NL2030120B1

NL2030120B1 - Vegetable material as insulation, filling or packaging

Info

Publication number: NL2030120B1
Application number: NL2030120A
Authority: NL
Inventors: Coenraad Verboom Johannes; Dijkstra Biense
Original assignee: Bouwgroep Dijkstra Draisma B V
Priority date: 2021-12-13
Filing date: 2021-12-13
Publication date: 2023-06-27

Abstract

The present invention relates to a composition for insulation, packaging and/or filling, comprising at least one biobased material that has been cut into particles and loose fill insulation material. It furthermore relates to a method for producing such.

Description

VEGETABLE MATERIAL AS INSULATION, FILLING OR PACKAGING

FIELD OF THE INVENTION

The invention relates to a composition for insulation, packaging and/or filling, such as for example filling of a cavity wall. The composition comprises at least one biobased material that has been cut into smaller pieces, such as for example cattail. The invention further relates to the method for producing such materials.

BACKGROUND

The use of bio-based materials within construction is seen as a means of improving sustainability within our built environment. Whilst historically, some of these materials have been the most used construction materials, there has been a renewed interest in the use of these traditional materials, as well as the use of other natural materials to develop more adaptable products. How these materials behave depends upon the chemical constituents and the structure of the materials.

The use of biobased materials as insulation material is relatively new in modern constructions.

Regardless of whether you are dealing with masonry or cavity walls, they will both need to be insulated although using different materials and applying different insulation methods. Biobased insulation material can also be applied under floors and roofs, both in residential and commercial buildings. Systems for spraying, pouring or injecting the insulation materials can be chosen.

Various plant materials are known that can be processed into isolation materials, having reasonable heat and sound insulation properties. Sometimes these materials are raw materials that are only available to a limited extent or require long transport routes, such as e.g. cork and coconut fiber.

Furthermore, many bio-based insulation materials have only moderate insulation properties due to the structure of the starting material.

In DE-A-19757418 cattail is being used as insulating material. The aerenchyma structure of the cattail leaves is still largely preserved. The leaf material is cut through longitudinally once or more, only at the outer skin, which is softened by steam or liquid processing. Insulating particles and a bonding agent are pressed in at right angles to the leaf surfaces, to form a solid isolating material.

The use of biobased materials as insulation material requires further optimization. Specially the insulating value requires further improvements. Also the flexibility in use of biobased materials can be further improved.

SUMMARY

There is a need for providing an insulation composition that comprises biobased materials, that can be suitably applied in both domestic and industrial applications, and offers a stable and sufficient insulation properties. One of the examples of a biobased material is cattail. Although cattail not always provides sufficient insulation properties, there are ways to improve this. There is also a need for providing an insulation material composition that comprises biobased materials, that can be used as loose fill material for various applications.

According to a first aspect of the invention, there is provided a composition for insulation, packaging and/or filling, comprising at least one biobased material that has been cut into particles and loose fill insulation material.

According to a second aspect of the invention, there is provided a use of the composition as insulation material into a cavity wall.

According to a further aspect of the invention there is provided a method for preparing the insulation material, comprising at least one biobased material, comprising the steps of cultivation of the biobased material in the field; harvesting the biobased material; cutting the biobased material into particles with a height h in the range of from 1 up to 100 mm; drying the cut biobased material to a dry matter content of at least 70%; sieving the dried biobased material into a small, middle and large fraction; and adding loose fill insulation material to the sieved biobased materials.

DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art which this invention belongs to. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The present invention is a composition for insulation, packaging and/or filling. The composition comprises at least one biobased material that has been cut into particles and loose fill insulation material. This loose fill material can be the same biobased material, but it might also another biobased material or a non-biobased material.

Generally speaking are biobased materials, materials that are intentionally made from substances derived from living (or once-living) organisms, These materials are sometimes referred to as biomaterials, but this word also has another meaning. Strictly, the definition could include many common materials such as wood and leather, but it typically refers to modern materials that have undergone more extensive processing. Bio-based materials or biomaterials fall under the broader category of bioproducts or bio-based products which includes materials, chemicals and energy derived from renewable biological resources. For the current application biobased materials are materials obtained from a biological source. This can be either plants, trees, grasses or fungi.

