EP4729260A1

EP4729260A1 - A method of manufacturing an insulation panel comprising hemp hurd, an insulation panel and an apparatus for manufacturing an insulation

Info

Publication number: EP4729260A1
Application number: EP25208301.9A
Authority: EP
Inventors: Ronald HOEX; Erwin THIJSSEN; Nik HEEREN
Original assignee: Hoex Systems BV
Current assignee: Hoex Systems BV
Priority date: 2024-10-14
Filing date: 2025-10-13
Publication date: 2026-04-22

Abstract

A method of manufacturing an insulation panel 2 comprising a housing 5, 6 provided with an interior 7 filled with hemp hurd 1, the method comprising the steps of:
- providing the housing 5, 6 for receiving hemp hurd 1;
- receiving, by the housing 5, 6, pieces of hemp hurd 1 in the interior 7 thereof;
- vibrating, by a vibrating apparatus, the housing 5, 6 comprising the pieces of hemp hurd 1 for compacting the hemp hurd 1 provided in the interior 7 and obtaining the insulation panel 2,
wherein the hemp hurd 1 and the interior 7 is free from a binder material.

Description

Technical field of the invention

According to a first aspect, the present disclosure relates to a method of manufacturing an insulation panel comprising hemp hurd.
According to a second aspect, the present disclosure relates to an insulation panel comprising hemp hurd obtained from a method according to first aspect of the present disclosure.
According to a third aspect, the present disclosure relates to an apparatus for manufacturing an insulation panel according to the second aspect of the present disclosure.
Hemp stalks comprise two main types of fibre: bast or long fibres found in the bark and hurd, also referred to as hemp hurd, hemp shive and hemp core, located in the core of the stem.
The bast fibres may be divided into two types primary and secondary bast fibres. The primary bast fibres typically make up 70-90% of the bast. They are characterized by a relative long length of up to 50 mm, a relative high cellulose content in the range of 50% to 70% and a relative low lignin content of about 7%. These fibres are the most valuable part of the stalk.
The secondary bast fibres are about 2 mm, more lignified as compared to the primary bast fibres and hence of lower value.
It is known to use the bast or long fibres to make an insulation material. The flexibility and toughness of the bast fibres during compression allows for compression and a relative easy implementation as a building material. The insulation material comprising the bast fibres may also be easily adjusted to different sizes and shapes by cut during the installation process.
Hurd comprises relative short fibres of about 0.5 mm and are woodier than the bast fibres. Hurd accounts for 70-80% of the stalk and typically contains 20-30% lignin. The inner fibres typically have low value industrial applications, such as mulch, animal bedding, and litter.
According to the first aspect the invention relates to a method of manufacturing an insulation panel comprising a housing provided with an interior filled with hemp hurd, the method comprising the steps of:

providing the housing for receiving hemp hurd; and
receiving, by the housing, pieces of hemp hurd in the interior thereof.

Background of the invention

A method according to the preamble of claim 1 is known from US2020/247001A1 . This known method relates to forming a wall using prefabricated panels comprising hemp hurd and a binder, in which the hemp hurd is compressed by shaking.

Summary of the invention

An object of the invention is to provide a method of manufacturing an insulation panel of the type described above in a more economical manner.
To this end the method according to the invention is characterized by vibrating, by a vibrating apparatus, the housing comprising the pieces of hemp hurd for compacting the hemp hurd provided in the interior and obtaining the insulation panel, wherein the hemp hurd and the interior is free from a binder material.
The housing of the insulation panel of the invention serves as a mold during manufacture of the insulation panel. So the interior of hemp hurd does not have to be taken out of a mold and can therefore be free of a binder.
The present disclosure relies at least partly on the insight that by vibrating a volume of hemp hurd, the hemp hurd may be compacted resulting in a relative dimensionally stable product such as an insulation panel.
In US2023/303440A1 a method for forming a masonry unit is disclosed comprising hemp hurd and a binder, in which the hemp hurd is vibro-compressed using a vibro-compression mold system.
Preferably, during the step of vibrating, additives other than a binder material are present in the interior.
In this regard, it is beneficial if the additives are chosen from the list comprising biocides, chalk, salts, amino acids and magnesium.
Adding a biocide to the hemp hurd is beneficial to destroy, deter, render harmless, or exert a controlling effect on any harmful organism that may be present in the hemp hurd. Within the context of the present disclosure, a biocide is to be understood as a diverse group of poisonous substances including preservatives, insecticides, disinfectants, and pesticides used for the control of organisms that are harmful to human or animal health or that cause damage to natural or manufactured products.
Chalk and/or magnesium as an additive to the hemp hurd is beneficial for increasing fire resistance. Adding a salt and/or an amino acid is beneficial for regulating the humidity of the hemp hurd and/or the insulation panel. In addition, a salt and an amino acid may be antimicrobial.
During the step of vibrating, the interior is free from a binder material. The absence of hemp hurd is beneficial for producing an insulation panel at a relative low cost, since the cost for the binder are avoided.
In an embodiment of the method according to the present disclosure, during the step of vibrating, pieces of hemp hurd mutually attach, preferably mutually attach by hooking.
The present disclosure relies at least partly on the insight that individual pieces hemp hurd may comprise splinters that cause a hooking action when the hemp hurd is vibrated, thereby causing the individual pieces of hemp hurd to mutually attach.
Preferably, during the step of vibrating, further hemp hurd is added to the interior. This is beneficial for allowing to fill the housing to a relative large extent, thereby allowing to manufacture a relative large insulation panel using a relative small housing.
In an embodiment, the method according to the present disclosure further comprises at least one of the steps of:

