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In the work, a kind of composite material with excellent stab/puncture resistance was prepared by resin bonded Kevlar fabric. Water-borne epoxy resin (PAEK), polyacrylamide (APAM), fatty alcohol polyoxyethylene phosphate potassium salt (TFPK) are formulated to form a novel sizing agent that can be used for the sizing Kevlar fabrics. The effects of the sizing agent on the mechanical and stab/puncture resistance are examined. A field emission scanning electron microscopy (SEM), an ultra-depth of field 3d microscope, and a universal testing machine were used to observe and evaluate the morphology of sizing fabrics, the stab/puncture morphology, mechanical properties, and quasi-static stabbing properties, respectively. The test results show that the puncture resistance of the sizing Kevlar fabrics increases first and then decreases with the increase of sizing agent concentration. Compared with non-sizing fabrics, the Kevlar fabrics that are treated with a sizing agent at a concentration of 10 wt% have 524 % higher puncture resistance, 301 % higher stab resistance, and a 6.9-fold increase in the burst strength. Because the fiber bundles in the sizing fabrics are confined due to the resin saturation, the friction among fibers is enhanced and thus better resists an external force and contributes a greater resistance against sharp objects.

Researches for the development of materials with less environmental impact have been more common. Pectin is a natural polysaccharide, presenting in plants and the peel of some fruits. It is atoxic, biocompatible, not expensive and is available as a byproduct of fruit juice industry. In the literature, pectin is commonly found mixed with other polymers. The objective of this work was to study the thermoplasticization with glycerol of high methoxylation pectin by extrusion/thermo-compression for films with industrial application compared to casting films. Properties of water vapor permeablility (1.27–2.47 g mm/KPa h m2), tensile strength (3.44–8.74 MPa), and puncture resistance (43.01–230.75 N/mm) of extrusion/thermo-compression films were evaluated. Color parameters exhibited possibility of samples application in packages that require the consumer to view the product. The results obtained for extruded/thermo-compressed films are similar or superior to those obtained in extruded thermoplasticized starch works. Results showed efficient production of plasticized pectin films with the possibility of industrial application for extrusion/thermo-compression process.

The problem of recycling polymer waste is one of the most actual problems. One way to solve this problem is to create biodegradable food packaging. By mixing solutions of starch and agar at different mass ratios of polymers in the presence of glycerol, biodegradable films are obtained. Their structural and mechanical characteristics are determined. It is shown that the values of strength, modulus of elasticity and puncture resistance of films are maximal at the mass ratio of agar/starch 7-9. A comparison of the roughness of the films obtained from starch, agar and their mixture showed that the greatest roughness is possessed by films based on starch. The introduction of agar into the films of starch leads to a significant reduction in their roughness. To regulate the structural and mechanical properties of films, it is proposed to use Cа and Mg salts. The influence of Ca2+and Mg2+ions on the strength and deformation characteristics of biofilms was studied. It is shown that Ca2+ions monotonically increase the strength characteristics of starch-agar films, while the curves of changes in these parameters in the presence of Mg2+ions have maxima at a concentration of 0.5%. The difference in the effect of Ca2+and Mg2+ions on the structural and mechanical properties of films is explained by the hydration degree of these ions. The biodegradability of starch-agar films was controlled by changing their IR spectra. The most significant changes are observed in the intensity and localization of peaks corresponding to O-H, C-H and C-C bonds, which can be evidence of changes in the structure of films due to the destruction of the grid of hydrogen bonds and hydrophobic interactions, as well as the break of hydrocarbon chains and the destruction of the skeleton of carbohydrate molecules.

A novel composition of industrial grade bitumen with polymer (polyurethane) additive was synthesized for development of a protective membrane which makes the structure water proof. A series of test were performed on membrane specimens to ascertain their mechanical properties. Blend of Bitumen and polyurethane in form of a membrane or thin film of varying thicknesses were prepared which was then subjected to tensile, elongation, tear, and puncture resistance test in accordance with relevant ASTM codes. Experimental investigations of mechanical properties conducted for development of water proofing membrane have been found to be very helpful in improving the index and structural properties. An optimum mix of both the materials for the membrane development was obtained by analyzing the test values. The study revealed that the tensile curves are significantly influenced by different factors such as strain rate, curing age and thickness of specimens. The presence of polyurethane polymer in the bituminous binder reduced water/moisture penetration and shorten the curing time compared to conventional bitumen. The amalgamation of PU and bitumen exhibits the enhanced property of elongation which is crucial property to counter structural moments and undulations along with tensile strength, tearing load and adhesion to different substrates such as metal, concrete. The end use of the resulting system developed depends on their physicomechanical properties relative to its constituent’s quantities, their interactions and the way product is processed. The main reason for use of this mix proportion is to incorporate advantageous properties of both materials to develop waterproofing. In this paper, testing of mechanical properties of polyurethane based bituminous waterproofing membrane developed has been discussed. These tests investigate the influence of composition on various credential values required in a waterproofing membrane. The research work discussed in the paper provides a scientific reference for the engineering application and design and development of polyurethane based bituminous waterproofing membrane.

A facile route for fabrication of polypropylene separators for lithium-ion batteries with high elongation and strong puncture resistance has been proposed in this work. Polypropylene separators imm...

Graphene-based materials are being developed for a variety of wearable technologies to provide advanced functions that include sensing; temperature regulation; chemical, mechanical, or radiative protection; or energy storage. We hypothesized that graphene films may also offer an additional unanticipated function: mosquito bite protection for light, fiber-based fabrics. Here, we investigate the fundamental interactions between graphene-based films and the globally important mosquito species, Aedes aegypti, through a combination of live mosquito experiments, needle penetration force measurements, and mathematical modeling of mechanical puncture phenomena. The results show that graphene or graphene oxide nanosheet films in the dry state are highly effective at suppressing mosquito biting behavior on live human skin. Surprisingly, behavioral assays indicate that the primary mechanism is not mechanical puncture resistance, but rather interference with host chemosensing. This interference is proposed to be a molecular barrier effect that prevents Aedes from detecting skin-associated molecular attractants trapped beneath the graphene films and thus prevents the initiation of biting behavior. The molecular barrier effect can be circumvented by placing water or human sweat as molecular attractants on the top (external) film surface. In this scenario, pristine graphene films continue to protect through puncture resistance—a mechanical barrier effect—while graphene oxide films absorb the water and convert to mechanically soft hydrogels that become nonprotective.