Bio-based materials are often biodegradable, but this is not always the case. The bio-based materials used in the present invention are preferably plant based materials. Various plant materials are known which can be processed into insulation materials and then have more or less good heat and sound insulation properties. Sometimes they consist of raw materials that are only available to a limited extent and / or require long transport routes, such as cork or coconut fiber. Many insulation materials have only moderate insulation properties due to the fabric structure of the starting material and / or due to the manufacturing process.

Advantageously, the composition of the present invention comprises at least 2 different biobased materials.

Advantageously, the biobased materials are selected from cattail, opium poppy, marsh plants, hemp, flax, miscanthus, common rush and soft rush, more preferably cattail, opium poppy, marsh plants, miscanthus, common rush and soft rush, even more preferably cattail.

Cattails (botanical name: Typha) with their most common species Typha latifolia L. and Typha angustifolia L. are wild plants that can be easily cultivated in the northern hemisphere, guarantee a high yield (10 to 40 t dry matter per hectare per year) and it can be environmentally friendly cultivated. They can be easily cultivated on wet areas, whereby the cultivation can be linked to measures for water protection. They are able to bind the excess nutrients from wastewater and surface water so that they can be used in sewage treatment plants. They can also be used to utilize and stabilize rewetted peat soils.

Opium poppy, also called bread seed poppy, or Papaver somniferum, is a species of flowering plant in the family Papaveraceae. It is the species of plant from which both opium and poppy seeds are derived and is also a valuable ornamental plant, grown in gardens. Its native range is probably the eastern Mediterranean, but is now obscured by ancient introductions and cultivation, being naturalized across much of Europe and Asia. Papaver somniferum is an annual herb growing to about 100 cm (40 in) tall. The plant is strongly glaucous. giving a greyish-green appearance, and the stem and leaves bear a sparse distribution of coarse hairs. The large leaves are lobed, the upper stem leaves clasping the stem, the lowest leaves with a short petiole. The flowers are up to 30-100 mm (1-4 in) diameter, normally with four white, mauve or red petals, sometimes with dark markings at the base. The fruit is a hairless, rounded capsule topped with 12-18 radiating stigmatic rays, or fluted cap. All parts of the plant exude white latex when wounded.

Common rush and soft rush are flowering plants distinguished by cylindrical stalks or hollow, stemlike leaves. They are found in temperate regions and particularly in moist or shady locations.

The rush family (Juncaceae) includes Juncus, the common rushes, and Luzula, the woodrushes.

Common rushes are used in many parts of the world for weaving into chair bottoms, mats, and basketwork, and the pith serves as wicks in open oil lamps and for tallow candles (rushlights). J. effusus, called soft rush, is used to make the tatami mats of Japan.

Marsh plants differ depending mainly on their location and salinity. Both of these factors greatly influence the range and scope of animal and plant life that can survive and reproduce in these environments. The three main types of marsh are salt marshes, freshwater tidal marshes, and freshwater marshes. These three can be found worldwide and each contains a different set of organisms. Marshes can often be found at the edges of lakes and streams, where they form a transition between the aquatic and terrestrial ecosystems. They are often dominated by grasses, rushes or reeds.

Advantageously, the biobased materials are from peat wetlands.

The composition of the present invention preferably comprises biobased material that at least comprises cattail, combined with at least one out of the group of rushes, opium poppy, marshy plants, miscanthus, common rush and soft rush.

Advantageously, the particles of the biobased material have a height h in the range of from 1 up to 100 mm. The height h is defined as the height along the axis of the leave of the plant. Figures 1 shows a drawing of a cattail, and in Figure 2 the height high is given, in this example of the leaves of a cattail. This applies also for other plant materials. In case more than one biobased material is present in the composition, preferably at least one of the biobased materials has been cut into particles with a height h in the range of from 5 up to 30 mm.

