WO2011075765A1

WO2011075765A1 - A condensate management system and material incorporating same

Info

Publication number: WO2011075765A1
Application number: PCT/AU2010/001708
Authority: WO
Inventors: Paramjeet Singh; Roland Tyson
Original assignee: Sea To Summit Pty Ltd
Priority date: 2009-12-21
Filing date: 2010-12-21
Publication date: 2011-06-30

Abstract

A condensate management system comprising an outermost layer (12) of breathable material; a second layer (14) of breathable hydrophobic material; and an innermost layer (16) of breathable material. The outermost layer (12) and the innermost layer (16) are connected to opposing sides of the second layer (14) such that, when placed near a fluid vapour source, fluid vapour (18a) is able to pass through the innermost layer (16) and the second layer (14) and where, when external weather conditions cause the fluid vapour (18a) to condensate, the condensate (18b) is contained between the second layer (14) and outermost layer (12) until such time as the external weather conditions cause the condensate (18b) to transform back to fluid vapour (18a), the fluid vapour (18a) thereafter able to pass through the outermost layer (12) over time.

Description

"A CONDENSATE MANAGEMENT SYSTEM AND MATERIAL INCORPORATING

SAME-

FIELD OF THE INVENTION

The invention relates to a condensate management system and material incorporating same. The material is particularly suited for use in a sleeping bag designed for cold weather environments.

BACKGROUND TO THE INVENTION

The following discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was published, known or part of the common general knowledge in any jurisdiction as at the priority date of the application.

While the present invention relates to a material having good condensate management properties generally, the problem which gave rise to the need for this material is best discussed in the context of sleeping bags and is therefore presented hereafter in such manner. This should not be taken, however, as restricting the material to sole use with sleeping bags - it can be used in any other article in which an identical or similar problem presents itself.

Sleeping bags for cold weather environments typically use down to provide insulation due to its excellent warmth to weight ratio. The insulation properties of the down degrade over time as a result of an accumulation of condensation formed from the perspiration of the person using the sleeping bag. ^/

To elaborate, Figure 1 shows a schematic representation of the construction of a cold weather down sleeping bag of the prior art. As is shown, perspiration from the person using the down sleeping bag is converted into fluid vapour. This fluid vapour then passes through the interior layer and the down layer of the sleeping bag. At this position, the exterior shell layer of the sleeping bag prevents the fluid vapour from passing through to the cold exterior atmosphere.

At the same time, the low temperatures of the cold exterior atmosphere cause the vapour to condense into liquid water form, causing down closer to the exterior insulation layer to become damp or even wet. This can eventually lead to collapsing of the down in the interior layer. Either situation can cause a significant reduction in the insulating properties of the down.

The problem is further exacerbated when the down sleeping bag undergoes a pack and use cycle as would be natural during a trip of more than one day. This is because in packing the down sleeping bag the wet down is compressed against dry down and thus transfers some of the accumulated moisture to the previously dry down. .

One proposed solution to this problem has been to introduce an interior vapour barrier layer to the sleeping bag. This prevents sweat from entering into the down insulated area in the sleeping bag. However, this is not a practical solution as this traps the fluid vapour in the vapour barrier lining, where the person using the sleeping bag is contained. This leaves the person feeling damp or wet after use.

it is therefore an object of the present invention to create a breathable material that preserves its insulating characteristics even in the presence of water condensate.

DICTIONARY

Within the context of the invention as hereafter described, unless the context otherwise suggests, the following words and phrases have the following meaning:

"Downproof by construction" means that the material is downproof without the need for additional coatings or treatment.

"Super high-density weave" in relation to fabric means a material that has a thread count that exceeds the minimum thread count required to achieve a weave in a given denier.

A reference to "materia!" includes fabrics, membranes and foils.

SUMMARY OF THE INVENTION

Throughout this document, unless otherwise indicated to the contrary, the terms "comprising", "consisting of, and the like, are to be construed as non-exhaustive, or in other words, as meaning "including, but not limited to".

