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This work relates to the development of recycled paper from waste paper with the objective of optimization of the composition. The paper properties are much affected with composition like amount of waste paper, fresh paper, cotton shreds, adhesives and water. Samples were made by taking different composites and tests were performed to evaluate properties i.e. thickness, coefficient of friction, moisture content, scott bond strength, tensile strength. The testing concluded that the samples which were having cotton shreds and adhesives showed very good results closer to the fresh paper. [ABSTRACT FROM AUTHOR]

The present researchers are trying to enhance the properties of paper sheet that used widely in many fields such as printing and packaging. The enhancement of paper quality is also possible to preserve paper documents of all kinds, as they are the true record, full of the history, achievements of the human being and the intellectual and cultural of the country. It is possible to improve its physical and mechanical properties and preserve them from damage through the use of some solutions of polymeric adhesives, which act as protective barriers against water and moisture penetration. The paper also has the advantage of porosity, which has been overcome by using three types of polymeric adhesives (Nitro Cellulose, Polyvinyl alcohol acetate, and Poly methyl methacrylate, as it formed a transparent layer, that led to an increase in thickness, hardness, ability to withstand folding and tensile, and a decrease in the intensity of brightness, as polymeric solutions showed their superiority in resisting moisture. [ABSTRACT FROM AUTHOR]

Biodegradable adhesives are essential to be developed to replace synthetic adhesives. This research aims to study the effects of α-amylase enzyme concentration on the process of making adhesives from glutinous rice flour dextrin by examining the ratio of dextrin: CMC: glycerin on glue adhesion. This research was conducted in two stages: the making of dextrin from glutinous rice flour, and then the making of glue from the dextrin. The dextrin was made by mixing glutinous rice flour with water with a concentration of 200 grams/600 mL, then adding the α-amylase enzyme with variations (2 mL, 4 mL, 6 mL, 8 mL, 10 mL) and heated to a temperature of 80oC for 30 minutes, while continuously stirred at 300 rpm. After that, the liquid dextrin was filtered, and then the wet dextrin flour was dried in the sun to a constant weight. The dextrin was then sieved using a 200-mesh sieve. The dextrin was mixed with CMC and glycerin in a specific ratio, then heated to a temperature of 85oC for 20 minutes, and cooled to produce glue. The resulting glue was tested for adhesion. The adhesive strength test was carried out on a paperboard measuring 2.5 cm x 15 cm and 1.15-mm thick. This study found that the weight ratio of dextrin: CMC: glycerin affected the glue adhesion. The best glue adhesion was obtained at the weight ratio of dextrin: CMC: glycerin of 10 grams: 4 grams: 2.1 grams with adhesion of 171.4 N. The highest adhesion was 171.4 N which was better than standard paper glue sold in the market with the adhesion of 65.5 N. [ABSTRACT FROM AUTHOR]

In recent years, adhesive bonding became a very common assembly technique in many industrial sectors, such as aeronautical, civil, energetic, automotive and biomedical engineering, as an alternative to conventional joining techniques, such as welding and riveting. Adhesive bonding provides several advantages, including reduced stress concentrations, higher corrosion resistance, water tightness, and the ability to join materials with dissimilar properties. In this paper, a general model of interfaces is presented. This model includes hard (the stiffness of the adhesive is of the same order as that of the substrates) or soft (the stiffness of the adhesive is lower than that of the substrates) interfaces. The model takes into account a damage parameter. The adhesive material is obtained by homogenizing a micro-cracked media. The porosity (or crack density) of the medium is chosen as the damage parameter. An evolution law based on the standard material theory is introduced. Academic examples are presented to show the evolution of the mechanical parameters and the relevance of the model. [ABSTRACT FROM AUTHOR]

In most of the engineering applications, the weight of the structure must be minimum for better performance of the system. The reduction of weight always presents a challenge. Honeycomb structures are the structures that have the geometry of a honeycomb to allow the minimization of the amount of used material to get the minimal weight and minimal material cost. The honeycomb structures are used to reduce the weight of structure with high strength. This paper is focusing to design a honeycomb structure for making dumper of a heavy vehicle and comparing the honeycomb sandwich panel with regular material by numerical and analytical method. Basically, honeycomb sandwich structure panel consists of three layers that are face sheets, adhesive bonds and one core. The main objective is to produce a honeycomb sandwich panel at same thickness as regular material and to analyse its high stiffness to the weight ratio. Also to check whether the structure has low deflection for the same weight as regular material. [ABSTRACT FROM AUTHOR]

