Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
  • D21H13/36—Inorganic fibres or flakes
  • D21H13/38—Inorganic fibres or flakes siliceous
  • D21H13/40—Inorganic fibres or flakes siliceous vitreous, e.g. mineral wool, glass fibres
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04D—ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS
  • E04D5/00—Roof covering by making use of flexible material, e.g. supplied in roll form
  • E04D5/02—Roof covering by making use of flexible material, e.g. supplied in roll form of materials impregnated with sealing substances, e.g. roofing felt

Definitions

• This invention relates to new and improved glass fiber mats which are particularly useful for built-up roofing membranes and systems.
• Built-up roofing (“BUR”) membranes and systems are used primarily on commercial buildings, and, to the substantial exclusion of other roofing types, on large industrial buildings of low profile. Its popularity arises from its relatively low cost combined with its effectiveness as a weather repellant surface and its durability. The major drawback in its use is that a unique combination of both high tensile and tear strength properties is required. These rigid requirements arise because built-up roofing systems, unlike residential roofing are subject to severe stresses induced internally or ' externally by the surrounding atmosphere, including expansion caused by the presence of moisture internal to the system, and both expansion and contraction forces caused by variation in ambient temperature conditions. For these and other reasons, it is essential that built-up roofing systems possess an excellent balance of both high tensile strength and tear resistance.
• Extended fiber elements are characterised structurally by being comprised of a plurality of longitudinally connected fibers formed from extension of bundles of fibers which slide apart during the process of dispersion of the fiber bundles.
• the extended fiber elements have an exaggerated length and a nonuniform diameter, being greater in the mid-section, where connection of fibers is greatest, and tapered towards its ends.
• it is rather difficult to disperse elongated fibers efficiently.
• the tensile strength of such products are rather modest.
• a new and improved glass fiber mat which can be used in place of organic felts to make BUR products characterized particularly by their unusual combination of both high tensile and tear strengths, and efficiency of manufacture, as compared to other commercially available products of similar construction.
• the tensile strengths range from 270 to 350 N/50 mm. width (MD), and the corresponding Elmendorf tear strengths range from 5.0 to 6.6 N (MD).
• the ratio of tensile to tear strengths ranges from 40:1 to 7:1.
• the BUR products of the invention are characterized particularly by their unusual combination of both high tensile and tear strengths, and efficiency of manufacture, as compared to other commercially available products of similar construction.
• the tensile strengths range from 490 to 600 N/50 mm. width (MD), and the corresponding Elmendorf tear strengths range from 6.0 to 8.1 N/50 mm. width (MD).
• the ratio of tensile to tear strength is about 60:1 to 100:1.
• the enmeshed glass fibers in the mat includes two fibrous components, namely, individual filament fibers and extended fiber elements, which are present in substantially equal amounts by weight.
• the number of fibers in a given extended element is about 2 to 200, generally about 20 fibers per element. Accordingly, there are usually about 20 times as many individual filament fibers as extended element fibers im the mat.
• the number of both fibrous components resides between 2.9 and 6.6 x 10 6 fibers per m 2 of the glass mat, at a glass weight of about 30 g/m 2 and a mat thickness of about 0.7 mm.
• the enmeshed glass fibers are made by a wet-laid process using sized glass fiber bundles having a critical fiber diameter of 13-14 microns and a fiber length between 19 and 44 mm.
• the bundles are maintained at a given fiber consistency, and are dispersed under vigorous agitation in the presence of a predetermined concentration of a chemical dispersant.
• a higher concentration of dispersant is used with fibers of greater length; most preferably it ranges from 60 to 160 ppm.
• the glass mat has a tensile strength of 300 N/50 mm. width (MD) and tensile to tear strength ratio of 53:1.
• This mat is made from glass fibers having a length of 32 mm. and a diameter of 13-14 microns, dispersed in 90 ppm. of dispersant.
