The use of fire‐retardant intumescent mats for fire and heat protection of glass fibre‐reinforced polyester composites: Thermal barrier properties

This study investigates the use of integral, hybrid intumescent thermal barriers (mats) to provide surface protection to the core fibre‐reinforced polyester composite structural integrity when exposed to a fire or heat source. Glass fibre‐reinforced composites protected by intumescent mats/fabrics containing silicate fibres, expandable graphite and in some cases borosilicate glass bounded together by an organic matrix have been evaluated for fire performance under a constant heat flux of 50kW/m². The effect of insulative fabric thickness as well as chemical composition on the flammability of the resultant hybrid composites is evaluated. Glass fibre‐reinforced polyester (GRP) composites without any surface protection have a relatively higher time‐to‐ignition and peak heat release rate values when compared with core composites protected by insulative fabrics. Thermograms representing the variation of temperature on the reverse side of the hybrid composites with time when exposed to a constant heat flux show that the inclusion of intumescent surface barriers results in retarded temperature increments within the core GRP composites. Copyright © 2009 John Wiley & Sons, Ltd.     

Comparison of cone and OSU calorimetric techniques to assess the flammability behaviour of fabrics used for aircraft interiors

Two test methods for measuring the heat release rate, HRR have been compared on fabric composites used for aircraft interior materials as side‐wall panels. These methods are based on the principles of direct measurement of the convective and radiant heat by thermopiles using an Ohio State University (OSU) calorimeter, and oxygen consumption using a cone calorimeter. It has been observed when tested by standard procedures, cone results at 35 kW/m² incident heat flux do not correlate with OSU results at the same heat flux. This is because in the cone calorimeter, the sample is mounted horizontally whereas the OSU calorimetric method requires vertical sampling with exposure to a vertical radiant panel. A further difference between the two techniques is the ignition source—in the cone it is spark ignition, whereas in the OSU it is flame ignition; hence, samples in the OSU calorimeter ignite more easily compared to those in the cone under the same incident heat fluxes. However, in this paper we demonstrate that cone calorimetric exposure at 50 kW/m² heat flux gives similar peak heat release results as the 35 kW/m² heat flux of OSU calorimeter, but significantly different average and total heat release values over a 2 min period. The performance differences associated with these two techniques are also discussed. Moreover, the effects of structure, i.e. type of fibres used in warp/weft direction and design of fabric are also analysed with respect to heat release behaviour and their correlation discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

Thermal response characteristics of fire blanket materials

The thermal response characteristics of over 50 relatively thin (0.15–3.7 mm) fire blanket materials from four different fiber groups (aramid, fiberglass, amorphous silica, and pre‐oxidized carbon) and their composites have been investigated. A plain or coated fabric sample was subjected to a predominantly convective or radiant heat flux (up to 84 kW/m²) using a Meker burner and a cone heater, respectively. In addition to conventional thermal protective performance ratings for protective clothing, two transient thermal response times (for the fabric back‐side temperature to reach 300 °C and for the through‐the‐fabric heat flux to reach 13 kW/m²) and a steady‐state heat‐blocking efficiency (HBE) were introduced for both convective and radiant heat sources. For most woven fabrics, the HBE values were approximately 70 ± 10% for both convection and radiation and only mildly increased with the fabric thickness or the incident heat flux. Nonwoven (felt) fabrics with low thermal conductivity exhibited significantly better insulation (up to 87%) against convective heat. Highly reflective aluminized materials exhibited exceptionally high HBE values (up to 98%) for radiation, whereas carbon and charred aramid fabrics showed lower HBEs (down to 50%) because of efficient radiation absorption. A relatively thin fire blanket operating at high temperatures can efficiently block heat from a convective source by radiative emission (enhanced by its T⁴‐dependence and high surface emissivity) coupled with thermal insulation and from a radiant heat source by surface reflection while the aluminum surface layer remains. Copyright © 2013 John Wiley & Sons, Ltd.     

