TECHNICAL PAPER

• Authors . . . . . . . . . . . . . . . . . . . . .2• Abstract . . . . . . . . . . . . . . . . . . . . .2• Introduction . . . . . . . . . . . . . . . . . .2• Glass Fiber Chemical Compositions . . .2• Glass Fiber Properties . . . . . . . . . . .3

– Physical Properties . . . . . . . . . . . .3– Chemical Resistance . . . . . . . . . . .3– Electrical Properties . . . . . . . . . . . .3– Thermal Properties . . . . . . . . . . . .4– Optical Properties . . . . . . . . . . . . .5– Radiation Properties . . . . . . . . . . .5

• Glass Fiber Size Treatments . . . . . . . .5• Fiber Composite Utility . . . . . . . . . . .5

– Composite Properties . . . . . . . . . .5– Environmental Durability . . . . . . . . .5

• Acknowledgements . . . . . . . . . . . . .6• References . . . . . . . . . . . . . . . . . . .6• Table 1 Composition Ranges

for Glass Fibers . . . . . . . . .7• Table 2 Properties of Glass Fibers --

Physical Properties . . . . . . .7• Table 3 Properties of Glass Fibers --

Chemical, Electricaland Thermal Properties . . .8

• Table 4 Glass Fiber Size ChemistrySummary . . . . . . . . . . . . .9

• Table 5 S-2 Glass® Fiber UnidirectionalEpoxy Composite Properties .9

• Figure 1 Continuous Glass FiberManufacturing Process . . .10

• Figure 2 Fiber Strength at Temperature . . . . . . . . . .10

• Figure 3 Fiber Weight Retention vs. pH Exposure . . . . . . . .10

• Figure 4 Fiber Strength vs. pH Exposure . . . . . . . . . . . . .11

• Figure 5 Glass Viscosity vs.Temperature . . . . . . . . . .11

• Figure 6 Thermal Expansion vs.Volume In Epoxy . . . . . . . .11

• Figure 7 Dielectric vs. Fiber Volume In Epoxy . . . . . . . .11

• Figure 8 Environmental Stress Rupture In Epoxy . . . . . . . .11

• Figure 9 Environmental Stress Rupture In Epoxy . . . . . . . .11

Table of ContentsHigh Strength Glass Fibers

High Strength Glass Fibers

AuthorsIn 1996 this paper was written incollaboration with David Hartman,Mark E. Greenwood, and David M.Miller who were employed at thetime by Owens Corning Corp. Mr. Hartman received his degree in chemistry from David LipscombUniversity and an M.S. degree inchemistry from Georgia Institute ofTechnology with emphasis in textileand plastic engineering. Mr. Greenwood received his B.S. and M.S. degrees in Civil Engineeringfrom Purdue University, with anemphasis in structural design. Dr. Miller received his Bachelor’s,Master’s, and Ph.D. degrees inCeramic Engineering from the Ohio State University.

AbstractContinuous glass fibers, first conceived and manufactured during1935 in Newark, Ohio, started arevolution in reinforced compositematerials which by 2000 led to aglobal annual glass fiber consump-tion of 2.6 million tons. During 1942glass fiber reinforced compositeswere first used in structuralaerospace parts. In the early 1960’shigh strength glass fibers, S Glass,were first used in joint work betweenOwens Corning Textile Products andthe United States Air Force. Later in 1968 S-2 Glass® fibers beganevolving into a variety of commercialapplications. High strength glassfibers combine high temperaturedurability, stability, transparency, and resilience at a very reasonablecost-weight-performance. The utilityof high strength glass fiber composi-tions are compared by physical,mechanical, electrical, thermal,acoustical, optical, and radiationproperties.

KEYWORDS: S-2 Glass;® C Glass,AR Glass, D Glass, ECRGLAS,®

R Glass; E Glass; Fiberglass, GlassReinforcements.

1. IntroductionAncient Egyptians made containersof coarse fibers drawn from heatsoftened glass. The French scientist,Reaumur, considered the potential of forming fine glass fibers for wovenglass articles as early as the 18thcentury. Continuous glass fiberswere first manufactured in substan-tial quantities by Owens CorningTextile Products in the 1930’s forhigh temperature electrical applica-tions. Revolutionary and evolutionarytechnology continues to improvemanufacturing processes for continuous glass fiber production,illustrated in Figure 1. Raw materialssuch as silicates, soda, clay, limestone, boric acid, fluorspar orvarious metallic oxides are blendedto form a glass batch which is melt-ed in a furnace and refined duringlateral flow to the forehearth. Themolten glass flows to platinum/rhodium alloy bushings and thenthrough individual bushing tips andorifices ranging from 0.76 to 2.03mm (0.030 to 0.080 in) and israpidly quenched and attenuated in air (to prevent crystallization) intofine fibers ranging from 3 to 35 µm.Mechanical winders pull the fibers at lineal velocities up to 61 m/s overan applicator which coats the fiberswith an appropriate chemical sizingto aid further processing and performance of the end products.