Auditory Emission (AE) approaches are well-known for their novel approach to understanding the intricacies involved in debonding sequence analysis, which is essential in substantiating joint validation. The calculations' applicability is based on the technique developed for increasing the clarity of the received AE signal during AE testing. The AE application's computing implementation simply avoids the confusions caused by signal clustering. As a consequence, it is critical to undertake an orderly review of the AE computation implementation process, which will certainly provide clarity and insight in the debonding prediction technique development. The goal of this paper is to go through a few techniques for debonding analysis of adhesive connections that are often utilised in AE applications. [ABSTRACT FROM AUTHOR]

The paper describes an experiment aimed at verifying the influence of the size of large-format tile segments and, primarily, the influence of various adhesives on the quality and behaviour of the tiles. Large-format tiles were attached in various ways to pre-prepared concrete panels with a thickness of 150 mm and surface dimensions of 2 m x 3 m. The adhesives used were varied as well as the size to which the large-format elements were cut. The quality of the tiling material was monitored non-destructively by running an ultrasonic pulse velocity test. It was found that while the size of the segments cut from the large-format tiles did not affect the ultrasonic pulse velocity, the adhesive used did. [ABSTRACT FROM AUTHOR]

The paper presents information on the effect of polymer modifiers on the variation in production conditions and the main operational properties of filled acrylic systems, cured by the mechanism of radical polymerization. By preliminary injection and dissolution in the monomeric phase of modifiers - suspension polystyrene and its copolymers (with methyl methacrylate, methyl methacrylate and acrylonitrile) acrylic compounds were obtained with acceptable indicators of technological viscosity and the ability to adjust its viability under normal conditions. The combination of manufacturability and realizable physical characteristics of modified acrylic polymers made it possible to carry out on their basis the directed development of filled adhesive compositions with improved adhesion characteristics. According to the experimental data of relaxation spectroscopy and the calculated values of linear dilatometry, it was evaluated that when a filler is injected into the acrylic system, a supramolecular structure with a characteristic surface layer is formed, which makes a significant contribution to the variation in the macrophysical characteristics of the material (an increase in the dynamic shear modulus from 1.6 to 2.4 GPa). Therefore, mobilization to preserve the resource of the adhesive contact (not less than 18 MPa) with permissible amounts of filler (from 10 to 30 mass parts in polyacrylate) and thicknesses of the adhesive layer occurs due to the total contribution of the dispersed phase to the strengthening of the polymer. The superposition of various factors, and first of all, a decrease in the density of the polymer phase in the filled system, contributes to a slight drop in the adhesion strength of acrylic glue to a metal substrate, which in general should provide an acceptable degree of reliability of adhesive building constructions. [ABSTRACT FROM AUTHOR]

Mixing of materials is used in many industries such as the chemical-, food-, and pharma-industry. One of the most used mixing devices, in suspensions with a very high solid loading of particles, is the twin sigma blades. These blades handle very viscous suspensions. Nevertheless, obtaining a homogeneous material post mixing, is a non-trivial task. In this paper, a Taguchi DOE is performed on a pilot-scale twin-sigma-blade mixer to study the homogeneity of adhesive materials. The batches are mixed with varying particle purity, initial fluid temperature, mixing-temperature, -time, and –rotation. The results illustrate that purifying the particles has a very positive impact on the homogeneity of the adhesive barriers. [ABSTRACT FROM AUTHOR]

The mechanical properties of fiber-reinforced composites largely depend not only on the properties of the matrix and fiber, but also on the behavior of the interface, that is, on the adhesion between the fiber and the matrix. The adhesion between the polymer resin and the reinforcing filler is largely determined by the adsorption interaction at the interface. The paper presents the results of studies of the effect of surfactants on the processes of interfacial interaction at the interface between the phases epoxy oligomer - carbon fiber. The possibility of regulating the adsorption interaction at the interface is shown. The use of an anionic surfactant made it possible to increase the adhesive interaction in the epoxy oligomer - carbon fiber system. [ABSTRACT FROM AUTHOR]