• the total number of fibrous components in this glass mat is 3.9 x 10 6 fibers per m 2 .
• the BUR membrane has a tensile strength of 550 N/50 mm. width (MD) and tensile to tear strength ratio of 79:1.
• This membrane is made from glass fibers having a length of 32 mm. and a diameter of 13-14 microns, dispersed in 90 ppm. of dispersant.
• a single source of raw material is used in the wet-laid process of making the glass fiber mats, namely, bundles of fiber glass, preferably sized. Each bundle contains about 20 to 2000 fibers.
• the glass fiber bundles are maintained in an aqueous medium in which a chemical dispersant is present at a predetermined concentration.
• a chemical dispersant may be used as long as it can effectively disperse the bundles.
• a particularly useful dispersant is a tertiary amine oride, such as fromx DNHT, which is dimethyl hydrogenated tellew amine oxide, sold by Armak Chemical Co. The use of this dispersant is described in U.S. patent 4,179,331. The description hereinafter will be directed to this compound.
• the fiber bundles are agitated vigorously in the aqueous dispersement medium to form a dilute fiber slurry of selected consistency. During this agitation, some of the bundles become unbundled or filamentized, i.e. form individual filaments. These filaments can become connected longitudinally to form an extended glass fiber element. Other bundles can slide apart to provide extended elements directly.
• the dispersant in the fiber slurry is maintained at a predetermined concentration of about 60 to 160 ppm.
• the lower concentration is more suitable for shorter fibers, while the higher concentration is used with longer fibers.
• a concentration of 90 ppm. is employed with fibers having a length of 32 mm. Under these conditions, vigorous agitation of the fiber slurry for about 10 minutes will form mats having the desired equal amounts of individual filaments and extended fiber elements and the prescribed total number of fibrous components.
• the fiber slurry suitably is maintained at a consistency of about 0.50 to 0.50% by weight of the fibers in the slurry. Preferably it is decreased in increments of about 0.05% for each 6 mm. increase in fiber length.
• the concentrated dispersion slurry is diluted with water before being applied to the mat-forming screen. Preferably the dispersion slurry is diluted about 5 to 25 times at the screen, and, optimally, about 10 times.
• the enmeshed glass fibers thus-formed are provided with a suitable binder to hold the fibrous components together.
• a suitable binder such as urea-formaldehyde or phenol-formaldehyde resins.
• the binder usually is applied in an amount of about 5 to 50% by weight of the finished mat, preferably about 10 to 30%, and, optimally, about 20%. Accordingly, the weight of fibers in the mat is about 50 to 95%, preferably 70 to 90%, and, optimally, about 80%, by weight of the mat.
• the basis weight of the finished glass fiber mat usually is about 90 to 110 g/m 2 .
• the mat generally is about 0.7 mm. thick.
• the glass fiber mat exhibits a porosity which is suitable for impregnation of asphalt to form BUR membranes.
• Such mats exhibit a porosity of at least 100 m 3 /m 2 /min., and usually 140 or more, as measured by the conventional Frazier ASTM-D737 test method.
• BUR membranes are fabricated by impregnation of the glass fiber mat with a suitable quantity of saturant asphalt, usually about 330% of asphalt based on the original weight of glass fiber mat. Then BUR roofing systems, e.g., 3-ply BUR systems, are made from multiple layers of BUR membranes which are held together with coatings of asphaltic adhesive.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Nonwoven Fabrics (AREA)
• Laminated Bodies (AREA)
• Seal Device For Vehicle (AREA)
• Multicomponent Fibers (AREA)
• Cell Separators (AREA)

Applications Claiming Priority (4)

Publications (1)

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ID=26910073

Family Applications (1)

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Cited By (2)

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Citations (2)

• 1981
  • 1981-11-03 DE DE19813143586 patent/DE3143586A1/de not_active Withdrawn
  • 1981-11-19 NO NO813937A patent/NO813937L/no unknown
  • 1981-11-25 EP EP81109892A patent/EP0054202A1/de not_active Withdrawn
  • 1981-12-03 FI FI813879A patent/FI813879L/fi not_active Application Discontinuation

Patent Citations (2)

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