Variable Binder Research Articles

Effective use of adaptive slicing in binder jetting using Taguchi method and surface roughness measurement with image processing

PurposeThe use of additive manufacturing in many branches of industry is increasing significantly because of its many advantages, such as being able to produce complex parts that cannot be produced by classical methods, using fewer materials, easing the supply chain with on-site production, being able to produce with all kinds of materials and producing lighter parts. The binder jetting technique, one of the additive manufacturing methods researched within the scope of this work, is predicted to be the additive manufacturing method that will grow the most in the next decade, according to many economic reports. Although additive manufacturing methods have many advantages, they can be slower than classical manufacturing methods regarding production speed. For this reason, this study aims to increase the manufacturing speed in the binder jetting method.Design/methodology/approachAdaptive slicing and variable binder amount algorithm (VBAA) were used to increase manufacturing speed in binder jetting. Taguchi method was used to optimize the layer thickness and saturation ratio in VBAA. According to the Taguchi experimental design, 27 samples were produced in nine different conditions, three replicates each. The width of the samples in their raw form was measured. Afterward, the samples were sintered at 1,500 °C for 2 h. After sintering, surface roughness and density tests were performed. Therefore, the methods used have been proven to be successful. In addition, measurement possibilities with image processing were investigated to make surface roughness measurements more accessible and more economical.FindingsAs a result of the tests, the optimum printing condition was decided to be 180–250 µm for layer thickness and 50% for saturation. A separate test sample was then designed to implement adaptive slicing. This test sample was produced in three pieces: adaptive (180–250 µm), thin layer (180 µm) and thick layer (250 µm) with the determined parameters. The roughness values of the adaptive sliced sample and the thin layer sample were similar and better than the thick layer sample. A similar result was obtained using 12.31% fewer layers in the adaptive sample than in the thin layer sample.Originality/valueThe use of adaptive slicing in binder jetting has become more efficient. In this way, it will increase the use of adaptive slicing in binder jetting. In addition, a cheap and straightforward image processing method has been developed to calculate the surface roughness of the parts.

Experimental Investigation on Influence of Binder Constituents on Workability, Strength and Microstructure of SCGC

Abstract: The present study investigates the influence of bacteria on varying binder constituents to enhance the workability, strength, and microstructure properties of self-consolidating geopolymer concrete (SCGC). Geopolymer concrete is a sustainable alternative to conventional cement-based concrete, as it utilizes industrial by-products and reduces carbon emissions. The bacterial strains, known for their ability to promote mineral precipitation and improve concrete properties, are introduced in varying proportions to the geopolymer binder constituents. The goal of this experimental investigation is to better understand how Bacillus Cohnii bacteria affect the workability and strength of alkali-activated Self-consolidating Concrete (SCC) mix compositions. Three mix formulations with variable binder contents in the range of 400 kg/m3 and 450 kg/m3 were the subject of experimental research. This research work aims on investigating various binder constituents on Strength, Workability and Microstructure. Three different SCGC mixes were prepared by varying the percentage fly ash and Alcofine in range of 0%, 10%, 30% and 0%, 5%, 5% to the quantity of GGBFS respectively. Alcofine increases final setting time. For all mixes, ambient curing was done. As per EFNARC recommendations, the fresh qualities of SCGC were determined using the Slump test, T50 slump test, L-Box test, V- funnel test, and J-ring test. By conducting compression tests, split tensile tests, and flexure tests after 7, 14 and 28 days, the strength characteristics of SCGC were identified. The SCGC's microstructure and chemical composition were both determined by SEM and EDS analyses, respectively. According to test results, an alkaline solution sample with a 13M concentration and 450 kg/m3 of binder produced the highest compressive, flexural, and split tensile strengths after 28 days producing values of 58.32 MPa, 3.5 MPa, and 4.27 MPa, respectively.

