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This paper aims to explore the fluid flow in the stereolithography process during the recoating step. The understanding of the flow dynamics can be used as an input for an active control of the resin surface height map. The recoating over a rectangular cavity has been considered to investigate the influence of the cavity depth on the resin surface height map.

Two-dimensional numerical simulations have been used to obtain the flow characteristics as function of the cavity depth. An experimental setup, which mimics the recoating process in the stereolithography process, was used to verify the results of simulations and to test the suitability of the 2D model. The surface height profile along the centreline was measured by a confocal chromatic distance sensor and compared to the 2D numerical results.

By means of computational fluid dynamics (CFD) simulation, the flow in the cavity and the free-surface behaviour of the resin was explained for different cavity depths and confirmed by experiments.

The study is focused only on the cavity depth variation to show feasibility and suitability of the presented CFD model and the proposed analytical expression to estimate the layer thickness.

The proposed approach can serve as a tool for designing the closed-loop control for the recoating system in the next generation of stereolithography equipment.

In the present work, the fluid flow behaviour, a source of significant imperfection in the recoating process, has been investigated during the recoating step over a rectangular cavity.

This study aims to investigate the influence of commercially available resins in water-based magenta pigment inkjet ink formulations on the properties of ink printability and the characteristics of ink application in food packaging. The impact of the resin on the jettability of the existing printability phase diagrams was also assessed.

Inks with different resin loadings were tested for selected properties, such as viscosity, particle size and surface tension. Stability was determined using a Turbiscan AGS turbidimeter and LumiFuge photocentrifuge analyzer. The ink layer fastness against abrasion and foodstuffs was evaluated using an Ugra device and according to PN-EN 646, respectively. JetXpert was used to assess Ricoh printhead jetting performance.

Printability diagrams successfully characterized the jettability of polyurethane inkjet inks on a multi-nozzle printhead and the binder improved droplet formation and printing precision.

Magenta water-based inkjet inks with commercial resins have been developed for printing on paper substrates. To the best of the authors’ knowledge, for the first time, inkjet ink stability was evaluated using the Turbiscan AGS and LumiFuge analyzers, and jettability models were verified using an industrial multi-nozzle printhead.

The purpose of this paper is to investigate the influence of binder effect on tribological behavior of brake friction composite materials: a case study of phenolic resin modified by N-Methylaniline.

Four different friction materials have been fabricated by varying modified phenolic resin content. The samples were prepared by the conventional powder metallurgy methods following ball milling, mixing, pre-forming, hot pressing and post-curing processes. Thermogravimetric analysis was used to determination of the degradation mechanism of organic components and study of thermal stability of the samples. A friction test was carried out in dry conditions using a vertical tribometer. Analysis of worn surfaces was performed using a scanning electron microscope.

The experimental results revealed that the sample containing 25 Wt.% phenolic resin has good mechanical and thermal properties with stable friction characteristics.

This paper presents the effect of N-methylaniline modified phenolic resin on friction composites to improve tribological performance by its thermal properties.

In this paper, we are interested in the forming of composite part by deep‐drawing and laying‐up processes. We present a new finite element model for the simulation of these processes. The augmented Lagrangian approach is adopted to treat the frictional contact between the composite fabric and the tools. It is based on a new way of writing the Coulomb’s friction law. The numerical simulation is carried out with Abaqus/Explicit software and some numerical results are given to validate the proposed numerical method.

The purpose of this paper is to investigate the effect of thermal‐oxidative aging at 150°C on the mechanical properties of carbon fibre reinforced bismaleimide composites.

Composites specimens after thermo‐oxidative aging at 150°C for various times (up to 1,000 h) were investigated by scanning electron microscopy (SEM) for fracture morphology, Fourier transform infrared (FTIR) spectroscopy for chemical structures, and flexural strength test and inter‐laminar shear strength (ILSS) test for mechanical properties.

The results indicated that the mechanical properties of carbon fibre/BMI composites were affected significantly by testing temperature rather than by aging time. SEM results showed that the good adhesion of fibre and matrix resulted in the better mechanical properties. The composites showed lower flexural strength and ILSS at 150°C due to the viscoelastic behaviour of matrix resin. The FTIR spectra confirmed the decomposition of crosslinked maleimide occurred just on the surface of composites during various aging times.

Results indicated that carbon fibre/BMI composites had excellent heat resistance and aging resistance.

Due to their excellent thermal and mechanical properties, the carbon fibre/BMI composites show greater potential for their applications in some extreme fields such as aerospace and machine.

The paper investigates the relationships of the fracture morphologies of composites and chemical structures of matrix resin to the mechanical properties after thermo‐oxidative aging.

Rapid prototyping of ceramics is accomplished with stereolithography by using an SLA machine to build the ceramic green from a UV‐curable suspension of ceramic powders ‐ a “ceramic resin”. Objects are later sintered in a separate furnace to complete the process. Aluminium oxide resins based on hexanediol diacrylate are characterized for curing behaviour by photo‐rheology and differential photo calorimetry with a UV lamp, and with an HeCd laser using “windowpanes”, single strings, and walls.

