Search

The purpose of this article is to investigate the effect of sandblasting surface treatment, before the bonding process, on the strength of the adhesive joints of the three types of aluminium alloy sheets. Three values of pressure were used during the sandblasting process, i.e. 0.41 MPa, 0.51 MPa and 0.56 MPa. After mechanical treatment, the samples of aluminium alloys sheets were degreased three times with acetone by immersion. The elements were bonded with single-lap joints using two components epoxy adhesive. After the curing process, the shear strength tests of the aluminium alloy adhesive joints were conducted, according to the DIN EN 1465 standard. The surface topography of all samples was measured, and the most important surface roughness parameter and its waviness were determined. Based on the experimental results, it was noticed that, among others, while using the same pressure value during sandblasting of different aluminium alloys, the roughness parameters Ra and Rz of the obtained surfaces differed depending on the type of alloy. It is also to notice that more than two times strength of the joints was obtained by those made of the aluminium alloy sheet, which was subjected to heat treatment.

The aim of this study was to determine the effect of abrasive treatment as a method of surface preparation on the strength of adhesive joints made of galvanised steel sheet. The subject of experimental investigations were adhesive joints of samples made of galvanised steel sheet DX51, 0.7 mm thick. The surfaces of the samples were abraded with coated abrasive tools of grain sizes P120, P180, P220, P400 and P600, and then degreased with PIKKO extraction solvent. The surface properties in terms of roughness and 3D surface topography were examined using a Hommel-Etamic T8000 RC120-400. The adhesive joints were made using Epidian 53 epoxy resin adhesive composition and IDA curing agent in a 100:40 weight ratio. Samples of single-lap adhesive joints were tested for strength on a Zwick/Roell Z150 testing machine, in accordance with the PN - EN 1465:2009 standard. The tests showed that the samples mechanically processed with an abrasive tool of P220 gradation show the best strength properties. Adhesive joints, in which the surface of the joined elements was mechanically processed with an abrasive tool of P120 gradation, obtained negative results. The obtained test results were subjected to further statistical analysis. The Shapiro-Wilk test was used to assess the normality of the distribution. Then, the non-parametric Kruskal-Wallis test and the median test were applied, which showed that there were no significant differences in the results obtained between the adhesive joints whose surfaces were prepared with P220 and P400 abrasive paper, i.e. both methods of surface preparation can be considered as the most favourable among those analysed during the adhesive bonding of DX51 galvanised sheets.

The article presents the results of a statistical analysis of adhesive joints with identical structural and material factors in relation to technological factors. Four types of adhesive joints were made: butt joints, lap joints, scarf joints and wedge joints. The joined materials were pine and oak wood. Each type of adhesive joint was joined in the following wood configurations: pine-pine, pine-oak, oak-oak. The technological factors were the type of adhesive, the humidity of the wood and the surface preparation of the samples. The U Mann-Whitney test was used to perform the statistical analysis. Results of statistical tests showed the influence of the used adhesive on pine-oak butt joints and wood moisture on pine-oak butt joints. Furthermore, the effect of wood configurations on the strength for each of the tested adhesive joints was compared using the Dunn’s statistical test. The test showed that there were not statistical differences between the joints in configurations pine-pine and pine-oak.

A series of new polymeric materials consisting of polylactide (PLA), polyethylene glycol (PEG) and berberine chloride (B) was evaluated. PEG was incorporated into the polymer matrix with the aim of obtaining a plasticizing effect, while berberine was added in order to obtain antibacterial properties in formed packaging materials. Materials were formed using the solvent-casting procedure. Fourier transform infrared spectroscopy and scanning electron microscopy were used so as to establish the structural changes resulting from the introduction of berberine. Thermogravimetry and differential scanning calorimetry were applied to study the thermal properties. Further, mechanical properties and differences in colour and transparency between the control sample and films containing berberine were also studied. The recorded data indicates that berberine formed a network on the surface of the PLA-based materials. Introduction of an active compound significantly improved thermal stability and greatly affected the Young’s modulus values of the studied polymeric films. Moreover, it should be stressed that the addition of the studied active compound leads to an improvement of the antibacterial properties, resulting in a significant decrease in growth of E. coli and the S. aureus bacteria cultures.