High strength glass fibers like S-2 Glass are compositions of aluminosilicates attenuated at highertemperatures into fine fibers rangingfrom 5 to 24 µm. Several othertypes of silicate glass fibers are manufactured for the textile andcomposite industry. Various glasschemical compositions describedbelow from ASTM C 162 were devel-oped to provide combinations of fiberproperties directed at specific enduse applications.

A GLASS – Soda lime silicate glassesused where the strength, durability,and good electrical resistivity of E Glass are not required.C GLASS – Calcium borosilicateglasses used for their chemical sta-bility in corrosive acid environments.D GLASS – Borosilicate glasses witha low dielectric constant for electri-cal applications.E GLASS – Alumina-calcium-borosili-cate glasses with a maximum alkalicontent of 2 wt.% used as generalpurpose fibers where strength andhigh electrical resistivity are required.ECRGLAS® – Calcium aluminosilicateglasses with a maximum alkali con-tent of 2 wt.% used where strength,electrical resistivity, and acid corrosion resistance are desired.AR GLASS – Alkali resistant glassescomposed of alkali zirconium silicatesused in cement substrates and concrete.R GLASS – Calcium aluminosilicateglasses used for reinforcementwhere added strength and acid corrosion resistance are required.S-2 GLASS® – Magnesium aluminosil-icate glasses used for textile substrates or reinforcement in composite structural applicationswhich require high strength, modulus, and stability under extremetemperature and corrosive environ-ments.

2. Glass Fiber ChemicalCompositionsChemical composition variation within a glass type is fromdifferences in the available glassbatch raw materials, or in the melting and forming processes, or from different environmental con-straints at the manufacturing site.These compositional fluctuations donot significantly alter the physical orchemical properties of the glasstype. Very tight control is maintainedwithin a given production facility toachieve consistency in the glasscomposition for production capabilityand efficiency. Table 1 provides the

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oxide components and their weightranges for eight types of commercialglass fibers [1-6].

3. Glass Fiber PropertiesGlass fiber properties, such as tensile strength, Young’s modulus,and chemical durability, aremeasured on the fibers directly.Other properties, such as dielectricconstant, dissipation factor, dielectricstrength, volume/surface resistivi-ties, and thermal expansion, aremeasured on glass that has beenformed into a bulk sample andannealed (heat treated) to relieveforming stresses. Properties suchas density and refractive index aremeasured on both fibers and bulksamples, in annealed or unannealedform. The properties presented inTables 2 and 3 are representative ofthe compositional ranges in Table 1and correspond to the followingoverview of glass fiber properties.

3.1 Physical Properties – Densityof glass fibers is measured andreported either as formed or as bulkannealed samples. ASTM C 693 isone of the test methods used fordensity determinations [7]. The fiberdensity (in Table 3) is less than thebulk annealed value by approximately0.04 g/cc at room temperature.The glass fiber densities used incomposites range from approximate-ly 2.11 g/cc for D Glass to 2.72g/cc for ECRGLAS reinforcements.

Tensile strength of glass fibers is usually reported as the pristinesingle-filament or the multifilamentstrand measured in air at room tem-peratures. The respective strandstrengths are normally 20 to 30%lower than the values reported inTable 2 due to surface defects intro-duced during the strand-formingprocess. Moisture has a detrimentaleffect on the pristine strength ofglass. This is best illustrated by measuring the pristine single-filamentstrength at liquid nitrogen tempera-tures where the influence of

moisture is minimized. The result is an increase of 50 to 100% instrength over a measurement atroom temperature in 50% relativehumidity air. The maximummeasured strength of S-2 Glassfibers at liquid nitrogen temperaturesis 11.6 GPa for a 12.7 mm gaugelength, 10 µm diameter fiber. Theloss in strength of glass exposed tomoisture while under an externalload is known as static fatigue [4.8].The pristine strength of glass fibersdecreases as the fibers are exposedto increasing temperature. E Glassand S-2 Glass fibers have beenfound to retain approximately 50% of their pristine room-temperaturestrength at 538°C (1000°F) and arecompared to organic reinforcementfibers in Figure 2.