Fire performance and post‐fire mechanical properties of polymer composites coated with hybrid carbon nanofiber paper

In this study, glass fiber reinforced polyester composites were coated with carbon nanofiber/clay/ammonium polyphosphate (CCA) paper and carbon nanofiber/exfoliated graphite nanoplatelets/ammonium polyphosphate (CXA) paper. The composites were exposed to a heat flux of 35 kW/m² during the cone calorimeter testing. The testing results showed a significant reduction in both heat release rates and mass loss rates. The peak heat release rate (PHRR) of CCA and CXA composite samples in the major decomposition period are 23 and 34% lower than the control sample, respectively. The time to reach the PHRR for the CCA and CXA composite samples are ～ 125% longer than the control sample. After the composite samples were exposed to heat for different time periods, their post‐fire mechanical properties were determined by three‐point bending testing. The three‐point bending testing results show that the composite samples coated with such hybrid papers exhibit more than 20% improvement in mechanical resistance at early stages of combustion. The mechanism of hybrid carbon nanofiber paper protecting the underlying laminated composites is discussed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Heat transmission of proban®-treated fabrics subjected to a radiant heat source

The apparatus described in DIN 4842 was used to measure the heat transmission of a series of Nomex, polyester–cotton, Proban®-Treated cotton, untreated cotton and wool workwear fabrics subjected to a radiant heat source. Heat transmission was found to be dependent on the incident heat flux, fabric weight and fabric thickness. At the heat flux levels tested, 10 KJ m^?2s^?1 and 20 KJ m^?2s^?1, heat transmission was found to be largely independent of the fibre composition of the fabric when single layers of fabric were tested. The level of heat transmission was reduced by the use of multiplayer assemblies or a reflective aluminium coating, but the greatest reduction was obtained when air spaces were interposed between the fabrics. Conbinaitons of fabrics were developed which transmitted less than 205 KJ m^?2s^?1 during testing at incident heat flux levels of 10 KJ m^?2s^?1 and 20 KJ m^?2s^?1.     

Drape behavior of 3D woven glass‐epoxy composites

This article deals with the drapability of 3D woven glass fabrics for composite applications. The study focuses on forming a 3D fabric over the mold, the result is a preform, which generally is then injected with a polymer matrix by so called Liquid Composite Molding (LCM) technique. When draping pre–impregnated composites, the fabric is embedded in the epoxy resin as matrix material. Various drape models for dry and pre‐impregnated fabrics have been proposed in the work. Solidworks and ANSYS are the software used for modeling and simulation of 3D woven fabric composites. Given the linear density (tex) and density of E‐glass fiber, the radius of the yarn was calculated. So far the cross section of yarn is assumed to be perfectly circular in shape, keeping the perimeter of yarn constant the circular cross section was deformed into a race track shape which is a much more practical and realistic shape of a yarn cross section. After calculating all the required dimensions, all the three 3D woven structures namely angle interlock, warp interlock and orthogonal were developed in solidworks. All the parameters like total number of warp and weft yarn per unit distance and thickness of the fabric were kept constant in all three structures. The analysis is based on first principles and the parameters of yarn and fabric construction. Results obtained through simulation are reported. These are validated with experimental composite samples. The model used to predict drapability of 3D woven glass‐epoxy composite gives good results. Orthogonal structure proves to be the best as far as resistance to deformation is concerned. However, if a relatively more flexible and formable prepreg is desired, it is advisable to use angle interlock or warp interlock structures. Warp interlock 3D structure proves most beneficial for draping on a mold. POLYM. COMPOS., 37:472–480, 2016. © 2014 Society of Plastics Engineers     

Bending properties of the multilayer‐connected biaxial weft knitted fabrics‐reinforced composites made with carbon fibers

This article presents an experimental study of bending properties of multilayer‐connected biaxial weft knitted (MBWK) fabrics‐reinforced composites made with carbon fibers. Three types of composites are used in bending test, which are three‐layer‐connected biaxial weft knitted fabric‐reinforced composite, four‐layer‐connected biaxial weft knitted fabric‐reinforced composite and five‐layer‐connected biaxial weft knitted fabric‐reinforced composite. Two‐way ANOVA analyzing method was used to deal with whether the carbon fiber volume fraction and the cutting direction have significant effect on the bending strength of the MBWK fabrics‐reinforced composites. Failure analysis is also available by means of samples debris examination to identify the failure mode. POLYM. COMPOS., 36:2291–2302, 2015. © 2014 Society of Plastics Engineers     

Preparation and oil–water separation evaluations of polypropylene/low‐melt‐point polyester composites reinforced by thermal bonding and one‐step solution immersion

