Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
  • E04H15/00—Tents or canopies, in general
  • E04H15/32—Parts, components, construction details, accessories, interior equipment, specially adapted for tents, e.g. guy-line equipment, skirts, thresholds
  • E04H15/54—Covers of tents or canopies
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
  • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04D—ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS
  • E04D12/00—Non-structural supports for roofing materials, e.g. battens, boards
  • E04D12/002—Sheets of flexible material, e.g. roofing tile underlay

Definitions

• the present invention relates to a reversibly steam transmitting plast material foil, comprising a water and steam proof, water impermeable and steam permeable barrier layer. Moreover, the invention relates to use of said foil as an underroof, as building foil for insufficiently ventilated constructions and as tent canvas .
• Suitable plast material foils for such underroofing lengths have, as already said, to be water and steam resistant, which first and foremost means that the plast material in such foils must not be chemically degradable by water or steam, not even after use for a long time with attendant risk of aging of this material. Furthermore, these foils have to be mechanically strong in order to substantially resist the influence of tearing and impacts which are inevitable in a building site. They have, to the same extent as steam impermeable plast material foils, to be able to resist a high water pressure, even during contact with another material ("tent effect") or after local contamination with e.g. detergents, and finally they have, in order to yield the desired effect, to possess a high permeability for steam.
• Plast material foils with the above-mentioned properties will not only be suited for underroofing lengths, but may also in a broader sense be usable as building foils for insufficiently ventilated constructions, i.e. in addition to said underroofing lengths also as moisture barriers, vapour inhibitors, wind barriers, steam traps, and the like.
• Steam permeable and water impermeable plast material foils may be divided into foils made from microporous plast materials and monolithic ones. In respect of the first-mentioned the transport of steam takes place through micropores transversely to the foil, these pores being produced mechanically or by choice of a suitable combination of materials in the manufacture of foil, e.g. by stretching of a mixture of incompatible particles for the attainment of micropores at the particle boundaries. In films of monolithic materials there are, as the name implies, no pores present.
• the foils are made from special, in particular hydrophilic polymers, and steam is transported through the foil material by activated diffusion, the steam being dissolved in the material at the surface, above which the partial pressure for gaseous water is highest, diffuses through the film and is desorbed from the surface being exposed to a lower steam partial pressure .
• the steam permeability for microporous materials depends on the thickness of the material and on the pore width, the risk, however, of water penetration also increasing with the pore width.
• the chemical composition is in addition to the material thickness of particular importance for the steam permeability, and such materials can to a high extent be made safe against water penetration.
• an underroofing length for the above purpose, said length consisting of an only slightly swellable polyurethane foil covered on one of the sides by a layer of non- woven fabric firmly connected with the polyurethane foil.
• the length is to protect subjacent construction members and spaces against penetrating thawing drift snow, rain, dust and soot, for which reason it is designed to be waterproof, but it is on the other hand designed to be water permeable to avoid condensation of steam thereon.
• a steam permeability has in practice been obtained of approx.
• DE-C-34 25 795 discloses an underroofing length in shape of a water collecting foil of polyester block amides (PEBA) of hydrophilic type.
• PEBA polyester block amides
• the document EP-A-708 212 describes in an attempt to overcome the above-mentioned problem an underroofing length constituted of three layers, viz. two water and steam permeable and water and steam resistant layers of non-woven fabric and a film-like barrier layer placed between these layers of non-woven fabric, which barrier layer in addition to being able to withstand water and steam should further be impermeable to water, but during water or steam uptake be permeable to steam.
• the presence of the two layers of non-woven fabric positioned in this manner is said to stabilize the adhesion between these layers and the barrier layer, such that an undesirable loosening of the connection between the layers of non-woven fabric and barrier layers does not occur.
• the barrier layers are preferably made from a plast material having the desired properties in respect of water impermeability and steam permeability, another possible solution being the use of a material which is normally water and steam proof, but which by microper- foration has been made adequately permeable to steam.
