Papers by Keyword: Adhesion

Abstract: In the textile industry, various 3D printing technologies are used in fashion design and functional clothing (protective, military and sportswear, including wearable electronics), where the textile substrate is functionalized using additive technology. 3D printing allows the personalization of the product, which translates in the apparel industry in the production of special clothing or the customized production of clothing parts with additional functions at a more rational cost. In our research, we developed and investigated textiles with enhanced protective properties produced by direct 3D polymer printing on fabrics. Twelve woven fabrics were produced in sateen, twill and hopsack with two different weft yarns and in two weft densities. A preliminary T-peel test was used to determine the optimal fabric structure that would ensure maximum adhesion for direct 3D printing of thermoplastic materials on fabric. 3D objects were printed on textile substrates using fused deposition modeling (FDM) technology and thermoplastic acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) filaments. The main objective was to develop functional textiles with improved protective properties. The results of the physical-mechanical and permeability properties of the functional textiles indicate a promising increase in abrasion resistance by at least 70%, although some other properties deteriorate.

Abstract: Different commercial Finite Element Codes proved to be able to describe the mechanical behavior of masonry materials externally reinforced by means of Carbon Fiber Reinforced Polymers (CFRP); the behavior of fracturing materials, characterized by low tensile strength, with adhered strips can be reproduced relying on parameters based on fracture mechanics and the theories of adhesion.In this report the comparison is made of previous experimental test results with numerical analysis, carried out on masonry panels reinforced with CFRP strips and subjected to out of plane actions. The comparison is especially addressed to the evaluation of the post peak branch; in addition to the slopes of the diagram in the pre-critic phase, available kinematic ductility and energy shares both prior and after the peak load were considered in order to interpret the capability of the micro-mechanical model implemented in the FEM Code to account for the local phenomena influencing the interaction between masonry and FRP strengthening systems.

Abstract: On 3DPC, the layers are made through a process where the cement mortar is extruded through a nozzle that follows a predetermined circuit. The classic method of formwork generates a uniform element, while 3D printing generates a non-homogeneous element. Such an innovative process offers new horizons to explore. One of these is the cohesion between the two printed layers and all their mechanical properties. The objective of this work is to study the shear action of two printed layers. To understand the mechanisms, the tested specimens were made in four different ways. The first using a formwork made for the occasion. The second way involves the creation of a printed specimen with a continuous printing path. The third has a time interval of about an hour between the second and third layer. The fourth also has an interval of one hour between the same layers with the addition of a special additive mortar used for the casting recovery. The results obtained reflect on the differences between different specimens and regulations. The differences between the specimens that are studied concern the single printed specimens, the formwork specimens and the printed ones. At a regulatory level, the results of the printed specimens are compared with the regulations concerning the same tests carried out on specimens made of masonry and mortar.

Abstract: The article examines the aspects of predicting the durability of equipment components assembled using polymer reinforcing compounds. A method for calculating the key parameters of joints that have a primary impact on the durability of friction units is presented.

Abstract: Carbide tools with mono/multilayer coating such as TiN, TiC, TiAIN, TiB₂ and Al₂O₃ on inserts of WC-Co generated key success for machining of ferrous materials without coolant/lubrication. So far dry machining of aluminium, manufacturing industries such as automobile and aerospace engineering are facing considerable challenges. Exploration of correct cutting tool for machining of aluminium still persists in the present day context. This paper experimentally investigated the affinity and performance of different cutting tool materials available in local tool shopping center along with the diamond coated tool insert prepared and developed in our own HFCVD reactor for machining of aluminium in dry condition. Finally it is revealed that, due to the low chemical affinity, small magnitude of cutting force, chemical inertness and remarkable anti-welding characteristics, diamond coated tool displayed improved performance as compared to other tools.

Abstract: The article presents a scientific review on the development of composite materials based on polyphenylene sulfide and glass fillers. The main ways (finishing of the filler surface, synthesis of a polymer matrix with functional groups, treatment of the filler and polymer matrix surface with a plasma flow) of increasing interfacial adhesion at the glass fiber-polyphenylene sulfide interface are considered.

Abstract: The paper presents the results of a study of the effect of radio-frequency (RF) plasma modification on the adhesion of ultra-high molecular weight polyethylene (UHMWPE) and polypropylene (PP) fibers to epoxy-diane (ED), epoxy-urethane (EU) and polyester (PES) binder. To assess the adhesive properties, the wet-pull-out method was used, which makes it possible to determine the normalized value of the destructive load of the microcomposite by the force of pulling out the fiber from the polymer matrix.

Abstract: In this work the properties of multilayer packaging materials based on PET/AlOx film with acrylic coating were studied. Multilayer packaging materials were produced on industrial laminators using three different adhesive compositions with different content of reactive groups. It is shown that the peculiarity of the chemical nature of adhesive components affects the bond strength and the seal strength of multilayer packaging materials.

Abstract: The paper presents results of the composite polymer-containing layers formation by plasma electrolytic oxidation (PEO) with subsequent application of the superdispersed polytetrafluoroethylene (SPTFE) aqueous suspension. The corrosion properties and adhesion of coatings have been investigated using potentiodynamic polarization and scratch tests. Incorporation of SPTFE decreased the corrosion current density for composite layers by more than 3 orders of magnitude in comparison with the base PEO-coating and increased the coatings adhesion by 30 %.

Abstract: This paper discusses the results of experimental studies on the selection of the repair mixture compound for recreating the surface layer of the historical brick of the 18^th century architectural monument “Commercial Bank” in Arkhangelsk. According to the research results, it was found that the historical brick has a relatively higher density and increased calcium content than the modern one. The characteristics of the surfaces of the analyzed materials based on the component indicators of specific surface energy showed that the brick of 1859, characterized by the highest degree of destruction, has the maximum value of the polar energy component. This fact may indicate a greater hydrophilicity of the surface in relation to atmospheric water and, as a result, a more intensive degradation process. It is established that the composition of the repair mixture with the addition of brick crumbs in the amount of 50 % has a value of the polar part of the surface tension equal to similar parameters for historical bricks (1786 and 1859) after their preliminary priming. The use of this mixture to recreate the surface layer of the brick will allow atmospheric water to pass freely through the repair compound and the body of the brick, without concentrating on the interface and without causing its destruction and detachment when drying.