Cavity wall insultation comprising cork and polymer foam beds

Abstract

The present invention relates to an insulation material suitable for insulating a building, the insulation material comprising a mixture of bio-based cork granulate, adhesive, and plastic beads, wherein the proportion of bio-based material is at least 50% by mass. The invention further relates to a composition of bio-based cork granulate, adhesive, and plastic beads and to the use of the insulation material for manufacturing an at least substantially dimensionally stable volume insulation material. The invention also relates to a method for manufacturing such an at least substantially dimensionally stable volume insulation material.

Description

[0001] The present invention, according to a first aspect, relates to an insulation material, either in a cured or uncured state, for environmentally friendly insulation of a building, particularly for insulating a cavity wall of a building.

[0002] Swiss patent document CH 230228 discloses an insulating wall comprising at least one hollow space filled with loose insulation material, which is made accessible via at least one sealable opening for inspection and replacement of the insulation material. Cork is mentioned as an example of such insulation material.

[0003] It is known in the prior art to insulate (existing) cavity walls by filling the cavity with cork granules, also referred to as cork aggregate, by blowing bio-based cork granulate into the cavity from the top of the wall. However, a disadvantage of loose-fill insulation materials, such as bio-based cork granulate, is that in the event of a wall leakage-due to wear, for instance-or if an opening is deliberately made in the cavity wall during construction work, the bio-based cork granulate may easily flow out of the opening. In the worst-case scenario, a cavity wall filled with loose-fill insulation material may completely empty out.

[0004] It is also known to inject polymer insulation beads mixed with a dispersion adhesive into a cavity as insulation material. The polymer insulation beads are bonded together by the curing adhesive, thereby preventing or at least minimizing the risk of the insulation beads flowing out through an opening in the wall.

[0005] However, a reliable adhesive for bonding cork granulate in a similar manner is not known. International patent application WO 2012 / 116461 discloses a cavity wall insulation material comprising a mixture of 22% by weight bio-based cork granulate, 70% by weight gypsum, and 8% additives, to which 22% water is subsequently added. The gypsum in the mixture then hardens, forming a dimensionally stable volume in which the bio-based cork granulate is incorporated as insulation material within the cavity wall.

[0006] A drawback of this known cavity wall insulation material is that only a small proportion of cork can be incorporated. Even if the cork used in the known insulation material is bio-based, it still accounts for less than a quarter of the total composition. Moreover, polymer insulation beads, such as expanded polystyrene (EPS), exhibit a significantly lower thermal conductivity value (lambda value) and therefore possess superior thermal insulation properties compared to gypsum.

[0007] Accordingly, the present invention aims, according to a first aspect, to provide an insulation material that comprises at least 50% by weight bio-based material and possesses at least equivalent insulating properties to 100% loose-fill bio-based cork granulate. To this end, the present invention provides an insulation material suitable for insulating a building, wherein the insulation material comprises a mixture of bio-based cork granulate, an adhesive, and polymer beads, with the proportion of bio-based material being at least 50% by weight.

[0008] Since cork granulate has a higher density (approximately 70 kg / m 3< ) than polymer beads (expanded polystyrene (EPS) beads, for example, approximately 13 kg / m 3< ), an insulation material containing 50% by weight bio-based cork granulate comprises half of its weight in cork granulate, yet the cork granulate accounts for only about 15% of the total volume. The polymer beads can be relatively easily bonded together by the adhesive, thereby also encapsulating the bio-based cork granulate within the polymer beads. Upon curing, an at least substantially dimensionally stable insulation material is formed.

[0009] Polymer beads, such as EPS, exhibit a superior thermal conductivity value (lambda value of 0.032 W / m·K) compared to cork (lambda value of 0.041 W / m·K). Consequently, the insulation value of the mixture is superior to that of bio-based cork granulate alone, particularly since air can more easily flow through loose-fill bio-based cork granulate compared to the bonded mixture. Accordingly, the objective of the present invention is achieved.

[0010] Bio-based cork granulate is challenging to bond, especially when a mixture of bio-based cork granulate and adhesive is injected into a substantially enclosed space where it must cure under ambient conditions. International patent application WO 2017 / 164757 discloses a mixture of cork and polyethylene, wherein the mixture is subjected to a pressure of 300-450 kN and a temperature of 160-200°C to form panels. However, within a cavity wall, such a mixture cannot be exposed to either such pressure or temperature. Thus, this mixture is unsuitable for cavity wall insulation, for example.