In accordance with a first aspect of the invention there is a condensate management system comprising: an outermost layer of breathable material;

a second layer of hydrophobic material; and an innermost layer of breathable material,

where the outermost layer and the innermost layer are connected to opposing sides of the second layer such that, when placed near a fluid vapour source, fluid vapour is able to pass through the innermost layer and the second layer and where, when external weather conditions cause the fluid vapour to condensate, the condensate is contained between the second layer and outermost layer until such time as the external weather conditions cause the condensate to transform back to fluid vapour, the fluid vapour thereafter able to pass through the outermost layer over time.

The second layer and the innermost layer may be integrally formed from a single material.

The system may further comprise a fourth layer of insulating material interposed between the innermost layer and the second layer. This insulating material may be down. Preferably, the insulating material has a thickness of between 10 and 20mm and is made from a three dimensional material.

The system may also further include a third layer of material interposed between the fourth layer and the second layer, the material operable to prevent migration of the insulating material of the fourth layer to the second layer. The weight of the third .layer is preferably 10gsnl

Where the fourth layer is made from down, preferably the material of the third layer is down resistant.

The innermost layer may be downproof by construction. Ideally, the innermost layer is made from a material having a thread count of at least 300T. The material of the innermost layer may be a a twenty denier nylon with two ctre finishes.

The outermost layer may be made from a super high density weave. Alternatively, or further, the outermost layer may be made from either a water proof or water resistant material. Preferably, the material of the outermost layer is chemically treated with nano-sized particles to improve water resistivity.

The outermost layer may be made from a material having a breathability measurement of at least 3000 mvtr/24 hr . The second layer may be made from a material having a waterhead value in excess of 200mm Preferably, the second layer is made from a material having a waterhead value in excess of 500mm.

The second layer may be made from a material having a breathability measurement of at least 3000 mvtr/24 hr. The material of any layer may be a non-woven material. Similarly, the material of any layer may be a composite material.

In accordance with a second aspect of the invention there is a fabric made in accordance with the condensate management system as described in the first aspect of the invention.

In accordance with a third aspect of the invention there is a sleeping bag made from fabric made in accordance with the condensate management system as described in the first aspect of the invention, where the innermost layer is used to contain a sleeping person and the outermost layer is exposed to the external weather conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic representation of material of the prior art as used in a sleeping, bag.

Figure 2 is a schematic representation of a first material incorporating a condensate management system according to the present invention as used in a sleeping bag.

Figure 3 is a schematic representation of a second material incorporating a condensate management system according to the present invention as used in a sleeping bag.

PREFERRED EMBODIMENTS OF THE INVENTION ln accordance with a first embodiment of the invention there is a sleeping bag 10. The material construction of the sleeping bag 10 is shown in Figure 2.

The outermost layer 12 of the sleeping bag 10 is made from a breathable material.

The second layer 14 of the sleeping bag 10 is made from a hydrophobic material. The width (W) of this second layer 14, in this embodiment, is between one and two centimetres.

The inner most layer 16 of the sleeping bag 10 is made from a downproof by construction, breathable material. In this embodiment, the inner most layer 16 is a twenty denier nylon with two cire finishes. The net benefit of this materia! can be shown by way of the following example.

As fluid vapour 18a is generated by a person (not shown) enclosed within the sleeping bag 10 it passes through the breathable material of the inner most layer 16. The fluid vapour 18a is then able to travel through the second layer 12 until it reaches the point where the second layer 14 meets the outermost breathable fayer 12.

It is here that, depending on the weather conditions of the environment external to the sleeping bag 10, the fluid vapour 18a may either:

• travel through the outermost layer 12; OR

• in circumstances of low temperature and/or high humidity, the fluid vapour 18a' may condense back to liquid form 18b. In this second situation, the hydrophobic nature of the second layer 14 prevents the^" condensate 18b from travelling back towards the person. At the same time, the outermost layer 12 prevents the fluid vapour 18a, in condensate form 18b, from travelling therethrough to the external environment. Thus, the fluid vapour 18a, in condensate form 18b, is effectively contained between the outermost layer 12 and the second layer 14.