Confined concrete technology significantly improves the properties of concrete in terms of compressive strength, tensile strength and flexural. It also makes the concrete more ductile, and more durable as it gives better resistance to acid and sulfate attacks. This paper provide an experimental study on the performance of concrete specimens confined by carbon fiber tube impregnated with a geopolymer adhesive under axial compression load after exposure to sulfuric acid attack for (30, 60, and 90) days. Fourteen cylinder concrete specimens with dimens ion 100mm×200mm were studied, that divided in to two groups, the first, included eight specimens were confined via two -layers of carbon fiber reinforced with geopolymer adhesive tube, and the other group was six specimens were unconfined. The results ind icated that the effect of erosion increases with the increase in the period of exposure to acids -attack. Also, the confined specimens gave a slightly decreas ing in compressive strength estimated by (4% to 9%). Finally, it becomes clear that the carbon fiber tube reinforced with geopolymer adhesive showed good anti-acid behavior, provided protection to concrete from corrosion i.e more durable, which increases the efficiency of the structural section subject to acids attack. [ABSTRACT FROM AUTHOR]

This paper investigates how concrete behaved when a carbon fiber reinforced geopolymer adhesive tube confined it. The effects of ground granulated blast furnace slag content on the geopolymer adhesive that used to reinforce the carbon fiber tube were investigated. The experimental program included, twenty-four cylinder concrete specimens confined by two layers of carbon fiber tube. Two specimens were confined by carbon fiber reinforced epoxy adhesive (CFREA) tube and twenty -two specimens were confined by carbon fiber reinforced geopolymer adhes ive (CFRGA) tube. Eleven mixes of geopolymer adhesive were prepared with replacement (0% to 100% by increment 10%) of binder by slag. Confinement specimens were tested under compression load. Based on the test results, the optimal geopolymer adhesive was found at the specimens confined by carbon fiber tube reinforced with a fully slag based geopolymer adhes ive, gave a s ig nificant axial stress enhancement ratio and deformation capacity by (2 and 10 times) respectively, which exceeded axial stresses of specimens confined by carbon fiber tube reinforced with fly ash based geopolymer adhesive tube by about (35%), which constituted about (98%) of epoxy adhesive tube. Finally, it is worth noting that it could be considered the geopolymer adhesive as a sustainab le and effective alternat ive to epoxy adhesive in concrete confinement techno logy. [ABSTRACT FROM AUTHOR]

The strengthening and rehabilitation of reinforced concrete structures is an important issue all over the world. Fiber reinforced composites are mainly used for the strengthen and rehabilitation of concrete members. However, its use is limited due to its high price and environmental effects and its adoption of epoxy as an adhesive, where epoxy is considered inefficient at high temperatures and loses most of its properties. The solution of this problem leads to the use of low-cost locally available geopolymer adhesive paste. This paper presents the experimental results of testing seven reinforced concrete columns confined by fiber reinforced geopolymer adhesive jacket. Variable include jacket materials used (carbon fiber, jute fiber, steel wire mesh, window mesh fabric, (3x3) mm polyethylene mesh, and (4x4) mm polyethylene mesh). The results where it was found that the geopolymer paste is an efficient adhesive with the various types of materials used in the formation of the confinement jackets. Carbon fiber jackets are considered the most efficient in terms of performance compared to other types, but the most expensive at 34$ per square meter. Where the improvement in the (load improvement ratio and deformation capacity) by (3.146 and 3.68), respectively, and the confinement jackets consisting of (jute fiber and steel wire mesh) are considered the most efficient in terms of cost and performance compared to other specimens, with load enhancement by (1.79 and 1.7) and deformation capacity by (2.43 and 16.2), respectively compared with unconfined RC columns. Finally, confinement by fiber reinforced geopolymer adhesive is more suitable for use in strengthening and rehabilitation of RC columns in areas with a hot climate. [ABSTRACT FROM AUTHOR]

The main goal of this paper was to ascertain the exact distribution of one-component polyurethane adhesive in the structure of spruce wood. The used polyurethane (PUR) adhesive meets the requirements set out by EN 301 for bonding structural timber. Fluorochrome Rhodamine B showed sufficient fluorescence when mixed with the PUR adhesive in the amount of 2.5% (diluted in N,N-Dimethylformamide) and subsequent fluorescence microscopy showed the distribution of adhesive in the lumen and in the medullary rays of spruce wood. The adhesive penetration in the transverse direction made its way to the 4th row of wood cells from the bondline. The existence of the adhesive in lumens that were further away was caused by adhesive penetration in medullary rays. Using transmission electron microscopy, the CaCO3 nanoparticles that were deagglomerated in the adhesive using ultrasound were only observed in the lumens of wood cells. The energy dispersive X-ray analysis of the bondline area only detected iodine (dispersed in an amount of 10% and 20% by weight in PUR) in the lumens of the wood cell, and in much higher amounts than in the cell wall. All of the experimental techniques used show that the one-component polyurethane adhesive is not able to penetrate the cell wall structure. [ABSTRACT FROM AUTHOR]