Using adaptive slicing method and variable binder amount algorithm in binder jetting

PurposeBinder jetting is one of the essential additive manufacturing methods because it is cost-effective, has no thermal stress problems and has a wide range of different materials. Using binder jetting technology in the industry is becoming more common recently. However, it has disadvantages compared to traditional manufacturing methods regarding speed. This study aims to increase the manufacturing speed of binder jetting.Design/methodology/approachThis study used adaptive slicing to increase the manufacturing speed of binder jetting. In addition, a variable binder amount algorithm has been developed to use adaptive slicing efficiently. Quarter-spherical shaped samples were manufactured using a variable binder amount algorithm and adaptive slicing method.FindingsSamples were sintered at 1250°C for 2 h with 10°C/min heating and cooling ramp. Scanning electron microscope analysis, surface roughness tests, and density calculations were done. According to the results obtained from the analyzes, similar surface quality is achieved by using 38% fewer layers than uniform slicing.Research limitations/implicationsMore work is needed to implement adaptive slicing to binder jetting. Because the software of commercial printers is very difficult to modify, an open-source printer was used. For this reason, it can be challenging to produce perfect samples. However, a good start has been made in this area.Originality/valueTo the best of the authors’ knowledge, the actual use of adaptive slicing in binder jetting was applied for the first time in this study. A variable binder amount algorithm has been developed to implement adaptive slicing in binder jetting.

DP structure and internally headed relatives in Washo

This paper contributes to recent lines of inquiry addressing the nature of indices in definite expressions. The primary language of investigation is Washo, a North American isolate spoken in the western United States. Building on previous claims about the structure of anaphoric definites, I propose a unified analysis of the Washo DP that lends novel evidence to the claim that indices are best thought of as syntactic objects in their own right, independent from D. The structurally encoded index—introduced by a head idx—is shown to be overtly realized by the morpheme gi/ge in both pronouns and demonstratives, as well as at the periphery of internally headed relative clauses, which are themselves complex DPs. An important aspect of this proposal is the argument that idx can play two related semantic roles: The semantic index it hosts can be interpreted either as a variable, as previously proposed for familiar definites, or itself as a variable binder. The availability of the latter explains the appearance of gi/ge in internally headed relatives. I show moreover that the exponence of idx in Washo is sensitive to the type of complement it takes, a proposal that makes sense of the observed distribution of gi/ge in a range of definite expressions.

PENGARUH UKURAN PERUSAHAAN, PERTUMBUHAN ASSET, PROFITABILITAS DAN PERTUMBUHAN PENJUALAN TERHADAP STRUKTUR MODAL PERUSAHAAN COSMETICS AND HOUSEHOLD DI BURSA EFEK INDONESIA

Capital markets are trading activity related to capital, such as bonds and securities. This market serves to connect investors, companies and government institutions through long-term financial instruments trading. Capital structure decisions are not thorough and will result in high capital that will be received by the company and will affect the decline in profitability, it will threaten the company's financial position. This study has the objective to determine whether there is influence between the size of the company (firm size), the growth of assets (assets growth), profitability (return on equity) and sales growth (sales growth) on the capital structure (debt equity ratio) on a company to go public namely in the sectors listed Cosmetics and Houshold Indonesia Stock Exchange (BEI). The method used is quantitative, meaning researchers will quantify all of the data obtained. The samples used in this study 6 companies with the financial statements between 2010 to 2015. The sampling method in this research is purposive sampling with criteria in accordance with the objectives of the study. Analysis of the data used in this study using a method that consists of classic assumption test, multiple linear regression analysis, and test the hypothesis that simultaneous partial test and test. Results obtained from the partial test showed that the variables significantly influence the size of the company's capital structure. Asset growth variable has no significant effect on the capital structure. Variables significantly affect the profitability of capital structure. Variable sales growth known to have no significant effect on the capital structure. While the results obtained from testing simultaneously is the independent variable (the independent variable) used in this study (size of companies, growth in assets, profitability, sales growth) have a significant effect on the dependent variable (variable binder) that the capital structure.Keywords: firm size, asset growth, profitability, sales growth.