[0011] From an environmental perspective, it is preferable for the bio-based cork granulate content to be at least 50% by weight, preferably at least 60% by weight, and even more preferably at least 70% by weight. At 70% by weight bio-based cork granulate and 20% by weight polymer beads, the volume of polymer material within the insulation material still exceeds that of cork, thereby ensuring effective encapsulation of the cork granulate within the polymer bead and adhesive mixture.

[0012] When the proportion of adhesive is at least 10% by weight, preferably at least 15% by weight, and more preferably at least 20% by weight, adequate adhesion between at least the polymer beads is ensured.

[0013] It is preferred that the insulation material consists of at least 95% by weight, preferably at least 97% by weight, more preferably at least 99% by weight, and most preferably 100% by weight of bio-based cork granulate, adhesive, and polymer beads. In other words, once the insulation material has cured, it consists at least substantially entirely of these three materials.

[0014] If the adhesive is a bio-based adhesive, such as natural latex derived from rubber tree sap or starch-based adhesive, the proportion of bio-based material is further increased, thereby enhancing the environmental sustainability of the insulation material.

[0015] In a preferred embodiment of an insulation material according to the present invention, the insulation material comprises 70 ± 5% by weight bio-based cork granulate, 20 ± 7.5% by weight polymer beads, and the remainder being adhesive.

[0016] It is preferred that the bio-based cork granulate and the polymer beads are at least substantially uniformly mixed within the insulation material. This mixing process can be performed well in advance of application, for example, by pre-mixing the materials in the correct ratio and packaging them accordingly, so that the mixture can be discharged from the packaging into a storage hopper at the construction site. If the mixture is not sufficiently uniform in the packaging, further mixing can take place in the hopper or later in the injection tool, which is referred to in this document as a mixing gun.

[0017] Mixing may also occur during application, wherein two separate storage hoppers at the construction site-one containing cork granulate and the other containing polymer beads-are connected to a suction hose leading to the injection or mixing gun. The desired mixing ratio is adjusted by valve settings below the hoppers. The mixing gun then ensures uniform mixing of the cork granulate and polymer beads.

[0018] For optimal adhesion of at least the polymer beads and effective encapsulation of the bio-based cork granulate within the polymer beads, it is preferred that the bio-based cork granulate, polymer beads, and adhesive are at least substantially uniformly distributed in the mixture.

[0019] It is preferred that the polymer beads comprise, and more preferably consist of, expanded polystyrene (EPS) beads. EPS beads exhibit excellent thermal insulation properties and can be effectively bonded together within a cavity wall.

[0020] The polymer beads are optimally processed and injected into a cavity wall when their particle size ranges from 1.5 to 6 mm, preferably from 2 to 4 mm or 3 to 5 mm.

[0021] A stable mixture of (dimensionally stable) insulation material is achieved when the particle size of the cork granulate also falls within the range of 2 to 6 mm, preferably 2 to 4 mm or 3 to 5 mm.

[0022] According to a second aspect, the present invention relates to a kit of components for producing an insulation material as defined in one or more of the preceding claims, wherein the kit comprises at least bio-based cork granulate, adhesive, and polymer beads. The kit is configured such that, when combined, the resulting insulation material may comprise at least 50% by weight bio-based material. With this second aspect, the present invention aims to achieve an objective corresponding to that of the first aspect.

[0023] According to a third aspect, the present invention relates to the use of a kit of components according to the second aspect for the production of an insulation material that is at least substantially, and in this aspect, dimensionally stable, as defined in the first aspect of the invention. The purpose of the third aspect is to provide an application method that corresponds to the objective of the first aspect.

[0024] According to a fourth aspect, the present invention relates to a method for manufacturing a volume of insulation material that is at least substantially dimensionally stable. The method comprises the steps of: providing a predetermined quantity of bio-based cork granulate; providing a predetermined quantity of adhesive; providing a predetermined quantity of polymer beads; mixing the predetermined quantity of bio-based cork granulate, the predetermined quantity of adhesive, and the predetermined quantity of polymer beads; and allowing the adhesive to cure to obtain a volume of insulation material that is at least substantially dimensionally stable.