The Bonded repair is broadly used in aging aircrafts to improve the structural integrity of damaged aircraft panels. The aim of this paper is to study the behaviour of multiple cracks on the flat panels using FEA. In this paper two twin collinear cracks are modeled and analyzed in terms of stress intensity factor(SIF). To improve the strength of the panel with multiple cracks it is repaired by adhesively bonded composite patch. It is shown that bonded repair reduces SIF near the crack tips of multiple cracks. Further, the adhesive is the weakest link which undergo failure under the applied load. Hence in this work debonding analysis of patch from the panel is carried out by appling load in increments. From the debonding analysis it is observed that the debonding of patch reduces the strength of repaired panel and leads to rise in SIF at the crack tips. [ABSTRACT FROM AUTHOR]

Aiming at the phenomenon that high-viscosity multi-component adhesives are difficult to control due to viscosity changes, a mechanism using piston to dispense is designed. By analyzing the flow properties of multi-component adhesives, a consistency coefficient related to the mixing time of each component of the glue is introduced to the shear stress of the colloidal by its physical meaning, so the viscosity changes could be characterized during the dispensing process. The model of the dispensing system was established by the viscous fluid mechanics and the estimation function of the flow rate out of needle was given. According to the experimental verification of the specific adhesive, the dispensing system designed in this paper can directly control the amount of dispensing by adjusting the motor pulse frequency and the dispensing time. In the case, the simulation results are basically consistent with the experimental results, and the flow error can be kept within 10-9m³/s to realize the quantitative dispensing of the high-viscosity multi-component adhesive. [ABSTRACT FROM AUTHOR]

A more accurate mathematical model of symmetric double-lap bonded joints is proposed. The symmetry of a structure allows us reduce tear-off stresses in the adhesive layer. Therefore, such structural solutions of joints are widespread. To describe the stress state of the adhesive layer, a two-parameter Vlasov-Pasternak model of the elastic base is used. According to this model the adhesive layer is considered as a mechanical system consisting of a membrane located in the middle of the adhesive layer thickness and elastic elements located between the membrane and the base layers. Tangential stresses are assumed to be constant throughout the thickness of the adhesive layer. Normal (tear-off) stresses in the adhesive are varying throughout the thickness of the adhesive layer. This approach makes it possible to describe various types of boundary conditions for tangential stresses in the adhesive at the butts of the glue line. Namely - the absence of tangential stresses at the edge of the gluing in the absence of the squeezed-out glue excess. Or, the tangential stresses reach their maximum at the edge of the glue line in the presence of the squeezed-out glue excess. The problem is reduced to a system of ordinary differential equations for tangential and normal stresses in the adhesive layer. The system is solved in a matrix way. Verification of a proposed model was performed using the finite element method. The adequacy and high accuracy of the proposed model is confirmed. [ABSTRACT FROM AUTHOR]

In this paper, a dynamic analysis of the free vibration of sandwich beams is performed using the mixed Refined Zigzag Theory (RZT(m)). This recently developed theory has been demonstrated to be very accurate in predicting transverse displacements, fundamental frequencies, buckling loads, and local through-the-thickness quantities such as in-plane displacements and stresses. The beam is modelled using the quadrilateral finite element formulated by Refined Zigzag Theory for plates and the Reissner's Mixed Variational Theorem in order to evaluate both flexural and torsional modes. Results of numerical models are compared with high-fidelity finite elements and those obtained with an experimental hammer test on sandwich beam specimens. It is concluded that the effect of the adhesive layers is crucial to assess the dynamic behavior of multilayered sandwich structures correctly. [ABSTRACT FROM AUTHOR]

Adhesive bonded joints are widely used in various industries like aerospace, automotive, and shipbuilding industries. The main advantage of this adhesive bonding over conventional join methods is that it can join almost all the engineering material without any physical damage to its components. The present study deal with enhancing the adhesive bonded joint strength through the use of adherent temperature. Mild steel is considered as an adherent and Acrylonitrile butadiene styrene (ABS), ARclad 7535, and ARclad 61946 are considered as adhesives. The single lap shear (SLS) joint has been fabricated through the use of an injection mould setup. The bond strength has been evaluated using the tensile shear load capacity and pushout shear strength of the joint. From the test data, it has been observed that the temperature of the adhesive has an impact on the adhesive joint strength. The maximum shear strength has been found with ARclad 61946 tape adhesive activated with heated ABS. [ABSTRACT FROM AUTHOR]