The Effect of Variable Binder Content and Sintering Temperature on the Mechanical Properties of WC–Co–VC/Cr3C2 Nanocomposites

WC powders with an average crystallite size of 10 nm were successfully prepared by ball milling of micron-sized tungsten carbide powders. Grain growth inhibitors (VC and Cr3C2) with concentrations of 0.6 wt% each were added to nanocomposites of WC–9Co and WC–12Co, in both as-received and milled WC. Powder mixtures were then consolidated using spark plasma sintering technique at 1200 and 1300 °C for 10 min under high vacuum and pressure of 50 MPa. The influence of WC crystallite size, Co content, and sintering temperature over microstructure and mechanical properties of the resulting composites were studied through XRD and FESEM. Densification and attained grain sizes of the sintered products were measured by Archimedes principle and Scherrer procedure, respectively. Moreover, microhardness (Hv30) and fracture toughness were measured and compared for each composition to comparatively assess the individual effect. It was observed that the addition of VC and Cr3C2 resulted in decreased densification of the synthesized composites. These grain growth inhibitors were found to limit grain sizes to 131 nm with an average hardness of 1592 Hv30 and fracture toughness of 9.23 Mpam1/2.

Use of a Variable Rate Spray Bar to Minimize Wheel Path Bleeding for Asphalt-Rubber Chip Seal Applications

Chip seals constructed in areas with a combination of high truck traffic volume and high climatic temperatures are susceptible bleeding in the wheel paths and raveling in nonwheel path areas. These failures arise from inherent differences in traffic loading in the two areas. Addressing this problem calls for the binder application rate for the two regions to be varied and using asphalt binders with a high stiffness at high temperatures to prevent bleeding. No well-established design methods that yield a different binder application rate exists. Although equipment for applying variable binder rates exists, there is limited performance data, and no guidelines for calibrating the equipment in the field exist. This paper presents the findings of field studies in which both uniform and variable application rates were used to construct asphalt-rubber chip seals in California. The results show that using different binder application rates in and out of wheel paths can mitigate bleeding and raveling. The paper also presents a new field calibration test method for both conventional and variable rate distributor spray bars.

Multi-Input Multi-Output (MIMO) Modeling and Control for Stamping

The binder force in sheet metal forming controls the material flow into the die cavity. Maintaining precise material flow characteristics is crucial for producing a high-quality stamped part. Process control can be used to adjust the binder force based on tracking of a reference punch force trajectory to improve part quality and consistency. The purpose of this paper is to present a systematic approach to the design and implementation of a suitable multi-input multi-output (MIMO) process controller. An appropriate process model structure for the purpose of controller design for the sheet metal forming process is presented and the parameter estimation for this model is accomplished using system identification methods. This paper is based on original experiments performed with a new variable blank holder force (or variable binder force) system that includes 12 hydraulic actuators to control the binder force. Experimental results from a complex-geometry part show that the MIMO process controller designed through simulation is effective.

Quantitative composition of ancient mortars from the Notre Dame Cathedral in Tournai (Belgium)

A combined micro- and macroscopical approach was implemented for the quantification of the main constituents in a set of 41 ancient mortar samples from Tournai (Belgium). The samples range in age from Roman to Romanesque. The microscopical study consisted of point counting on thin sections prepared from these mortars. If sufficiently large samples were available, Image Analysis on plane polished surfaces was used to quantify the larger objects (> 1 mm) as lime lumps or ceramics. In spite of possible uncertainties, general conclusions about these mortars could be drawn. The Roman and Palaeochristian mortars are all comparable in containing a considerable amount of ceramic fragments, whereas their presence was not systematic during later times. The binder/aggregate ratios varied from 0.4 to 2.3. Romanesque mortars seem to have a less variable binder to aggregate content compared to the older mortar samples.