This study investigated the quasi-static mechanical properties of tomato peels of three cultivars - Hz 5608, Seminis DRI 319 and Seminis HP 849. The peels were produced from infrared (IR) heating with three targeted tomato surface temperatures of 109, 112 and 115 °C at two loading rates which reflected the different heating rates. Peels from conventional lye peeling method using a solution of 10% NaOH at 95 °C were used for comparison. Fresh tomato peels were used as control. A texture analyzer was used to determine the tensile strength to failure, puncture resistance strength, and adhesive strength of peels. It was found that mechanical strengths of tomato peels obtained from both IR and lye peeling processes were significantly (α = 0.05) lower than those of the control. However, the mechanical strengths of tomato peels under IR treatment at the temperatures of 109 and 112 °C were significantly (α = 0.05) higher than those of the peels obtained from lye treatment. The mechanical strength of the peels produced from IR treatment at 115 °C was similar to those produced from lye treatment. The reductions in tensile, puncture and adhesive strengths of peels were up to 88, 87.3 and 74.3%, respectively, for IR heated tomatoes, whereas these were 95.1, 99.3 and 91.3%, respectively, for lye treated tomatoes compared to control. The peels obtained from IR peeling had more integrity than those obtained from lye peeling. Increasing the loading rates of tomatoes during IR heating corresponding to lowered heating rate significantly (α = 0.05) decreased the mechanical strengths of peels due to increased residence time for reaching the targeted temperatures. Tomato cultivars had a significant (α = 0.05) effect on the adhesive strength of peel but not on tensile and puncture resilience strengths. These results provide important information about the changes of mechanical properties of tomato peel under different processes.

The work aimed to evaluate the influence of the type of matrix and the number of reinforcement layers on the puncture of aramid laminates. The samples were examined under laboratory conditions and in ballistic tests. Two series of aramid laminates were produced with different types of the polymer matrix. The epoxy resin (EP) and the styrene-butadiene-styrene (SBS) copolymer were used as the matrix. For comparison, a puncture test was performed for the fabric with the same number of layers in contrast to the laminates. Laboratory tests were carried out using the InstronDynatup 9250 HV drop hammer. The results obtained during the laboratory and ballistic examinations were compared. The samples were fired with a 9 × 19 mm Parabellum projectile. Research into the low-velocity range have shown that SBS laminates absorb impact energy more effectively than epoxy resin ones, but they are similar to fabrics without a polymer matrix. The results of ballistic tests are divergent and indicate that unbound materials are more efficient at absorbing energy than laminates. The reason for this is the different damage mechanisms.

In order to deeply explore the fiber characteristics influencing on stab resistance of shear thickening fluid (STF)- impregnated fabrics, two different weaving fabrics, ultra-high molecular weight polyethylene (UHMWPE) fabric and Kevlar fabrics are saturate the various concentrations and particle size of STFs. Result shows that, SiO2/PEG-200 blends demonstrate quick shear-thickening property, and the critical shear rate lowers to 1.2-45 s-1 with higher concentration of 75 nm SiO2. STF concentration and particle size significantly affect spike puncture resistance property, but the knife stab resistance mainly depends on fiber characteristics. Comparatively, STF-UHMWPE composite fabrics exhibit better knife stab resistance but weaker spike puncture resistance than STF-Kevlar fabrics. This study can provide an optimization for structure design of stab resistance armors in the future.

Now-a-days with the advent in technological advancements, bituminous compositions modified with polymer are being used for numerous applications such as joint filers, adhesives, protective layers, impregnating agents and roofing material The bitumen exhibits a number of mechanical properties but the conventional bitumen doesn’t congregate many requirements because of its drawback of high susceptibility to temperature. Hence from a product design point of view; the most preferred form is modified bitumen. With this aim, a composition in the form of waterproofing product has been developed by modifying bitumen with polyurethane. Polyurethane because of its attractive morphology and wide range of advantageous mechanical properties is a highly promising material having the ability to alter its microstructure to suite niche applications. The developed matrix incorporates the basic useful properties of bitumen along with excellent properties of polyurethane. This modification will maximize the efficiency of product developed in different scenarios making it a resourceful product in terms of waterproofing, insulation properties and enhanced durability. This paper highlights the experimental investigations of physico–mechanical properties of the matrix developed in the form of membrane of varying thickness made from different ratios using different grades of polyurethane and bitumen. Different ratios, grades and thickness of material have been used in trail mixes to attain optimized matrix for the product. The properties such as tensile, elongation, tear, shore hardness, puncture resistance, etc. of membrane developed of various matrixes are examined with relevant ASTM codes. The research work presented here provides an experimental implication for design; development and application of membrane developed for use in engineering purpose.

Ensuring material performance reliability and lifetime is crucial for practical operations. Small cracks on the material surface are often detrimental to its safe operation. This study describes the development of a hydrogen bond-rich puncture-resistant polyurethane elastomer with supertoughness. The as-prepared polyurethane transparent films feature high tensile break strength (57.4 MPa) and great toughness (228 MJ m-3). Additionally, a facile, low-cost, crack self-diagnostic approach through photoluminescence using a small luminous pen is reported. The materials efficiently achieved self-healing at 90 °C after the crack formation. The change of fluorescence intensity on the crack can be used to track the self-healing process. Therefore, this work provides a guideline for the material design of supertough, puncture-resistant, transparent, and healable elastomers and a crack self-diagnosis and healing approach.

