Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F41—WEAPONS
  • F41H—ARMOUR; ARMOURED TURRETS; ARMOURED OR ARMED VEHICLES; MEANS OF ATTACK OR DEFENCE, e.g. CAMOUFLAGE, IN GENERAL
  • F41H5/00—Armour; Armour plates
  • F41H5/02—Plate construction
  • F41H5/04—Plate construction composed of more than one layer
  • F41H5/0471—Layered armour containing fibre- or fabric-reinforced layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2305/00—Condition, form or state of the layers or laminate
  • B32B2305/08—Reinforcements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2305/00—Condition, form or state of the layers or laminate
  • B32B2305/10—Fibres of continuous length
  • B32B2305/18—Fabrics, textiles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/558—Impact strength, toughness

Definitions

• the invention relates to the use of a high strength laminated composite sheathing for the reinforcement of walls and doors to resist penetration by wind-borne debris such as that generated by severe storm events, particularly tornadoes.
• Storm shelters and cellars are necessary to provide a safe haven for protection against severe storm events in regions prone to tornado or hurricane activity. These shelters have been typically constructed of poured concrete, steel reinforced masonry, or heavy weight sheet metal. Details of adequate designs for storm shelters and cellars are detailed in publications from the Federal Emergency Management Agency (FEMA) such as Taking Shelter from the Storm - Publication 320 and Design and Construction Guidance for Community Shelters - Publication 361. The current designs rely on the use of common heavyweight construction materials such as concrete and steel to provide the resistance to wind-borne debris generated in the storm event.
• FEMA Federal Emergency Management Agency
• the present invention is directed to: a composite comprising:
• the material is particularly adapted for construction of storm shelters and residences located in areas of the world which are subjected to windblown debris not only by hurricanes but also from the substantially higher wind speeds of tornadoes.
• a necessary starting material is a fabric containing high strength fiber.
• the fabric may be a woven or non-woven although a woven fabric is preferred.
• High strength fibers are well known and as employed herein means fibers having a tenacity of at least 10 grams per dtex and a tensile modulus of at least 150 grams per dtex.
• Yarns can be made from fibers such as aramids, polyolefins, polybenzoxazole, polybenzothiazole, glass and the like, and may be made from mixtures of such yarns.
• the fabric may include up to 100 percent aramid fiber.
• aramid is meant a polyamide wherein at least 85% of the amide (-CO-NH-) linkages are attached directly to two aromatic rings. Examples of aramid fibers are described in Man-Made Fibers -Science and Technology-i Volume 2, Section titled Fiber-Forming Aromatic Polyamides, page 297, W. Black et al., Interscience Publishers, 1968. Aramid fibers are, also, disclosed in U.S. Patents 4,172,938; 3,869,429; 3,819,587; 3,673,143; 3,354,127; and 3,094,511.
• Para-aramids are common polymers in aramid yarn and poly(p- phenylene terephthalamide) (PPD-T) is a common para-aramid.
• PPD-T poly(p- phenylene terephthalamide)
• PPD-T is meant the homopolymer resulting from mole-for-mole polymerization of p- phenylene diamine and terephthaloyl chloride and, also, copolymers resulting from incorporation of small amounts of other diamines with the p- phenylene diamine and of small amounts of other diacid chlorides with the terephthaloyl chloride.
• PPD-T means copolymers resulting from incorporation of other aromatic diamines and other aromatic diacid chlorides such as, for example, 2,6- naphthaloylchloride or chloro- or dichloroterephthaloyl chloride or 3,4 - diaminodiphenylether.
• polyolefin polyethylene or polypropylene.
• polyethylene is meant a predominantly linear polyethylene material of preferably more than one million molecular weight that may contain minor amounts of chain branching or co-monomers not exceeding 5 modifying units per 100 main chain carbon atoms, and that may also contain admixed therewith not more than about 50 weight percent of one or more polymeric additives such as alkene-1 -polymers, in particular low density polyethylene, propylene, and the like, or low molecular weight additives such as anti- oxidants, lubricants, ultra-violet screening agents, colorants and the like which are commonly incorporated. Such is commonly known as extended chain polyethylene (ECPE).
• ECPE extended chain polyethylene
• polypropylene is a predominantly linear polypropylene material of preferably more than one million molecular weight.