Loose fill insulation may comprise small particles of fibber, foam, granules, flakes, shreds or other particles that may conform to any space without disturbing structures or finishes. Advantageously, it is blown or poured into a cavity or hand packed. The air pockets created within- and/or between the material contributes heavily to the insulating qualities of the material.

The loose fill material of to the present invention, preferably has a lower lambda ( so higher insulation value) than the biobased materials. Lambda (2) Value (thermal conductivity) is a measure of the rate at which heat passes through a material. The lambda value, also portrayed as ‘K-value’ or “A-value’, measures a product’s thermal conductivity in units of watts per unit

S thickness per degree temperature difference across that unit thickness (W/m-K). A good insulation will have as low a lambda value as possible to reduce heat loss. The lambda value of the biobased material is preferably in the range of from 0.04 up to 0.06, while for the loose fill material the lambda value is preferably in the range of from 0.01 up to 0.05. Materials that might be used as loose fill material, besides the biobased materials as described earlier, are the more conventional materials, such as cellulose (with a à of between 0.036 and 0.038) , expanded polystyrene beads (with a à of between 0.035 and 0.036) or flakes from mineral wool or fiberglass (with a à of between 0.032 and 0.040).

The size of the loose fill material is preferably smaller than the particle size of the biobased material. The loose fill material preferably has a size of which the height h is at most 30 mm. more preferably at most 20 mm, even more preferably at most 10 mm. The height of the loose fill material is preferably at minimum 5 mm for biobased materials. For conventional loose fill materials it may even be lower, as these materials may comprise isolating air pockets in the material itself. The height of the loose fill material based on conventional materials is preferably at minimum 2 mm. The loose fill material fills the cavities between the larger particles of the biobased material, which improves the insulating effect. A minimum size of 5 mm is preferably used to prevent smaller so called dust particles from filling the room which occurs between the biobased particles. This allows for extra standing air in the material which will increase the insulating properties of the material. In addition to improving the insulating properties of the material it might also become easier to apply the product due to the tendency of dust to blow out of the hollow wall during the application of the insulation material. A maximum of 50 mm is preferably used to prevent the blowing in machines and the tubes connection the wall to the machine from jamming.

The insulation material might be created from several different types of (biobased) feedstock, harvested from plants. These can be cultivated with the specific goal of producing insulation material. However, it is also possible to use materials not specifically cultivated for this purpose

This is most likely waste material. By using waste material the environmental impact of the material is decreased and the availability of the feedstock is increased. It is preferred that at least one of the biobased materials is a material specifically cultivated for the purpose of insulation, while at least the other biobased material is a waste material.

In case the composition of the invention comprises at least 2 biobased materials, the ratio between the at least two biobased materials varies depending on the availability during the seasons. More preferably, at least 30 wt% cattail is present. Preferably, all material is applied with a pressure between 50 and 110 kg/m.

The cut biobased material is preferably sieved using a drum sieve and/or a shaking sieve. The difference between the sieves is the motion used to separate the material. Separation takes place by forcing the material through the steve. Each sieve has different parts which filter out different particle sizes. The material has to pass through all of them. In a drum sieve rotation is used to force the material through. In a shake sieve a shaking motion is used. So far the best results are achieved using a shaking sieve. It is thus more preferred to use a shaking sieve to sieve the biobased material.

Preferably, sieving of the cut biobased materials leads to 3 fractions, a fine fraction, a middle fraction and a large section, wherein the fine fraction comprises particles having a size smaller than 10 mm, more preferably smaller than 5 mm, the middle fraction comprises particles with a size in the range of from 5 up to 100 mm, more preferably in the range of from 5 up to 50 mm, even more preferably in the range of from 5 up to 30 mm and the large fraction comprises particles larger than 100 mm, more preferably larger than 50 mm, even more preferably larger than 30 mm. The large fraction is preferably cut again into smaller pieces and fed back to the sieving process.

Additives can be used in the composition, Preferably, at least one additive is added to the composition. More preferably, at least one of the additives is an adhesive, even more preferably a latex based adhesive or a starch based adhesive, even more preferably a starch based adhesive.