The fluid vapour 18a, in condensate form 18b, so contained is thereafter able to transform back into fluid vapour as external weather conditions permit This fluid vapour is then able to evaporate through the breathable outermost layer 12 over time. ln accordance with a second embodiment of the invention there is a sleeping bag 100. The material construction of the sleeping bag 100 is shown in Figure 3.

The outermost layer 102 of the sleeping bag 100 is made from a super high-density weave fabric chemically treated with nano-sized particles (not shown). The nano-sized particles attach to the fibres to provide a long lasting water repellent finish. The end result is a fabric that will not absorb water even after more than a hundred washes and has a breathability measurement of at least 3000 mvt/24hr and a water head in excess of 500mm.

The second layer 104 of the sleeping bag 100 is made from a hydrophobic non-woven material. The width (W) of this second layer 104 is between one and two centimetres.

The use of non-woven material in the second layer 104 allows the material to be very light within the required thickness. At the same time, the high surface area and very low density (in comparison to woven material) allows moisture to pass easily therethrough and potentially dry before reaching the outermost layer 102.

The third layer 106 is made from .a non-woven material having a material weight of 10 gsm.

The fourth layer 108 is made from down. The width of the fourth layer 108 determines the level of warmth of the bag, with the thicker the insulation the greater the warmth imparted. In this case, the fourth layer has a width of 10mm.

The inner most layer 110 of the sleeping bag 100 is made from a downproof by construction, breathable material. In this embodiment, the inner most layer 110 is a twenty denier nylon with two cire finishes.

The net benefit of this material can be shown by way of the following example.

As fluid vapour 112a is generated by a person (not shown) enclosed within the sleeping ' bag 10 it passes through the breathable material of the inner most layer 110. The fluid vapour 112a is then also able to pass through the fourth and third layers 108, 106 respectively until it reaches the second layer 1,04. At this point, the fluid vapour is able to travel through the second layer 104 until it reaches the point where the second layer 104 meets the outermost layer 102. It is here that, depending on the weather conditions of the environment external to the sleeping bag 100, the fluid vapour 112a may either:

• travel through the outermost layer 102; OR

• in circumstances of low temperature and/or high humidity, the fluid vapour 112a may condensate back to liquid form 112b.

In this second situation, the hydrophobic nature of the second layer 104 prevents the condensate 112b from travelling back towards the person. At the same time, the outermost layer 102 restricts the fluid vapour 108a, in condensate form 112b, from travelling therethrough to the external environment. Thus, the fluid vapour 112a, in condensate form 1 12b, is effectively contained between the outermost layer 102 and the second layer 104.

The fluid vapour 112a, in condensate form 112b, so contained is thereafter able to transform back into fluid vapour as external weather conditions permit. This fluid vapour is then able to evaporate through the outermost layer 102 over time.

Jt should be appreciated by the person skilled in the art that the above invention Is not limited to the embodiment described. In particular, the following modifications and improvements may be made without departing from the scope of the present invention:

• Ideally this second layer 14 is made from 40gsm Primaloft One as available from Albany International Corp of Albany, New York. However, layers of other gsm values and width of this material can be used as required for the particular application of the material incorporating the condensate management system the subject of the invention.

The third layer 106 may be omitted from the second embodiment. However, omitting the third layer can reduce the overall efficiency of the resulting material as down tends to migrate through the second layer over time-

• In principle, the mvt/24hr value of the outermost layer 12 can be any value. That said, the mvtf24hr value chosen must be correlated with the condensation management ability of the second layer 14. For this reason, while the general position is that the higher the mvt/24hr value of the outermost layer 12 the better the performance, where the outermost layer 12 practically becomes 100% impermeable to vapour, the performance degrades. A known value where the material provides satisfactory performance is at least 3000 mvt/24hr or more.

Again, in principle, where the outermost layer 12 is water proofed, the water head value of the outermost layer 12 can be any value above 200mm. However, there is no necessity to waterproof the outermost layer 12. The outermost layer 12 may have only the natural water resistivity characteristics of the material used or may be further treated with a water-proof or water-resistant chemical composition.

The second layer 14 must, primarily, be hydrophobic. Secondary attributes for the layer include breathability, weight and insulating properties. Of these secondary attributes, breathability is considered the most important.