The Young’s modulus of elasticityof unannealed silicate glass fibersranges from about 52 GPa to 87GPa. As the fiber is heated, themodulus gradually increases. E Glassfibers that have been annealed tocompact their atomic structure willincrease in Young’s modulus from72 GPa to 84.7 GPa [4]. For mostsilicate glasses, Poisson’s ratio fallsbetween 0.15 and 0.26 [9]. ThePoisson’s ratio for E Glasses is 0.22± 0.02 and is reported not tochange with temperature when measured up to 510°C [10].

High strength S-2 Glass fibers’annealed properties measured at20°C are as follows:Young’s Modulus 93.8 GPa

Shear Modulus 38.1 GPa

Poisson’s Ratio 0.23

Bulk Density 2.488 g/cc

3.2 Chemical Resistance – Thechemical resistance of glass fibersto the corrosive and leaching actionsof acids, bases, and water isexpressed as a percent weight loss.The lower this value, the more resis-tant the glass is to the corrosivesolution. The test procedure involvessubjecting a given weight of 10micron diameter glass fibers, with-

out binders or sizes, to a known volume of corrosive solution held at96°C. The fibers are held in the solu-tion for the time desired and thenare removed, washed, dried, andweighed to determine the weightloss. The results reported are for24-hr (1 day) and 168-hr (1 week)exposures. As Table 3 shows, thechemical resistance of glass fibersdepends on the composition of thefiber, the corrosive solution, and theexposure time.

It should be noted that glass corrosion in acidic environments is a complex process beginning withan initial fast corrosion rate. (Notethe similarity in weight loss betweenthe 1-day and 1-week samples treat-ed with acid in Table 3.) With furthertime, an effective barrier of leachedglass is established on the surface ofthe fiber and the corrosion rate ofthe remaining unleached fiber slows,being controlled by the diffusion ofcompounds through the leachedlayer. Later, the corrosion rate slowsto nearly zero as the non-silica compounds of the fiber are depleted.For a given glass composition, thecorrosion rate may be influenced bythe acid concentration (Figure 3),temperature, fiber diameter, and thesolution volume to glass mass ratio.In alkaline environments weight lossmeasurements are more subjectiveas the alkali affects the network and reprecipitates the metal oxides.Tensile strength after exposure is abetter indicator of the residual glassfiber properties as shown in Figure 4for 24-hour exposure at 96°C.

3.3 Electrical Properties – Theelectrical properties in Table 3 weremeasured on annealed bulk glasssamples according to the testingprocedures cited [11-13]. Thedielectric constant or relative permit-tivity is the ratio of the capacitanceof a system with the specimen asthe dielectric to the capacitance ofthe system with a vacuum as thedielectric. Capacitance is the ability

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of the material to store an electricalcharge. Permittivity values are affect-ed by test frequency, temperature,voltage, relative humidity, waterimmersion, and weathering.

The dissipation factor of a dielectric is the ratio of the parallelreactance to the parallel resistance,or the tangent of the loss angle,which is usually called the loss tan-gent. It is also the reciprocal of thequality factor, and when the valuesare small, tangent of the loss angleis essentially equal to the power factor, or sine of the loss angle. Thepower factor is the ratio of power in watts dissipated in the dielectric to the effective volt-amperes. Thedissipation factor is dimensionless. In almost every electrical application,a low value for the dissipation factoris desired. This reduces the internalheating of the material and keepssignal distortion low. The dissipationfactor is generally measured simultaneously with permittivity mea-surements, and is greatly influencedby frequency, humidity, temperature,and water immersion.

The loss factor, or loss index, as it is sometimes called, is occasionallyconfused with the dissipation factor,or loss tangent. The loss factor issimply the product of the dissipationfactor and permittivity and is propor-tional to the energy loss in thedielectric.

The dielectric breakdown voltage,is the voltage at which electrical fail-ure occurs under prescribed testconditions in an electrical insulatingmaterial that is placed between twoelectrodes. When the thickness ofthe insulating material between theelectrodes can be accurately measured, the ratio of the dielectric breakdown voltage to the specimen thickness can beexpressed as the dielectric strengthin kV/cm. Breakdown voltages areinfluenced by electrode geometry,specimen thickness (because dielec-tric strength varies approximately asthe reciprocal of the square root of

the thickness), temperature, voltageapplication time, voltage wave form,frequency, surrounding medium, relative humidity, water immersion,and directionality in laminated andinhomogeneous plastics.