More preferably, at least one of the additives is a fire deterrent and / or a mould deterrent, even more preferably boric acid, boric salts, aluminum sulphate and/or ammonium sulphate, most preferably ammonium sulphate.

The composition of the present invention might be used as insulation material into a cavity wall.

Preferably, it is used as vapor open construction. This construction is used to allow moisture which might accumulate in the construction by condensation to exit the construction. Because the material is biobased keeping the moisture levels in the construction as low as possible is preferred.

The composition for insulation comprising at least one biobased material is prepared via the following steps: a. cultivation of the biobased material in the field;

b. harvesting the biobased material; c. cutting the biobased material into particles with a height h in the range of from 1 up to 100 mm; d. drying the cut biobased material to a dry matter content of at least 70%; e. sieving the dried biobased material into a small, middle and large fraction; and f. adding loose fill insulation material to the sieved biobased materials.

The large fraction is preferably recycled to step c.

In the method for the composition for insulation, the composition comprises preferably at least 2 different biobased materials. These biobased materials are preferably selected from cattail, opium poppy, marsh plants, miscanthus, common rush and soft rush.

Cultivation of the biobased material is preferably performed in at least one field specifically designed for wet agriculture. The advantage of wet agriculture on peatlands is a large reduction of

CO: per ha used for wet agriculture. Dry peatlands will oxidize over time and emit a large amount of CO». By wetting these peatlands oxygen can no longer reach the peat and does not oxidize anymore. This can save tens of tons of CO: per hectare depending on the amount of water added to the peatlands.

Harvesting of the biobased material is preferably performed using a technique that keeps the material as intact as possible, more preferably the technique used is a bucket mower.

The biobased material is preferably cut into at least particles with a height h in the range of from 1 up to 100 mm, preferably in the range of from 5 up to 50 mm, more preferably in the range of from 5 up to 30 mm. The height h is defined as the height along the axis of the leave of the plant.

Figures 1 shows a drawing of a cattail, and in Figure 2 the height high is given, in this example of the leaves of a cattail. This applies also for other plant materials. In case the leaves of the plant are broader than 100 mm, it is preferred to cut the leaves of the plant also in the longitudinal direction such that the width of the particles is preferably at most 100 mm, more preferably at most 50 mm, even more preferably at most 30 mm. Thus the shape of the biobased material is preferably varying between approximately squares and approximately rectangles and approximately trapezoid.

Advantageously, the particles used in the insulation material are of different sizes varying between approximately squares and approximately rectangles and approximately trapezoid. The best way to describe the sizes is preferably between 5 mm and 30 mm in width and preferably between 5 mm and 30 mm in height and any of the corresponding sizes between these widths and heights. The thickness will always be the thickness of the part of the plant that is being used. This might range of from 0,1 mm up to 2 mm for leaves and up to 15 mm for the stem for example.

For example: one particle can be 5 mm x 5 mm, the other one Smm x 30 mm and the last one 30 mmx 10mm or 11 mm x 26 mm. As long as either the height and/or the width is in a preferred embodiment not greater than 30 mm.

The cut biobased material is preferably dried naturally. Drying naturally occurs for example by using potato boxes measuring roughly 1m x 1m x 1m. These are filled with the wet material and placed in well ventilated halls. The dry matter content is measured regularly until the required dry matter content of preferably > 70% is achieved. Drying using potato boxes while using waste heat of a higher temperature is preferred due to the speed of the process. More preferably, the cut biobased material is dried to a dry matter content of at least 80%, preferably at least 85%, more preferably at least 90%.

The dried biobased material is preferably sieved using a drum sieve or a shaking sieve, more preferably a shaking sieve.

In the method of the present invention, preferably the at least one additive is added to the composition that is an adhesive. more preferably a latex based adhesive or a starch based adhesive, even more preferably a starch based adhesive is added.

In the method of the present invention, preferably at least one of the additives is a fire deterrent and / or a mould deterrent, more preferably boric acid, boric salts, aluminum sulphate and/or ammonium sulphate, even more preferably ammonium sulphate.