Epoxy resin of the adhesives consist of structural adhesive and no structural adhesive. The one of structural adhesive is the S-CFN epoxy resin. Adhesive bonding is an effective method of joining many materials. In the other hand, welds, bolts, screws, rivets, and other mechanical fasteners are generally used for cold-formed steel joints. The AISI Specification contains only the design provisions for welded connections, bolted connections, and screw connections. The adhesive joint provides a more uniform stress distribution along the bonded area, which enables to have a higher stiffness and load transmission, reducing the weight and thus the cost. Adhesives can bond dissimilar materials in a thin joint efficiently. In this paper, the one of new connections method due to flexure loading on the cold-formed steel in civil engineering structures has been investigated. A research of new joints method due to flexure load on the cold-formed steel has been investigated. The Joint failure was modeled using finite element analysis (FEM) with a cohesive zone model (CZM) approach where the governing parameters were determined from fracture mechanics test specimens. Under middle uniform bending, the S-CFN joint undergoes an elastic stage first, then followed by a plasticity behavior accompanied by the formation of a number of micro cracks on the elements. Using a displacement control of 0.55 mm, the reaction force of beam is 6550 N. Using a displacement control of 0.55 mm, the maximum Von Mises stress (S11) of the S-CFN joint beam is 840 MPa. The types of stress distribution for yield moment based on different locations of the neutral axis. For balanced sections, a part of elements in the top and bottom flanges reach the yield point at the same time. The stress distribution at the S-CFN joint follows the behavior of the damage distribution. The strength capacity of cold-formed steel beam was successfully predicted. The modeling results have a good correlation with the experimental works. Strength capacity deviation of experimental work to FEM is 10.45 % [ABSTRACT FROM AUTHOR]

This work presents the results of the electrical and optical characterization of a new transparent conductive adhesive (TCA) that combines the techniques of spray pyrolysis and a sol-gel like process. This approach is of particular interest since the adhesive itself forms both the electrical and the mechanical interconnection of the bonded sub-cells. The electrical and optical characterization of the developed TCA shows a minimum connecting resistivity of 17 Ωcm² and a simulated reflection at the Si-TCA interface of ≈ 20%. By coating both substrate surfaces with a TiO2 anti reflection coating (ARC), the reflectance at the Si-TCA interface was successfully reduced down to <5%. The efficiency potential of a glued dual junction device was simulated in dependence of the electrical and optical properties of the TCA. The reported values of 17 Ωcm² connecting resistivity and 20% reflection limit the device efficiency to 22.3% (71% of the maximum achievable efficiency). Reducing the reflection to below 5%, as practically demonstrated in this paper, allows to increase this value to 25.3% (>80% of maximum), while additionally reducing the connecting resistivity to 10 Ωcm² or 1 Ωcm² allows for a further increase to 27.3% and 30.0%, respectively. [ABSTRACT FROM AUTHOR]

Adhesive bonding offers many advantages over mechanical fastening, but requires accurate surface preparation, which is widely recognized as the key step to producing reliable and durable adhesive bonds. The use of laser cleaning processes helps to increase the reactivity of the topmost layers of substrates, without affecting the bulk material properties. These methods are often applied to treat polymers, which are generally characterized by high chemical inertia, very low surface energy values and, consequently, poor adhesive properties and this is particularly true for polyolefins. Furthermore, laser treatment provides an alternative to the polluting and less accurate practices such as manual abrasion and primer. In this paper the effect of different laser pre-treatments on polypropylene (PP) and high density polyethylene (HDPE) substrates was studied, by microscopic investigation and single lap- shear tests. As a comparison, untreated and primer treated specimens were also included in the experimental campaign. The results show that laser treatment significantly affected the substrates’ surface and the mechanical properties of adhesive bonded joints. Finding the optimal combination of the working parameters, it is possible to enhance the strength of both untreated and primer-treated joints. [ABSTRACT FROM AUTHOR]