drying the hemp hurd; and
breaking the hemp hurd into pieces having a size in the range of 0.5 to 4 cm.

Preferably, during the step of receiving, by the housing, pieces of hemp hurd in the interior thereof, the hemp hurd, has a humidity in the range of 10% to 20%, preferably a humidity in the range of 15% to 18%.
Preferably, the step of adding additives is performed before performing the step of vibrating.
It is advantageous, if, during the step of vibrating, the housing is vibrated at a frequency in the range of 500 to 4000 Hz, preferably in the range of 1250 to 3500 Hz. It was found that vibrating the hemp hurd in the range of 500 to 4000 Hz causes the hemp hurd to compact to an extent that corresponds to an insulation value that is attractive for instance for insulating a building.
The preferred range of 1250 to 3500 Hz resulted in a surprising effect in that the compacted hemp hurd has a relative high insulation value allowing for the use of a relative thin insulation panel. A relative thin insulation panel is attractive for manufacturing an insulation panel having a relative low cost due to the relative low amount of hemp hurd required.
According to the second aspect, the present disclosure relates to an insulation panel obtained from a method according to the first aspect of the present disclosure.
Embodiments of the insulation panel correspond to embodiments of the method according to the first aspect of the present disclosure. The advantages of the insulation panel correspond to advantages of the method according to first aspect of the present disclosure presented previously.
Preferably, pieces of hemp hurd, preferably all pieces of the hemp hurd, of the insulation panel are mutually mechanically interlocked.
In a practical embodiment of the insulation panel, pieces of hemp hurd, preferably all pieces of the hemp hurd, of the insulation panel are attached to each other without a binder material.
It is beneficial if the insulation panel comprises a housing surrounding the hemp Hurd, wherein the pieces of hemp are provided in an interior of the housing.
Preferably, the insulation panel has a width and/or height in the range of 0.5 to 8.5 m and a thickness in the range of 0.1 - 0.5 m.
In an embodiment of the insulation panel, the insulation of the hemp hurd is in the ranged of 0.045 W/mK and 0.05 W/mK determined according to NEN-EN 12664:2001.
Preferably, the density of the hemp hurd is in the range of 120 kg/m3 to 200 kg/m3, preferably in the range of 150 kg/m3 to 180 kg/m3.
In this regard, it is noted that a relative low density corresponds to the presence of relative large spaces between individual pieces of hemp hurd which allows for the presence of a relative large amount of air which is beneficial for realising a relative high insulation value.
The present invention relies at least partly on the insight that a balance between the compaction and the insulation value is to be made, wherein a relative high compaction level results in a relative robust hemp hurd product having a lower insulation value and a relative low compaction level resulting in a somewhat more fragile hemp hurd product having a relative high insulation value.
According to the third aspect the present disclosure relates to an apparatus for manufacturing an insulation panel according to the second aspect of the present disclosure, the apparatus comprising:

a support arranged for supporting a housing provided with a receiving space for receiving hemp hurd;
a vibration arrangement, mechanically coupled with the support, arranged for generating a vibration at a predetermined frequency and amplitude.

Embodiments of the apparatus correspond to embodiments of the method according to the first aspect of the present disclosure. The advantages of the apparatus correspond to advantages of the method according to first aspect of the present disclosure presented previously.
Preferably, the apparatus further comprises:

a damping arrangement arranged for supporting the apparatus at a ground surface and further arranged for damping, during use of the apparatus, vibrations transmitted to the ground surface.

In this regard, it is advantageous if the damping arrangement is coupled, via the support, with the vibration arrangement.
In an embodiment, the damping arrangement comprises a first damping unit and a second damping unit, wherein the vibration arrangement is attached to the support between the first damping unit and the second damping unit.
Preferably, the vibration arrangement comprises an amplitude setting device arranged for setting the amplitude of the vibration generated, during use, by the vibration arrangement.
It is beneficial, if the vibration arrangement comprises a frequency setting device arranged for setting the frequency of the vibration generated, during use, by the vibration arrangement.
In this regard, it is advantageous if the frequency setting device is arranged for setting the frequency of the vibration generated, during use, by the vibration arrangement in the range of 500 to 4000 Hz, preferably in the range of 1250 to 3500 Hz.
Preferably, the vibration arrangement comprises an unbalance motor.