Natural rubber (NR) latex gloves are widely used as a very important barrier for healthcare workers. However, they can still be perforated easily by sharp devices and instruments. The aim of this study was to investigate the effect of the addition of graphene oxide (GO) to low-ammonia NR latex on its puncture resistance, mechanical properties and thermal stability. GO was synthesized using modified Hummers’ reaction. The produced GO was mixed into the NR latex solution at various doses (0.01-1.0 wt. %), followed by a coagulant dipping process using ceramic plates to produce film samples. Puncture resistance was enhanced by 12% with 1.0 wt. % GO/NR. Also, the incorporation of GO improved the stress at 300% and 500%, the modulus at 300% and 500% and the tear strength of low-ammonia NR latex films.

For structures that carry dynamic loads, the requirements are imposed for safety reasons. The requirements apply to both materials and construction. This requires searching for optimal calculation methods, including geometric and physical nonlinearity, which are results from the construction of the structure. An example is various ballistic structures (ballistic shields), which are hit by bullets in which huge energy is accumulated. In this case, the hitting in the shield with a bullet can be considered as a load due to mass impact. Loads at high strain rates are described by various mathematical models. The mathematical model is complex because a large number of "coefficients" is required, moreover, the obtained test results are not always repeatable. The paper presents the results of shooting multilayer plates with composite materials with 7.62 mm caliber bullets. The shield consisted of three layers, the outer layers were steel or aluminum, the inner layer was natural or modified wood. The samples had the shape of a shield and were 50 mm in diameter and of different thickness. The results of the research allowed to assess the impact of wood modification on its puncture resistance.

Composite materials offer a number of distinct advantages in a wide range of low and high technology engineering applications. Considering the fact, in this study, a facile fabrication method of highly cut resistant composite fabrics using Kevlar and polyethylene is reported. 100% Kevlar, 100% Polyethylene and 50% Kevlar/50% Polyethylene composite fabrics are fabricated by weaving and knitting techniques. These fabrics were tested for cut index, abrasion, and puncture resistance for comparative exploration. Owing to higher mechanical strength and greater number of interlacements; the woven fabrics demonstrated twice cut resistance in contrast to knitted fabrics. The surface morphology of deformed samples investigated by Scanning Electron Microscopy (SEM) also proved that the woven fabrics of all types offered much resistance towards cutting than the knitted fabrics. Moreover, it is found that greater thickness of fabrics leads to intensification of the cut resistance. Furthermore, the effect of fiber type on cut resistant property of the fabrics was also measured and it was found that the composite fabric exhibited double cut resistance than 100% Kevlar and 100% Polyethylene fabrics. The 50% Kevlar/50% Polyethylene composite woven fabric resisted up to 35 consecutive strokes of sharp steel cutter whereas the knitted fabric completely torn apart at 20 strokes only. Thus, the as synthesized 50% Kevlar/50% Polyethylene composite woven fabric exhibiting superior cut resistance property offer a judicious choice for the preparation of efficient cut resistant fabric for industrial and domestic applications.

Bombyx mori cocoon, a natural nonwoven material has excellent puncture resistance and unique structure. Based on the structure of cocoon, this paper designed a biomimicry composite, aiming to improve the static puncture resistance through polyurethane impregnated treatment. In this article, four different types of polyurethane (TPU 85 A, TPU 90 A, PEUR 855 A, PEUR 991 A) are selected and five concentration gradients (5, 7, 9, 11, 13 wt%) are set. The tensile and static puncture resistance of the impregnated composites and damaged morphology after puncture are systematically studied. The results show that the static puncture resistance of nonwovens impregnated by polyurethane is improved obviously. This study provides a new way to design better static puncture resistant materials.

Uncovering energy absorption and surface effects of various penetrating velocities on laminar structures is essential for designing protective structures. In this study, both quasi-static and dynamic penetration tests were systematical conducted on the front surfaces of metal sheets coated with a graphene oxide (GO) solution and other media. The addition of a GO fluid film to the front impact surface aided in increasing the penetration strength, improving the failure extension and dissipating additional energy under a wide-range of indentation velocity, from 3.33 × 10−5 m/s to 4.42 m/s. The coated -surfaces improved the specific energy dissipation by approximately 15~40% relative to the dry-contact configuration for both single-layer and double-layer configurations, and specific energy dissipations of double-layer configurations were 20~30% higher than those of the single-layer configurations. This treatment provides a facile strategy in changing the contact state for improving the failure load and dissipate additional energy.

Polyurethane is a polymer adaptable to different scientific and industrial requirements, nevertheless it is also extremely susceptible to UV radiation, which compromises the physical and mechanical functionality. In this framework, our study investigated the effect of waterborne polyurethane dispersion (WPUD) applied to a polyester (PET)-based fabric, through the impregnation method, on the puncturing and water resistance of the pristine material, before and after UV weathering. Results confirmed an increment of both features in the prepared fabrics, attributed to the PUR textile treatment, but a partially loss of the gained properties in the samples due to the UV weathering. In order to improve the efficiency of the impregnating dispersions, in protecting the durability of the treated materials, the addition of different UV light stabilizers, or/and of crosslinking agent into WPUD was also tested. From the experimental data, it can be concluded that formulations based on WPUD, containing both the crosslinker and UV organic absorber, have displayed an increment of their perforation and water resistance for the treated samples with respect to the starting textile, and contemporary have preserved the features against the UV light. Finally, microscopic and spectroscopic analyses have been performed as further characterization techniques of the samples surface.

This study focuses on the puncture resistance performance of woven high modulus polypropylene (HMPP) fabric impregnated with shear-thickening fluids (STFs) composed of fumed silica nanoparticles suspended in polyethylene glycol (PEG). The puncture resistance performance of STF-treated HMPP fabrics were evaluated by the quasi-static puncture test. The results showed that the STF-treated fabric exhibited significant enhancement in puncture resistance performance as compared to neat fabric. The possible improving mechanisms responsible for puncture resistance performance of STF-treated fabric were also discussed.