The use of corn husk waste as a sound absorber material with latex adhesive presented in this paper. The acoustical performance measured by using two microphone impedance tube refers to the ASTM-E1050 standard for transfer function-based sound absorption measurement. The composite made of both treated and untreated corn fiber with mass fraction variation of 30% and 50% and the thickness are 2 mm and 4 mm respectively. Treated corn fiber soaked in 5% Sodium hydroxide (NaOH) solution for two hours before it rinsed with the fresh water and dried in open air. The test specimen produced manually. Treated and untreated corn fiber were put separately in the different tray and sprayed with a certain volume of a latex according to the mass fraction variation until the whole fiber completely fitted in the tray before it pressed manually and dried in open air. The similar process has done for both specimens with a thickness of 2 mm and 4 mm. It found that the untreated corn husk fiber (CHF) based composite has a better sound absorption performance compared to the treated one. As the specimen tested for cavity backed structure the sound absorption performance shifted to lower frequency band according to the stiffness of the composite layer and its oscillation increase the viscous damping effect accordingly. [ABSTRACT FROM AUTHOR]

The aim of this paper is to study the effect of substrate roughness parameters on the mechanical and adhesive properties of a coating based on the ETP-2 hot-setting one-component epoxy glue. Specimens with different surface roughness made of an AMg6 aluminum-magnesium alloy plate are used as a substrate. The surface mechanical properties (hardness and reduced elastic modulus) of the coatings are estimated with the use of a Hysitron TI 950 Triboindenter system. Scratch tests are performed with the use of a Zwick-2.5 universal testing machine. The value of the surface energy of adhesive failure serves as an evaluation parameter. It has been found that surface roughness significantly affects the adhesive properties of the ETP-2 one-component epoxy glue; this manifests itself in a change in the surface peel energy and tells on the form of the scratches. The highest adhesive strength is reached when the glue is applied onto a surface with a roughness Ra = 0.35 μm. [ABSTRACT FROM AUTHOR]

This paper addresses the mechanical performance study on epoxy nano-modified adhesives by graphene. The incorporation of graphene inside the epoxy paste used to join the adherents made of unfilled epoxy matrix, leads to an enhancement of joint strength. The experimental results show that the incorporation of graphene inside the epoxy matrix up to 1%wt, enhanced significantly the mechanical behavior of the bonded joints. On the contrary, the addition of 4%wt graphene, degraded the behavior of the bonded joints, probably due to the poor dispersion of the nanoplatelets in the adhesive which led to agglomerations that served as defects. [ABSTRACT FROM AUTHOR]

The aim of the paper is to assess the adhesive shear strength using static tension test. Research was carried out for "clean" adhesive and for adhesive surrounded by artificial saliva. Two kind of tests estimated the influence of saliva on the adhesive connection in dental implant system. RelyX Temp NE was used as the adhesive and stainless steel was used as joined metallic material. Getting the shear strength value allows the authors to continue the research connected with adhesive fatigue. Finally, this knowledge could help with finding the solution for prosthetic crowns falling out trouble. [ABSTRACT FROM AUTHOR]

In this paper, a modified phenolic-nitrile-butadiene rubber heat-cured adhesive was studied. Its adhesive properties to rubber and metal, and its adhesive properties were characterized by peel strength. Self-made modified phenolic resin in the laboratory, using phenol and formaldehyde as raw materials, using ammonia as catalyst, synthesizes a thermosetting high methylol resol resin under alkaline conditions. After the reaction is completed, polyvinyl butyral is added to modify the phenolic resin to synthesize a grafted or block copolymer, thereby changing the brittleness of the phenolic resin and improving the toughness. The self-made modified phenolic resin is mixed well with the kneaded nitrile rubber and other auxiliary agents to obtain a modified phenolic resin-butyronitrile heat vulcanized adhesive. And characterize the bonding performance. [ABSTRACT FROM AUTHOR]

In this paper, the main parameters of laser surface texturing of polymeric substrates have been studied. The final aim of the texturing is to increase the performance of bonded joints of grey-pigmented polypropylene substrates. The experimental investigation was carried out starting from the identification of the most effective treatment parameters, in order to achieve a good texture without compromising the characteristics of the bulk material. For each of these parameters, three values were individuated and 27 sets of samples were realised. The surface treatment was analysed and related to the mechanical characteristics of the bonded joints performing lap-shear tests. A statistical analysis in order to find the most influential parameter completed the work. [ABSTRACT FROM AUTHOR]

