Reduce Production Time Research Articles

Prefabricated taper crowns for the retention of implant superstructures: Three-year results of a prospective clinical trial

Statement of problemNonrigid retainer systems for removable implant superstructures are associated with negative effects such as rocking and increased load on the denture base. Rigid retainer systems such as telescopic crowns reduce these negative effects, but their fabrication demands highly skilled dental technicians and is therefore expensive. Whether a protocol with prefabricated retainers will reduce production time is unclear. PurposeThe purpose of this prospective clinical trial was to evaluate a prefabricated telescopic retainer and a treatment protocol including the intraoral luting of a framework. Material and methodsA total of 23 participants (15 women and 8 men with a mean age of 61.6 ±2.9 years) were included. After 3 dropouts, 21 removable dentures (9 mandibular and 12 maxillary) retained by 91 delayed loaded Ankylos implants were investigated. All implants were restored with prefabricated conically shaped abutments (SynCone-abutment). The prefabricated corresponding cone matrix was assembled intraorally into a metal frame with autopolymerizing resin. After a loading period of 3 years, a follow-up examination investigated the fit of the framework, the prosthetic aftercare, the technical failures, and the retention force. A questionnaire was used to evaluate participant satisfaction. In addition, laboratory fabrication time and costs were compared with those of individually fabricated restorations. ResultsOne mandibular implant was lost after 25 months (survival rate, 98.9%). The removable dentures showed no apparent rocking and minimal prosthetic maintenance during the 36-month trial. No dentures required relining. The retention force was scored as good in 17 participants and high (with 6 implants in the maxilla) and low (with 2 implants in the mandible) in 2 participants each. No technical failures occurred. An assessment of laboratory fabrication time and costs revealed reduced time and costs. Patient satisfaction was significantly increased (P<.001) over the entire observation time. ConclusionsThe SynCone retainer presented a time- and cost-efficient treatment option with sufficient long-term retention for removable dentures and high patient satisfaction. Mandibular prostheses restored with 2 implants had limited success.

Multi-Sensor Data Fusion for Real-Time Surface Quality Control in Automated Machining Systems.

Multi-sensor data fusion systems entail the optimization of a wide range of parameters related to the selection of sensors, signal feature extraction methods, and predictive modeling techniques. The monitoring of automated machining systems enables the intelligent supervision of the production process by detecting malfunctions, and providing real-time information for continuous process optimization, and production line decision-making. Monitoring technologies are essential for the reduction of production times and costs, and an improvement in product quality, discarding the need for post-process quality controls. In this paper, a multi-sensor data fusion system for the real-time surface quality control based on cutting force, vibration, and acoustic emission signals was assessed. A total of four signal processing methods were analyzed: time direct analysis (TDA), power spectral density (PSD), singular spectrum analysis (SSA), and wavelet packet transform (WPT). Owing to the nonlinear and stochastic nature of the process, two predictive modeling techniques, multiple regression and artificial neural networks, were evaluated to correlate signal parametric characterization with surface quality. The results showed a high correlation of surface finish with cutting force and vibration signals. The signal processing methods based on signal decomposition in a combined time and frequency domain (SSA and WPT) exhibited better signal feature extraction, detecting excitation frequency ranges correlated to surface finish. The artificial neural network model obtained the highest predictive power, with better behavior for the whole data range. The proposed on-line multi-sensor data fusion provided significant improvements for in-process quality control, with excellent predictive power, reliability, and response times.

Crosslinking of chitosan films processed by compression molding

An alternative approach towards more sustainable chitosan films, through their manufacture by thermo-compression molding, was explore in this work. This strategy permitted the reduction of production times and avoided the use of organic solvents since biopolymer and acid were mixed in their solid form. Furthermore, the acid used as a crosslinker was citric acid, a natural policarboxylic acid, which promoted the reaction with chitosan, as shown by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). This crosslinking reaction led to the formation of homogeneous structures, as observed by scanning electron microscopy (SEM), indicating a good compatibility among all the components of the mixture and enhancing the mechanical properties of the resulting films. In particular, an increase of 80% for tensile strength and an increase of 3000% for elongation at break were observed for the crosslinked films. In addition to the homogeneous surface of citric acid-incorporated films, all the films showed hydrophobic character and the addition of citric acid led to a more amorphous structure. In sum, citric acid-incorporated chitosan films manufactured by compression molding were found to show potential for food and pharmaceutical applications.