• the examples state layers of non-woven fabric of polyethylene, polypropylene and polyester fibres and barrier layers made from a water-absorbent, thermoplastic polyurethane, a hydrophilic polyether polyamide block copolymer and a water-absorbent polyether ester, and the three-layer composition optionally being reinforced by a netting inserted in the barrier layer, e.g. embedded therein.
• a steam permeability of 700-1000 g/m per 24 hours was obtained hereby.
• the object of the invention is to provide a reversibly steam transmitting plast material foil for building purposes of the above- mentioned kind, which, apart from retaining mechanical strength, preventing water from penetrating and providing a better steam permeability than is the case in the known lengths described, is of a simple construction .
• the reversibly steam transmitting plast material foil for building purposes according to the invention is characterized in that the barrier layer therein is made from a monolithic, hydrophilic and while swelling steam absorbing and steam transmitting plastic material with a steam permeability measured according to DIN 53122 at 38°C and 90% relative humidity at a foil thickness of 0.15 mm of at least 1000 g/ (m 2 x 24 hours).
• the monolithic, hydrophilic and while swelling steam absorbing and steam transmitting plast material with no additives added possesses a tensile strength according to DIN 53 504 of at least 38 MPa, an elongation at break according to DIN 53 504 of at least 500% and a tear resistance according to DIN 53 515 of at least 60 kN/m.
• Said plast material is preferably a thermoplastic polyurethane material .
• Such materials have a high tensile strength and elongation at break and they are moreover hard-wearing, resistant to chemicals and water as well as to UV degradation.
• the permeability for steam may be adjusted.
• one or more additional thermoplastic polyurethanes may be added to said thermoplastic polyurethane material, the first thermoplastic polyurethane material, in a smaller amount, preferably 0 to 10% by weight and especially 0 to 5% by weight as a master batch containing additives common to the field, such as e.g. finishing aids and UV stabilizers and further extenders and white/coloured pigments.
• additives common to the field such as e.g. finishing aids and UV stabilizers and further extenders and white/coloured pigments.
• the additives used may, however, also be mixed directly with the utilized first thermoplastic polyurethane material. All additives used are well- known to the skilled man in the field of plast material foils and thus need no detailed comments here.
• the plast material used for the plast material foil of the invention comprises 90-100% by weight, preferably 95-100% by weight, of a first thermoplastic polyurethane material, and 0-10% by weight, preferably 0-5% by weight of one or more thermoplastic polyurethane materials in combination with additives common to the field and, optionally, extenders, pigments and/or coloured pigments.
• thermoplastic polyurethane materials with 5 to 6 times higher steam permeability than standard thermoplastic polyurethanes are now available on the market .
• These improved polyurethanes are sold under the trade names Estane ® 58237 and Estane ® 58245 (B.F. Goodrich Company, Cleveland, Ohio, USA) ; the "58245" has according to the manufacturer approx. 50% higher steam permeability than the "58237", but is made of a somewhat softer material.
• Both the Estane ® materials are most resistant to water 8 penetration, as, with a thickness of 25 ⁇ , they are able to resist a water pressure from a water column beyond 10 meters.
• the materials are according to the sales leaflets of said firm especially suited for use within the textile industry, e.g. as coatings on textiles for sportswear. None has, however, been mentioned or suggested about their suitability for building purposes .
• the first thermoplastic polyurethane material is Estane ® 58237 and/or Estane ® 58245.
• Reversibly steam transmitting plast material foils for building purposes in which the barrier layer is made from other monolithic, hydrophilic and while swelling steam absorbing and steam transmitting plast materials other than the ones mentioned specifically above, are also to be considered as belonging within the field of the invention provided their steam permeability meets the requirements of claim 1.
• the present steam transmitting plast material foil has contrary to the hydrophilic PEBA foil according to DE-C-34 25 795 proved most suitable as building foil for direct positioning on or in immediate vicinity of an insulation layer.
• the said plast material foil may, however, also be plane stabilized.
• non-swelling (water vapour impermeable) barrier foils mechanically by embedding a netting therein of a suitable material which is compatible with the foil material, and the above described already stabilized .
• three layer system above may as mentioned also as an additional reinforcement comprise a netting. It is, however, as far as Applicant knows, not known to reinforce a steam permeable (swelling) barrier layer for water, in particular a monolithic such layer, by embedding therein a reinforcing/plane stabilizing structure without a simultaneous double faced protection and/or reinforcement of the barrier layer with layers of non-woven fabric.