Spring up trends and necessities make the pipelines for the brand new Technologies. The same way, Multimaterial structures emerging as fruitful alternatives for the conventional structures in the manufacturing sector. Especially manufacturing of transport vehicles is placing a perfect platform for these new structures. Bonding or joining technology plays a crucial role in the field of manufacturing for sustainability. These latest structures are purely depending on such joining technologies so that multi-material structuring can be possible practically. The real challenge lies on joining dissimilar materials of different properties and nature. Escalation of thermoplastic usage in large structural components also faces similar ambiguity for joining multi-material structures. Adhesive bonding, mechanical fastening and are the answering technologies for multi-material structures. This current paper analysis the prospects of these bonding technologies to meet the challenges of tomorrow. [ABSTRACT FROM AUTHOR]

This paper discusses the use of pulse echo based ultrasonic testing for the inspection of adhesive bonds between very thick composite plates (thickness greater than 30 mm). Large wind turbine blades use very thick composite plates for its main structural members, and the inspection of adhesive bond-line is very vital. A wide gamut of samples was created by changing the thickness of plate and the adhesive. The influence of experimental parameters such as frequency on measurement is studied in this paper. Two different frequencies are chosen, and the measurement error bars are determined experimentally. T-Ray measurements were used to verify and correct results, and conclusions are made based on the combined results. [ABSTRACT FROM AUTHOR]

The possibility of using long range ultrasonic guided wave non-destructive testing for the inspection of metallic structures coated with attenuative layers is extremely attractive. However, the material damping may cause severe attenuation of the acoustic signal, resulting in reduction of the test range. This paper addresses the dispersion of shear horizontal waves propagating in metallic plates coated with viscoelastic layers and the implications for long range testing. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

A description of interface stability is not possible without considering the role of adhesive forces. In this paper the factors determining the magnitude of adhesive forces in adsorbent/adsorbate complexes are discussed, such as the contact zone between adsorbent and adsorbate, and the elastic properties of the adsorbate. [ABSTRACT FROM AUTHOR]

In the last decade, the applications of polyvinyl alcohol have expanded for its notable characteristics like high mechanical properties, chemical and thermal stability, non-toxic nature, film forming capabilities, and low manufacturing cost [1]. Poly-vinyl alcohol has a wide range of industrial application like textile, paper industry, food packaging industry, and as a biodegradable product like backing rolls, adhesives, coatings, surfactant etc. But hitherto, Poly-Vinyl alcohol has certain disadvantages like lower breaking elongation. Also, it is difficult to mold as it is highly viscous nature during the melting process [2]. The present research work is focused on preparation and studying the characterization of Bromelain based Poly-vinyl Alcohol fiber to improve its flexibility, thermal and mechanical characteristics. The fiber thus prepared may be employed in 3D printing application as support structures for modeling intricate shapes, production of bandages or wipes for inflammation wounds, Food packaging containers etc. For the present study, polyvinyl alcohol is tailored with Bromelain (Pineapple enzyme) which is used as an additive in this process and was analyzed in different stoichiometric ratios. Glycerin was employed as plasticizer to improve its flexibility and strength. The results that was inferred from the tests are namely: maximum tensile strength of 7.66 Mpa, maximum brake load and stress from three-point bending test was found to be 35 N and 2.593 Mpa, the temperature range shifts on addition of Bromelain was derived from TG/DTA analysis to understand its ductility, tensile strength, strength enhancement, thermal stability etc., and observation and recording of SEM images for studying its internal structure. Therefore, the tailored feedstock was tested and analyzed to understand the variation in its properties thus broadening its applications. [ABSTRACT FROM AUTHOR]

The production of a cement binder generates a high amount of CO2 and has high energy consumption, resulting in a very adverse impact on the environment. Therefore, use of pozzolana active materials in the concrete production leads to a decrease of the consumption of cement binder and costs, especially when some type of industrial waste is used. In this paper, the hydration of blended cement pastes containing waste ceramic powder from the Czech Republic and Portland cement produced in Argentina is studied. A cement binder is partially replaced by 8 and 40 mass% of a ceramic powder. These materials are compared with an ordinary cement paste. All mixtures are prepared with a water/cement ratio of 0.5. Thermal characterization of the hydrated blended pastes is carried out in the time period from 2 to 360 days. Simultaneous DSC/TG analysis is performed in the temperature range from 25 °C to 1000 °C in an argon atmosphere. Using this thermal analysis, we identify the temperature, enthalpy and mass changes related to the liberation of physically bound water, calcium-silicate-hydrates gels dehydration, portlandite, vaterite and calcite decomposition and their changes during the curing time. Based on thermogravimetry results, we found out that the portlandite content slightly decreases with time for all blended cement pastes. [ABSTRACT FROM AUTHOR]