Ideally the material making up the second layer 14 is fibrous in nature. The three-dimensional nature of such fibrous material increases the hydrophobic properties of the second layer 14.

The third layer 106 is characterised by the requirements of down resistance and weight.

The innermost layer 110 must be down proof and breathable. Within the industry, a twenty denier fabric with a thread count above 300T is considered down proof, however, each material must be tested to confirm this.

Treatment of the outer layer 12 with nano-particles is an advantageous, but not essential, element of the invention in that it increases the water resistivity of the material forming the outer layer 12. However, it should be appreciated that the outer later 12 may be formed from any other material that is breathable and has additional water repellent properties.

While the layers of the two embodiments have been described in the context of a single material, such as polyester, there is no requirement for the layers to be made up of a single material. Each layer may be formed from composite materials.

The fourth layer 108 may be made from any material. However, as mentioned above down is preferable due to its high insulating properties compared to its weight. Examples of alternate insulating material including but not limited to natural fibres like wool, fur, cotton, silk from plant and animal sources or synthetic fibres like polyester in woven or non-woven form or synthetic insulation foams.

• The materia! forming any layer may be either a woven material or a non-woven material, provided it has the designated characteristics for that layer.

• As mentioned above, while the invention has been described in the context of sleeping bags, it is not restricted to such uses. The invention could just as easily be applied to tents, clothing, etc.

It should be further appreciated by the person skilled in the art that one or more of the above modifications and improvements, not being mutually exclusive, may be combined to form yet further embodiments considered within the scope of the present invention.

Claims

We Claim:

1. A condensate management system comprising:

an outermost layer of breathable material;

a second layer of hydrophobic breathable material; and

an innermost layer of breathable material,

2. A condensate management system according to claim 1 , where the second layer and the innermost layer are integrally formed from a single material.

3. A condensate management system according to any preceding claim further comprising a fourth layer of insulating material interposed between the Innermost layer and the second layer,

4. A condensate management system according to claim 3, where the insulating material is down.

5. A condensate management system according to claim 3 or claim 4, where the fourth layer has a thickness between 10 and 200mm.

6. A condensate management system according to any one of claims 3 to 5, where the fourth layer is made from a three dimensional material.

7. A condensate management system according to any one of claims 3 to 6 further comprising a third layer of material interposed between the fourth layer and the second layer, the material operable to prevent migration of the insulating material of the fourth layer to the second layer.

8. A condensate management system according to claim 7, where the weight of the third layer is 10gsm.

9. A condensate management system according to claim 7 or claim 8, as dependent on claim 4, where the material of the third layer is down resistant. 10. A condensate management system according to any preceding claim, where the innermost layer is downproof by construction.

11. A condensate management system according to claim 10, where the innermost layer is made from a material having a thread count of at least 300T.

12. A condensate management system according to any preceding claim, where the material of the innermost layer is a twenty denier nylon with two cire finishes.

13. A condensate management system according to any preceding claim, where the outermost layer is made from a super high density weave.

14. A condensate management system according to any preceding claim where the outermost layer is made from either a water proof or water resistant material. 15. A condensate management system according to any preceding claim where the material of the outermost layer is chemically treated with nano-sized particles to improve water resistivity.

16. A condensate management system according to any preceding claim where the outer layer is made from a material having a breathability measurement of at least 3000 mvt/24hr

17. A condensate management system according to any preceding claim, where the second layer is made from a material having a waterhead value in excess of 200mm

18. A condensate management system according to claim 17, where the second layer is made from a material having a waterhead value in excess of 500mm.

19. A condensate management system according to any preceding claim where the outer layer is made from a material having a breathability measurement of at least 3000 mvt/24hr 2_,0. A condensate management system according to any preceding claim, where the material of any layer is a non-woven material.

21. A condensate management system according to any preceding claim, where the material of any layer is a composite material.

22. A fabric made in accordance with the condensate management system as described in any one of claims 1 to 20.

23. A sleeping bag made from fabric made in accordance with the condensate management system as described in any one of claims 1 to 20, where the innermost layer is used to contain a sleeping person and the outermost layer is exposed to the external weather conditions.