AN INSULATING MATERIAL

Field of the Invention

The present invention relates to an insulating material and in particular to an insulating material for use in clothing and soft furnishings. Certain embodiments are also suitable for use in building insulation or other forms of insulation.

Background to the Invention

Materials which can be used for garments, soft furnishings etc. (and also including certain materials which are also suitable for use in the insulation of buildings against heat loss, for example as roofing felt), and which have low heat transfer properties across their surfaces are well known. Usually such materials are utilised to retain heat inside a volume and are typically used for cold-weather clothing. With respect to the latter usage, the materials used usually comprise multiple layers in which at least an outer layer is water resistant allowing the wearer to use the clothing in showery weather. This outer layer can often be utilised with one or two further layers.

In order to retain heat within the garments an insulating layer is provided. The insulating layer typically relies on a fibrous network to retain air within its bulk and so restrict heat transfer between the wearer and the exterior. A third layer can often also be utilised, the third layer backing on to the insulating layer and in effect sandwiching the insulating layer between the outer layer and the third layer.

One problem with conventional non-woven insulation materials is that although many are designed to be waterproof, or at least showerproof, in the event that water does penetrate the water resistant layer, the insulating material beneath this layer easily absorbs the water and loses its insulating properties and at the same time becomes significantly heavier due to the absorbed water. The ability of the garment to protect the wearer from the cold environment is thereby significantly reduced. Moreover, the breathability of the material, enabling water to escape from the inside of the garment is also compromised.

It is an object of the current invention to provide a material, which when incorporated or utilised to make items such as garments, addresses the above problems. Summary of the Invention

According to a first broad independent aspect of the invention, there is provided a non- woven insulation material, suitable for use in the manufacture of clothing, furnishing or the like, said material comprising a layer of fibres comprising a plurality of discrete apertures extending at least partially through the material.

This configuration is particularly advantageous because the apertures enable air to reside within the apertures until the air, which is behind, is heated, which will then act to push the air as well as any moisture through the holes away from the wearer, preventing moisture from entering the fibre matrix, therefore providing a material that is both insulating and has a greatly improved breathability due to an increased water vapour permeability.

Preferably, the apertures extend entirely through the material.

Preferably, the apertures are distributed uniformly throughout the material.

This configuration is particularly advantageous because it ensures there is an even distribution to allow for the uniform travel of water and moisture through the apertures which ensures maximum efficiency for breathability. Preferably, the apertures are circular in cross-section.

This configuration is particularly advantageous because it provides a uniform diameter enabling maximum movement of water and moisture through the apertures and prevents trapping of water within corners.

Optionally, apertures are arranged in a square array. Further optionally, the centre of adjacent apertures in a row or in a column are separated by a distance of from 6.0 - 25.0mm, preferably 6.0 - 15.0mm.

Preferably, an aperture has a diameter of from 1.0 - 5.0mm, and further preferably from 2.0 - 4.0mm. Further preferably, an array has apertures of different diameters.

Preferably, the apertures are frustoconical, the cone axis being directed across the width of the fabric.

This configuration may increase the breathability of the fabric by increasing the travel speed of the moisture though the apertures.

Alternatively the apertures are elongate in cross-section.

This configuration is particularly advantageous because elongate apertures increase the elasticity and stretch of the material. These apertures would also be preferable for when an increased number of apertures is required.

Preferably the layer of material is of a thickness of between 3mm to 250mm.

This range of thickness is advantageous for the range of items in which the material may be used, for instance a thinner layer of 3mm will be required for clothing such as socks and jackets whereas a larger thickness of up to 250mm would be required for items such as furniture, horse-rugs and building insulation. Preferably, the material is comprised of multiple sub-layers stacked together, preferably with the apertures aligned, to achieve a greater thickness of the material.

This configuration is particularly advantageous because it provides a simple means to alter the thickness of the material by adjoining single layers and only single layers are therefore required to be made during manufacture. Preferably, the material comprises a mixture of fibres of different densities.

This configuration is particularly advantageous because it allows the material to be adapted for use in different environments with the higher density fibres used where increased insulation is required and lower density fibres used for where less insulation is required such as a warm weather jacket.

More preferably the material comprises a fibre mix including Clo™ fibres.

This fibre mix is particularly advantageous because the specific features of the Clo™ fibres provide a high standard of insulation and warmth as well as softness which can provide additional comfort to the user.

