due to the adhesive effect of the original adhesive properties.The fibers of the nonwoven material are sufficiently firmly bonded to the flakes of the PU foam insulation material, provided the size ratios are adequately maintained, due to the existing adhesive properties, which are only further reduced during the shredding process. This provides a novel, entirely recycled material for insulation purposes, incorporating the composite material according to the invention. The term "original adhesive properties" as used in the present invention refers to the adhesive layer present on the foam sheets used here as recycled material, which is incorporated into the new product with or without a cover film on the recycled foam sheets or foam layers.The original adhesive residues, which still adhere to the shredded flakes of foam material of the insulation material, are simply reused and are sufficiently strong in their adhesive effect to provide the firm bond with the nonwoven material and the fibers of the nonwoven material for a compact, surprisingly well-cohesive web material or sheet-shaped material.

[0007] According to the invention, the composite material is composed of flakes of residue from a PU foam-based insulation material and at least one other non-foam material, namely a nonwoven fabric. The nonwoven fabric itself can also be recycled residue from another manufacturing process or be based on new, non-recycled products. The inventors' investigations have revealed that the combination of the foam-based insulation flakes with residual adhesive on the one hand and the nonwoven fabric on the other has surprisingly demonstrated a good opportunity for the combined reuse of such materials for insulation purposes in the aforementioned applications: The adhesive could, for example, be an adhesive originally intended for the recycled foam material or the like.The inventive mixture of nonwoven materials, such as polyester nonwoven fibers and PU foam flakes, with residues of the adhesive finish, results in a novel composite material with a high proportion of recycled materials. This material also exhibits surprisingly good sound absorption and thermal insulation properties for the aforementioned application in buildings or similar structures. Surprisingly, tests have shown that the residues from the adhesive finish on the foam materials can be used to produce flakes that can be readily combined with nonwoven fibers in a heat-based compaction process.This process creates a compact, novel composite material for insulation purposes from essentially two materials: on the one hand, the residues of PU foam with adhesive in shredded flake form, and on the other hand, the fibers of the nonwoven material, which is either shredded nonwoven material or in the form of flat elements. These fibers are then combined in a heating oven under light mechanical compaction to form the composite. Through compaction under a heat and / or forming process according to the invention, the PU foam materials in flake form, along with the remaining original adhesive components, and the nonwoven material in the form of fibers, fiber layers, or nonwoven mats are effectively bonded together. The heat process is not a true melting process, and the materials are not bonded to each other by the fibers of the nonwoven due to a melting effect.Surprisingly, the adhesive effect of the original adhesive equipment alone results in good cohesion of the different recycled materials in this material mix within the novel composite material.

[0008] Preferred materials for the nonwoven fabric include, in particular, polyester fibers, although other fibers, such as polypropylene and / or viscose fibers or natural fibers, for example, cotton, hemp, or similar materials, can also be used. The recycled PU foam materials with adhesive finishes used in the invention are, for example, PU-based, PUR-based, or similar foams. The adhesive finishes, which are firmly bonded to the foam in the base material, are generally a combination of a firmly adhering adhesive layer and a plastic or paper release liner, which is removed before the foam material is applied in other applications. By flocculently flaking the combined adhesive finish / PU foam, new, effective insulating composite materials with a high recycled content can be produced.The composite material also has improved properties compared to other such materials without material mixing for insulation in such applications, both with regard to acoustic insulation and for thermal insulation purposes.

[0009] According to an advantageous embodiment of the invention, the flakes of insulation material, for example, PU foam with adhesive residues, are bonded together without additional adhesive or binder in the form of adhesive layers or coatings. The bonding to form a compact new product thus requires no additional application of environmentally harmful adhesive layers or adhesives or binders that are complex to apply during manufacturing. The foam residues and the nonwoven material are simply combined by placing them in a heating oven at a predetermined temperature and subjecting them to a certain degree of mechanical compaction to compact the resulting composite material according to the invention.

[0010] According to an advantageous embodiment of the invention, the nonwoven material, which can be a recycled nonwoven or a non-recycled material (i.e., new nonwoven fibers), contains a proportion of bi-component fibers with an additional adhesive effect that can be activated by heat. Such bi-component fibers enable an even better bond and adhesion between the individual components, namely the flakes of PU foam and the fibers of the nonwoven material. Thus, in the composite material according to the invention, the materials are even more firmly bonded together, and the fraying or detachment of individual components from the final product is reliably prevented.