The aim of this work was to investigate selected biological and toxicity properties of cured epoxy resin-based compounds based on a bisphenol A epoxy resin, cold-cured by a polyamide and containing two types of metal powders (aluminum and copper). This study involved cytotoxicity analysis, pH measurements, absorbance measurements and sterilization. The cytotoxicity analysis was conducted to determine the harmful degree of the cured epoxy resin. Aimed at identifying toxic agents in cured compounds, the cytotoxicity analysis involved absorbance measurements in an entire wavelength range. Cytotoxicity and absorbance results demonstrated that the extracts of all the tested resin samples had no cytotoxic effects on the cells of living organisms. The absorbance values obtained over the entire wavelength range did not point to the formation of aggregations, which proved that no toxic agents harmful to living organisms were extracted from the resin samples. Based on the results obtained, it can be concluded that all tested compounds, based on epoxy resins, which are also used as adhesives in various applications, are essentially safe materials when using such formulations in a cured state.

One of the most important design factors in the constitution of adhesive joints is the correct choice of adhesive. Currently, there is a full range of options on the commercial market in this regard, but there is increasing research into modifying adhesives for specific engineering applications. The aim of this study was to analyze the effect of physical modification with fillers on the properties of the adhesive composition and the adhesive joints. The adhesives used in the study were a composition of Epidian 5 epoxy resin and PAC curing agent modified with 1% montmorillonite, 5% calcium carbonate and 20% activated carbon. The adhesive compositions in the cured state were subjected to strength tests and SEM and DSC analyses. Using these compositions, adhesive joints of EN AW 2024 T3 aluminum alloy sheets were also made. The tests carried out showed that, due to the use of different fillers, their effects on certain properties of the adhesive compositions are different types. It was shown that physical modification of the adhesive composition does not always result in positive effects. The study also attempted to determine the correlation between the properties of the adhesive compositions in the cured state and the strength of the adhesive joints.

The paper aims to determine the mechanical properties of the adhesive joints made with acrylic pressure-sensitive adhesives. Two types of double-sided acrylic pressure-sensitive adhesive tapes are used. Three construction materials are used to prepare the adhesive joints: structural steel sheet (C45), aluminium alloy sheet (EN-AW 5754), and titanium sheet (Grade 2). Strength tests of adhesive joints made with the pressure-sensitive adhesive tapes are carried out both after conditioning time at room temperature (23 °C) and subjected to thermal shocks (500 cycles: +60 °C / –40 °C). Strength tests are carried out based on the DIN EN 1465 standard on a Zwick/Roell Z150 testing machine. The main conclusion from the tests carried out was the positive effect of thermal shocks on the mechanical strength of joints bonded with pressure-sensitive adhesive tape.

The aim of the paper is to determine the influence of the surface treatment on the adhesive properties of steel sheet surfaces and the strength of the adhesive joints of steel sheets. The paper also aims to assess the degree of steel sheets’ surface treatment in the bonding process. Due to the many methods of surface treatment and types of materials, the assessment of the surface treatment method is extremely important in adhesive processes. Two variants of the surface treatment were used: without a paint coating and with a paint coating, divided into two groups (without degreasing and with degreasing). Additionally, in the case of the analysis of the steel samples without the paint coating, mechanical treatment was applied. Two-component epoxy adhesive, prepared on the basis of bisphenol A and a polyamide curing agent, was used to prepare the single-lap adhesive joints of the steel sheets. The tests determined: (i) the adhesive properties of the steel sheets’ surface based on the measurement of the contact angle of polar and apolar liquids (including wettability, work of adhesion, and surface free energy), (ii) surface roughness parameters (PN EN ISO 4287), and (iii) mechanical properties (load capacity and shear strength) of the steel sheets’ adhesive joints (EN DIN 1465). Contact angle measurements of the steel sheet surfaces showed that the polar liquid better reflects the obtained strength results of the analyzed adhesive joints than the apolar liquid. Furthermore, better wettability of the surface of steel sheets with both polar and apolar liquids was obtained for samples whose surface was subjected to degreasing. It can also be concluded that the wettability of the surface can be used as one of the indicators of the degree of the surface treatment for the bonding process.