More preferably the polyester fibres are bonded with heat or glue

This configuration is particularly advantageous because it increases the strength and rigidity of the matrix layer.

Preferably, the apertures are produced by thermally melting the material.

This configuration is particularly advantageous because the melting action seals the inside face of the aperture, structuring the inner diameter of the aperture and therefore allowing greater travel of any water and moisture through the apertures, preventing water going sideways into the main body of the material.

More preferably, the apertures are produced by a laser.

This configuration is particularly advantageous because a laser would have the same effect as thermal treatment in that the inner face of the aperture would be sealed.

Alternatively, the apertures are produced by a stamp (for example a punch and die).

This configuration is particularly advantageous as it is a simple mechanism by which multiple apertures may be created simultaneously.

Alternatively, the apertures are produced by an ultrasonic cutting device

This configuration is particularly advantageous because it can produce the apertures at a greater speed and with the use of less power. Alternatively, the apertures are produced by a water jet cutter.

This configuration is particularly advantageous because no heat is used which has a potential to harm or change the intrinsic properties of the layer of material itself. In a further broad, independent aspect, the invention provides a method for producing a material, said material suitable for use in the manufacture of clothing, furnishing or the like, said method comprising selecting a layer of fibres and forming a plurality of discrete apertures extending through the material.

This method is particularly advantageous because the apertures provide an increased water vapour permeability for the material.

Preferably, said apertures being formed by thermal melting.

This method is particularly advantageous because the thermal action of producing the apertures seals the inside face of the aperture, structuring the inner diameter of the aperture, preventing water going sideways into the main body of the material and therefore allowing greater, more efficient travel of any water and moisture through the apertures.

Preferably, said thermal melting is produced through application of a laser.

This method is particularly advantageous because lasers can provide the desired product at high speed and accuracy.

Alternatively, said apertures are produced by a stamp (for example a punch and die).

This method is particularly advantageous because a stamp may simultaneously produce the desired apertures in a short amount of time and for a lower cost.

Alternatively, said apertures are produced by an ultrasonic cutting device. This method is particularly advantageous because less power is required for producing apertures at a fast speed.

Alternatively, said apertures are produced by means of a water jet cutter.

This method is particularly advantageous because no heat is used which has a potential to harm or change the intrinsic properties of the layer of material itself as well as requiring less raw materials, and does not produce any chips or potentially hazardous gases. Preferably the water jet cutter uses a high velocity stream of Ultra High Pressure Water 30,000-90,000 psi (210-620 MPa) which is produced by an intensifier pump with possible abrasive particles suspended in the stream.

Preferably the nozzle is made of sintered boride.

Alternatively, preferably said apertures are produced by a pneumatic punch. Brief Description of the Drawings

The invention will now be described with reference to the accompanying drawings which show by way of example only, embodiments of a material. In the drawings: Figure 1 illustrates a perspective birds-eye view of a portion of the material;

Figures 1 a and 1 b illustrate an array of apertures, said apertures having different sizes in material; Figure 2 illustrates a diagrammatic view of a single fibre;

Figure 3 illustrates a side view of an embodiment of the material; Figure 4 illustrates a side view of an embodiment of the material; and

Figure 5 illustrates a perspective birds-eye view of an embodiment of the material.

Detailed Description of the Embodiments The following illustrates a material particularly for use within a garment for use in cold weather where said garments are also required to be "breathable" and allow moisture out, such as a jacket, although the material is suitable for use in soft furnishings, building insulation and related technical areas. The material is particularly suited for use in garments such as ski jackets or hiking jumpers, snow boots and hats, where it is both insulating as well as breathable, as the user will be doing physical exertion in cold weather and the certain features and characteristics of the material, as hereinafter described, enable it to be particularly suited to this function as the insulating properties are not impacted by any moisture, such as sweat, from the user.

Referring initially to Figure 1, this illustrates a first embodiment of the invention. The material referenced 10 comprises a first matrix layer or network of fibrous material such as felt, polyesters, polypropylene, Clo™ mixed fibres, wool, goose down, bamboo or any mix or recycled mix of these materials or other suitable nonwoven fibres or other suitable materials. The matrix layer itself may be comprised of just a single sub-layer or multiple sub-layers. The individual fibres themselves are bonded together with heat or glue or another suitable bonding means. The fibres are tearable and can stretch. Figure 2 illustrates the cross-section of an individual Clo™ fibre.