BRIEF DESCRIPTION OF THE FIGURES

The above and other advantages of the features and objects of the invention will become more apparent and the invention will be better understood from the following detailed description when read in conjunction with the accompanying drawings, in which:

Fig. 1 illustrates the cattail.

Fig. 2 illustrates the height h of the particles in which for example cattail is being cut.

DESCRIPTION OF AN EMBODIMENT

The following, non-limiting examples are provided to illustrate the invention.

Experiments

Several different examples can be used to describe the difference in the production process depending on the mixture: 1. Insulation material made from 1 material (cattail) cultivated purposely for the production

IO of insulation material. 2. Insulation material made from 2 materials where 1 is cultivated purposely for the production of insulation material and the other is a waste material. 3. Insulation material made from 2 materials where 1 is cultivated purposely for the production of insulation material and the other is a fossil additive to improve the insulating properties. The fossil material is pre-treated for fire and mould. 4. Insulation material made from 2 materials where 1 is cultivated purposely for the production of insulation material and the other is a fossil additive to improve the insulating properties. The fossil material is not pre-treated for fire and mould.

Experiment 1

Production of Typha (cattail) for application as insulation material.

Collecting material

The Typha material was cultivated purposely for the goal of insulation material. The material was cultivated on peatlands and to reduce the CO; emission from these grounds. The material was harvested with a bucket mower in order to preserve the root structure in the soil. In contrary to other harvesting methods the peat did not have to be drained to harvest the material.

Drying material

The material was collected and transported to the drying facility where it was dried using waste heat. The material was dried to a Dry Matter content (dm%) of at least 90%. The material was then transported to the processing facility.

Processing material

When the material arrived from the drying step it was separated based on particle size. 3 fractions were collected. The following fractions were collected: . Small fraction, < 5 mm . Middle fraction between 5 mm and 30 mm

Large fraction, > 30 mm

The smallest fraction was not used as insulation material because it will fill up the cavities between the larger particles and reduce the insulating properties of the material. Instead it was used to produce sheet material. The middle fraction was collected for further processing into insulation material. The large fraction was collected and cut into smaller pieces and fed back into the separation process.

The middle fraction was collected and fed into the first treatment step. In this step the material was coated with a fine layer of adhesive. Water and latex based adhesive was used but other, more environmentally friendly, products are possible. The product was mixed while the adhesive was added to ensure good and equal distribution.

When the adhesive was added the material was transferred to the second step where the deterrents were added. The deterrents were added as a dry powder. The deterrent was a sulphate mixture with fire and mould deterring properties. The deterrents were added after the adhesive to ensure good attachment distribution of the deterrents to the material.

After the second mixing step the material was left to dry 24h and stored until used to insulate a cavity.

Experiment 2

Insulation material made from 2 materials where 1 is cultivated purposely for the production of insulation material and the other is a waste material.

Collecting material.

The Typha (cattail) material was cultivated purposely for the goal of insulation material. The material was cultivated on peatlands and reduce the CO: emission from these grounds. The material was harvested with a bucket mower in order to preserve the root structure in the soil. In contrary to other harvesting methods the peat does not have to be drained to harvest the material.

The second material used was not purposely cultivated to be used as insulation material but was a waste stream created by the maintenance of nature reserves. This waste material is commonly destroyed by incineration or composting. This is a costly process which destroys the value of the material. By collecting the waste material, threating it and combining it with Typha a larger supply of insulation material was created. This is desirable since the supply of Typha is limited and the demand for insulation material is large.

Experiment 3

Insulation material made from 2 materials where 1 was cultivated purposely for the production of insulation material and the other is a fossil additive to improve the insulating properties. The fossil material was pre-treated for fire and mould. As the material was pre-treated it was added after the adhesive and deterrents were added to the Typha.

Collecting material.

The Typha (cattail) material was cultivated purposely for the goal of insulation material. The material is cultivated on peatlands and reduce the CO: emission from these grounds. The material was harvested with a bucket mower in order to preserve the root structure in the soil.