3.4 Thermal Properties – The viscosity of a glass decreases as the temperature increases. Figure 5shows the viscosity-temperatureplots for E Glass and S-2 Glassfibers. Note that the S-2 Glassfibers’ temperature at viscosity is150-260°C higher than that of E Glass, which is why S-2 Glassfibers have higher use temperaturesthan E Glass.

Several reference viscosity pointsare defined by the glass industry asused in Table 2. The softening pointis the temperature at which a glassfiber of uniform diameter elongatesat a specific rate under its ownweight when measured by ASTM C338 [14]. The softening point isdefined as the temperature at whichglass will deform under its ownweight; it occurs at a viscosity ofapproximately 106.6 Pa.s (107.6 P). The annealing point is thetemperature corresponding to eithera specific rate of elongation of aglass fiber when measured by ASTMC 336 [15], or a specific rate ofmidpoint deflection of a glass beamwhen measured by ASTM C 598[16]. At the annealing point of glass,internal stresses are substantiallyrelieved in a matter of minutes. Theviscosity at the annealing point isapproximately 1012 Pa.s (1013 P).The strain point is measured follow-ing ASTM C 336 or C 598 asdescribed above for annealing point.At the strain point of glass, internalstresses are substantially relieved ina matter of hours. The viscosity at thestrain point is approximately 1013.5

Pa.s (1014.5 P).The mean coefficient of thermal

expansion over the temperaturerange from -30° to 250°C is provid-ed in Table 3. The expansion

measurements were made onannealed bars using ASTM D 696[17]. A lower coefficient of thermalexpansion in the high strength glass-es allows higher dimensional stabilityat temperature extremes.

The specific heat data in Table 3was determined using high tempera-ture differential scanning calorimetrytechniques. In general, the averagespecific heat values can berepresented as follows: 0.94kJ/kg•K at 200°C, 1.12 kJ/kg•Kjust below the transition point, and1.40 kJ/kg•K in the liquid stateabove the transition. These valuesare accurate to about ±5%. Abovethe transition temperature, no fur-ther increase in specific heat wasobserved. The transition temper-ature is nearly identical to theannealing temperature of bulk glass.Thermal conductivity characteristicsin glasses differ considerably fromthose found in crystalline materials.For glasses, the conductivity is lowerthan that of the corresponding crystalline materials. Also, the con-ductivity of glasses drops steadilywith temperature and reaches verylow values, near absolute zero. Forcrystals, the conductivity continuesto rise with decreasing temperatureuntil very low temperatures arereached [18]. Thermal conductivitydata for glass varies among investi-gators for materials which arenormally identical [19]. In generalfused silica glass and the alkali andalkaline earth silicate glasses haverelatively similar conductivities atroom temperature, whereas conduc-tivities of borosilicate and glass thatcontain lead and barium are some-what lower. Near room temperature,the thermal conductivity for glassesranges from 0.55 W/m•K for leadsilicate (80% lead oxide, 20% silicondioxide) to 1.4 W/m•K for fused silica glass [20]. E. H. Ratcliffe developed property coefficients forpredicting thermal conductivity fromthe percentage weight compositionsof component oxides making up the

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glass [20]. Using this calculation, itis found that the approximate thermalconductivity of C Glass is 1.1 W/mK,E Glass is 1.3 W/m•K, and S-2Glass fibers is 1.45 W/m•K nearroom temperature.

3.5 Optical Properties – Refractive index is measured oneither unannealed or annealed glassfibers. The standard oil immersiontechniques are used with monochro-matic sodium D light at 25°C. Ingeneral, the corresponding annealedglass will exhibit an index that willrange from approximately 0.003 to0.006 higher than the as-formedglass fibers given in Table 2.

3.6 Radiation Properties – E Glassand S-2 Glass fibers have excellentresistance to all types of nuclearradiation. Alpha and beta radiationhave almost no effect, while gammaradiation and neutron bombardmentproduce a 5 to 10% decrease intensile strength, a less than 1%decrease in density, and a slight discoloration of fibers. This data was true to 1020 NVT neutrons orgamma radiation up to 105 J/g.Glass fibers resist radiation becausethe glass is amorphous, and theradiation does not distort the atomicordering. Glass can also absorb afew percent of foreign material andmaintain the same properties to areasonable degree. Also, becausethe individual fibers have a smalldiameter, the heat of atomic distor-tion is easily transferred to a surfacefor dispersion.