The layer of the matrix of material preferably has a thickness of between 3mm to 250mm. Between 3 and 75mm is suited to clothing insulation and between 75 and 250mm is suited to building insulation. The material comprises apertures 20 extending through the material 10. In a preferred embodiment the apertures 20 are dispersed evenly throughout the matrix layer 10 and are situated uniformly in rows 1 1 and columns 12, as illustrated in Figure 1. Although, in alternative embodiments the apertures 20 may be scattered randomly or gathered more densely or sparsely in certain locations of the material depending on the required use of the material. For example, if the material is in use in the lining of a ski jacket, the apertures 20 may have an even, uniform distribution, such as that shown in Figure 1, throughout the body of the jacket with a more densely populated region located in the axilla region where increased permeability is required due to increased sweating of the user in that region. Additionally, the number of rows may again differ depending on the required use of the material including the exact location within the use.

The apertures 20 may be all the same size and cross-section as one another, although the size may differ depending on the required use of the material. Use in building insulation would require a larger size and diameter of hole to enable sufficient water vapour permeability.

In a preferred embodiment the apertures have a diameter ranging from 0.5mm to 1.5cm, and preferably, 1.0 - 5.0mm. As examples of an arrangement of the apertures, this is typically a square array, with the centre of, for example, a circular aperture being equidistant from the centre of a neighbouring aperture in the same row or the same column. The distance between the centres is greater than the sum of the diameters and is selected to be from 6.0 - 25.0mm, preferably 6.0 - 15.0mm. As examples, 4mm diameter apertures can be set in a square array such that the centres are 10mm apart or 12mm apart from the closest neighbour in a row or a column of the array. Further, apertures of 3.5mm in diameter can be set in a square array such that the centres are 8mm apart or 10mm apart from the closest neighbour in a row or a column of the array. Other arrays can however be used such as those having rows or columns, laterally offset from a neighbouring row or column.

In the embodiment illustrated in Figure 1 a, the square array comprises apertures 17 of 2mm diameter whose centres are 6.5 mm from each other. Included in alternate rows and columns are apertures 18 of 3.5mm diameter. Examples with such diameters are illustrated in Figure 1 b. The size of the diameter may also differ throughout one piece of the same material.

In a preferred embodiment, the inner circumferential face 30 of the apertures 20 is sealed due to the method of thermal treatment used to create the apertures 20, which is detailed further below. This sealing of the inner circumferential face 30 acts to increase the efficiency and movement of water traveling through the aperture and therefore increases the water vapour permeability, due to water vapour being prevented from travelling sideways into the body of the matrix layer, which would otherwise be likely due the perforated nature of the matrix layer.

In the preferred embodiment, the apertures 20 extend entirely through the material 10. Figure 3 illustrates an alternative embodiment whereby the apertures 23 do not extend entirely though the material 13 and instead extend only partially though. In this embodiment, the breathability of the fabric 13 is still increased due to moisture entering the apertures 23 and remaining within the aperture rather than being forced out the other side of the fabric 13.

In a further alternative embodiment, the apertures 24 are frustoconical, as shown in Figure 4. In this embodiment, the diameter of the opening gradually increases through the material from a narrow opening 44 to a larger aperture 54, as illustrated in Figure 4. In use, the narrower end 44 of the frustoconical aperture may be orientated either away from the user or towards the user, as desired. Although the apertures 20 are circular in cross-section in the preferred embodiment, in alternative embodiments, the apertures 20 may have any suitable cross-section. Figure 5 illustrates an alternative embodiment of the material in which the apertures 25 are elongate or 'slits', which may be produced by any of the means mentioned below. In this embodiment, where the apertures 25 are slits rather than circular, the material 15 has been shown to have an increased elasticity which may be preferable for certain types of clothing which require a high degree of stretchiness. The slits 25 can have dimensions of 10mm by 0.5mm.

The sealed inner circumferential face 30 ensures that moisture is directed entirely out of the apertures and that entry into the matrix layer is minimised or prevented, where there are multiple small openings due to the nature of the matrix.

The specific fibres used in the material matrix may vary, as mentioned above, however the use of Clo™ fibres is may be advantageous due to the combination of features which includes an extremely high quality of softness and high loft (contains more air then fibre, low-density material that retains a high amount of warmth). The weight of the material is ideally within the range of 35-450gsm. Each Clo™ fibre has an individual cross-section which is shaped such as that shown in Figure 4. Other fibres that can be included as constituent of the matrix fibre mix include felt which is one of the more dense materials and therefore would be particularly suitable where increased warmth is required such as outdoor, cold weather garments or building insulation. Polyester fibres are less dense and would be particularly suitable for a lighter weight garment. It is envisaged that the matrix layer may comprise a mixture of any combination of the fibres mentioned herein or any suitable fibre or may comprise a matrix of one single fibre only, such as only felt, or only Clo™ fibres. It is also envisaged that the material layer is hypoallergenic, making it suitable for use in the various garments.