The second material was a fossil lose fill insulation material. This material was mixed with the biobased material in order to improve the insulating properties of the material. Typha (with an labda of 0,04) was mixed with PE beads with an lambda of 0,033. By mixing the material the lambda was averaged at 0,036 instead of 0,04. The material was mixed during the treatment steps.

Processing material

When the material arrived from the drying step it was separated based on particle size. 3 fractions were collected. The smallest fraction was not used as insulation material because it will fill up the cavities between the larger particles and reduce the insulating properties of the material. Instead it was used to produce sheet material. The middle fraction was collected for further processing into insulation material. The large fraction was collected and cut into smaller pieces and fed back into the separation process.

The middle fraction was collected and fed into the first treatment step. In this step the material was coated with a fine layer of adhesive. This was a water and latex based adhesive. The product was mixed while the adhesive was added to ensure good and equal distribution.

When the adhesive was added and mixed in the material was transferred to the second step where the deterrents were added. The deterrents were added as a dry powder. The deterrents were added after the adhesive to ensure good attachment distribution of the deterrents to the material.

After adding the adhesive and deterrents to the Typha the material was mixed with the fossil material. It was thoroughly mixed to ensure an equal distribution.

Experiment 4

Insulation material made from 2 materials where 1 is cultivated purposely for the production of insulation material and the other is a fossil additive to improve the insulating properties. The fossil material is not pre-treated for fire and mould.

Collecting material.

The Typha (cattail) material was cultivated purposely for the goal of insulation material. The material was cultivated on peatlands and reduce the CO: emission from these grounds. The material was harvested with a bucket mower in order to preserve the root structure in the soil.

The second material was fossil loose fill insulation material. This material was mixed with the biobased material in order to improve the insulating properties of the material. For example, Typha (with an labda of 0.04) was mixed with PE beads with an lambda of 0,033. By mixing the material the lambda was averaged at 0,036 instead of 0,04. The material was mixed during the treatment steps.

Processing material

When the material arrived from the drying step it was separated based on particle size. 3 fractions were collected. The smallest fraction is not used as insulation material as it will fill up the cavities between the larger particles and reduce the insulating properties of the material. Instead it was used to produce sheet material. The middle fraction was collected for further processing into insulation material. The large fraction was collected and cut into smaller pieces and fed back into the separation process.

The middle fraction was collected and fed into the first treatment step. The first step was mixing the biobased material with the fossil material. Because the material was not pre-treated it was added to the Typha before mixing it with the adhesive and deterrent. After mixing the material the mix was coated with a fine layer of adhesive. This was a water and latex based adhesive. The product was mixed while the adhesive is added to ensure good and equal distribution.

When the adhesive was added the material was transferred to the second step where the deterrents were added. The deterrents were added as a dry powder. The deterrents were added after the adhesive to ensure good attachment distribution of the deterrents to the material.

In the above, the invention has been disclosed using examples thereof. However, the skilled person will understand that the invention is not limited to these examples and that many more examples are possible without departing from the scope of the present invention, which is defined by the appended claims and equivalents thereof.

Claims

CONCLUSIONS

1. Composition for insulation, packaging and/or filling, consisting of at least one bio-based material that has been cut into particles and loose-fill insulation material.

The composition according to claim 1, wherein the composition comprises at least 2 different bio-based materials.

A composition according to any one of the preceding claims, wherein the bio-based materials are selected from cattail, poppy, marsh plants, miscanthus, reeds and soft reeds, preferably cattail.

A composition according to any one of the preceding claims, wherein the bio-based material comprises at least bulrush combined with at least one from the group of reeds, poppy, marsh plants, miscanthus, rushes and soft reeds.

A composition according to any one of the preceding claims, wherein the particles of the bio-based material have a height h in the range of 1 to 100 mm.

A composition according to any one of the preceding claims, wherein the loose fill material has a lower lambda (insulation value) than the bio-based materials.

