Classifications

• • 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
  • B32B43/00—Operations specially adapted for layered products and not otherwise provided for, e.g. repairing; Apparatus therefor
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F30/00—Computer-aided design [CAD]
• • 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
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/10009—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets
  • B32B17/10036—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets comprising two outer glass sheets
• • 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
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/1055—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer
• • 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
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/1055—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer
  • B32B17/10743—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer containing acrylate (co)polymers or salts thereof
• • 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
  • B32B39/00—Layout of apparatus or plants, e.g. modular laminating systems
• • 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
  • B32B2307/70—Other properties
  • B32B2307/718—Weight, e.g. weight per square meter

Definitions

• This method uses effective thickness principles to calculate the structure of a laminate that has equal strength and lighter weight compared to a target monolith.
• safety glass laminates are designed.
• the safety glass laminates have lower areal weight at equal strength, compared to a monolithic glass sheet of thickness equal to that of the safety glass laminate.
• complementary materials may improve the performance of a structural component.
• reinforced concrete uses the high strength and flexibility of steel bars to balance the brittleness of concrete.
• a polymeric interlayer having a good tensile strength provides needed toughness to a glass laminate.
• structures may be made more economically, for example when a relatively inexpensive polymer replaces some portion of a specialty metal or ceramic.
• the basic material is selected.
• a thickness is selected for a monolith of the basic material. For example, the design of a large storage tank may require stainless steel having a certain thickness.
• a candidate for an interlayer is selected, for example a rigid polymer such as polycarbonate, or a lightweight ceramic.
• the intersection of the value of the shear transfer coefficient rand the curve for the targeted weight reduction provides the ratio s of the thicknesses of the interlayer and the outer layers.
• Another mathematical relationship provides the thicknesses of the individual layers. Because the Woelfel-Bennison approach is followed, the strength of the steel/interlayer/steel laminate is the same as that of the monolithic steel at equal thickness.
• FIG. A is a cross-sectional view of a monolithic sheet.
• FIG. B is a cross-sectional view of a laminate.
• FIG. 5 is a graph of s vs. / " for deflection matching weight reduction ratio
• the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about” or “approximate” whether or not expressly stated to be such.
• ranges set forth herein include their endpoints unless expressly stated otherwise in limited circumstances. Further, when an amount, concentration, or other value or parameter is given as a range, one or more preferred ranges or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether such pairs are separately disclosed. Moreover, where a range of numerical values is recited herein, unless otherwise stated in specific circumstances, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the invention be limited to the specific values recited when defining a range. Finally, when the term "about” is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to.
• indefinite articles “a” and “an” are employed to describe elements and components of the invention. The use of these articles means that one or at least one of these elements or components is present. Although these articles are conventionally employed to signify that the modified noun is a singular noun, as used herein the articles “a” and “an” also include the plural, unless otherwise stated in specific instances. Similarly, the definite article “the”, as used herein, also signifies that the modified noun may be singular or plural, again unless otherwise stated in specific instances.
• the term "monolithic”, as used herein, refers to a sheet, layer or block fabricated of a single bulk material and having uniform properties throughout its mass, for example a glass sheet, a concrete layer, or a metal block.
• laminate refers to a structure having at least two layers that are adhered or bonded firmly to each other.
• the layers may be adhered to each other directly or indirectly.
• Directly means that there is no additional material, such as an interlayer or an adhesive layer, between the two layers, and "indirectly” means that there is additional material between the two layers.
• area density refers to the weight of a laminate divided by its projected surface area.
• the projected surface area is the product of the length and width of the laminate, and does not include the surface areas of the laminate's sides and bottom.
• the effective thickness can be used in place of the laminate's actual thickness in analytic equations for the deformation of laminated beams.
• the mechanical properties of laminates having the structure "material/interlayer/material” are modelled using effective thickness principles. More specifically, effective thickness principles are based on the shear coupling / " between the two plies of material through the interlayer.
• the shear coupling ⁇ depends primarily on the interlayer's shear stiffness or modulus, the interlayer's material properties, and the laminate's geometry and length scale.
• material/polymer/material laminates are lighter than monolithic sheets having the same thickness.