The use of lathe chucks in machine building companies is the result of a great deal of work and the develop-ment of technical thought. Due to the progress and the possibility of increasing efficiency and at the same time relieving people from work that requires a lot of effort, especially physical effort, the use of better and more efficient production methods is a target that should be pursued nowadays. In the manufacturing pro-cess, these objectives can be achieved with the use of dedicated equipment. The following work will present an example of a lathe chuck specialized in turning operations. The aim of the work was to use a universal chuck as a base for designing and manufacturing a specialized chuck so that it is possible to mount rope wheels with diameters from 240 to 580 mm. This would eliminate the necessity of time-consuming changeo-vers. In addition, it is assumed that the handle must meet the conditions imposed by the limited number of tools and the working dimensions of the machine. The machining process itself was also important, where the most advantageous solution was to perform most of the operations in one clamping.

A huge amount of waste comes into being from tyres which cannot already be used for their purpose. There are many ways how to utilize this waste but material recyclation is a priority. Waste tyre rubbers can be processed into a form of granulate which can be used into polymeric composite materials. This research deals with possibili-ties of tyre waste composite material utilization in areas distinguished for wear. The aim of the research was an assessment of a usage possibility of rubber powder (RP) coming into being from tyre recyclation process as a filler into a thermosetting matrix from firm Havel Composite applied into composite boards made by a vacuum infu-sion. The research focused on an evaluation of wear by friction against loosely fixed abrasive particles according to GOST 23.208-79, hardness and interaction of the matrix and the reinforcement by means of SEM analysis of the polymeric composite materials reinforced with waste microparticles arisen from tyre recyclation process. Research results proved a positive influence of the filler on the improvement of the wear resistance depending on the size of active rubber powder.

The paper evaluates the effect of the surface treatment on the strength of single-lap adhesive joints made of C45 steel. The samples were joined using an adhesive composition consisting of Epidian 57 epoxy resin and PAC curing agent. The study also used Greinplast mosaic plaster with a grain size of 1.0-1.6 mm as coating. The experiment was carried out for 3 variants of joints: sheet/sheet, sheet+plaster/sheet+plaster, sheet/sheet+plaster. Each variant was divided into 3 methods of surface treatment. The strength tests were carried out on the Zwick/Roell Z150 testing machine. The roughness parameters of the surface’s samples were measured using the HOMMEL TESTER T1000 profilometer.

The aim of the study was to compare the welded and adhesive joints made of polypropylene pipes. The pipes were butt jointed. Two pipe diameters were used: ø20 mm and ø25 mm. Welded joints were made by hot gas welding, while adhesive joints were made by two epoxy adhesive compositions. The base for both compositions was Epidian 6 epoxy resin, which was mixed with IDA and TFF curing agents in recommended quantitative ratios. Experimental tests consisted in determination and comparison of strength properties of the made joints, therefore the analyzed joints were subjected to destructive strength tests, which determined their tensile strength in accordance with ISO 527-1 standard. On the basis of the obtained results it was observed that welded joints obtained the highest average strength. The lowest strength was characteristic for adhesive joints made with Epidian 6/TFF/100:27 adhesive. The obtained results were subjected to statistical analysis, which showed that the strength of ø20 mm diameter pipe joints did not differ significantly from the strength of ø25 mm diameter pipe joints, comparing the results for each type of joint with the assumed level of confidence α = 0.05.