7. Composition according to claim 5 or 6, wherein the loose filling materials have a size of which the height is maximally 30 mm, preferably maximally 20 mm, more preferably maximally 10 mm.

A composition according to any one of the preceding claims, wherein at least one of the bio-based materials is a material specifically grown for isolation purposes, while at least the other bio-based material is a waste material.

The composition of claim 8, wherein the bio-based materials originate from peat bogs.

A composition according to any one of the preceding claims, wherein the ratio between the at least two bio-based materials varies according to seasonal availability.

A composition according to claim 10, wherein at least 30% by weight cattail is present.

A composition according to any one of the preceding claims, wherein at least one of the bio-based materials has been cut into particles with a height h in the range of 5 to 30 mm.

A composition according to claim 12, wherein the cut bio-based material is screened using a drum screen and/or a vibrating screen.

A composition according to claim 12 or 13, wherein the sieving of the cut bio-based materials leads to 3 fractions, a fine fraction, a medium fraction and a large fraction, the fine fraction having particles with a size smaller than 10 mm, at preferably smaller than 5 mm, the middle fraction comprises particles with a size in the range of 5 to 100 mm, preferably in the range of 5 to 50 mm, more preferably in the range of 5 to 30 mm and the large fraction particles larger than 100 mm, preferably larger than 50 mm, more preferably larger than 30 mm.

A composition according to claim 14, wherein the large fraction is again cut into smaller pieces and returned to the sieving process.

A composition according to any one of the preceding claims, wherein at least one additive has been added to the composition.

A composition according to claim 16, wherein at least one of the additives is an adhesive, preferably a latex-based adhesive or a starch-based adhesive, more preferably a starch-based adhesive.

A composition according to claim 16 or 17, wherein at least one of the additives is a flame retardant and/or an antifungal agent, preferably boric acid, boron salts, aluminum sulphate and/or ammonium sulphate, more preferably ammonium sulphate.

19. Use of the composition according to any one of the preceding claims as insulating material in a cavity wall.

Use of the composition according to claim 19 as vapour-permeable construction.

21. Method for manufacturing an insulation material consisting of at least one bio-based material, comprising the following steps:

a. cultivation of the bio-based material in the field;

b. harvesting the bio-based material;

c. cutting the bio-based material into particles with a height h in the range of 1 to 100 mm;

d. drying the cut bio-based material to a dry matter content of at least 70%;

e. sieving the dried bio-based material into a small, medium and large fraction; and f. adding loose insulation material to the sieved bio-based materials.

The method of claim 21, wherein the composition comprises a minimum of 2 different bio-based materials.

A method according to claim 21 or 22, wherein the bio-based materials are selected from cattails, reeds, poppy, marsh plants, miscanthus, common reed and soft reed.

A method according to claims 21 to 23, wherein the cultivation of the bio-based material is carried out in at least one field specifically designed for wet farming.

A method according to claims 21 to 24, wherein the large fraction is returned to step c.

A method according to claims 21 to 25, wherein the harvesting of the bio-based material is carried out with a technique that keeps the material as intact as possible, preferably a bucket mower is used.

A method according to claims 21 to 26, wherein the bio-based material is cut into at least particles with a height h in the range from 1 to 100 mm, preferably in the range from 5 to 50 mm, more preferably in the range from 5 to 30 mm.

The method of claims 21 to 27, wherein the cut bio-based material is dried naturally.

A method according to claims 21 to 28, wherein the cut bio-based material is dried to a dry matter content of at least 80%, preferably at least 85%, more preferably at least 90%.

A method according to claims 21 to 29, wherein the dried bio-based material is screened using a drum screen or a vibrating screen.

A method according to claims 21 to 30, wherein additives are added to the sieved bio-based material(s) at least one additive to the composition which is an adhesive, preferably a latex-based adhesive or an adhesive based on starch, more preferably a starch based adhesive.

A method according to claims 21 to 31, wherein at least one of the additives is a flame retardant and/or an antifungal agent, preferably boric acid, aluminum sulphate and/or ammonium sulphate, more preferably ammonium sulphate.