• Equation (A) is a determinant equation describing the relationship of the ratio s of interlayer/material thickness and that of the moduli of the interlayer E in t and the material E mt i. int
• the monolith 100 may be made of any basic or "structural" material including, without limitation, glass; metal; ceramic; concrete; minerals such as granite, marble, limestone, and mica; wood; composites of wood with polymers, for example cardboard and paper; cloth, for example nonwoven fiber mats; polymers; and composites of minerals and polymers.
• glass as used herein includes window glass, plate glass, silicate glass, sheet glass, low iron glass, tempered glass, tempered CeO-free glass, float glass, colored glass, specialty glass (such as glass that includes ingredients to control, e.g., solar heating), coated glass (such as glass sputtered with metals (e.g., silver or indium tin oxide) for solar control purposes), E-glass, Toroglass, and SolexiaTM glass (available from PPG Industries, Inc., of Pittsburgh, PA).
• specialty glasses are disclosed in U.S. Patent Nos. 4,615,989; 5,173,212; 5,264,286; 6,150,028; 6,340,646; 6,461 ,736; and 6,468,934, for example.
• the outer layers 21 and 23 of the laminate 200 are made of the same structural material that is used in the monolith 100.
• Glass is a preferred rigid structural material.
• the laminate 200 need not be symmetrical, that is, the thickness of the first outer layer 21 need not be equal to that of the second outer layer 23.
• the interlayer 22 comprises a material that whose properties complement those of the structural material in the outer layers in some way. For example, a polymeric interlayer having a good tensile strength provides needed toughness to a safety glass laminate. Similarly, a polymeric interlayer having a good viscoelasticity can compensate brittleness of glass materials and add safety performance to glazing, for example by preventing the scattering of glass pieces upon breakage.
• Suitable materials for the interlayer include the materials that are suitable for use in the monolith 100. Also suitable are less rigid materials, such as for example polymers having a modulus of 200 MPa to 600 MPa.
• Equation (A), above may be used to identify materials that are suitable for use in the methods described herein. Specifically, Equation (A) may be used to identify a suitable range of moduli for candidate materials, based on the modulus of one selected material and in light of the parameter s, the ratio of layer thicknesses in the laminate 200.
• Polymers are preferred interlayer materials, and particularly preferred are polycarbonates; polystyrenes; silicone elastomers; epoxy resins;
• polystyrenes polyvinylchlorides; polyurethanes; polyethylene homopolymers and copolymers of ethylene with other alkenes, including metallocene- catalyzed materials such as linear low density polyethylenes; polyolefin block elastomers; ethylene acid copolymers such as those available under the trademark Nucrel® from E.I. du Pont de Nemours and Company of Wilmington, DE ( hereinafter "DuPont”); ionomers of ethylene acid copolymers such as those available from DuPont under the trademark SentryGlas®;
• polyvinyl acetals including polyvinyl butyrals) such as those available from Kuraray America, Inc., of Houston, TX, under the trademark Butacite®;
• copolymers of ethylene with polar comonomers such as vinyl acetate (for example, those available from DuPont under the trademark Elvax®) and alkyl (meth)acrylates including methyl acrylate and butyl acrylate (for example, those available from DuPont under the trademark Elvaloy®).
• polar comonomers such as vinyl acetate (for example, those available from DuPont under the trademark Elvax®) and alkyl (meth)acrylates including methyl acrylate and butyl acrylate (for example, those available from DuPont under the trademark Elvaloy®).
• the effective thickness principles described herein apply to a wide variety of laminates comprising a wide variety of materials.
• the following discussion focusses on glass laminates having the structure "glass/interlayer/glass", wherein the interlayer is polymeric.
• G Shear modulus of an interlayer 22 to be tested for suitability.
• the shear modulus of interlayer 22, G is obtained by dynamic mechanical analysis (DMA) followed by time-temperature superposition and calculation of shear relaxation modulus.
• DMA dynamic mechanical analysis
• One specific methodology for measuring the shear modulus is described in S. J. Bennison, A. Jagota, and C. A. Smith, "Fracture of glass/poly.vinyl butyral/ .Butacite®/ laminates in biaxial flexure", J. Am. Ceram. Soc. 1999; 82(7); 1761-1770.
• the parameters h and t are not determined at this step; however, they do not have a strong effect on the shear transfer coefficient ⁇ . Therefore, these calculations use 1/3 of the thickness of the target monolithic glass 100 thickness as tentative values for h and t.
• a desired weight reduction can be selected based on design criteria. Again, the weight reduction is the difference between the areal weight of the laminate 200 and the areal weight of the monolith 100.
• a value for thickness ratio s can be selected from the graphs in FIGS. 1 and 2. To maintain deflection performance equal to that of the monolith 100 (deflection matching), use the graph of FIG.1. To maintain breakage resistance equal to that of the monolith 100 (stress matching), use the graph of FIG. 2.
• the effective thickness h ef of the laminate 200 is determined using Equations (2) and (3).
• the targeted effective thickness h ef can be used to calculate the exact thickness of outer layer thickness h necessary to achieve target stiffness, using Equations (2') and (3'). s + (1 + ⁇ )
• a structure for laminate 200 is selected whose effective thickness is same or larger than that of target monolithic glass.
• the h and t determined in this approach are not necessarily viable in terms of commercial availability. Therefore, a practical design strategy may require that the layer thicknesses h and t be determined via an iterative process or otherwise fine-tuned.
• a desired weight reduction can be selected based on design criteria.