The article defines rather complex and unpredictable movement of the dough in the gap between the working rolls and suggests the calculation for the optimal parameters for rolls shape (particular-ly the parameters and their effect on the dough). The functional dependences of the permissible diameter and the gap between rotating rollers are substantiated. The block diagram of the geomet-ric bounding parameters of the gradient field of the viscous fluid flow is proposed herewith and the equation on the basic constructive parameters (h, r) affecting the pouring process efficiency is presented. Analysis of experimental results revealed that the main features of the machine provide the necessary stable shape products and good rheological parameters of these products. Rheologi-cal testing indicators allow for a rational approach to decision to operate a rolling process. At the same time they improve quality control methods and will have an impact on design parameters of rollers and chambers’ modes. The proposed method not only allows obtaining a predetermined pressure, but also allows defining the optimal shape of the gap, wherein the pressure gradient is constant.

The aim of the present article was to analyse the adhesive joints of different types of the furniture boards used for the furniture production. The present article included a comparative analysis of the adhesive joints of the particle board and the medium-density fireboard (MDF) pressed with the following types of film: A 0.3 mm thick PVC film and a 0.8 mm thick acrylic film, made with use of a single-component reac-tive hot-melt adhesive based on the PUR 706.2 ME polyurethane. It was observed that, among others, the adhesive joints made of the particle board with a pressed 0.3 mm thick PVC film and the adhesive’s basis weight of 24 g/m2 is characterised by better strength properties than the adhesive joints of the particle board with the adhesive’s basis weight of 48 g/m2.

In this study, the influence of sandblasting process parameters as a surface preparation method on the strength of single-lap adhesive joints of EN AW 2024 T3 aerospace aluminium alloy sheets was determined. Eleven sets of sandblasting parameters were used, which were determined according to a determined experimental plan. The variable factors in the sandblasting process were pressure, nozzle distance, and workpiece displacement speed. The sand jet incidence angle was constant. Garnet 80 E+ was the abrasive material that was used. The joints were made using an epoxy adhesive composition of Epidian 5 epoxy resin and a PAC curing agent. The influence of the surface preparation method on the surface roughness and contact angle to determine the surface free energy was evaluated. The shear strength of the adhesive joints was also determined, which finally allowed the evaluation of the applied surface treatment variants. The obtained results were subjected to statistical analysis, which indicated that the highest shear strength of the adhesive joints was obtained for samples whose surfaces were treated by sandblasting at parameter configurations in which the pressure was 5–6 × 105 Pa, the distance between the nozzle and the sandblasted surface should not be greater than 97 mm, and the speed at which the workpiece moves in relation to the nozzle should not be greater than 75 mm/min.

The purpose of the paper is to determine the impact of surface treatment on the strength of adhesive joints, made from various steel sheets. Two variants of the surface treatment steel adherends were used: without the varnish coat and with the varnish coat, using three polymer-based varnishes (a simple, a hybrid, and a gel). Two types of the adhesives were used to prepare the adhesive joints: a single-component cyanoacrylate adhesive and a two-component epoxy adhesive. A strength test of the adhesive joints (EN DIN 1465 standard), a coating adhesion test (ASTM D3359-B standard), and surface topography, as well as surface roughness, parameters (PN-EN ISO 11562, PN-EN ISO 4287, and PN-EN ISO 25178 standards) were used. Based on the strength tests, it was observed that the adhesive joints, with the hybrid varnish onto the adherend’s surface, achieved markedly lower shear strength. The best results, in terms of the adhesive joint strength, made using the cyanoacrylate adhesive were achieved for the joints where the adherends were coated with a simple varnish, while in the joints made using the epoxy adhesive, the highest shear strength was achieved by the joints of sheets whose surfaces were coated with the gel varnish.

The parameters of surface roughness Ra, Rz and Rmax as well as surface topography Sa, Sz, Sp and Sv of the two-layer sandwich structure composed of an AW-2024 T3 aluminum alloy (Al) and a carbon-fiber-reinforced polymer (CFRP) were measured to determine an impact of the machining configuration (arrangement of the materials forming a sandwich structure) and the type of tool (presence of the tool coating) on the quality of the surface obtained through circumferential milling. The measurements revealed that milling produced different values of surface roughness for the aluminum alloy and the CFRP composite with values of 2D and 3D surface roughness being higher for the composite layer. The highest value of Ra of 1.10 µm was obtained for the surface of the CFRP composite using the CFRP/Al configuration and a TiAlN-coated tool. The highest values of the Rz (6.51 µm) and Rmax (8.85 µm) surface roughness parameters were also obtained for the composite layer using the same machining configuration and type of tool.