[0011] According to a further advantageous embodiment of the invention, at least 75% of the foam insulation material and the nonwoven material are recycled. With such a comparatively high proportion of residual materials from other production processes, such as those generated when cutting panels or insulation bodies for foam insulation products, a high recycling rate is achieved with the new composite material according to the invention. The sustainability of such a composite material is therefore high. Mere disposal without any useful reuse of the raw materials is thus largely avoided, since a novel and highly effective composite material for insulation purposes can be produced from these raw materials.

[0012] According to a further advantageous embodiment of the invention, the original adhesive coating of the insulating material on the PU foam consists of an adhesive layer and a cover film or paper attached to it. After shredding such insulating material into flakes containing adhesive residues and remnants of paper covers or films, a flake material made of mixed materials is produced, which possesses a special property based on the adhesion between the adhesive coating and the foam. After bonding with nonwoven material, either recycled or non-recycled, a novel composite material is created by heating and bonding or compaction with the fibers of the nonwoven material. This composite material contains both the shredded residues of the insulating material and nonwoven fibers.Surprisingly, it has been shown that a novel recycled composite material can be created with relatively little effort, which also has particularly good properties with regard to the desired insulation effects.

[0013] According to a further advantageous embodiment of the invention, the nonwoven material contains at least 30% recycled material. The nonwoven component of the composite material thus consists of at least 30% recycled material from nonwoven waste and a further proportion of recycled material based on the foam material with adhesive properties. Overall, the recycled content in the final composite material can therefore range, for example, from 75% to 100%. With such a high proportion of nonwoven material of at least 30%, a strong bond and mat-like structure are achieved between the flakes of the foam-based insulation material. The nonwoven material with its fibers maintains the bond between the different materials, resulting in a compact composite material that allows for good further processing and use in various insulation applications.

[0014] According to a further advantageous embodiment of the invention, the foam-based insulation material and the nonwoven material are distributed essentially uniformly throughout the composite material, particularly in the width and / or thickness direction. This results in a generally homogeneous composition of the various components of the composite material. Both the at least one foam-based insulation material, or optionally other foam-based insulation materials, and the nonwoven material are distributed uniformly throughout the final composite material, thus ensuring consistent properties with regard to strength, insulation performance, and the like.

[0015] According to a further advantageous embodiment of the invention, the nonwoven material and the foam-based insulation material are combined after a comminution process by heating and / or pressing in a heating oven at temperatures in the range of at least 100°C, preferably 120°C to 150°C, under a certain degree of mechanical compaction. Heating to this temperature range causes the fibers of the nonwoven material to bond firmly with the foam flakes of the insulation material, which contain adhesive residues. Compaction occurs, for example, in the range of 20% to 100%, preferably 50% to 90%, based on the starting material. The production of the composite material thus requires no additional binder or complex joining of the individual materials. By simply heating and compacting, or...Compaction through light mechanical pressure from above and below produces a firmly bonded material from a mix of recycled materials.

[0016] According to a further advantageous embodiment of the invention, a cover layer or additional functional layer made of a film material, in particular based on PU or polyolefin films, aluminum, or in the form of a nonwoven fabric with optionally additional water-repellent properties, is provided on one side of the composite material. The cover layer or functional layer can provide additional insulation benefits or optimize the composite material for further processing. For example, aluminum foil on one side of the composite material can provide enhanced thermal insulation properties and also create other functionalities such as a vapor barrier.By applying films made of, for example, cardboard or paper to one side of the composite material, it becomes easier to process further and, for example, to mount simply by gluing them to the application surfaces. Additional functional films or layers can also be provided on the composite material made of recycled material mix within the scope of the invention, both on one side and in intermediate areas between the two outer sides of the composite material.