Nonwoven fabrics have been fabricated for oil–water separation, but simplifying the manufacturing processes is still a challenge. In this work, a facile and easily scaled up approach based on thermal bonding and one‐step solution immersion has been successfully developed to prepare nonwoven fabrics with high separation efficiency and flux of oil. Here, polypropylene (PP) and low‐melt‐point polyester (LPET) fibers with a unique sheath–core structure are employed to form PP/LPET nonwoven fabrics. Thermal bonding by hot press and hydrophobic treatment with 1H,1H,2H,2H‐perfluorodecyl‐1‐thiol (PFDT) are used to manufacture oil–water separation nonwoven fabrics. Effects of the ratio of LPET fibers and the concentration of PFDT are discussed in terms of mechanical properties, morphology, surface chemical composition, water contact angle and performance of oil–water separation and flux of the nonwoven fabrics. The results show that the strength of the nonwoven fabrics gradually increases with increasing ratio of LPET fibers. After immersion in PFDT, the nonwoven fabrics show high hydrophobicity with a water contact angle of 143°. They can be used to separate oil–water mixtures. The separation efficiency is 97–99% and the oil flux is 62 364.92 L m^?2 h^?1. This study provides a new prospect for simple introduction of a hydrophobic agent on a nonwoven fabric to achieve various functional oil–water separation materials. © 2020 Society of Chemical Industry     

渐变系列色织床上用品面料的设计与织造

以25 tex×2涤纶纱为原料,采用联合组织、平纹组织、缎纹组织,织物经纬密度均为273根/10 cm、经纬紧度均为50%,结合色彩流行趋势进行色彩设计,并通过CAD模拟、小样织机织造,设计并织造出黄色渐变、红色渐变、蓝紫渐变、沙滩渐变4种床上用品面料。设计织造的4种面料都具有良好的视觉效果和手感,满足了床上用品面料舒适美观的要求。     

Characterization of the draping behavior of jute woven fabrics for applications of natural‐fiber/epoxy composites

In this study, we investigated the draping behavior of jute woven fabric to study the feasibility of using natural fabrics in place of synthetic glass‐fiber fabrics. Draping behavior describes the in‐mold deformation of fabrics, which is vital for the end appearance and performance of polymer composites. The draping coefficient was determined with a common drapemeter for fabrics with densities of 228–765 g/m² and thread counts under different humidity and static dynamic conditions. The results were compared to glass‐fiber fabrics with close areal densities. Characterization of the jute fabrics was carried out to fill the knowledge gap about natural‐fiber fabrics and to ease their modeling. The tensile and bending stiffnesses and the shear coupling were also characterized for a plain woven jute fabric with a tensile machine, Shirley bending tester, and picture frame, respectively. As a case study, the draping and resin‐transfer molding of the jute fabric over a complex asymmetric form was performed to measure the geometrical conformance. The adoption of natural fibers as a substitute for synthetic fibers, where the strength requirements are satisfied, would thus require no special considerations for tool design or common practices. However, the use of natural fibers would lead to weight and cost reductions. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1453–1465, 2013     

Hybrid fiber fabric composites from poly ether ether ketone and glass fiber

Poly ether ether ketone (PEEK) polymer was extruded into filaments and cowoven into unidirectional hybrid fabric with glass as reinforcement fiber. The hybrid fabrics were then converted into laminates and their properties with special reference to crystallization behavior has been studied. The composite laminates have been evaluated for mechanical properties, such as tensile strength, interlaminar shear strength (ILSS), and flexural strength. The thermal behavior of the composite laminates were analyzed using differential scanning calorimeter, thermogravimetric analyzer, dynamic mechanical analyzer (DMA), and thermomechanical analyzer (TMA). The exposure of the fabricated composite laminates to high temperature (400 and 500°C) using radiant heat source resulted in an improvement in the crystallanity. The morphological behavior and PEEK resin distribution in the composite laminates were confirmed using scanning electron microscope (SEM) and nondestructive testing (NDT). Although DMA results showed a loss in modulus above glass transition temperature (T_g), a fair retention in properties was noticed up to 300°C. The ability of the composite laminates to undergo positive thermal expansion as confirmed through TMA suggests the potential application of glass–PEEK composites in aerospace sector. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117:1446–1459, 2010     