The aim of the article was to determine the compressive strength and compressive strain of an unmodified and a modified epoxy compounds containing a montmorillonite filler, as well as to determine the effect of temperature and an aging time on the mechanical parameters of the considered epoxy compounds. The subject of the research was both the unmodified and the modified adhesive compounds. The unmodified epoxy compounds were made in four variants, which included the epoxy resins based on a bisphenol A as well as the curing agents: a triethylenetetramine and a polyamide curing agent. The modified compounds containing the montmorillonite filler, were also made in four variants. The samples were subjected in a thermal chamber at 80 °C for 1 and 2 months and in a thermal shock chamber in the temperature range from − 40 °C to 80 °C for 1 and 2 months. The reference samples were seasoned at room temperature 20–25 °C. The epoxy compounds samples were subjected to the compression strength tests in accordance with ISO 604 standard. The compressive strength is influenced by the environment and temperature, the aging time and the presence of the modifying agent. The epoxy compounds subjected at elevated or variable temperatures have higher compressive strength than the reference epoxy compounds. The operation of the climatic chamber or the thermal shock chamber makes the samples more deformable than the reference samples.

The aim of the present article is to compare the strength of the adhesive lap joints of the selected materials used in aviation. The joints were made in the similar and dissimilar systems with the use of three epoxy adhesives. Three different adherends were used: the EN AW-7075 aluminium alloy, the aramid-epoxy composite and the carbon-epoxy composite. Three adhesive compounds based on the Epidian 53 epoxy resin and three types of curing agents: two amine curing agents—Z1 (triethylenetetramine curing agent) and IDA, and one polyamide curing agent—PAC (polyaminoamide C) were used to make the adhesive joints. Three variants of similar joints and two variants of dissimilar joints were prepared for the tests. The shear strength was defined according to the ISO 4587 standard, with the use of Zwick/Roell 150 testing machine. In addition, the joined materials’ surface roughness was measured. Based on the strength test’s results, it was observed that the highest strength was obtained by the adhesive joints made with the Epidian 53/PAC/100:80 adhesive compound and that, in the majority of cases; similar joints show higher strength.

The influence of temperature on the fatigue properties of pseudoelastic NiTi under low-cycle fatigue are investigated. Tests were performed under the uniaxial tensile deformation (pull-pull) at 0°С and 20°С which is above the austenite finish temperature. Experimental results indicate that the fatigue life of NiTi alloy increases with the decrease of test temperature from 20°С to 0°С in the case of presenting the results depending on the strain range and Odqvist’s parameter. Regardless the test temperature, with the increase of number of cycles to failure, the stress and strain ranges, as well as the dissipation energy decrease, and the total dissipation energy and Odqvist’s parameter increase. The slope of the fatigue curves of NiTi alloy is greater at the temperature of 0°С in comparison with the 20°С in the case of employing the stress range, strain range, Odqvist’s parameter, and total dissipation energy as the failure criteria, and is less while employing the dissipation energy as the failure criterion.

Adhesive bonding technology present a perspective method of various materials bonding and replacing conventional bonding e.g. welding. A geometric shape modification of bonding material and an adhesive reinforcing by glass fibres to increase tensile strength of adhesive bond was subject of this research. The bonding material was modified into preformed angles 5°, 10°, 15°, 20° and adhesive bond with 0° was se t as the etalon. The adhesive was modified by glass fibre with weight 80, 110 and 160 g.m-2. The research proved tensile strength increase from 4 to 48% by various preformed adherent angles. The research also proved tensile strength increase from 4,8 to 93,7% by adhesive reinforcing with glass fibres with various weight. Statistical analyse proved significant difference between measured values on significance level 0.05 (p < 0.05) i.e. influence of adhesive bond modification on mechanical properties was proved.