Approach for Multicriteria Equipment Redesign in Sterile Manufacturing of Biopharmaceuticals

There is a continuous search for efficient optimization methods in the production of biopharmaceuticals, with a special focus on reducing production time and costs. Pharmaceutical production is currently dominated by batch production processes that have a relatively long downtime for cleaning and reconfiguration of the plant equipment when the product or its format size is changed. The geometry and design of the equipment can strongly affect process performance. This work presents an approach for generating and assessing design alternatives for process equipment used in the sterile filling of biopharmaceutical drug products. A case study is presented based on background information provided by Hoffmann-La Roche for a surge tank used in the filling of liquid vials. Three criteria—namely equipment cleanability, production efficiency, and flexibility—are used to evaluate the proposed shape alternatives for the surge tank. Computational fluid dynamics (CFD) was applied to investigate the flow behavior of cleaning water inside the tank. A trade-off in the results was observed between the different evaluation criteria for the investigated basic shapes. However, it was found that a different part of the tank controls the results obtained for each criterion. An alternative tank design is presented that combines the optimal features to achieve the best possible performance for all assessment criteria. The transfer and application of the established CFD technique to the field of sterile manufacturing of biopharmaceuticals were demonstrated and facilitated by the introduction of appropriate model simplifications. Valuable insights on equipment cleanability and on the measures required to achieve cleanliness were obtained, which proves the importance of the application of such techniques. Redesigning equipment and applying geometrical changes were shown to be effective measures for process performance optimization.

Productivity analysis of machining milled surfaces

Milling is a widely applied procedure because its kinematic versions and applied tools allow the machining of several surfaces and surface combinations. In this study the efficiency of material removal performed by face milling was analyzed when machining aluminum alloys by diamond tools. The analyzed material is the material of an automotive industrial component that is produced in large scale. When producing components in large scale the analysis of material removal efficiency and profitability of machining is particularly important. The efficiency of material removal has a direct impact on the time parameters characterizing the production. The focus of the paper is how the productivity can be increased by the selection of technological data that reduce the machining time of the procedure or increase the values of material removal rate or surface rate. Experiments and analyses were carried out for machining prismatic components among operating conditions. It is found that in a given workpiece-gadget-machine-tool system, a significant reduction in production time and therefore cost savings can be reached by appropriately chosen cutting data while the geometric accuracy and surface quality of the component remain as specified in the part drawing.

On-Demand Intraoperative 3-Dimensional Printing of Custom Cranioplastic Prostheses.

Currently, implantation of patient-specific cranial prostheses requires reoperation after a period for design and formulation by a third-party manufacturer. Recently, 3-dimensional (3D) printing via fused deposition modeling has demonstrated increased ease of use, rapid production time, and significantly reduced costs, enabling expanded potential for surgical application. Three-dimensional printing may allow neurosurgeons to remove bone, perform a rapid intraoperative scan of the opening, and 3D print custom cranioplastic prostheses during the remainder of the procedure. To evaluate the feasibility of using a commercially available 3D printer to develop and produce on-demand intraoperative patient-specific cranioplastic prostheses in real time and assess the associated costs, fabrication time, and technical difficulty. Five different craniectomies were each fashioned on 3 cadaveric specimens (6 sides) to sample regions with varying topography, size, thickness, curvature, and complexity. Computed tomography-based cranioplastic implants were designed, formulated, and implanted. Accuracy of development and fabrication, as well as implantation ability and fit, integration with exiting fixation devices, and incorporation of integrated seamless fixation plates were qualitatively evaluated. All cranioprostheses were successfully designed and printed. Average time for design, from importation of scan data to initiation of printing, was 14.6 min and average print time for all cranioprostheses was 108.6 min. On-demand 3D printing of cranial prostheses is a simple, feasible, inexpensive, and rapid solution that may help improve cosmetic outcomes; significantly reduce production time and cost-expanding availability; eliminate the need for reoperation in select cases, reducing morbidity; and has the potential to decrease perioperative complications including infection and resorption.

Retos y desafíos de la educación superior para responder a la demanda de profesionales en la subregión del Oriente Antioqueño Colombiano

El objetivo de la investigación fue el de establecer las necesidades de formación a nivel de educación superior, en la subregión del oriente antioqueño colombiano. Esta se adelantó a través de una revisión bibliográfica, contrastada luego con un acercamiento cualitativo a los empresarios de sectores productivos, como: Tecnologías de la Información y la Comunicación, TIC, Agro y Aeropuertos, Puertos y Terminales Aéreas. Se encontró que, aunque la mayoría de los programas de educación superior ofertados son pertinentes, no responden a las demandas emergentes de competencia laboral requeridas por los sectores productivos de la región. El principal desafío de los nuevos programas académicos es el aprovechamiento de las TIC, para el mejoramiento de la productividad empresarial. En este sentido, la apuesta debe ser por programas de formación con una mirada transdiciplinar, que posibiliten mejoras en los procesos productivos, diseño de programas a la medida, reducción de tiempos de producción, optimización y automatización de procesos.

Test Stand for the Experimental Investigation of Turbochargers with 3D Printed Components

Abstract The paper discusses the universal test stand which allows determining the characteristics of turbochargers. Currently, there are works carried out in the world aimed to develop innovative fluid-flow machines, made partly with the use of rapid prototyping technology. This type of manufacturing technology allows reducing production time and costs in comparison to conventional methods of prototyping. This article also discusses start-up tests of the experimental test stand using a commercial turbocharger and the comparison between calculated and experimental results. In this paper, there are also described some modifications of the test stand, made prior to the start-up test, which were necessary to get more accurate characteristics of turbochargers. This work is an introduction to the investigation on turbomachines, whose elements were manufactured using the rapid prototyping technology.