[0017] Further advantages, features, and aspects of the present invention will be described in more detail below with reference to several exemplary embodiments, which are further explained in conjunction with the accompanying drawings. The drawings show:

[0018] Fig. 1 shows a sectional view of a starting material for the production of the composite material according to an embodiment, wherein the PU foam material provided with an adhesive finish is made from recycled or residual materials;

[0019] Fig. 2a and

[0020] Fig. 2b shows an intermediate step in the production of an embodiment of the composite material according to the invention with the starting material of foam insulation material crushed into flakes (Fig. 2a) and a nonwoven material (Fig. 2b); and

[0021] Fig. 3 shows a schematic cross-sectional view of an embodiment of the composite material according to the invention in its finished state with crushed flakes of insulation material and with adhesive residues and nonwoven material.

[0022] Figures 1, 2a, 2b, and 3 show a first embodiment of a composite material 10 according to the invention, made of recycled material based on foam-based insulation material 1 and a nonwoven material 2, together with the starting materials for the realization of the composite material 10 according to the invention, as shown in Figure 3 as the final product, which can be used for acoustic or thermal insulation in various applications. In this embodiment, the composite material 10 essentially consists of a first insulation material 1 and a portion of nonwoven material 2 combined with it. The first insulation material 1 can also be a mixture of different insulation materials and may, for example, comprise a first, a second, a third, or a fourth insulation material based on foam materials.The composite material 10 is essentially composed of shredded insulation material 1, wherein both the foam of the insulation material 1 and an associated adhesive 3 are contained within the shredded flakes, as illustrated in Fig. 2a. In this embodiment shown in Figs. 1 to 3, the adhesive 3 of the foam-based insulation material 1 is an adhesive layer 31, which was provided with a protective film 32, for example, in the form of a release paper or a film material. Other forms of adhesive 3 may also be provided. The foam materials of an insulation material 1 thus far have been disposed of without further use, since recycling these compounds of the foam on the one hand and the adhesive 3 on the other hand was difficult to accomplish.

[0023] The adhesive 3 is thus reused in its original form with the original adhesive effect: The adhesive material still adhering to the foam flakes is simply reused to bond with the fibers of the nonwoven material 2 in the new composite material 10. The foam residues, normally present as waste products with the adhering and difficult-to-remove adhesive 3, are simply reduced in size to flakes and provided in the new composite material 10 as an aggregated, compact sheet material. The various adhesive layers and adhesive residues of the original adhesive 3 provide sufficient adhesion if the size of the flakes and the proportion of original adhesive 3 are specifically selected for the production of the new composite material 10 according to the invention.Alternatively, but not necessarily, additional new adhesives can be added if a stronger bond between the components is required. However, the main, i.e., actual, adhesive effect is produced by the original residual components of the adhesive 3 from the recycled PU foam of the insulation material 1 according to the present invention.

[0024] According to the invention, a new composite material 10 is now provided from recycled materials 1, 2, in which, despite the adhesive equipment 3, a new and effective insulation material can be provided: For this purpose, the starting material of the insulation material 1 shown in Fig. 1 is crushed into flakes while remaining together with the adhesive equipment 3 in the form of the adhesive layer 31 and the cover film 32, which are also found again in the final product of the composite material 10, distributed and fragmented.

[0025] In addition to the insulation material 1, according to the invention, a residual material or a new product of nonwoven material 2 made from nonwoven fibers, for example, on a plastic base, is used with the shredded flakes of the insulation material 1 (see Fig. 2a and Fig. 2b). Both materials are brought together in a uniform shape in the width and thickness directions such that a mixture is created between the foam flakes 1, which contain residues of the adhesive 3, and the nonwoven material 2. These two components are then subsequently combined in a heating oven under heat treatment and slight pressure by mechanical compression to form the new composite material 10 according to the invention, as shown in a schematic cross-sectional view in Fig. 3. Thus, a certain degree of mechanical compression of, for example, 20% to 90% relative to the initial material mix takes place, with simultaneous heating.

[0026] Fig. 3 shows that both the residues of the adhesive equipment 3 in the form of the cover film 32 and the adhesive layer 31, as well as the foam flakes, are firmly bonded to the added fibers of the nonwoven material 2, and a predefined thickness D according to a desired density and thickness is then present in the final product of the composite material 10.