• High molecular weight linear polyolefin fibers are commercially available.
• Polybenzoxazole and polybenzothiazole are preferably made up of polymers of the following structures:
• While the aromatic group shown joined to the nitrogen atoms may be heterocyclic, they are preferably carbocyclic; and while they may be fused or unfused polycyclic systems, they are preferably single six-membered rings. While the group shown in the main chain of the bis-azoles is the preferred para-phenylene group, that group may be replaced by any divalent organic group which does not interfere with preparation of the polymer, or no group at all. For example, that group may be aliphatic up to twelve carbon atoms, tolylene, biphenylen, bis-phenylene either, and the like.
• a further requirement in the present invention is the use of a resin to bind individual fibers of the high strength fibers in the employed fabric.
• the resin may be selected from a wide variety of components such as polyethylene, ionomers, polypropylene, nylon, polyester, vinyl ester, epoxy and phenolics and thermoplastic elastomers.
• the resin may be applied to the fabric containing high strength fibers by coating or impregnation, such as under pressure.
• test procedure E1886-97 is specific to the various requirements such as the use of 2 x 4 lumber missile, missile propulsion device, speed measuring system and use of a high speed video or photographic camera. It is understood, herein, that the test procedure for purposes of the present disclosure involves attaching any test specimen, i.e., the high strength fabric / resin combination, with one layer of 3/4-inch plywood using #10d common nails spaced per the nailing schedule described in FEMA Publication 320, Revision 1 , specific to Drawings AG-5 and 14, to a wall frame built in accordance with same publication, with plywood as outermost layer from said frame. Such wall system is then impacted on the plywood face at the center of one of the two middle bays.
• the 2 x 4 lumber missile should be marked with suitable indexing marks to allow the tracking of the depth of penetration of the projectile.
• the photographic or video camera should be positioned to monitor the depth of penetration of the projectile and such camera should have a minimum frame rate of 1000 frames per second.
• the combination of the fabric containing high strength fibers bonded with a resin will deflect within a range from 5.0 to 17.5 cm. More preferably the deflection will be in a range from 8.0 to 16.0 cm and most preferably 10.0 to 15.0 cm. The degree of deflection may be determined by its final use in a building structure.
• a maximum stated deflection of the fabric / resin combination may be undesirable in a residence due to the proximity of an occupant adjacent a wall containing the cloth / resin combination.
• a minimum deflection within the above range can require an added thickness of the fabric resulting in a high cost of construction.
• fabric is inclusive of more than one layer of a cloth.
• deflection means the maximum measured distance of separation of the high strength fabric / resin combination from the structural sheathing. It is understood that the measurement must be undertaken in conjunction with high speed photography. For purposes of illustration for deflection measurement, if during the test procedure with the projectile, there may be some bowing of the structural sheathing.
• the measurement for deflection is the distance, i.e., the separation, of the high strength fabric / resin combination from the bowed portion of the sheathing. It can be determined from review of the photographic or video record collected during previously described testing, determining the maximum depth of penetration during the event, and subtracting the thickness of the structural sheathing.
• Kevlar® aramid a fabric containing high strength fibers
• Kevlar® aramid a fabric containing high strength fibers
• plywood has been previously tested in the Clemson University report referenced in the Background of the Invention.
• complete penetration of the Kevlar® aramid / plywood took place with a nine pound projectile at a speed of 73 miles per hour.
• the combination of the fabric containing the high strength fibers / resin is for employment with a wood based or other structural sheathing material, since an additional purpose of the combination is the structural reinforcement of a wall or door.
• structural sheathing is inclusive of any material which provides structural building support. The preferred material is wood, particularly plywood, due to extensive use in the building industry. However other materials are known for structural sheathing serving as building support: a typical example is fiberboard reinforced with cement.
• the fabric / resin combination is generally flexible and will be employed with the sheathing which for purposes of illustration may be at least 0.65 cm (one quarter inch) and preferably for purposes of support, at least 1.27 cm (one half inch). The type of structural sheathing is not critical to the success of the present invention.
• the sheathing may be solid such as from hard or soft woods or may be in the form of a composite such as plywood or a non-wood sheathing such as cementous fiberboard.
• a composite such as plywood or a non-wood sheathing such as cementous fiberboard.