Despite the fact that Titanium alloys are frequently used in medicine, aviation industry and also in machine manufacture due to their strength and resistance against external influences. Moreover, their innovation to obtain better and more suitable parameters still proceeds. Regarding their mechanical properties, they are considerably less machinable which affects surface integrity of a machined area. That is why a proper selection of a machine tool and cutting conditions are extremely important. This paper deals with a finishing grinding process of the material VT9 by means of specific grinding wheels 5TG and DIA under specified cutting conditions. Based on experimental verifications it can be defined which grinding Wheel is more suitable in specific conditions with an impact on integrity of the ground surface. From the standpoint of grinding parameters such as surface roughness, thermal impact and acting of cutting forces as well as arising residual stress in the surface layer are key for surface integrity.

The objective of this study was to determine the effect of selected curing conditions on the mechanical properties of the cured adhesive compounds and adhesive joints made with these adhesives. Fou...

The aim of this study is to determine the effect of cataphoretic and powder coatings and also the method of application the primer on the adherends surface on the strength and failure modes of EN AW-5754 aluminium alloy adhesive joints. The study is performed on lap joints made of EN AW-5754 aluminium alloy, subjected to three different types of surface treatment; namely a) polyurethane cataphoretic coating, b) powder coating based on black mat RAL 9005 UL polyester resin and c) no coating. The tested adhesive joints were made using a one-component polyurethane adhesive Terostat 8596, which was dedicated for automotive and cured under a constant load of 0.018 MPa at 20 ± 2 °C. In addition, this study investigates the effect of the application of Terostat 8519P adhesion promoter which is a liquid polyurethane-based primer containing solvents and which is corresponding to Terostat 8596 polyurethane adhesive. Terostat 8519P adhesion promoter was applied in two different ways: a) to one substrate and b) to both substrates. The produced adhesive joints were subjected to strength tests using the Zwick/Roell Z150 testing machine. The examination of fracture in the tested adhesive joints was performed in accordance with the EN ISO 10365 standard. The shear strength results have demonstrated that both the method of application of the adhesion promoter (Terostat 8519 P) and the presence of cataphoretic coating had an influence on adhesive joints strength. The use of the adhesion promoter significantly affects the strength of both uncoated EN AW-5754 aluminium alloy adhesive joints and the adhesive joints subjected to powder coating. The use of the adhesion promoter has a less significant effect on the cataphoretic-coated samples.

The influence of chromate, phosphate, glossy and brightening coatings on the performance of adhesive joints of hot-dip zinc-coated steel sheets was compared. The contribution of this study has been to compare the adhesive joint strength in adherends with two types of coatings: steel sheet with zinc coating and additional coating. Two types of bisphenol A (BPA) epoxy adhesives were used to assemble the joints, that were subject to shear stresses. The surface of the adherends was described in terms of surface roughness parameters. The highest value of the shear strength was recorded for the adhesive joints of the hot-dip zinc-coated steel sheets with chromate passivation and brightening. The poorest performing joints were of the glossy galvanized steel sheets.

A series of new films with antibacterial properties has been obtained by means of solvent casting method. Biodegradable materials including polylactide (PLA), quercetin (Q) acting as an antibacterial compound and polyethylene glycol (PEG) acting as a plasticizer have been used in the process. The effect of quercetin as well as the amount of PEG on the structural, thermal, mechanical and antibacterial properties of the obtained materials has been determined. It was found that an addition of quercetin significantly influences thermal stability. It should be stressed that samples containing the studied flavonoid are characterized by a higher Young modulus and elongation at break than materials consisting only of PLA and PEG. Moreover, the introduction of 1% of quercetin grants antibacterial properties to the new materials. Recorded results showed that the amount of plasticizer did not influence the antibacterial properties, it does, however, cause changes in physicochemical properties of the obtained materials. These results prove that quercetin could be used as an antibacterial compound and simultaneously improve mechanical and thermal properties of polylactide-based films.