The optimization of the variable binder force in U-shaped forming with uncertain friction coefficient

In this paper, an uncertain optimization method is suggested to obtain the optimal variable binder force in U-shaped forming. The friction coefficient is regarded as the uncertain coefficient, and the stepped variable binder force model is used. The finite element method is employed to simulate the forming process, and an uncertain objective function which represents the springback magnitude is created. The uncertain friction coefficient is treated as an interval, no need to know its probabilistic distribution. Through a nonlinear interval number programming method, the uncertain optimization problem is converted into a deterministic two-objective optimization problem. A hybrid optimization algorithm based on the intergeneration projection genetic algorithm and neural network is used to obtain the optimum. The presented method is applied to optimize the variable binder force parameters of the model from NUMISHEET’93. The forming quality based on the optimal variable binder force from the presented method is compared with constant binder force. The results indicate that the presented method can find the fair variable binder force to obtain both of the small springback and strain under the uncertain friction coefficient.

Occurrence of thaumasite in gypsum lime mortars for restoration

For restoration purposes, it is essential to have compatible mortars for historic masonry built originally with gypsum mortars. For that reason, gypsum lime mortars with high weathering resistance were developed. Due to the added hydraulic components and carbonate components of the used limes of these mortars, the occurrence of thaumasite can take place. Different mortar mixtures with variable binder contents, using lime with differing amounts of hydraulic components, were prepared and stored under two contrasting curing conditions. Over 90 days of curing, these mortars were investigated using physical–mechanical and chemical–mineralogical techniques. The results have shown that the potential for the growth of thaumasite depends on the composition of the raw materials, especially of the lime. In gypsum lime mortars which were used for restoration purposes, small amounts of thaumasite were also detected, but these small amounts of thaumasite do not reduce mechanical properties. This assumption was confirmed by investigations of gypsum lime mortars, which were exposed outdoors for 13 years.

An inversion procedure for determination of variable binder force in U-shaped forming

In this article, a neural network procedure is suggested to inversely determine the variable binder force in U-shaped forming from the deforming shape of the part. The finite element method (FEM) is used to simulate the forming process. The inputs of the neural network (NN) model come from the deformation shape of the part. The outputs of the NN are the stepped variable binder force parameters. To reach the desired deformation, the NN model will go through a progressive retraining process. A constant binder force simulation method is also recommended to obtain the desired deformation shape. The numerical result for model NUMISHEET’93 demonstrates the efficiency of the present procedure.

The influence of processing variables on the energy absorption of composite tubes

Abstract The aim of this work is to quantify the effect of process-related parameters on the level of specific energy absorption (SEA). This study comprises two sections: the first studies the effect of variable binder levels in the part (0–10% based on equivalent fibre mass). Highly soluble polyester powder binder is added to the resin to simulate the resin state near the end of injection and no binder is incorporated in the preform. The aim for the second part is to study the effect of processing variables on the level of voids in the composite and subsequently characterise the effect of void level on the energy absorption of the parts. Two thermosetting composite materials are examined; a continuous filament random mat (CoFRM) and a non-crimp fabric (NCF) at volume fractions of 22 and 38%, respectively. The parts moulded are generic tubular energy absorbing structures with double cantilever beam (DCB) and in-plane tensile and compressive specimens as secondary tests. An unsaturated polyester resin developed for automotive RTM applications is used for all parts. Mode-I fracture toughness shows significant changes with binder content, however, the SEA of the composite tube is observed to be very tolerant of binder level. Three processing regimes were used yielding void levels between ∼0 and over 10%. The SEA levels for both materials are seen to be tolerant of high void levels allowing potential cost reduction through rapid processing.

Next generation stamping dies — controllability and flexibility

In sheet metal forming, external energy is transferred to sheet metal through a set of tooling to plastically deform a workpiece. The design of the tooling and its associated forming process parameters play important roles in this manufacturing process since they directly affect the quality and cost of the final product. With increasing demands from customers, government regulations, and global competition, the controllability and flexibility of stamping dies have been challenged. In this paper, we will summarize the research activities conducted at the Advanced Materials Processing Laboratory at Northwestern University in the area of sheet metal forming. An overview of our approach towards the system will be given followed by a summary of individual projects in the areas of failure prediction, design and control of a variable binder force, and the segmented die design with local adaptive controllers.