Polyurethane foam has been develocped for years. In the past, the most study is focused on one function of Polyurethane foam including noise absorption, thermal protection, and mechanical impact as well as cushioning properties, and thus interdisciplinary functions of these foam boards become an innovation research. Therefore, the objective of study is to develop the multifunctional protective composite boards which are suitable for diversified environments. In this study, the carbon fibers (CF) and glass fibers (GF) are used as reinforcements for PU composite boards which are denoted as CFR-PU and GFR-PU respectively. The composite boards are made with different thickness and different contents of reinforcing fibers. The drop-weight impact test adopts a circular drop weight that falls from a certain height in order to observe the deformation mechanism of the boards. Different fracture modes that are caused by the bursting, compression, drop-weight impact, and puncture resistance tests are then examined. The test results indicate that the CFR-PU and GFR-PU fiberreinforced composite boards have a satisfactory impact load of 90 % and a favorable absorption coefficient at a certain frequency, and also have improved mechanical properties.

This study focuses on the puncture resistance performance of woven high modulus polypropylene (HMPP) fabric impregnated with shear-thickening fluids (STFs) composed of fumed silica nanoparticles suspended in polyethylene glycol (PEG) and those containing carbon nanotubes (CNTs). The shear-thickening characteristics and rheological features of suspensions were determined at steady and oscillatory shear stress using a stress controlled rheometer. The puncture resistance performance of STF-treated HMPP fabrics were evaluated by the quasi-static puncture test. To gain a better understanding of the effect of these two suspensions on puncture resistance mechanism of fabric, yarn pull-out test was conducted to examine internal shear strength and inter yarn frictional behavior of fabric. The results showed that both the STF-treated fabrics exhibited significant enhancement in puncture resistance performance as compared to neat fabric. However, the fabric impregnated with the suspension containing CNTs showed lower enhancement, due to its lower degree of shear-thickening as confirmed by rheological measurement. The possible improving mechanisms responsible for puncture resistance performance of STF-treated fabrics were also discussed.

Polylactic acid (PLA) is a biodegradable plastic that is relatively new compared to other plastics in use throughout industry. The material is produced by the polymerization of lactic acid which is produced by the fermentation of starches derived from renewable feedstocks such as corn. Polylactic acid can be manufactured to fit a wide variety of applications. This study details the mechanical and morphological properties of selected commercially available PLA film products. Testing was conducted at Iowa State University and in conjunction with the United States Department of Agriculture (USDA) BioPreferred Program®. Results acquired by Iowa State were compared to a similar study performed by the Cortec Corporation in 2006. The PLA films tested at Iowa State were acquired in 2009 and 2010. In addition to these two studies at ISU, the films that were acquired in 2009 were aged for a year in a controlled environment and then re-tested to determine effects of time (ageing) on the mechanical properties. All films displayed anisotropic properties which were confirmed by inspection of the films with polarized light. The mechanical testing of the films followed American Society for Testing and Materials (ASTM) standards. Mechanical characteristics included: tensile strength (ASTM D882), elongation of material at failure (ASTM D882), impact resistance (ASTM D1922), and tear resistance (ASTM D4272). The observed values amongst all the films ranged as followed: tensile strength 33.65 – 8.54 MPa; elongation at failure 1,665.1% – 47.2%; tear resistance 3.61 – 0.46 N; and puncture resistance 2.22 – 0.28 J. There were significant

Molded silicone rubbers are common in manufacturing of soft robotic parts, but they are often prone to tears, punctures, and tensile failures when strained. In this article, we present a fabric compositing method for improving the mechanical properties of soft robotic parts by creating a fabric/rubber composite that increases the strength and durability of the molded rubber. Comprehensive ASTM material tests evaluating the strength, tear resistance, and puncture resistance are conducted on multiple composites embedded with different fabrics, including polyester, nylon, silk, cotton, rayon, and several blended fabrics. Results show that strong fabrics increase the strength and durability of the composite, valuable in pneumatic soft robotic applications, while elastic fabrics maintain elasticity and enhance tear strength, suitable for robotic skins or soft strain sensors. Two case studies then validate the proposed benefits of the fabric compositing for soft robotic pressure vessel applications and soft strain sensor applications. Evaluations of the fabric/rubber composite samples and devices indicate that such methods are effective for improving mechanical properties of soft robotic parts, resulting in parts that can have customized stiffness, strength, and vastly improved durability.

A very important characteristic of geosynthetic materials, besides the breaking force and deformation, is the puncture strength of geotextiles. Considering that the purpose of installation geosynthetic materials and inter alia to stabilize and strengthen the soil in which they are installed, it is necessary that they have a high puncture strength in order to fulfill its function. Geotextile materials suffer a great burden and at the installation process, in contact with smaller and larger sharp rocks, and if they have poor puncture resistance they may be damaged. In addition to stabilizing the soil in which they are installed, geotextile materials are used for the protection of geomembranes from puncturing or as an obstacle to sharp materials that are used in a construction to damage geomembrane. For this purpose it is necessary to withstand a lot of pressure on their surface, and to prevent the contact of the sharp material with the geomembrane. This paper presents the analyzed samples of nonwoven geotextile materials made from regular polyester, recycled polyester and polypropylene fibers. Based on the obtained values, it is possible to create an image of the values of the forces that these materials can be submitted to, as well as the differences between geotextiles produced from regular and recycled polyester and polypropylene.

This paper presents the studies of the puncture resistances of conventional blend and multilayered structure sheets. The polypropylene homopolymer (HPP)/ethylene 1-octene copolymer (POE) alternating multilayered sheets were prepared though multilayered coextrusion. Polarized optical microscope (POM) photographs revealed that HPP and POE layers aligned alternately vertical to the interfaces and continuously parallel to the extrusion direction, indicating a better laminate structure. Puncture results demonstrated the conventional blend was less puncture-resistant than the multilayered samples. Obvious interfacial delamination occurred in the multilayered structure during crack propagation, causing the puncture behavior to develop into a staged rupture behavior. Hence the puncture resistance was enhanced by the special energy absorbing mechanisms including the plastic deforming independently, interfacial delamination and ductile tearing of the layers.