[0025] The step of mixing the three materials may, but need not, be performed in a single operation. For example, two of the three materials may be mixed first, followed by the addition of the third material either immediately thereafter or at a later stage. In one embodiment, the cork granulate and polymer beads may be pre-mixed at a production facility or storage location, and the adhesive is added at a later stage, such as at the construction site where a building is being insulated.

[0026] Preferably, the adhesive comprises a type of adhesive that cures under "normal" environmental conditions. This means that during the curing step, no external factors such as pressure or elevated temperature need to be applied, and the mixture does not need to be exposed to pressure or high temperatures for curing.

[0027] In a preferred embodiment of the method according to the present invention, the at least substantially dimensionally stable volume of insulation material is formed as a hardened insulation material within the cavity of a cavity wall. In other words, after or during the step of mixing the predetermined quantity of bio-based cork granulate, the predetermined quantity of adhesive, and the predetermined quantity of polymer beads, the mixture is transported into the cavity wall, where it cures into an at least substantially dimensionally stable volume of insulation material.

[0028] It is preferred that the bio-based cork granulate, polymer beads, and adhesive are supplied from respective storage reservoirs containing bio-based cork granulate, polymer beads, and adhesive, respectively, to a mixing gun, from which the mixture is injected into the cavity of a cavity wall. The mixing gun may serve a dual function as both a mixing gun and an injection gun. In this case, the various materials are mixed shortly before being injected into the cavity wall.

[0029] If the adhesive is transported separately from the bio-based cork granulate and polymer beads to the mixing gun, where it is then combined with the bio-based cork granulate and polymer beads, a fast-curing adhesive can be used. As a result, the insulation material mixture collected within the cavity solidifies into a dimensionally stable form shortly after injection into the cavity.

[0030] The present invention will now be further explained with reference to the accompanying drawings, which depict a preferred embodiment of the invention. The following figures are shown: Fig. 1: A schematic view of an arrangement for filling a cavity of a cavity wall with a mixture of bio-based cork granulate, insulation beads, and adhesive according to the present invention; Fig. 2: A schematic view of a mixing gun, including the adhesive supply line, bead supply line, and compressed air supply line, for insulating a cavity wall with an insulation material according to the present invention; Fig. 3: A view of an arrangement for producing a dimensionally stable volume of a mixture of bio-based cork granulate, insulation beads, and adhesive in an enclosed space according to the present invention; and Fig. 4: A top view of a dimensionally stable volume of insulation material produced with the arrangement from Fig. 3 according to the present invention.

[0031] Fig. 1 schematically illustrates an arrangement for filling a cavity 1 of a cavity wall 2 with a mixture of bio-based cork granulate, insulation beads, and adhesive. A cavity wall consists of two parallel components: an outer and an inner wall, also known as the outer and inner leaves. The open space between these walls is referred to as the cavity. This cavity prevents moisture penetration from the exterior and also serves as an insulating barrier. To enhance thermal insulation, insulation material can be added to the cavity.

[0032] A reservoir 3 contains a mixture of 80% bio-based cork granulate and 20% EPS beads, which have been pre-mixed by stirring. A mixture conduit 4 connects the reservoir 3 to a mixing gun 5. Compressed air is supplied to the mixing gun 5 via a compressed air line 6 from an unshown compressed air cylinder. The compressed air causes the bio-based cork granulate and EPS beads to be drawn into the mixing gun 5. Dispersion adhesive from an adhesive container 7 is also supplied via an adhesive line 8 to the mixing gun 5. In the mixing gun 5, described in more detail with reference to Fig. 2, the dispersion adhesive is mixed with the bio-based cork granulate and EPS beads. The resulting mixture is then injected through an opening in the outer leaf 2a of the cavity wall 2 into the cavity 1, where the dispersion adhesive hardens to form a dimensionally stable volume of insulation material. The mixing gun 5 can also be used for insulating other spaces, but it is primarily intended for insulating cavity walls in existing buildings.

[0033] Fig. 2 provides a more detailed view and elucidation of the mixing gun 5. The mixing gun 5 is configured to mix the bio-based cork granulate, EPS beads, and dispersion adhesive, that are transported to the mixing gun as described hereinabove and to successively apply the mix as insulation material into the cavity of cavity wall 2.