Comparison of the Mechanical Behavior of Plain Weave and Plain Weft Knit Jute Fabric-Polyester-Reinforced Composites

The tensile and impact behavior of jute fabrics—polyester composites–were evaluated as a function of the fabric style (knitted or weaved cloths), fiber weight fraction, and direction of the applied load. The tensile properties of plain-weave-fabric-reinforced composites (PWF) were higher than those of plain weft knit cloth composites (WKT) and were dependent on fiber content and test direction. The properties of the WKT, however, were independent of these variables. The results obtained indicate that the orthogonal fiber alignment of weaved cloths favors anisotropy, while the interconnected loops in knit fabrics favors isotropy. The results also indicate weak fiber-matrix interactions in both fabrics and a better fabric impregnation for the plain weave fabric if compared with that of the knit fabric. The impact strengths of both composites were higher than that of the matrix and were shown to increase with fiber content. WKT-reinforced composites showed better impact absorption capacity than PWF composites. This behavior is attributed to the influence of the weaving pattern of the fabrics and to the differences in fabric impregnation by the matrix.     

Bonding in fabric-cement systems: Effects of fabrication methods

This paper compares the effects on the bond between fabric and cement matrix of three different processing methods: casting, pultrusion and vacuum condition. The fabrics included bonded glass mesh, woven polyvinylalcohol, and warp knitted weft insertion polypropylene. Pullout tests were performed to examine the bond between fabric and cement matrix. A microstructural analysis was conducted and correlated with pullout data. Improved bonding was obtained for fabric-cement composites produced with the pultrusion process, particularly for fabrics composed of multifilament yarns that have open junction points and no sizing to seal individual yarns. This improved bonding results from the impregnation of the fabric in the cement chamber during the pultrusion process, which filled the spaces between the filaments of the multifilament yarns.     

Experimental characterization of traditional composites manufactured by vacuum‐assisted resin‐transfer molding

The primary purpose of this study is to investigate the anisotropic behavior of different glass‐fabric‐reinforced polyester composites. Two commonly used types of traditional glass fabrics, woven roving fabric and chopped strand mat, have been used. Composite laminates have been manufactured by the vacuum infusion of polyester resin into the fabrics. The effects of geometric variables on the composite structural integrity and strength are illustrated. Hence, tensile and three‐point‐bending flexural tests have been conducted at different off‐axial angles (0, 45, and 90°) with respect to the longitudinal direction. In this study, an important practical problem with fibrous composites, the interlaminar shear strength as measured in short‐beam shear tests, is discussed. The most significant result deduced from this investigation is the strong correlation between the changes in the interlaminar shear strength values and fiber orientation angle in the case of woven fabric laminates. Extensive photographs of fractured tensile specimens resulting from a variety of uniaxial loading conditions are presented. Another aim of this work is to investigate the interaction between the glass fiber and polyester matrix. The experiments, in conjunction with scanning electron photomicrographs of fractured surfaces of composites, are interpreted in an attempt to explain the interaction between the glass fiber and polyester. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Mechanical properties of fire‐damaged glass‐reinforced phenolic composites

Changes to the mechanical and physical properties of a glass‐reinforced resole phenolic composite due to intense radiant heat and fire are investigated. Fire testing was performed using a cone calorimeter, with the composite exposed to incident heat fluxes of 25, 50, 75 or 100 kW/m² for 325 s and to a constant flux of 50 kW/m² for different times up to 1800 s. The post‐fire tensile and flexural properties were determined at room temperature, and these decreased rapidly with increasing heat flux and heat exposure time due mainly to the chemical degradation of the phenolic resin matrix. The intense radiant heat did not cause any physical damage to the composite until burning began on exposure to a high heat flux. The damage consisted of cracking and combustion of the phenolic matrix at the heat‐exposed surface, but this only caused a small reduction to the mechanical properties. The implication of the findings for the use of glass‐reinforced resole phenolic composites in load‐bearing structures for marine craft and naval ships, where fire is a potential hazard, is discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

Establishment of a color tolerance for yarn-dyed fabrics from different color-depth yarns