Brief description of the drawings

The above-mentioned and other features and advantages of the invention are illustrated in the following description with reference to the enclosed drawings which are provided by way of illustration only and which are not limitative to the present invention.

Fig. 1 shows schematically an embodiment of an insulation panel comprising hemp hurd according to the second aspect of the present disclosure;
Fig. 2 shows schematically an embodiment of a method according to the first aspect of the present disclosure, for manufacturing the insulation panel of Fig. 1;
Fig. 3 shows schematically an embodiment of an apparatus according to the third aspect of the present disclosure, for manufacturing an insulation panel of Fig. 1.

Detailed description of the drawings

Figure 1 shows schematically an embodiment of an insulation panel 2 comprising hemp hurd 1 according to the second aspect of the present disclosure. The pieces of hemp hurd 1 are mutually mechanically interlocked and are attached to each other without a binder material.
The insulation panel 2 comprises a housing 5, 6 surrounding the hemp hurd 1, wherein the pieces of hemp 1 are provided in an interior 7 of the housing 5, 6. The housing comprises a bottom housing part 5, having a bottom wall and side walls, and an upper housing part 6, for enclosing the hemp hurd 1 inside the interior 7 of the housing.
The insulation panel 2 furthermore has a width and a height in the range of 0.5 to 8.5 m and a thickness in the range of 0.1 - 0.5 m, wherein the density of the hemp hurd 1 is in the range of 150 kg/m³ to 180 kg/m³ and the insulation value of the hemp hurd 1 is in the ranged of 0.04 W/mK and 0.05 W/mK determined according to NEN-EN 12664:2001.
Figure 2 shows schematically an embodiment of a method 100 according to the first aspect of the present disclosure. The method 100 is arranged for manufacturing the insulation panel 2 as described above and comprises the steps of:

Drying 101 the hemp hurd 1.
Breaking 102 the hemp hurd 1 into pieces of hemp hurd 1 having a size in the range of 0.5 to 4 cm.
Providing 103 a housing 20 comprising a interior 21 arranged for receiving hemp hurd 1.
Receiving 104, by the housing 20, pieces of hemp hurd 1 in the interior 21 thereof.
Vibrating 105, by a vibrating apparatus 31, the housing 20 comprising the pieces of hemp hurd 1 for compacting the hemp hurd 1 provided in the interior 21 and obtaining the insulation panel 2.
Removing 106, the insulation panel from the vibrating apparatus.

During the step of drying 101, the hemp hurd 1 is dried such that the hemp hurd 1 has a humidity in the range of 15% to 18% during the step of receiving 104 the pieces of hemp hurd 1 in the interior 21 of the housing 20.
During the step of vibrating 105 the pieces of hemp hurd 1 mutually attach to each other by hooking. Optionally, additives 3 other than a binder material, for example biocides, chalk, salts, amino acids and magnesium, are present in the interior 21 of the housing 20, while the interior 21 is free from a binder material. Preferably, the additives 3 are mixed with the hemp hurd 1 prior to receiving the hemp hurd by the housing 20.
During the vibrating 105, the housing 20 is vibrated at a frequency in the range of 1250 to 3500 Hz for compacting the hemp hurd 1, and further hemp hurd 1 is added to the interior 21 for completely filling the interior 21 of the housing 20.
In an embodiment, the housing 20 is the housing of the insulation panel 2, in particular the bottom housing part 5 with the upper housing part 6 removed. After receiving 104 the pieces of hemp hurd 1 in the housing and vibrating 105 the housing, the housing is completely filled with compacted hemp hurd 1. After removing 106 the housing from the vibrating apparatus 31, the upper housing part 6 is attached to the bottom housing part 5 for enclosing the hemp hurd 1 inside the interior 7 of the housing and realizing the insulation panel 2.
Optionally, a further step of applying 107 an adhesive layer to a side of the insulation panel 2 is performed, wherein the insulation panel 2 is provided with a vapor barrier and/or and reflective foil.
Figure 3 shows schematically an embodiment of an apparatus 10 according to the third aspect of the present disclosure, for manufacturing the insulation panel 2 as described above.
The apparatus 10 for the manufacturing of an insulation panel 2, comprises a support 31, arranged for supporting the housing 20 provided with the interior 21 for receiving hemp hurd 1, and a vibration arrangement 32, mechanically coupled with the support 31, arranged for generating a vibration at a predetermined frequency and amplitude.
The apparatus 10 furthermore comprises a damping arrangement 33, arranged for supporting the apparatus 10 at a ground surface 34 and further arranged for damping, during use of the apparatus 10, vibrations transmitted to the ground surface 34. The damping arrangement 33 comprises a first damping unit and a second damping unit, wherein the vibration arrangement 32 is attached to the support 31 between the first damping unit and the second damping unit.
The vibration arrangement 32 comprises an amplitude setting device 37, arranged for setting the amplitude of the vibration generated during use by the vibration arrangement 32, and a frequency setting device 38, arranged for setting the frequency of the vibration generated preferably in the range of 1250 to 3500 Hz during use by the vibration arrangement 32. The vibration arrangement 32 furthermore comprises an unbalance motor 39.