[0034] The mixture of bio-based cork granulate, EPS beads, and adhesive is discharged into the cavity wall 2 of a building through an outlet 30 with an outlet opening 37, under the influence of compressed air. In this example, an extension and / or nozzle 31 is screwed onto the outlet 30. The extension and / or nozzle 31 is configured to penetrate through a pre-drilled filling hole in the inner leaf 2a into the cavity 1 of cavity wall 20. The extension and / or nozzle 31 serves as an extension of the outlet 30. The diameter of extension and / or nozzle 31 is typically adjusted to match the diameter of the filling hole drilled in the wall to penetrate into the cavity 1. Typically, drilling diameters are 18 mm, 16 mm, or 14 mm.

[0035] The mixing gun 5 further includes a transition section 29 that connects the mixing chamber 28 to the outlet 30. This transition section is thus configured to facilitate the flow of the mixed biobased cork, EPS beads and adhesive toward the outlet 30. The mixing gun 5 also features a compressed air connection 27 for connecting a compressed air supply line to drive the mixture to the mixing gun toward the outlet opening 37.

[0036] The connection 35 for the mixture of bio-based cork granulate and EPS beads is configured for connection to a mixture conduit 4 for supplying the mixture of biobased cork granulate and EPS beads into mixing chamber 28. As shown in Fig. 2, the mixture conduit 4 is arranged in a loop 22 near its connection to mixing gun 5, ensuring that the mixture supplied therein follows a curved path before entering the mixing chamber 28. The peripheral velocity of the mixture through loop 22 corresponds to the velocity at which it enters the mixing chamber 28. This advantageously results in the mixture entering the mixing chamber 28 in under a predetermined angle, the angle being chosen such that the resistance to which the mixture is exposed as it flows toward outlet 30 is minimized.

[0037] The adhesive-connection 36 is configured for connection of a adhesive line 8 for supplying adhesive into mixing chamber 28 for the supply of adhesive to the mixing chamber 28. Adhesive line 8 includes a shut-off valve 25 and a control valve 24 for completely shutting off, or opening, respectively, the line 8 of adhesive for controlling the flow of adhesive.

[0038] The connection 36 of the line of adhesive is oriented perpendicularly to the mixing chamber 28, meaning it is perpendicular to the direction of compressed air flow in the mixing gun 5.

[0039] As elucidated hereinabove, reaching the mixing chamber 28, the adhesive that is supplied passes through control valve 24 and then through shut-off valve 25. This arrangement advantageously reduces the amount of adhesive present in the line of adhesive 8 between shut-off valve 25 and mixing chamber 28. When the adhesive line 8 is shut off by the shut-off valve 25, it is possible that adhesive present in the line 8 of adhesive between shut-off valve 25 and mixing chamber 28 is pressed into the mixture conduit 4. A disadvantageous effect thereof is that the mixture conduit 4 may become clogged or polluted. The sequence of the control valve 24 and the shut-off valve 25 in the line 8 of adhesive results in the amount of adhesive stocked between the line 8 of adhesive and the mixing chamber being reduced, which has a positive effect on the clogging and pollution of the mixture conduit 4.

[0040] Fig. 3 shows a view of an arrangement, at least in a cutaway view and a part thereof, with which a dimensionally stable volume of a mixture of bio-based cork granulate, insulation beads, and adhesive according to the present invention can be produced in an enclosed space. The starting point is a wooden mold 40, of which only a part of the bottom 41 and partition walls 42 are visible in Fig. 3. The mold 40 further has a top wall and perimeter walls, which are not visible in Fig. 3. The perimeter walls, the bottom 41, the top wall, and the four partition walls enclose four chambers. Before use, the top wall is removed, and the chambers are filled with, in this embodiment, a mixture 43 of 70% by mass bio-based cork granulate, 20% by mass EPS beads, and 10% by mass adhesive. The top wall is placed, and the mixture 43 cures. Thereafter, the top wall and, in this embodiment, also the perimeter walls are removed. Fig. 3 shows the mold 40 with three dimensionally stable volumes of thus-formed insulation material.

[0041] Fig. 4 shows a top view of a dimensionally stable volume insulation material manufactured with the arrangement from Fig. 3. In Fig. 4, it can be seen that the bio-based cork granulate and the EPS beads are not entirely uniformly distributed but are sufficiently mixed. This figure clearly shows that the bio-based cork granulate is enclosed between the bonded EPS beads. It is evident that, in the manner described with reference to Figs. 3 and 4, various different shapes and sizes of forms can be manufactured.