E Glass and C Glass are not rec-ommended for use inside atomicreactors because of their high boroncontent. S-2 Glass fibers are suitablefor use inside atomic reactors.Because quite a wide variety oforganic products are used in diverseradiation environments, it is usuallynecessary to try out most productsin simulated conditions to determinewhether the organics will be satisfactory.

4. Glass Fiber Size TreatmentsThe surface treatment chemistry of glass fiber follows the necessaryproduct function. Textile sizechemistries based on starch orpolyvinyl alcohol film formers arecapable in weaving, braiding, or knitting processes. Typically theweaver then scours or heat cleansthe glass fabric and applies a finishcompatible with the end product.Nonwoven size chemistries ofteninclude dispersants compatible withwhite water chemistry for wetformed mats or additives compatiblewith dry or wet binder chemistry fordry formed mats. Reinforcementsize chemistries must be compatiblewith a multitude of processes andwith the composite material end useperformance criteria. Processessuch as injection molding requirechopped fibers with compatibility for thermoplastic compounds.Filament winding and pultrusionrequire continuous fibers with utilityin thermoset and thermoplastic compounds. Typically three basiccomponents are used with highstrength glass size chemistries: afilm former, lubricant, and couplingagent. Table 4 outlines evolutionaryresearch for glass fiber size chem-istry by each component’s role.

5. Fiber Composite Utility5.1 Composite Properties –Application of glass fiber compositematerials depends on proper utiliza-tion of glass composition, sizechemistry, fiber orientation, and fibervolume in the appropriate matrix fordesired mechanical, electrical, ther-mal, and other properties. Table 5gives typical mechanical propertiesfor high strength S-2 Glass fibersepoxy with unidirectional fiber orien-tation. The elastic constants andstrain allowables are used for design input. The effect of glasscomposition and fiber volume inepoxy are shown in Figure 6 for thecoefficient of thermal expansion andin Figure 7 for dielectric constant.

The S-2 Glass fibers lower dielectricconstant and therefore the potentialfor better radar transparency.

5.2 Environmental DurabilityThe durability of glass fiber compos-ite materials is one of the featuresthat attract users to them.Composites do not corrode like metals and are low maintenancematerials. However, the durabilityand reliability in specific applicationsis often requested for design input.In load bearing structures, the long-term behavior of the material isneeded to complete the design ofthe structure. How much load willthe structure hold and survive for agiven period of time? Or, how thickmust the part be to handle a loadfor a given period of time?

These questions are usuallyaddressed empirically, with accelerat-ed testing. ASTM D 2992 andASTM D 3681 for example aremethods often incorporated in thepractice of evaluating and designingcomposite pipe. In these methods,actual prototype products are manu-factured and loaded in simulatedenvironments for which the productis intended. To accelerate testing,the loads are significantly higher thanoperating conditions to induce failurein a relatively short period of time.The extrapolation of short-term datato the expected life of the productallows engineers to predict safeoperating loads (stresses) for thepurpose of design. This practice hasserved the composites industry wellfor over 30 years.

To demonstrate this process, the results of several test series are reported. Tests were conductedusing pultruded rods made of glassfibers and thermoset resins. Thesetests are similar to those referencedin ASTM except the loading conditionis pure tension and under a constantload. Figure 8 summarizes stressrupture testing using S-2 Glassfibers in epoxy with and without anadverse environment, a calcium

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hydroxide solution with a pH of 13.For reference, the initial tensilestrength of the composite rod was2070 MPa. The stress rupturebehavior of an S-2 Glass fibers/epoxy rod in this test indicates along-term stress capability of 65% of the initial ultimate tensile stress.As expected, the stress rupturebehavior of the composite material is affected by the presence of theenvironment. The long-term stresscapability of this material in the highpH environment is roughly 50% ofthe initial ultimate tensile strength.

A second test series comparedthe stress rupture performance of E glass and S-2 Glass reinforce-ments in epoxy resin with the highpH environmental exposure. Figure 9summarizes this data. The S-2 Glassfibers reinforced composite rod hada higher initial tensile stress than theE Glass reinforced rod. The influenceof the combined effects of stressand environment were similar for thetwo materials.

AcknowledgementsThe authors thank Cathy Holton forassistance with the manuscript.

References[1] D. M. Miller. “Glass Fibers,Engineered Materials Handbook,”Vol. 1 – Composites, ASMInternational. 1987, pp. 45-48.

[2] G. J. Mohr, and W. P. Rowe,“Fiber Glass,” Van Nostrand ReinholdCo., (1978), pp. 207.