Hybrid laminated composites were fabricated based on high-density flexible polyurethane foam and reinforced with inter/intra-ply hybrid laminates. Transient responses of hybrid composites under quasi-static and dynamic loadings with various thicknesses and expansion factors were comparatively investigated. Experimental results revealed that foam cell collapse and hybrid laminates rupture were dominant mechanisms of energy absorption. Interlaminar stress and composite tensile strength determined the compressive potential energy and double-peak behavior. Quasi-static bursting and puncture resistances exhibited totally different relationships to various constructions and expansion factors. Energy dissipation capacity is influenced more significantly by the constant rate of transverse (CRT) puncture than dynamic puncture process. CRT puncture resistance is superior to the corresponding dynamic puncture resistance for all constructions. The hybrid laminated composites contributes to eliminate more than 95% of the incident force in the drop weight impact test. Compared with non-laminated panel, the hybrid laminated composites exhibited higher resistance to static and dynamic loadings.

A mixture design was used to analyse the effects of polyvinyl alcohol (PVA) on glycerol-plasticised cassava starch sheets obtained by flat extrusion from a twin-screw extruder. PVA was the main component that improved the properties of the sheets, and glycerol presented the opposite effect. The properties ranging: tensile strength (0.22–1.5 MPa), Young's modulus (0.45–7.29 MPa), elongation at break (59–111%), puncture resistance (10–107 N/mm), puncture elongation (5.64–10.13 mm), crystallinity index (17–21%) and water vapour permeability (3.39–7.40 × 10−5 g m−1 day−1 kPa−1) for the sheets. Scanning electron microscopy showed good compatibility between the components of the blend because the resultant materials were continuous and cohesive and did not exhibit phase separation. The sheets were not significantly different from others, based on XRD and FTIR analyses, consistent with the literature. PVA was able to improve the mechanical and barrier properties of starch-based sheets.

In this article, the mesh fabric and porous filler are combined with polyurethane (PU) foam to fabricate sound-absorbing composite boards with puncture resistance and cushion protections, after which sound absorption and static puncture resistance are improved. Effects of fillers (vermiculites and perlites) content and mesh opening ratio on sound absorbing, puncture resisting and cushioning properties are explored respectively. Result shows that, mesh fabric improves the low-frequency coefficients, and also increases the puncture resistance by 2 times and 1.5 times for 2-mm-diameter and 4.5-mm-diameter probes penetrations. Absorption peak shifts to the lower frequency with increase of fillers content and mesh opening, but static puncture resistance against 4.5-mm-diameter probe decreases with mesh opening ratio. The fabricated composite foam boards can absorb 90 % of impact energy when compounding with 10 wt% vermiculite fillers and 45 % opening fabric, which shows the favorable cushioning protection. This mesh-reinforced composite foam boards can be applied as protective compartment walls whatever in gerocomium, women and children care center, kindergarten or karaoke TV room.

Logistics industry becomes the mainstream with promotion of life quality. The selection of delivery type and aging is subjected to limitations of packaging materials. In order to protect from product’s damage, this study purposes to use recycled high-strength fibers, including high-strength PET fiber, and Kevlar fibers, and thermal bonding PET fiber as well as glass fabric forming needle-punched 3D composite. For comparison of varying reinforcement on mechanical property, thermal bonding and water polyurethane impregnation are used to reinforce the 3D composite which is composed of nonwoven fabrics and glass fabrics. Result shows that, mechanical property from water polyurethane impregnation displayed much higher than that from thermal bonding. Thermal bonding remarkably improved burst strength and static puncture resistance. Therefore, 3D composite impregnated with water polyurethane reaches higher puncture protection level.

International audience; The aim of this paper is to study the durability of polyvinyl chloride (PVC-P) geomembranes reinforced with a synthetic fabric in hydraulic works in the Spanish Mediterranean basin. Therefore, a set of six geomembranes installed in irrigation reservoirs for 18-31 years were analysed. The initial characteristics of the geomembranes were determined to verify fulfilment of the Spanish regulations in force at the time. The characteristics were then assessed, and the results were interpreted with reference to the loss of plasticisers, tensile characteristics, foldability at low temperatures, dynamic impact resistance, puncture resistance, seam strength, reflected optical microscopy (ROM) and scanning electron microscopy (SEM). Additionally, the identification of the plasticisers in the geomembranes involved Fourier transform infrared spectroscopy (FTIR), gas chromatography (GC) and mass spectrometry (MS) tests. For the analysed samples, the loss of plasticisers was significant, ranging from 71.0% to 84.3%. However, the tensile strength results indicated current, regular waterproof working performances in the reservoirs. The results suggest that the durability of PVC-P geomembranes is a function of the loss of plasticisers and the state of the synthetic reinforced fibres.

In order to realize recycling of polypropylene selvages, polypropylene nonwoven selvages with different plied orientation were inserted between Kevlar/Nylon/low-melting polyester nonwoven fabrics forming composite nonwoven. Low-melting polyester content of nonwoven fabric and hot-pressing temperature of composite nonwoven were both optimized after static and dynamic puncture resistances. Moreover, effects of hot-pressing and plied orientation on static and dynamic puncture resistances, sound absorbing and thermal insulating properties of composite nonwoven were discussed respectively. Result shows that, optimal low-melting polyester fiber content was 30%, and best hot-pressing temperature for composite nonwoven was 180°C. Polypropylene nonwoven selvages improved static puncture resistance, sound absorbing and thermal insulating properties. Hot-pressing slightly increased puncture resistance and obviously improved thermal insulation, but decreased sound absorption coefficient significantly. Plied orientation affected static and dynamic puncture resistance insignificantly, but influenced on sound-absorbing and thermal-insulating properties significantly. When composite nonwoven was plied with 90°/90° polypropylene selvages and hot-pressed at 180°C, the static and dynamic puncture resistances reached 120 N and 80 N, respectively, and thermal conductivity was 0.047 W/mK. Five layers of composite nonwoven before hot-pressing had sound absorption coefficient of above 0.94 at frequency of higher than 1890 Hz.