This paper describes the influence of high temperatures on some physical and mechanical properties of gypsum mixtures. Two gypsum mixtures were designed, first one was composed of gypsum and citric acid and the second one contained standardized sand also. The samples were exposed to temperatures from 50°C to 1000°C. Results show, that strength changes caused by high temperatures are significant in both mixtures and that the thermal shrinkage is reduced by adding sand to a gypsum mixture. [ABSTRACT FROM AUTHOR]

High performance polymer based-cements (i.e. cements having a water to cement ratio, w/a, close to 0.1) almost totally free of defect, have been developed in recent years claiming a great interest for their very high tensile strength compared with traditional cements. These materials can be produced utilizing very simple unit operations and further formed in complex shapes with high surface quality. Indeed these materials have the disadvantage of being too much brittle and for this main reason they are rarely utilized in practice. Toughening the Macro Defect Free Cements (MDF) implies the strict control of the structure. The structure is governed by the process-induced paste modifications. In this paper we show that toughening can be achieved with elastomeric particles having well defined size distribution and physico-chemical characteristics in relation with both the binder polymer and the cement chemistry. [ABSTRACT FROM AUTHOR]

Pressure sensitive adhesives (PSA) were microencapsulated using simple and complex coacervation and aminoplaste. The microcapsules thus prepared were characterized by FTIR spectroscopy, particle size distribution, rheological behavior and peeling tests. The microcapsules were isolated and found to be out of sticky indicating that the PSAs were indeed encapsulated. The prepared suspensions were deposited at the surface of a paper sheets and the dried labels were then pressed against each other. The ensuing complex was then characterized in terms of peeling forces and showed that the encapsulation using aminoplaste technique of a commercial PSA yielded peel energy of 170 J/m2, which constitutes the recovering of about 68% of the adhesive power of the original non encapsulated PSA. [ABSTRACT FROM AUTHOR]

The utilization of agricultural secondary products such as straw or shive can provide a wide range of possible applications in building composites and concurrently decrease the environmental burden. The most frequently studied material of this type is hemp concrete consisting of shive and mineral binder. The use of bio-concrete is though limited by its low compressive strength, which does not reach 1 MPa in most cases. This paper is focused on the design of a new composite material based on bone glue modified with sodium lignosulfonate as eco-friendly binder and rape straw as filler. The experimental results make it possible to identify the optimal straw : bone glue : sodium lignosulfonate ratio. [ABSTRACT FROM AUTHOR]

Sintered Nano-silver (Ag) provides an alternative to current solder material due to its excellent thermal and electrical properties. It has been widely perused in power electronic devices as an interface between substrate and chip to enhance the device performance. This paper also discusses the relationship between porosity and adhesion strength of Ag material for power semiconductor device applications. Two best candidates of material have been selected based on thermal conductivity (> 80 W/mK) and electrical resistivity (< 10-6 Ocm). Material A possess 16% porosity in average when it cured at 250°C for 60 minutes. While for material B shown 22% porosity at the same curing condition. Shear strength test has been performed for this selected materials. Average of 19.7 kg at 25°C and 19.8 kg at 260°C for material A and 15.9 kg at 25°C and 14.9 kg at 260°C for material B were observed in this test. The results show that material A possess higher adhesion strength compared with material B. However, micro-crack on the material surface was observed for material A. [ABSTRACT FROM AUTHOR]

In this paper, some of the recent achievements in surface-activation-based nanobonding technology are described. This bonding technology allows for the combination of electronic, photonic, fluidic and mechanical functionalities into small form-factor systems for emerging applications in health diagnostics and screening, for example. These nanobonding technologies provide void-free, strong, and nanoscale bonding at room temperature or at low temperatures (<200 °C), and they do not require chemicals, adhesives, or high external pressure. The interfaces of the nanobonded materials in ultra-high vacuum and in air correspond to the covalent bonds, and hydrogen and hydroxyl bonds, respectively, which gives rise to excellent bonding properties. Further, these nanobonding technologies are well-suited for the development of low-cost, high-performance miniaturized systems such as biophotonic imaging systems. [ABSTRACT FROM AUTHOR]