• the structural sheathing face the direction of any wind-borne debris such that the debris strikes the wood with penetration before contact and containment with deflection of the combination of cloth / resin. It is understood that the invention is particularly advantageous since conventional building construction and techniques with structural sheathing may be employed.
• a 3-foot wide by 4-foot long fiber reinforced composite sheathing panel was prepared by stacking 3 layers of a 13.5 oz. / square yard, plain weave fabric made from aramid fiber, between 2 layers of 0.0045 thick film made from an ionomeric polyethylene resin.
• the stack of fabric and resin was placed in a heated hydraulic press that had been pre-heated to 300°F.
• a pressure of 160 psi was applied to the stack of material for 1 hour to melt the outer layers of polymer and infuse it into the layers of fabric that were in between.
• the press was then cooled below 150°F and the pressure released.
• the resulting sheathing was nailed to a wooden frame made from 2x4 framing timber as prescribed in FEMA Publication 320. #10 power driven nails were used to fasten the composite sheathing to the wooden frame, with a single layer of 3/4" plywood covering the sheathing on the face to be impacted.
• the wall panel was mounted on a rigid test frame with the 3-foot dimension on each side of the wall panel fully supported.
• the sample was impacted with a 15-lb 2x4 timber projectile traveling at 100 mph, to access ability to meet the "Windborne Missile Impact Resistance on Shelter Wall and Ceiling" provisions of the National Performance Criteria for Tornado Shelters, First Addition, FEMA, May 28, 1999.
• Cannon set-up and firing was done in accordance with ASTM E 1886 -97.
• the wall segment stopped the projectile from passing through it as required by the FEMA provisions, and the projectile was rebounded back.
• High speed photography taken during the event showed the projectile to penetrate approximately 15.2 cm into the wall cavity before being rebounded back.
• Deflection of the composite sheathing was calculated to be 13.4 cm.
• the plywood layer on the outside of the wall showed damage only locally around the point of projectile entry.
• a 3-foot wide by 4-foot long fiber reinforced composite sheathing panel was prepared by stacking 7 layers of a 10 oz. / square yard, plain weave fabric made from S-2 glass fiber, with 4 layers of 0.0045 thick film made from an ionomeric polyethylene resin.
• the stack of fabric and resin was placed in a heated hydraulic press that had been pre-heated to 300°F.
• a pressure of 160 psi was applied to the stack of material for 1 hour to melt the layers of polymer and infuse it into the layers of fabric that were in between.
• the press was then cooled below 150°F and the pressure released.
• the resulting sheathing was nailed to a wooden frame made from 2x4 framing timber as prescribed in FEMA Publication 320. #10 power driven nails were used to fasten the composite sheathing to the wooden frame, with a single layer of 3/4" plywood covering the sheathing on the face to be impacted.
• the wall panel was mounted on a rigid test frame with the 3-foot dimension on each side of the wall panel fully supported.
• the sample was impacted with a 15-lb 2x4 timber projectile traveling at 100 mph, to access ability to meet the "Windborne Missile Impact Resistance on Shelter Wall and Ceiling" provisions of the National Performance Criteria for Tornado Shelters, First Addition, FEMA, May 28, 1999.
• Cannon set-up and firing was done in accordance with ASTM E 1886 -97.
• a 3-foot wide by 4-foot long dry fabric sheathing material was prepared by sewing 3 layers of a 13.5 oz. / square yard, plain weave fabric made from aramid fiber around the edges.
• the resulting fabric pack was nailed to a wooden frame made from 2x4 framing timber as prescribed in FEMA Publication 320. #10 power driven nails were used to fasten the fabric sheathing to the wooden frame, with a single layer of 3/4" plywood covering the sheathing on the face to be impacted.
• the wall panel was mounted on a rigid test frame with the 3-foot dimension on each side of the wall panel fully supported.
• the sample was impacted with a 15-lb 2x4 timber projectile traveling at 100 mph, to access ability to meet the "Windborne Missile Impact Resistance on Shelter Wall and Ceiling" provisions of the National Performance Criteria for Tornado Shelters, First Addition, FEMA, May 28, 1999.
• Cannon set-up and firing was done in accordance with ASTM E 1886 -97.
• the wall segment stopped the projectile from passing through it as required by the FEMA provisions, and the projectile was rebounded back.