• a value for thickness ratio s can be selected from the graphs in FIGS. 3(a,b) and 4(a,b).
• FIG. 4(a) is used when the load is applied only from the thicker glass side of the laminate 200.
• FIG. 4 (b) is used when the load is applied only from the thinner glass side. If the load is applied from both sides of the laminate 200, use the area above the "discriminant line" in FIG. 4(a), or the area below the "discriminant line” in FIG.4 (b).
• FIG. 3(a) is used when the load is applied only from the thicker glass side of the laminate 200.
• 3(b) is used when the load is applied only from the thinner glass side. If the load is applied from both sides of the laminate 200, use the area above the "discriminant line" in FIG. 3(a), or the area below the "discriminant line” in FIG. 3(b).
• the effective thickness h ef of the laminate 200 is determined using Equations (5) and (6).
• Equation (5) For deflection matching, use Equation (5).
• a 4 and a 5 may be calculated from Equation (7'):
• Equation (7) is used when the load is applied only from thicker glass side of the glass.
• Equation (7') is used when the load is applied only from the thinner glass side.
• the targeted effective thickness h ef can be used to calculate the exact thickness of outer layer thickness h necessary to achieve target stiffness, using Equations (5') and (5').
• a structure for laminate 200 is selected whose effective thickness is same or larger than that of the targeted glass monolith.
• a desired weight reduction can be selected based on design criteria.
• a value for thickness ratio s can be selected from the graphs in FIGS. 5(a,b) and 6(a,b).
• FIG. 6(a) is used when the load is applied only from the thicker glass side of the laminate 200.
• FIG. 6(b) is used when the load is applied only from the thinner glass side. If the load is applied from both sides of the laminate 200, use the area above the "discriminant line" in FIG. 6(a), or the area below the "discriminant line” in FIG. 6(b).
• FIG. 5(a) is used when the load is applied only from the thicker glass side of the laminate 200.
• FIG. 5(a) is used when the load is applied only from the thicker glass side of the laminate 200.
• 5(b) is used when the load is applied only from the thinner glass side. If the load is applied from both sides of the laminate 200, use the area above the "discriminant line" in FIG. 5(a), or the area below the "discriminant line” in FIG. 5(b).
• Equation (7) governs when the load is applied only from the side of the laminate 200 on which the glass layer 21 or 23 is the thicker layer
• Equation (7') governs when the load is applied only from the side on which the glass layer 21 or 23 is the thinner layer.
• Equation (7) applies when employing s in the area above the "discriminant line", or use the equation (7') when employing s in the area below the "discriminant line” in Fig. 6(b).
• the targeted effective thickness h ef can be used in Equation (5') or (6') to calculate the exact thickness of outer layer thickness h necessary to achieve the target stiffness.
• a structure for laminate 200 is selected whose effective thickness is same or larger than that of the targeted glass monolith. The same provisos set forth above with respect to smaller values of k also apply in this instance.
• Equation (9) pertains:
• Equations (8) and (9), a? through ae are calculated using Equation (7), above.
• Equation (1 1 ) pertains:
• the discriminant line in stress matching is generated by Equation 12.
• articles comprising the laminates 200 designed using the methods provided herein.
• the articles include, but are not limited to, buildings; other architectural structures; building panels; other components of architectural structures; storage tanks; vehicles such as boats, trains, airplanes, automobiles and trucks and components of the vehicles, such as, for example, door panels; and glass laminates for use as
• windshields architectural safety glass, photovoltaic modules, and structural glass.
• Smaller objects such as housings for computer equipment and household appliances such as microwave ovens, may comprise laminates of the invention.
• handheld objects such as smart phones and tablet computers, in which may the laminates may be touch screens or other components, such as housings or circuit boards.
• Comparable weight reduction percentage was calculated by the equations above from thickness ratio s and shear transfer coefficient ⁇ .
• Shear transfer coefficient, s, and weight reduction percentages of laminate Nos.1 to 5 in Table 1 fall within the range of FIGS. 1 and 2, which demonstrates the consistency of the methodology presented herein with the results of actual experiments.
• the laminate glass should have equivalent stress resistant properties to 4mm glass, i.e., stress matching conditions
• the interlayer is DuPont SentryGlas® and the shear modulus 200MPa (24 deg.C, 1 s load duration) is used for calculation.
• the shear coefficient is calculated. Though it varies for glass and interlayer thickness, it is almost 1 in any case. From FIG. 2, we can find s should be more than 2 to achieve more than 25% weight reduction. Possible structures are shown in Nos.1 to 4 of Table 1 . Weight reduction from equivalent stiffness monolithic glass is about 26% in any case. Among them, No.4 has stiffness close to 4mm monolithic glass.
• SentryGlas® / 1 .1 mm glass

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• Evolutionary Computation (AREA)
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• General Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Laminated Bodies (AREA)
• Joining Of Glass To Other Materials (AREA)
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• 2015
  • 2015-05-26 US US14/721,372 patent/US20150347635A1/en not_active Abandoned
  • 2015-05-27 WO PCT/US2015/032541 patent/WO2015183868A1/en not_active Ceased
  • 2015-05-27 KR KR1020167032727A patent/KR20170012252A/ko not_active Withdrawn
  • 2015-05-27 JP JP2016568625A patent/JP2017522200A/ja not_active Ceased
  • 2015-05-27 DE DE112015002478.6T patent/DE112015002478T5/de not_active Withdrawn

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