Claims

A method (100) of manufacturing an insulation panel (2) comprising a housing (5, 6) provided with an interior (7) filled with hemp hurd (1), the method (100) comprising the steps of:
- providing (103) the housing (5, 6) for receiving hemp hurd (1);

- receiving (104), by the housing (5, 6), pieces of hemp hurd (1) in the interior (7) thereof;
characterized by:
- vibrating (105), by a vibrating apparatus (31), the housing (5, 6) comprising the pieces of hemp hurd (1) for compacting the hemp hurd (1) provided in the interior (7) and obtaining the insulation panel (2),
wherein the hemp hurd (1) and the interior (7) is free from a binder material.
The method (100) according claim 1, wherein, during the step of vibrating (105), additives (3) other than a binder material are present in the interior (7), wherein the additives (3) are chosen from the list comprising biocides, chalk, salts, amino acids and magnesium.
The method (100) according to any one of the preceding claims, wherein, during the step of vibrating (105), further hemp hurd (1) is added to the interior (7).
The method (100) according to any one of the preceding claims, wherein the method (100) further comprises at least one of the steps of:
- drying (101) the hemp hurd (1); and

- breaking (102) the hemp hurd (1) into pieces having a size in the range of 0.5 to 4 cm,
wherein, during the step of receiving (104), by the housing (5, 6), pieces of hemp hurd (1) in the interior (7) thereof, the hemp hurd (1) has a humidity in the range of 10% to 20%, preferably a humidity in the range of 15% to 18%.
The method (100) according to any one of the claims 1 to 7, wherein, during the step of vibrating (105), the housing (5, 6) is vibrated at a frequency in the range of 500 to 4000 Hz, preferably in the range of 1250 to 3500 Hz.
An insulation panel (2) comprising hemp hurd (1) obtained from a method (100) according to any one of the preceding claims.
The insulation panel (2) according to claim 9, wherein pieces of hemp hurd (1) of the insulation panel (2) are mutually mechanically interlocked.
The insulation panel (2) according to claim 9 or 10, wherein the pieces of hemp hurd (1) of the insulation panel (2) are attached to each other without a binder material.
The insulation panel (2) according to any one of the claims 6 to 8, wherein the density of the hemp hurd (1) is in the range of 120 kg/m³ to 200 kg/m³, preferably in the range of 150 kg/m³ to 180 kg/m³.
An apparatus (10) for manufacturing an insulation panel (2) according to any one of the claims 6 to 9, the apparatus (10) comprising:
- a support (31) arranged for supporting a housing (5, 6) provided with an interior (7) for receiving hemp hurd (1);

- a vibration arrangement (32), mechanically coupled with the support (31), arranged for generating a vibration at a predetermined frequency and amplitude.
The apparatus (10) according to claim 10, wherein the apparatus (10) further comprises:
- a damping arrangement (33) arranged for supporting the apparatus (10) at a ground surface (34) and further arranged for damping, during use of the apparatus (10), vibrations transmitted to the ground surface (34).
The apparatus (10) according to claim 11, wherein the damping arrangement (33) is coupled, via the support (31), with the vibration arrangement (32).
The apparatus (10) according to claim 11 or 12, wherein the damping arrangement (33) comprises a first damping unit and a second damping unit, wherein the vibration arrangement (32) is attached to the support (31) between the first damping unit and the second damping unit.
The apparatus (10) according to any one of the claims 10 to 13, wherein the vibration arrangement (32) comprises an amplitude setting device (37) arranged for setting the amplitude of the vibration generated, during use, by the vibration arrangement (32).
The apparatus (10) according to any one of the claims 10 to 14, wherein the vibration arrangement (32) comprises a frequency setting device (38) arranged for setting the frequency of the vibration generated, during use, by the vibration arrangement (32), wherein the frequency setting device (38) is arranged for setting the frequency of the vibration generated, during use, by the vibration arrangement (32) in the range of 500 to 4000 Hz, preferably in the range of 1250 to 3500 Hz.