In use, the material may comprise the lining of a garment such a jacket. Moisture such as sweat from the user of the garment will permeate more efficiently through the material due to the presence of the apertures 20. Initially, air will remain in the aperture before use, however once the air behind the materials and apertures, on the side of the skin of the person, is heated, for instance due to the body heat of the user beneath the garment, during physical activity or exertion, then the air will be pushed through the aperture along with any moisture such as perspiration from the user. In this way, all or most moisture travels through the apertures 20, rather than entering the material matrix which is perforated and the material therefore has a high breathability. Once through the material the moisture will be released into the atmosphere. This prevents the material matrix from absorbing too much of the moisture and reducing or losing its insulating properties as well as becoming heavier due to the absorbed water. In another example, where the material is used in home insulation for instance within an attic lining, then the heat of the house will act to push the air through the apertures as well as any moisture in the air. In this way moisture is released, outside the house's insulation whilst retaining warmth within the house on the underside of where the material is acting as insulation.

Use of the material includes, but is not limited to, the following list: coats, jumpers, jackets, gilets, trousers, shoes, boots, snow boots, snowsuits, salopettes, horse-rugs, dog coats, hats, gloves, building insulation, soft furnishings, breathable furniture, sleeping bags, outdoor rugs, socks, vests, bullet proof vests, Wellington boots, gaiters, string vests and sportswear that requires a high breathable performance.

When tested with a "BS EN ISO 15496: 2004 Inverted Cup" test, the material shows an increase in breathability compared to the same material without holes. This increase may be at least 5% increase. The breathability is measured in units of g/m ² /day. Below summarises the various tests performed to test the properties of the material.

Thermal insulation in fabric systems is tested using the following methods:

ASTM D 1518 "Thermal and Evaporative Resistance of Batting Systems Using a Hot Plate"; ASTM F 1868 "Thermal and Evaporative Resistance of Clothing Materials Using a Sweating Hot Plate Test";

ISO 1 1092 "Textiles-Determination of Physiological Properties - Measurement of Thermal and Water-Vapour Resistance"; and

BS7209, BS EN ISO 15496: 2004 Inverted Cup Test

Evaporative Resistance in fabric systems is tested using ASTM F 1868 "Thermal and Evaporative Resistance of Clothing Materials Using a Sweating Hot Plate Test" (Procedure Part B) and ISO 1 1092 "Textiles— Determination of Physiological Properties— Measurement of Thermal and Water- Vapour Resistance"

NFPA Total Heat Loss in fabric systems is tested using ASTM F 1868 "Thermal and Evaporative Resistance of Clothing Materials Using a Sweating Hot Plate Test" (Procedure Part C).

Thermal Insulation and Temperature Ratings in cold weather clothing are tested using ASTM F 2732 "Standard Practice for Determining the Temperature Ratings of Cold Weather Clothing".

Thermal Insulation in clothing systems is tested using ASTM F 1291 "Standard Test Method for Measuring the Thermal Insulation of Clothing Using a Heated Manikin" and ISO 15831 "Clothing - Physiological Effects - Measurement of Thermal Insulation by Means of a Thermal Manikin."

Evaporative Resistance in clothing systems is tested using ASTM F 2370 "Measuring the Evaporative Resistance of Clothing Using a Sweating Manikin".

Personal Cooling Systems (Cooling Effectiveness and Duration) is tested using: ASTM F 2371 "Standard Test Method for Measuring the Heat Removal Rate of Personal Cooling Systems Using a Sweating Heated Manikin" and EN 13537 "Requirements for Sleeping Bags" which is being revised as ISO 23537 "Part 1: Thermal and Dimensional Requirements".

Thermal Insulation and Temperature for Sleeping Bag Systems is tested using ASTM F 1720 "Standard Test Method for Measuring the Thermal Insulation of Sleeping Bags Using a Heated Manikin". This is tested according to military specifications. Sleeping bag loft is tested using ASTM F 1932 "Test Method for Measuring Sleeping Bag Loft".