[3] K. L. Lowenstein, “TheManufacturing Technology ofContinuous Glass Fibers.” Elsevier,(1973), pp. 28-30.

[4] R. D. Lowrie, Glass Fibers forHigh-Strength Composites, in“Modern Composite Materials,”Addison-Wesley Publishing Co.,(1967), pp. 270-323.

[5] W. W. Wolf. “The Glass FiberIndustry – The Reason for the Use of Certain Chemical Compositions,”Seminar at University of Illinois,Urbania, IL, (Oct. 1982).

[6] J. C. Watson, and N.Raghupathi, “Glass Fibers,Engineered Materials Handbook. Vol. 1 – Composite,” ASMInternational, (1987). pp. 107-111.

[7] “Standard Test Method forDensity of Glass by Buoyancy, C693,Annual Book of ASTM Standards,”American Society for TestingMaterials.

[8] P. K. Gupta, “Examination of theTextile Strength of E-Glass Fiber inthe Context of Slow Crack Growth,Fracture Mechanics of Ceramics.”Vol. 5, (1983), pp. 291.

[9] J. R. Hutchins, III and R. W.Harrington, Glass in “Encyclopedia of Chemical Technology,” Vol. 10.2nd Ed., pp. 533-604.

[10] R. T. Brannan, “Am. Ceram.Soc.,” Vol. 36, (1953). pp. 230-231.

[11] “Standard Test Methods for A-CLoss Characteristics and Permittivity(Dielectric Constant) of SolidElectrical Insulating Materials,” D. 150, “Annual Book of ASTMStandards.” American Society forTesting and Materials.

[12] “Standard Test Methods for D-C Resistance or Conductance of Insulating Materials.” D. 257,“Annual Book of ASTM Standards,”American Society for Testing andMaterials.

[13] “Standard Test Methods forDielectric Breakdown Voltage andDielectric Strength of Solid ElectricalInsulating Materials at CommercialPower Frequencies.” D. 149,“Annual Book of ASTM Standards,”American Society for Testing andMaterials.

[14] “Standard Test Methods forSoftening Point of Glass,” C. 338,“Annual Book of ASTM Standards,”American Society for Testing andMaterials.

[15] “Standard Test Methods forAnnealing Point and Strain Point ofGlass Fiber Elongation,” C. 336.“Annual Book of ASTM Standards,”American Society for Testing andMaterials.

[16] “Standard Test Methods forAnnealing Point and Strain Point ofGlass by Beam Bending,” C. 598.“Annual Book of ASTM Standards,”American Society for Testing andMaterials.

[17] “Standard Test Methods forCoefficient of Linear ThermalExpansion of Plastics,” D. 696.“Annual Book of ASTM Standards,”American Society for Testing andMaterials.

[18] C. Kittel, Phys. Rev., Vol. 75,(1949), pp. 972.

[19] C. L. Babcock, Symposium onHeat Transfer Phenomena in Glass.J. Am. Ceram, Soc., Vol. 44 (No. 7), (July 1961).

[20] E. H. Ratcliffe, “ThermalConductivities of Glass Between -150°C and 100°C, GlassTechnology,” Vol. 4 (No. 4), (August 1963).

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Table 1 Composition Ranges for Glass Fibers

Table 2 Properties of Glass Fibers

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Table 3 Properties of Glass Fibers

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Table 4 Glass Fiber Size Chemistry Summary

Table 5 S-2 Glass® Fiber Unidirectional Epoxy Composite Properties

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Figure 1 Continuous Glass Fiber Manufacturing Process

Figure 2 Fiber Strength at Temperature Figure 3 Fiber Weight Retention VS pH Exposure

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Figure 4 Fiber Strength VS pH Exposure Figure 5 Glass Viscosity VS Temperature

Figure 6 Thermal Expansion VS Volume In Epoxy Figure 7 Dielectric VS Fiber Volume In Epoxy

Figure 8 Environmental Stress Rupture In Epoxy Figure 9 Environmental Stress Rupture In Epoxy

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Disclaimer of Liability

This data is offered solely as a guide in the selection of a reinforcement. The information contained in this publication is based on actual laboratory data and field test experience. We believe thisinformation to be reliable, but do not guarantee its applicability to the user’s process or assume any liability arising out of its use or performance. The user, by accepting the products describedherein, agrees to be responsible for thoroughly testing any application to determine its suitability before committing to production. It is important for the user to determine the properties of itsown commercial compounds when using this or any other reinforcement.

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