The quasi-static (QS) puncture resistance of p-aramid Twaron fabric impregnated with shear thickening fluid (STF) based on the molecular weight variation of the base liquid has been investigated. To synthesis the STF, the 12 nm silica particles have been dispersed in polyethylene glycol (PEG) with two different molecular weights, 200 and 400 g/mol by means of mechanical mixing. The weight percentages of silica particles in the continuous phase were selected as 15, 25 and 35 wt%. The results of rheological tests indicate that with the increase of the polymer’s molecular weight, the viscosity and instability of the suspension increase, while its critical shear rate diminishes. The STF impregnated Twaron fabrics were subjected to QS puncture resistance tests according to the ASTM standard D6264. The quasi-static puncture resistance increased about 4.5 fold for Twaron fabric impregnated with 35 wt% concentration STF relative to the neat Twaron. Also, with the increase of the PEG’s molecular weight in Twaron fabrics impregnated with 15 and 25 wt% concentration STFs, the QS puncture resistance of Twaron fabrics improved considerably, but it didn’t change too much in the Twaron fabric impregnated with 35 wt% concentration STF.

In this study, the production of starch films reinforced with cellulose fibers was performed by the tape-casting technique, which allows preparing films with much larger dimensions, if compared with the classical casting technique. Tape casting is well known in other areas; however, there is a lack in the literature about its use for manufacturing biodegradable films. Using this technique, it was possible to develop bags with 100% biodegradable materials. Puncture and tear propagation resistance, and tensile strength of films prepared with different thicknesses were determined. The films heat sealability, wettability and printability were also studied. Overall, the mechanical properties showed that the thicker films had higher tensile strength. The most suitable heat-sealing temperature was 150°C. The results indicate that the obtained biodegradable bags have potential to be used for packaging products with dry surfaces (some fruits, clothes), contributing to reduce the impact of oil-based plastic in the environment. Practical Applications The starch film, classically prepared by the casting technique, presents small dimensions, which does not allow large-scale production. With tape-casting technique, it can be produced films with much larger dimensions, which can be used to form 100% biodegradables packages. These packages can be used to pack products with dry surfaces like some fruits, clothes and others. The present work studies the starch-cellulose fibers films properties with the purpose of forming biodegradable packages. Some parameters like sealability, wettability, printability, puncture resistance, tensile resistance and tear resistance were determined in order to produce a bag with good characteristics.

This study aims to examine the thickness of a sandwich structure and the lamination number of the Kevlar nonwoven fabrics o n the punch resistance strength and impact resistance strength of the nonwoven composites. Kevlar nonwoven fabrics and Nylon/low-melting-point polyethylene terephthalate (LPET) nonwoven fabrics are laminated with various combinations to form sandwich-structured nonwoven composites. The experiment results show that an increasing number of Kevlar nonwoven fabrics results in low dynamic and constant rate puncture resistance but high impact strength; and conversely, an increasing thickness of sandwich-structured nonwoven composites causes high dynamic and constant rate puncture resistances but low impact strength.

This study aims to examine the influence of the temperatures of heat treatment on the puncture-resistance of Nylon6/LPET compound nonwoven fabrics. Polyamide 6 (Nylon 6) fibers and low-melting-point polyester (LPET) fibers are combined and undergo a heat treatment to make three-dimensional (3-D) Nylon 6/LPET compound nonwoven fabrics through a nonwoven process. The nonwoven fabrics are tested for their dynamic puncture resistance, constant rate puncture resistance, and impact strength. The experiment results show that when thermally treated at a high temperature, the compound nonwoven fabrics are rendered with a lower dynamic puncture resistance and a lower constant rate puncture resistance, but a greater impact strength.

Geotextiles are generally made from natural or synthetic fibers and both fibers offer their own advantages and disadvantages for geotechnical applications. In this study, the jute fibers were treated with 4 wt.% sodium hydroxide (NaOH) solution in order to enhance their tensile properties. A series of needlepunched nonwoven geotextiles were then fabricated by formulating blends of untreated jute and polypropylene fibers and corresponding sets of nonwovens containing alkali treated jute and polypropylene fibers in defined weight proportions. Subsequently, a comparison has been made between the physical and mechanical properties of these blended nonwoven geotextiles. In general, the alkali treated jute blended nonwoven geotextiles offer higher puncture resistance in addition to higher tensile and tearing strengths in the cross-machine (preferential) direction than their corresponding blended geotextiles consisting of untreated jute fibers. Blended nonwoven geotextiles consisting of more than 40 wt.% jute fibers were not found to be useful in enhancing the mechanical properties.

Global warming increases each day and causes people to pay more attention to the reduction of carbon dioxide emission in order to mitigate the increase in temperature. Reducing, reusing, and recycling can effectively reduce the emission of carbon dioxide, to attain goals of energy conservation and carbon reduction. This study aims to explore the difference in the punch resistance and impact strength between the polyethylene terephthalate (PET) nonwoven fabrics and PET/TPU honeycomb grid/PET (P/T/P) composites. Recycle PET, high strength PET, and low melting PET are made into PET nonwoven fabrics, two layers of which are laminated with a TPU honeycomb grid, the interlayer, to form P/T/P composites. The constant rate puncture resistance, dynamic puncture resistance, and impact strength of PET nonwoven fabrics and P/T/P composites are evaluated. The experiment results show that both the constant rate and dynamic puncture resistances of P/T/P composites are lower than those of PET nonwoven fabrics.

We describe herein a method for quantifying and ranking the puncture resistance of lithium-ion battery separators, which can be used as a quality-control tool for determining the in-plane uniformity of their mechanical properties. Mechanical properties were probed over length scales comparable to the size of electrode active material particles. We determined the elastic modulus and hardness of four polymeric and four organic–inorganic composite separators through nanoindentation, and examined their morphology with scanning electron microscopy. Our results show that ceramic-enhanced separators can have improved mechanical properties compared to polymeric separators (3× increase in elastic modulus, 2× increase in hardness). Composite separators made of ultra-high molecular weight polyethylene and fumed alumina displayed the highest hardness. The results also indicate that the mechanical properties of ceramic-enhanced separators depend strongly on materials choices and processing conditions (in particular, their thermal history). Furthermore, inclusion of ceramics into a separator does not guarantee improved mechanical properties.