Yarn-dyed fabric is often woven from warp and weft yarns in the same color depth to ensure a uniform color appearance. The difference in color depth between warp and weft tends to result in the uneven color of the yarn-dyed fabric. This article aims to establish a color tolerance for yarn-dyed fabric that can be woven with a qualified color appearance but from the warp and weft yarns in different color depths. A total of 27 yarn-dyed fabric samples in three color series (red, yellow, and blue) were evaluated by using the yarn-dyed fabric from warp and weft yarns in the same color depth of 2% (on weight of fabric, owf) as the standard. Visual assessment and instrumental measurement of color were carried out to establish the color tolerance ellipse that was defined as CMC (Color Measurement Committee) color differences (2:1) of no more than 1.00. It was found that the color strengths (K/S) and color differences (ΔE_CMC(2:1)) of these fabric samples for each color series had linear relationships with the color depths of warp and weft yarns. The color tolerance ellipses indicated that, even though the warp and weft yarns had an apparent color difference, they could be woven in fabrics with relatively uniform color appearance and meet the requirements for yarn-dyed fabric. This work provided valuable insight into the production of qualified yarn-dyed fabrics from unqualified dyed yarns.     

GA747织机生产新型玻璃纤维纱罗网布的实践

新型玻璃纤维纱罗网布的地经和纬纱采用玻璃纤维无捻直接纱,绞经采用涤纶丝生产,取代传统网布使用的有捻纱线,并去除传统纺织中的整经工序,在GA747织机上安装绞综综框且采用合理的织造工艺,有效降低原料成本,提高产品品质。     

Ignition and combustion of low‐density polyimide foam

The ignition, flaming and smoldering combustion of low‐density polyimide foam have been studied using a cone calorimeter. Low‐density polyimide foam exhibits a high ignition resistance. The minimum heat flux for the ignition of flaming combustion ranges from 48 to 54 kW/m². This minimum heat flux also indicates the heat flux for transition from smoldering to flaming combustion. The flaming combustion results show that the heat release rate of low‐density polyimide foam is very low even at a high incident heat flux of 75 kW/m². The smoldering combustion results show that the smoldering of low‐density polyimide foam becomes significant when the incident heat flux is greater than 30 kW/m². The smoldering combustion of low‐density polyimide foam cannot be self‐sustaining when the external heat source is removed. Copyright © 2003 John Wiley & Sons, Ltd.     

Cone calorimeter evaluation of two flame retardant cotton fabrics

Unbleached (gray) cotton needle‐punched nonwoven (NW) fabrics with 12.5% polypropylene scrim were treated with two phosphate–nitrogen‐based flame retardant (FR) formulations, Southern Regional Research Center (SRRC)‐1 and SRRC‐2. The SRRC‐1 formulation contains diammonium phosphate as the FR chemical along with urea and dimethyloldihydroxyethyleneurea. Because a trace amount of formaldehyde was still expected to be released from SRRC‐1‐treated FR cotton under high heat, it was preferable to eliminate the dimethyloldihydroxyethyleneurea, leading to the revised formulation SRRC‐2. It has a higher content of diammonium phosphate and did not use the polyethylene emulsion that was in SRRC‐1. Both formulations were of low cost as they were developed at SRRC using industrial grade chemicals. The fabrics were evaluated with a cone calorimeter using three heat flux levels, 20, 30, and 50 kW/m². On the basis of the overall cone calorimeter results for heat released and ignition times, FR NW fabrics that were treated with SRRC‐2 were found to be slightly superior in flammability properties to those treated with the earlier SRRC‐1 formulation, but the differences were statistically insignificant. Both preparations were much less flammable than the untreated control cotton NW fabrics. Compared with the untreated NW fabrics, the FR fabrics had higher visible smoke production. Copyright © 2012 John Wiley & Sons, Ltd.     

凉感纤维织物导热系数影响因素的探讨

采用普通涤纶、含1%云母颗粒的涤纶(1%云母/涤纶)以及含5%云母颗粒的涤纶(5%云母/涤纶)三种材质,上机纬密采用200根/10 cm、300根/10 cm、400根/10 cm,组织采用平纹、斜纹、缎纹试织试样。通过Hot Disk热常数分析仪,采用正交试验及极差、方差分析,研究了纤维材质、上机纬密、组织对凉感纤维织物导热系数的影响。结果表明:在试验设置变量范围内,纤维材质对导热系数的影响显著,上机纬密、组织对导热系数的影响高度显著,影响因素从大到小顺序为上机纬密>组织>纤维材质。