Thermal Insulation and Temperature Ratings for bedding systems are tested using ASTM F 1720 "Standard Test Method for Measuring the Thermal Insulation of Sleeping Bags Using a Heated Manikin".

The physiological and subjective responses of human subjects wearing protective clothing, personal cooling systems (PCS), or sleeping bags can be measured under controlled conditions in environmental chambers.

Physiological Responses:

A. mean skin temperature (3-8 skin thermocouples)

B. body core temperature (ingestible temperature sensors to swallow)

C. heart rate (Polar™ S180i heart rate strap with electronic download of data into a computer)

D. sweat rate (weigh subject and clothing before and after experiment)

E. oxygen consumption and metabolic rate (metabolic cart)

Subjective Responses:

A. Thermal sensation scale (ASHRAE)

B. Borg perceived exertion scale

C. Clothing comfort, acceptability scales

The following methods can be used: ASTM F 2300 "Standard Test Method for Measuring the Performance of Personal Cooling Systems Using Physiological Testing";

ASTM F 2668 "Standard Practice for Determining the Physiological Responses of the Wearer to Protective Clothing Ensembles";

ISO 9886 "Ergonomics - Evaluation of Thermal Strain by Physiological Measurements"; and

ISO 8996 "Ergonomics of the Thermal Environment - Determination of Metabolic Rate".

As mentioned above, the apertures 20 in the material may be produced by a thermal treatment. The heat will act to seal the inner circumferential face 30 of the apertures 30 which consequently will ensure a more efficient and complete movement of water or moisture entirely through the aperture rather than into any openings within the material matrix layer 10 itself. The mechanism for the thermal means may be by means of either a thermal knife or a blow torch to make the apertures and the apertures 20 may be created either simultaneously by multiple separate thermal means or individually by movement of either the initial material or movement of the thermal means.

In an embodiment, the thermal treatment is a laser which can be used for melting, burning, oxidising or vaporizing the material. A protective back may be used during the process to protect any surfaces. This protective layer may then be peeled away. As an example, the lasers may be a CO2 laser which is moved over the material to create the apertures in the desired locations.

In a preferred embodiment, two laser cutters are attached to a mechanical arm, the two laser cutters simultaneously producing the series of apertures in the material as the material sheet is fed through underneath the arm. The two cutters may be spaced apart from one another or may be directly in contact. There may be a greater number of cutters on the arm to enable an increased rate of aperture production. A roll of the material will be fed past the two cutters on a conveyor belt. The conveyer belt will have openings in its base to prevent damage during the creation of the apertures.

In an alternative embodiment, the apertures are created a stamp press. For instance a template with protruding portions may be used either on one side or either side of the material sheet to produce the apertures. The stamp press will be designed to create apertures depending on the requirements.

In a further alternative embodiment, the apertures are produced by an ultrasonic cutting device.

In a further alternative embodiment, the apertures are produced by a water jet cutter. In this embodiment, the power of the water jets creates apertures in the material.

In use, the cutter is connected to a high pressure water pump, water is then ejected out of nozzles of various sizes depending on the requirements for the apertures. The material is cut through by the bombardment of the matrix layer 10 with the stream of high— speed water. This method is advantageous because no heat is used which has a potential to harm or change the intrinsic properties of the layer of material itself depending on the fibres used.

In an alternative embodiment, the material is comprised of multiple sub-layers of matrix layers 10 stacked together, with the apertures aligned, to achieve a greater thickness of the material. In a further alternative embodiment, the material may comprise multiple stacked layers of the fibres wherein the layers are stacked in such a way that the apertures of each layer overlay only partially or at certain portions so as to form a particular pathway for the moisture to travel through. Examples of these pathways may include a slanted pathway or spiral pathway or a skewed cylinder.

It is also possible that the apertures are formed from pulling or breaking the fibres in a particular region to create an aperture.

The material comprises apertures 20 extending the cross - section of the depth of the material matrix. In a preferred embodiment the apertures 20 are dispersed evenly throughout the material although in alternative embodiments they may be scattered randomly. The apertures 20 are discrete openings through the entire depth of the material layers. By "discrete" this means the apertures 20 differ from the remainder of the matrix layer 10 which is capable of having gaps and openings at various locations due to the nature of the fibre network.

The apertures 20 are of a certain uniform size although the uniform sizing will differ depending on the required use of the material. Use in building insulation would require apertures with a larger diameter to enable sufficient water vapour permeability. For use in a jacket, holes of a smaller diameter would be sufficient.