Glass woven fabric interlayered nonwovens composed of Nylon 6 staple fibers, recycled Kevlar fibers, and low-Tm polyester fibers are prepared into the glass-interlayer plank. Afterwards, their tensile strength, bursting strength, quasistatic and dynamic puncture resistances are evaluated by changing low-Tm polyester and Kevlar fibers mass fractions. The results show that when comprising 30 wt% of low-Tm polyester fibers and 20 wt% of Kevlar fibers, the composite plank yields the maximum tensile strength, bursting strength, quasi-static and dynamic puncture resistances. The double planks arranged in cross direction have higher quasi-static and dynamic puncture resistances than those oriented in parallel direction. According to stereoscope observations, the quasi-static and dynamic puncture resistances of glass-interlayer plank have different fracture mechanism for resisting against spike penetration. In addition, the bursting strength is proportional to quasistatic puncture resistance.

We studied the strength of the individual threads in the longitudinal and transverse rupture, the state of threads, as well as the strength of a single layer of aramid fabric exposed to the piercing influence of the conical indenter. Materials used in the experiments: special high molecular material of the brand DZh (SHMM-DZh) and ultra-high molecular weight polyethylene (UHMWP). It is found that the effect of electromagnetic field on the aramid threads and fabrics based on them, as well as the threads made of UMWP increases the tensile strength at 2 and 1.6-1.7 times respectively. Aramid fabric puncture resistance in the delivery state and in the wet state, after exposure to the electromagnetic field increases by 1.7-1.8 times. A significant reduction of the fiber bundle processed in the electromagnetic field of aramid fibers and UHMWP after exposure to tensile load was ascertained.

Recycled high-modulus Kevlar fibers were blended with Nylon 6 staple fibers and biocomponent low- Tm/high- Tm polyester fibers to form high-modulus puncture-resistance nonwoven fabrics via opening, mixing, carding, lapping, needle-punching, as well as hot-pressing processes. In this paper, biocomponent low- Tm/high- Tm polyester fiber content, needle-punching density, and hot-pressing temperature were changed to evaluate the tensile strength, bursting strength and static puncture resistance of resulting nonwoven fabrics as related to aforementioned three parameters based on response surface methodology. The result shows that the tensile strength is highly related to needle-punching density and hot-pressing temperature; but the bursting strength and static puncture resistance are significantly involved with the aforementioned three parameters. The tensile strength, bursting strength, and static puncture resistance all present increasing and then decreasing trend with increase of its respective concerning parameters. Moreover, the static puncture resistance strength has linear dependence on bursting strength.

A study was conducted on the puncture resistance of high-strength nonwoven natural rubber latex (NRL)-coated fabrics. High strength unidirectional (UD) polyethylene fabrics were coated using single dipping (SD), double dipping (DD), and triple dipping (TD) methods. The puncture resistance of the uncoated and coated fabrics was determined by measuring the force needed to penetrate the fabrics using a blunt probe. The mechanisms and modes of deformation involved during penetration were observed as well. In comparison with the uncoated fabrics, the SD, DD, and TD NRL coated fabrics gave higher puncture resistance of 39%, 47%, and 62%, respectively. The increments of the penetration force were proportional with the increase in the NRL-coated fabric thickness. For the uncoated fabric, the force given by the probe resulted in yarns stretching and yarn slippage upon penetration. However, the NRL-coated fabrics were not severely damaged but resulted in a curvature formed at the frontface of the fabric with minimal backface deformation. From the observations, the modes of failure were similar among the NRL-coated fabrics, that is, fiber stretching, delamination of NRL layer, and stretch marks on the fabric surface. The NRL layer acted as a protective sheath and increases the energy absorption and elasticity characteristics of the UD fabric.

A new self-repairing membrane for inflatable light weight structures such as rubber boats or Tensairity® constructions is presented. Inspired by rapid self-sealing processes in plants, a thin soft cellular polyurethane foam coating is applied on the inside of a fabric substrate, which closes the fissure if the membrane is punctured with a spike. Experimental tests are carried out with a purpose built setup by measuring the air mass flow through a leak in a damaged membrane sample. It is shown that the weight per unit area of the self-repairing foam as well as the curing of the two component PU-foam under an overpressure influence the repair efficiency. Curing the foam under overpressure affects the relative density as well as the microstructure of the foam coatings. Maximal median repair efficiencies of 0.999 have been obtained with 0.16 g·cm−2 foam cured at 1 bar overpressure. These results suggest that the bio-inspired technique has the potential to extend the functional integrity of injured inflatable structures dramatically.

70% Nylon 6 fiber and 30% low melting polyester fiber were manufactured into nonwoven fabrics, after which the nonwoven fabrics and Nylon 66 grids were needle-punched and heat-treated, forming the Nonwoven/ Nylon 66 grid composite fabrics. The optimum parameter for heat treatment was 150°C for 5 minutes, improving the mechanical property of the composite fabrics. Subsequently, with a fixed pick-up ratio of 200%, two waterborne PU resin (SE-5030 and SE-5070) with 0, 5, 10, 15, 20, and 25 wt% of cross-linking agent were used, offering the impregnation for Nonwoven/ Nylon 66 composite fabrics. After impregnation, the Nonwoven/ Nylon 66 grid composite fabrics were measured with drop tower stab testing, quasistatic stab testing and tensile strength testing. SE-5030 contributed greater tensile strength to the composite fabrics (1129.5 N in cross machine direction (CD) and of 816.4 N in machine direction(MD)); however, SE-5070 offered the composite fabrics the optimum stab-resistance strength of 69.9 N.