Stereolithography (SLA) is one of the most important techniques used in rapid prototyping processes. It has a great industrial interest because it allows for dramatic time savings with respect to traditional manufacturing processes. One of the main sources of error in the final dimensions of the prototype is the curl distortion effect owing to the shrinkage of the resin during the SLA process. Presents a study of the influence of different constructive and numerical parameters in the curl distortion, an analysis which was made using the computer code stereolithography analysis program, developed to model SLA processes using the finite element method. Also briefly presents this code.

The tear strength (Ts) is a significant property for any kind of soft polymeric material such as rubber, elastomer, viscoelastic material and its composites, to quantify the suitability of a material for any shape memory applications. Many times, the soft elastomeric polymer material has to be capable enough to deform to a maximum extent of displacement but at the same time, it has to withstand the maximum load without fail. Along with shape recovery properties (i.e. the ability to recover its shape from programmed to the original), the success of the shape memory cycle is mainly depending on its stiffness and strength. It has to resist tear during stretching (i.e. programming stage) as repeatedly subjected to deformation, and, hence, it is important to study the tear behaviour for shape memory polymers (SMPs) and their composites. The purpose of the work is to investigate the effect of parameters on Ts of 4D printed specimen using Taguchi method.

The objective of the work is to tailor the Ts of SMPs by reinforcing the graphene nano particles (GNPs) in a blended photopolymer (PP) resin with flexible PP and hard PP resin. In this study, a total of nine experiments were designed based on the L9 orthogonal array (OA) using the design of experiments (DOEs). All the shape memory photopolymer composite’s (SMPPCs) specimens are fabricated using masked stereolithography (MSLA), also known as resin three-dimensional printing (R3DP) technique.

Specimens are tested using universal testing machine (UTM) for maximum tear force (F_max) and displacement (δ) caused by tearing the specimen to evaluate the strength against the tear. The results showed that the Wt.% of resin blend highly influenced both F_max and δ, while GNPs also had an impact on δ. The specimens are offering more tear resistance for those specimens blended with less Wt.% of flexible PP at the same time the specimens enable more δ for those specimens reinforced with 0.3 Wt.% GNPs at 10-s exposure time. The optimum combinations are A1, B1 and C3 for the F_max and T_s and at the same time A1, B3 and C3 for δ.

To customise the tear resistance of SMPPCs using MSLA 3 D printing, this study suggested a blend of PP resins reinforced with GNPs. This opens up a new path for creating novel, inexpensive multi-functional 4-dimensional (4D) printed parts.

The use of flexible PP and hard PP resin blends, fabricating the SMPPCs specimens using 3 D printed MSLA technology, investigating the effect of GNPs, resin blend and exposure time, optimizing the process parameters using Taguchi and the work were all validated using confirmation tests and regression analysis using test train method, which increases the originality and novelty.

The purpose of this paper is to study the ablative behavior of the silicone resin-coated carbon fabric (coated fabric) that will swell significantly during ablation.

The ablation experiments of three coated fabrics were conducted by quartz lamp radiant. Based on the experimental analysis, a numerical model was proposed for the coated fabrics to study the ablative process in term of the energy balance, mass conservation and thermal decomposition equations.

Results showed that the average relative errors between the simulated temperatures and experimental values of back surfaces of coated fabric 1, 2 and 3 were 10.01, 7.53 and 7.32%, respectively. The average density of silicone resin of coated fabric 1 was reduced by 47.96%, and the closer the distance from the heated surface was, the more the density decreased. The thermal conductivity and specific heat capacity of silicone resin of coated fabric 1 increased with time. Before 50 s, each decomposition rate curve showed an inflection point, at which the silicone resin decomposed most intensely.

Based on experimental observations, the ablative behavior of the material with fixed expansion layer was simulated. In the further research, the moving expansion layer could be considered.

This paper provides the theoretical basis to evaluate the effectiveness of thermal protection materials that will swell during ablation.

In this study, organo clay modified alkyd resins were synthesised and these modified alkyd resins were cured with different ratios of phenol formaldehyde resin. The purpose of this paper is to investigate the physical and chemical properties of the films and thermal behaviours of the resins.

Alkyds formulated to have an oil content of 40 percent were prepared with phthalic anhydride (PA), glycerine (G), coconut oil fatty acid (COFA), dipropylene glycol (DPG) and organo clay. “K alkyd constant system” was used for the formulation calculations of the alkyd resins. Alkyd resins were blended with 30 percent of a phenol–formaldehyde. The films of the alkyd–phenol formaldehyde (A‐PF) resins were prepared from 60 percent solid content xylene solutions by using 50 μm applicators. After the films were cured at 150°C for 2 h in an oven, properties of the films were determined.

The effect of organo clay addition on the film properties such as drying degree, hardness, adhesion strength, impact resistance, water, acid, alkaline, solvent resistance and thermal behaviours of the resins were investigated. The addition of organo clay has a positive effect on the physical and chemical film properties for phenol formaldehyde resin.

The paper reports on a study in which organo clay modified A‐PF resins for manufacturing of industrial baking enamels were synthesised for the first time.