[0027] The composite material 10 consists of an insulating material 1 based on PU foam material or another foam material, which is provided with an adhesive coating 3 both initially and in the final product. The adhesive coating 3 can be a simple layer of adhesive material or an adhesive coating 3 consisting of an adhesive 31 or binder with a cover film 32 attached to it. In the preparation of the composite material 10 according to the invention, both are ground into flakes of a defined size and further processed without prior separation of the adhesive coating 3 from the foam of the insulating material 1. The use of nonwoven material 2 serves to combine the various recycled materials into a compact, planar composite material 10 with improved insulating and soundproofing properties, both thermally and acoustically.For example, a polyester fleece or other materials such as polypropylene and / or viscose fibers or natural fibers, for example cotton, hemp and similar materials, can be used as nonwoven material 2.

[0028] The essential properties of the novel composite material 10 for insulation applications according to the invention are, according to this embodiment shown in Figs. 1 to 3, as follows:

[0029] Thickness of the composite material 10: in the range of 10 mm to 100 mm, measured according to the standard DIN 53370

[0030] Density (bulk density of the composite material) 10:50 to 150 kg / m³ 3 , preferably 75 to 120 kg / m² 3 , measured according to DIN / EN ISO 845)

[0031] Recycled material content: at least 50%, preferably at least 75% to 100%, measured on the final product of the composite material 10. Use of additional bi-component fibers in the fiber material of the nonwoven material 2 with heat-activated adhesive functionality (alternatively or optionally). Possible functional additional layers on one side of the outside of the composite material 10: films based on PU or polyolefin films, aluminum, or in the form of a nonwoven fabric with optional additional water-repellent properties for additional technical functionalities and / or to improve further processing. The technical advantages of the composite material according to the invention are: high recycling rate for otherwise non-recyclable materials and raw materials, improved thermal insulation properties, high acoustic insulation properties, and easy processing; easy production with relatively low additional costs.

[0032] The use of this composite material in products, for example as sound and / or heat insulation material, improves the environmental footprint of any end application in which this material or composite material is used.

Claims

Claims 1. Composite material (10) for realizing thermal and / or acoustic insulation, particularly in vehicles, buildings or machinery, with an overall planar, plate-like or strip-shaped basic form, comprising at least one first insulation material (1) based on PU foam or other foam materials and at least one nonwoven material (2) made of a fiber material, in particular polyester fibers, connected to or mixed with the insulation material (1), wherein the nonwoven material (2) and the insulation material (1) are brought together via a heat and / or forming process with compaction of the starting material to form a firmly bonded, uniform mixture product of a defined thickness D, characterized in thatthat the insulation material (1) consists of recycled residues based on a PU foam with an associated adhesive equipment (3) and that the insulation material (1) is intended to be mixed with the nonwoven material (2) in the composite material (10) in the form of flakes as a recycled material including residues of the adhesive equipment (3).

2. Composite material (10) according to claim 1 , characterized in that the nonwoven material (2) and the flakes of insulating material (1) are bonded together without additional adhesive material or binder in the form of adhesive layers or layers.

3. Composite material (10) according to claim 1 or 2, characterized in that the nonwoven material (2) contains a proportion of bi-component fibers (4) with an additional adhesive effect that can be activated by heat.

4. Composite material (10) according to one of the preceding claims, characterized in that it contains at least 75% recycled material from the foam insulation material (1) and the nonwoven material (2).

5. Composite material (10) according to one of the preceding claims, characterized in that the original adhesive equipment (3) of the insulating material (1) on the PU foam consists of an adhesive layer (31) and a cover film (32) or paper.

6. Composite material (10) according to one of the preceding claims, characterized in that a proportion of recycled material of the nonwoven material (2) of at least 30% is provided.

7. Composite material (10) according to one of the preceding claims, characterized in that the insulating material (1) and the nonwoven material (2) are present in a substantially uniform distribution.

8. Composite material (10) according to one of claims 1 to 6, characterized in that the nonwoven material (2) and the insulation material (1) are brought together after a comminution process by a heating / pressing treatment in a heating oven with temperatures of at least 100° C, preferably 120°-150° C, under simultaneous mechanical compression, in particular a compression of 20% to 90% based on the starting material.

9. Composite material (10) according to one of the preceding claims, characterized in that a functional or covering layer (4) made of a film material, in particular based on PU or polyolefin films, aluminum, or in the form of a nonwoven fabric with optional additional water-repellent properties, is provided on one side of the composite material (10) for additional functionalities and improvement of further processing.

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