The cut and puncture resistance of thermoplastic (TP) impregnated, woven aramid fabric is characterized under quasi-static and dynamic stab testing conditions. Polyethylene, Surlyn®, and co-extruded polyethylene–Surlyn films of various thicknesses are laminated into fabrics and compared with neat fabrics at equal weights and layer counts. The results show that TP-laminated fabrics improve the stab and puncture resistance of the fabrics, through a combination of increased cut resistance and reduced windowing. All films are shown to be effective, although thin Surlyn films appear to provide the best overall performance. The results also show that the TP films need to be integrally bonded to the fabrics in order to achieve synergistic property enhancement.

This paper presents an experimental study to develop a design procedure for the puncture behavior of polyvinyl chloride (PVC) geomembranes. The puncture resistance was measured using the truncated cone test, in which truncated cones are used as puncture points. The heights of the truncated cones are varied to determine the critical cone height, which is the height at which geomembrane puncture occurs for a given pressure. A cushion geotextile is not used in any test to enhance puncture resistance because of the large cone heights required to puncture PVC geomembranes. Critical cone heights are presented for 0.5 mm, 0.75 mm and 1.0 mm thick PVC geomembranes. The results of these tests show that as the thickness of the PVC geomembrane increases, the critical cone height increases. This indicates an increased puncture resistance with increasing geomembrane thickness. The results of the puncture tests on PVC geomembranes are compared with other types of geomembrane, e.g. smooth and textured 1.5 mm thick high-density polyethylene and 1.0 mm thick linear low-density polyethylene. This comparison shows that the puncture resistance of PVC geomembranes used in this investigation exceeds that of polyethylene geomembranes, even though the PVC geomembranes are thinner.

When self-pressurized containers, or aerosols, are accidentally dropped they are susceptible to puncture. The likelihood of puncture depends on the distance of the fall, the nature of the object that the aerosol might strike, the orientation of the impact, and the aerosol’s materials of construction, including microstructure. Due to the flammable nature of the propellants common to aerosols as well as other flammable contents, the accidental puncture of an aerosol has on occasion resulted in significant personal injury and property damage. While the Department of Transportation regulates several aspects of aerosol containers, there are no government regulations concerning puncture resistance. Likewise, there are no standard tests for the puncture resistance of aerosol containers. This article presents two different test methods that can be used to quantify the puncture resistance of aerosol containers. One mode of puncture is not a pure puncture, but rather an impact-induced circumferential puncture or crack. This is due to the anisotropic microstructure of the body material of most 3-piece steel aerosol containers. Experimental testing has shown that the most common type of aerosol container is highly vulnerable to impact-induced impact circumferential puncture. Free falls from a little as 20.32 cm (8 in.) onto wood pyramids are able to induce this type of puncture. This is a hidden and unexpected vulnerability inherent in most 3-piece steel aerosol containers. Experimental tests show that this susceptibility to impact-induced circumferential puncture as well as pure puncture can be greatly reduced, if not eliminated, by using container bodies with more isotropic microstructures.

Kevlar has demonstrated the ability to protect well against ballistic threats but has low resistance to puncture. Correctional Kevlar has shown good resistance to puncture. However, the fabric is expensive, difficult to manufacture because of its tight weave construction, and has limited protection against ballistic threats. In an effort to produce materials that are less bulky, more flexible, and resistant to puncture, thermoplastic-Kevlar (TP-Kevlar) composites have been examined. Kevlar fabric was impregnated with thermoplastic film using a hot press to produce the composites. Static and dynamic puncture resistant properties of the TP-Kevlar composites were investigated using a National Institute of Justice (NIJ Standard 0115.00) Stab Tower. The TP-films used in this study were polyethylene, Surlyn, and co extruded-Surlyn, which is a co extrusion of Surlyn and polyethylene. Response of the polyethylene (PE)-Kevlar composites, Surlyn-Kevlar composites, and co extruded (COEX)-Kevlar composites to spike and knife threats under static and dynamic conditions were compared with that of neat Kevlar. The infusion of thermoplastic films into the Kevlar fabric was shown to dramatically increase puncture resistance during quasi-static and dynamic testing with spikes. The TP-film type also made a difference when examining the resistance on a comparative basis of the TP-Kevlar targets. The TP-Kevlar composite targets showed more resistance to quasi-static spike testing than quasi-static knife testing. Weapon comparisons revealed that the TP-Kevlar composite targets had more resistance to dynamic knife testing than dynamic spike testing.

Films are among the most important products to be made of polyolefins. Since they are primarily mass-produced, even slight reductions in the film thickness have the potential to lead to considerable savings. Robert Huber and Jorg Auffermann of BASF explain how Styroflex® 2G 66 SBS block copolymer can be used to increase the puncture resistance and the tear propagation resistance of mLLDPE and PP films. However, this is only the case if the additive is optimally distributed in the polyolefin phase and is present in dispersed form within the nano range.

We introduce a silicone-based vascular prosthesis that may be optimized in various ways. The current work describes the theoretical background, the fabrication process, and the mechanical properties of these new prostheses, allowing objectification and comparison of materials used in vascular surgery. A production process to coat polyester prostheses with silicone-rubber (polydimethylsiloxane, PDMS) was established. Further modifications (surface improvements, drug incorporation for release) can be performed wet-chemically. Measurement of the physical properties included longitudinal and circumferential stability and elasticity, suture retention strength and puncture resistance (tensile testing machine), permeability, and compliance (circulation model). Prostheses can be multiply coated with PDMS. Sufficiently low levels of permeability (5 mL/cm(2)/min at 120 mm Hg) were achieved with a PDMS content15 mg/cm(2). Considering stability, elasticity, and compliance, prostheses with a silicone-rubber content of 15-20 mg/cm(2) are comparable to conventional, primarily tight prostheses. Coating with PDMS decreases suture retention strength and puncture resistance compared to conventional alloplastic materials (collagen-coated polyester and expanded polytetrafluorethylene) materials. The silicone coating surrounds the passing threads ("self-sealing surface") and is resistant to clamping trauma. The complete measurement procedures described here allow for a comparison of new materials with conventional ones and allow the handling characteristics of implants to be objectified. The primarily tight, silicone-coated prostheses can be compared to conventional bovine-coated materials without drawbacks regarding physical properties.