[0042] The present invention has been explained based on some embodiments shown in the accompanying figures and described above. However, it should be clear that many variations, whether or not obvious to a skilled person, are conceivable within the scope of protection of the present invention as defined in the appended claims. For instance, this document is based upon the use of bio-based cork granulate. In the example, 70% by mass of bio-based cork granulate is used because, at least according to Dutch regulations, insulation material may be referred to as bio-based if it comprises at least 70% by mass of bio-based material. If compliance with that percentage is not required, the proportion of bio-based cork granulate can be reduced. However, cork granulate has better sound insulation properties than EPS beads. That may be a reason to increase the proportion of cork granulate. Naturally, as an alternative to the EPS beads in the embodiment, a different type of bead may be used.Reference Numerals

[0043] 1 -cavity 2 -cavity wall 2a -outer leaf of cavity wall 3 -reservoir 4 -mixture conduit 5 -mixing gun 6 -compressed air line 7 -adhesive container 8 -line of adhesive 27 -compressed air connection 28 -mixing chamber 29 -transition section 30 -nozzle 31 -extension / nozzle 35 -mixture connection 36 -adhesive connection 37 -outlet opening 40 -mold 41 -base 42 -partition wall

Claims

1. An insulation material suitable for insulating a building, the insulation material comprising a mixture of bio-based cork granulate, adhesive, and plastic beads, wherein the proportion of bio-based material is at least 50% by mass.

2. The insulation material according to claim 1, wherein the proportion of bio-based cork granulate is at least 50% by mass, preferably at least 60% by mass, and more preferably at least 70% by mass, and / or wherein the proportion of adhesive is at least 10% by mass, preferably at least 15% by mass, and more preferably 20% by mass.

3. The insulation material according to claim 1 or 2, wherein the insulation material consists of at least 95% by weight, preferably at least 97% by weight, further preferably at least 99% by weight or 100% by weight of bio-based cork granulate, adhesive, and plastic beads.

4. The insulation material according to one or more of the preceding claims, wherein the adhesive is a bio-based adhesive, preferably natural latex derived from the sap of the rubber tree or an adhesive based on starch.

5. The insulation material according to one or more of the preceding claims, comprising 70 ± 5% by mass of bio-based cork granulate, 20 ± 7.5% by mass of plastic beads, and the remainder being adhesive.

6. The insulation material according to one or more of the preceding claims, wherein the bio-based cork granulate and the plastic beads are at least substantially uniformly mixed, and / or wherein the bio-based cork granulate, the plastic beads, and the adhesive are at least substantially uniformly mixed.

7. The insulation material according to one or more of the preceding claims, wherein the plastic beads comprise EPS beads, preferably are EPS beads.

8. The insulation material according to one or more of the preceding claims, wherein the particle size of the plastic beads is 1.5-6 mm, preferably 2-4 mm or 3-5 mm, and / or wherein the granulate size of the cork granulate is 2-6 mm, preferably 2-4 mm or 3-5 mm.

9. A set of components for manufacturing an insulation material according to one or more of the preceding claims, the set comprising at least the components bio-based cork granulate, adhesive, and plastic beads.

10. Use of a set of components according to claim 9 for manufacturing a dimensionally stable volume insulation material.

11. A method for manufacturing a dimensionally stable volume insulation material according to claim 1.

12. The method according to claim 11, the method comprising the steps of: - providing a predetermined amount of bio-based cork granulate; - providing a predetermined amount of adhesive; - providing a predetermined amount of plastic beads; - mixing the predetermined amount of bio-based cork granulate, the predetermined amount of adhesive, and the predetermined amount of plastic beads; and - allowing the adhesive to cure to obtain the dimensionally stable volume insulation material.

13. Use of the method according to claim 11 or 12 for insulating a cavity wall, wherein the dimensionally stable volume insulation material is a cured insulation material in the cavity of the cavity wall.

14. The method according to claim 12, wherein the bio-based cork material, the plastic beads, and the adhesive are supplied from respective reservoirs of bio-based cork material, plastic beads, and adhesive to a mixing gun and introduced from the mixing gun into a cavity of a cavity wall.

15. The method according to claim 14, wherein the adhesive is transported separately from the bio-based cork material and the plastic beads to the mixing gun and mixed with the bio-based cork material and the plastic beads within the mixing gun.

Images