• High speed photography taken during the event showed the projectile to penetrate approximately 17.8 cm into the wall cavity before being rebounded back.
• Deflection of the fabric sheathing was calculated to be 16 cm, which was 2.6 cm more than that noted in example 1 with the resin present.
• the plywood layer on the outside of the wall also showed significant cracking beyond the point of impact. There was as well, significant pull-out of the fabric around the fasteners.
• a 4-foot wide by 8-foot long fiber reinforced composite sheathing panel was purchased from the Sioux Manufacturing Company that had been produced from 3 layers of 13.5 oz / square yard plain weave aramid fabric coated with phenolic resin and molded as described in the MIL-L-6247A specification for ballistic armor.
• the resulting sheathing was nailed to a wooden frame made from 2 x 4 framing timber as prescribed in FEMA Publication 320. #10 power driven nails were used to fasten the composite sheathing to the wooden frame, with 2 layers of 3/4" plywood covering the sheathing on the face to be impacted.
• the wall panel was mounted on a rigid test frame with the 4-foot dimension the wall panel supported. The sample was impacted with a 15 lb. 2 x 4 timber projectile traveling at 100 mph, to assess ability to meet the "Wind-borne Missile Impact Resistance on Shelter Wall and Ceiling" provisions of the National Performance Criteria for Tornado Shelters, First Addition, FEMA, May 28, 1999. Cannon set-up and firing was done in accordance with ASTM E1886-97.
• a 3-foot wide by 4-foot long fiber reinforced composite sheathing panel was prepared by stacking 3 layers of a phenolic prepreg produced from 13.5 oz. / square yard, plain weave fabric made from aramid fiber in accordance with Mil Spec MIL-L-62474.
• the stack of prepreg was placed in a heated hydraulic press that had been pre-heated to 330°F.
• a pressure of 160 psi was applied (versus 200 psi as required by MIL-L-62474) to the stack of material for 30 minutes to cure the resin.
• the press was then cooled below 150°F and the pressure released.
• the resulting material was more flexible than the commercially acquired laminate pressed in accordance with the Military Specification.
• the resulting sheathing was nailed to a wooden frame made from 2x4 framing timber as prescribed in FEMA Publication 320. #10 power driven nails were used to fasten the composite sheathing to the wooden frame, with a single layer of 3/4" plywood covering the sheathing on the face to be impacted.
• the wall panel was mounted on a rigid test frame with the 3-foot dimension on each side of the wall panel fully supported.
• the sample was impacted with a 15-lb 2x4 timber projectile traveling at 100 mph, to access ability to meet the "Windborne Missile Impact Resistance on Shelter Wall and Ceiling" provisions of the National Performance Criteria for Tornado Shelters, First Addition, FEMA, May 28, 1999.
• Cannon set-up and firing was done in accordance with ASTM E 1886 -97.
• the wall segment stopped the projectile from passing through it as required by the FEMA provisions, and the projectile was rebounded back.
• High speed photography taken during the event showed the projectile to penetrate approximately 10.2 cm into the wall cavity before being rebounded back.
• Deflection of the composite sheathing was calculated to be 8.4 cm.
• the plywood layer on the outside of the wall showed damage only locally around the point of projectile entry.

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• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Laminated Bodies (AREA)
• Woven Fabrics (AREA)
• Panels For Use In Building Construction (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2001
  • 2001-10-15 US US09/977,648 patent/US20030079430A1/en not_active Abandoned
• 2002
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  • 2002-10-11 CA CA002462440A patent/CA2462440A1/en not_active Abandoned
  • 2002-10-11 BR BR0213648-1A patent/BR0213648A/pt not_active Application Discontinuation
  • 2002-10-11 KR KR1020047005470A patent/KR20050035160A/ko not_active Ceased
  • 2002-10-11 WO PCT/US2002/033259 patent/WO2003033252A1/en not_active Ceased
  • 2002-10-11 EP EP02776228A patent/EP1448372A1/en not_active Withdrawn
  • 2002-10-11 CN CNB028204042A patent/CN100469566C/zh not_active Expired - Fee Related
  • 2002-10-11 JP JP2003536022A patent/JP2005506217A/ja active Pending
• 2004
  • 2004-06-11 US US10/866,348 patent/US20040221534A1/en not_active Abandoned

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