A variable force binder for a draw press

Improvements in manufacturing quality, flexibility, and efficiency require innovations in both tooling technology and process control strategies to speed the transition from art to part. An innovative forming press using a variable force binder (VFB) is proposed as the first step in attaining these goals. This paper presents the design, development and qualification of a VFB for a deep-drawing forming operation. The VFB is capable of varying the binder force profile both spatially and temporally, allowing for a complete customization of the binder force profile. The benchmark axisymmetric cup-forming experiment serves as a proving ground for demonstrating the VFB's performance. Experimental results illustrate the VFB's ability to regulate material flow at localized regions around the blank perimeter. An electrohydraulic control system has been designed and implemented to track predetermined binder force trajectories in real time. Tracking performance is illustrated and explained. A quantitative measurement technique for describing the end product, i.e. the drawn cup, is presented to provide a standard for error analysis and for future work developing closed-loop process control strategies.

A Predictive Tool for Delaying Wrinkling and Tearing Failures in Sheet Metal Forming

In the sheet metal forming industry, there is increasing demand to lower manufacturing costs while also providing a decrease in product development turnaround period as well as lighter weight products. These demands have put increasing pressure on the development and use of predictive numerical simulations and in the design and optimization of new forming technologies. In this paper, two of the primary in-process failure modes of sheet metal, wrinkling and tearing, are examined followed by construction of an advanced forming technology—Variable Binder Force—using numerical tools. Specifically, a methodology of capturing the onset of wrinkling and postbuckling behavior proposed in Cao and Boyce (1997) is used to predict wrinkling failure in conical and square cup forming. The results obtained from simulations and experiments demonstrate that the proposed method is not only accurate, but also robust. A tearing criterion based on Forming Limit Diagrams of non-proportional loading paths is then developed and again shows excellent predictability. Finally, a Variable Binder Force (VBF) trajectory for conical cup forming is designed using simulations which incorporate feedback control to the binder based on the predictions of wrinkling and tearing of the sheet. Experiments using this predefined VBF trajectory show a 16 percent increase informing height over the best conventional forming method, that is, constant binder force. The uniqueness of this paper is that numerical simulation is no longer utilized only as a verification tool, but as a design tool for, advanced manufacturing process with the help of the predictive tools incorporated directly into the numerical model.

Production of TiC-base cermets of different Fe + Ni binder concentrations in alternating layers

A dominant influence on the formation of structure in a P/M composite material of variable binder metal content is played by the extent to which its solid phase is wetted by the liquid: The action of capillary forces tends to equalize the pressure within the system, which leads to migration of the liquid and a partial equalization of the binder metal concentration. The redistribution of liquid is hindered by the formation of a skeleton of sintered TiC particles in the “ceramic” layer. A major role in the process of structure formation in such a P/M material of variable binder metal content is played by the starting porosity, ratio between the volumes of the liquid and solid phases in layers, ratio between the weights of the layers, and formation of a skeleton of solid particles in the “metallic” layer. As a result of this investigation, nonporous specimens have been produced characterized by a steep internal gradient of binder metal concentration.

Binding of progesterone by human uterine cytosol.

Progesterone binding by 100,000 X g cytosols of human myometria from patients undergoing hysterectomy for various reasons was assayed using equilibrium dialysis or DEAE-cellulose filtration. The estimates of high-affinity porgesterone binding obtained by both techniques showed a significant correlation. Dialysis and filtration assays with cortisol competing with [3H]progesterone for binding indicated that the specific progesterone binding by the cytosols was the result of progesterone interaction with two high-affinity constitutents. Myometrial cytosols from tissues under progestin stimulation (secretory endometrium or pregnancy) had low concentrations of progestin binders. Cytosols from uteri with atrophic endometrium showed consistently high concentrations of progestin binders and those tissues under estrogen stimulation (proliferative endometrium or hyperplasia) and variable binder concentrations. No differences were detected between grouped observtions classified into 10 clinical categories. The DEAE-cellulose filtration is an effective method for evaluating progesterone binding which uses well-established statistical techniques and requires less tissue, less time for incubations, and fewer points for reliable analysis than does equilibrium dialysis.