• a plane stabilizing by means of a film, a web or a netting laminated with the barrier layer does in view of the above-mentioned discouraging experiences with lamination of a single layer of non-woven fabric on a hydrophilic PEBA foil not appear to be attractive to the skilled man.
• the plast material foil according to the invention intended for building purposes is characterized in that the barrier layer is stabilized by means of a plane stabilizing structure of a water and steam proof and water and steam impermeable material .
• the plane stabilizing structure is a film, web or netting laminated with the barrier layer.
• the plane stabilizing structure is a web or open netting of mono or multi filaments or split fibres embedded in the barrier layer 10 and having a mesh of 0.1 to 5 cm.
• the film, web or netting laminated with the barrier layer may be a known material of non-woven fabric, e.g. polyethylene, polypropylene or polyester fibres, or it may be a netting as described hereafter.
• the embedded structure is preferably a web or an open netting with a mesh of 0.1 to 5 cm.
• the structure may be made from natural materials (cellulose, cotton, flax) and is in this case often multifilamentary, i.e. consisting of yarns of thin filaments; it may, however, also be made from synthetic materials and may in this connection be mono- or multifilamentary or consist of split fibres.
• the choice of material is not especially critical to the invention, as long as the requirements of claim 5 of a water and steam resistant and steam impermeable material, which can be plane stabilizing, are met; among preferred synthetic materials for the reinforcing structure may be mentioned high density polyethylene, polypropylene, nylon and polyester materials.
• a preferred plane stabilizing structure is an open netting of polypropylene split fibres with a mesh of 0.5 to 1.5 cm.
• the thickness of the reversibly steam transmitting plast material foil according to the invention may vary within rather wide limits, balancing requirements of mechanical strength, steam permeability and the price of the material against each other.
• the thickness is normally within the range of 0.02 to 0.5 mm and is preferably 0.1 to 0.2 mm.
• the reversibly steam transmitting plast material foil according to the invention is made by a technique known per se within the field of manufacture of previously known water and steam impermeable plast material foils, and details of the manufacutring are not of importance to the invention and need no detailed discussion here.
• the plast material foil In the manufacture of the plast material foil according to the invention, which foil has been plane stabilized by laminating as described above, the plast material foil itself is made, as mentioned above, by a technique known within the field, and a lamination thereof by a film, web or netting is also a commonly known method.
• the reinforcing structure When manufacturing a plast material foil according to the invention, which foil having been plane stabilized by embedding of a web or netting in the barrier layer, the reinforcing structure may be placed on a film of the material used for the barrier layer and the structure either coated with a layer of said material or hot-laminated with an additional film thereon.
• the reversibly steam transmitting plast material foil according to the invention is of a simple construction, is mechanically strong and has a superior steam permeability compared to known steam transmitting and water retaining underroofing plast material foils. Moreover, it is transparent, except when plane stabilized by an opaque web or film laminated with the barrier layer or when being very darkly pigmented to resist UV ageing, in contrast to underroofing films reinforced by non-woven fabric on both sides, which makes it easy to inspect a subjacent insulation, and it 12 is on account of its far smaller surface than foils reinforced on both sides by non-woven fabric far less exposed to ageing due to UV action than the films reinforced by non-woven fabric.
• the inventive reversibly steam transmitting plast material foil may according to the invention be used as a building foil, either as a foil immediately adjacent to the surface of insulation material facing the deck of the roof, or in a plane stabilized condition as an underroofing length, moisture barrier, vapour inhibitor, wind barrier, steam trap and similar building foils.
• the inventive plane stabilized plast material foil may also be used as a tent canvas for accommodation tents, service tents or storage tents.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8089475

Family Applications (1)

Country Status (8)

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Family Cites Families (2)

• 1998
  • 1998-01-22 DK DK199800077A patent/DK7798A/da not_active Application Discontinuation
• 1999
  • 1999-01-22 HU HU0100239A patent/HUP0100239A3/hu unknown
  • 1999-01-22 AU AU21501/99A patent/AU2150199A/en not_active Abandoned
  • 1999-01-22 WO PCT/DK1999/000035 patent/WO1999037427A1/en not_active Application Discontinuation
  • 1999-01-22 PL PL99342065A patent/PL342065A1/xx not_active Application Discontinuation
  • 1999-01-22 EE EEP200000426A patent/EE200000426A/xx unknown
  • 1999-01-22 EP EP99901582A patent/EP1049554A1/de not_active Ceased
• 2000
  • 2000-07-20 NO NO20003727A patent/NO20003727L/no not_active Application Discontinuation

Non-Patent Citations (1)

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