Design and Manufacturing of Micro-Turbomachinery Components with Application of Heat Resistant Plastics

Abstract The article discusses issues associated with the use of modern plastics for the construction of high-speed fluid-flow machines. Currently available plastics exhibit high chemical resistance as well as dimensional and shape stability across a wide temperature range. This allows them to be used for manufacturing components of micro turbomachinery, thereby reducing production time and costs. This article discusses the criteria for the selection of plastics suitable for a particular machine, namely micro turbogenerator operating in the organic Rankine cycle (ORC). In addition to the initial selection of materials based on their chemical and physical properties, strength calculations of selected turbogenerator subassemblies were carried out. The obtained results confirmed that some plastics can replace traditional materials used in the manufacture of ORC turbogenerators. This concerns, in particular, the components of the microturbine blade system. After the manufacture of a trial series of such components, it became apparent that, with appropriately chosen plastics, it is possible to shorten the machining time and reduce production costs, all while maintaining the required dimensional tolerances. The results obtained so far prove that it is possible to use plastics to produce components of modern turbomachines, for instance, parts of high-speed microturbines that have to withstand high operating temperatures.

Experimental investigations on the incremental sheet forming of commercial steel ASTM A653 CS-A G90 to predict maximum bending effort

Single point incremental sheet forming stands out mainly by using traditional CNC machines to produce small batches of parts or customized products. Thus, any excessive force in the process may compromise the integrity of the machining center or even damage the component itself, limiting its formability. Hence, this work presents the design of experiments to investigate the behavior of mechanical forming forces and optimize the process. The main goal was to build a mathematical function by regression analysis that best represents the theoretical model. The equation proposed here allows to locate and estimate the maximum effort Fz_peak based on five input parameters: tool diameter; wall angle; sheet thickness; vertical step size; and tool feed rate. At the same time, determine the set of data that maximize the required formability. The test was carried out using a carbide coated tool K40 and a commercial sheet steel ASTM A653 CS-A G90. The following were found: the feed rate is not significant and can be maximized to reduce production time; the tool diameter and wall angle are significant, and they have a slight influence on the forces and both depends on the design area; the vertical step size is significant and the most important parameter to leveling the process to reach maximum formability. Finally, the sheet thickness is obviously significant; however, it is also specified by the design.

A novel 6-axis hybrid additive-subtractive manufacturing process: Design and case studies

Additive manufacturing has been employed in numerous areas owing to its advantages of fabricating complex geometries and creating less material waste. Nevertheless, parts manufactured by additive manufacturing processes tend to have poor surface quality and low dimensional accuracy. To overcome the limitations of additive manufacturing technologies, the favorable capabilities of subtractive manufacturing, i.e., high surface quality, can be integrated to form a hybrid process. A novel 6-axis hybrid additive-subtractive manufacturing process is proposed and developed in this paper. The hybrid process is realized using a six degrees of freedom (DOF) robot arm, equipped with multiple changeable heads and an integrated manufacturing platform. Based on the obtained results from different case studies, the hybrid additive-subtractive process has shown to have potentials in reducing production time, fabricating parts with better surface quality by removing the staircase error, manufacturing high quality freeform surfaces through the dynamic adjustment of tool axis direction, and eliminating the need for support structure because of the 6-DOF flexibility.

The perspective of using 3D-modeling in the designing of technological solutions for chassis design

In the modern world 3D-technologies plays an important and significant role in almost every spheres of human life. This is particularly pronounced in industry. Perspectives of using these technologies allow optimizing the production of products of varying complexity, reducing production time and reducing the possibility of defects in the early stages of designing. For the showing the application of 3D modeling its application in vehicle designs considered in this paper. For this purpose a vehicle chassis is designed and then the tension distribution of chassis in the bump condition and its analysis are provided.

Method of calculation overall equipment effectiveness in fertilizer factory

This research was conducted at a fertilizer company in Sumatra, where companies that produce fertilizers in large quantities to meet the needs of consumers. This company cannot be separated from issues related to the performance/effectiveness of the machinery and equipment. It can be seen from the engine that runs every day without a break resulted in not all of the quality of products in accordance with the quality standards set by the company. Therefore, to measure and improve the performance of the machine in the unit Plant Urea-1 as a whole then used method of Overall Equipment Effectiveness (OEE), which is one important element in the Total Productive Maintenance (TPM) to measure the effectiveness of the machine so that it can take measures to maintain that level. In July, August and September OEE values above the standard set at 85%. Meanwhile, in October, November and December have not reached the standard OEE values. The low value of OEE due to lack of time availability of machines for the production shut down due to the occurrence of the engine long enough so that the availability of reduced production time.

Fast Synthesis of Spherical Silica Aerogel Powders by Emulsion Polymerization from Water Glass

AbstractIn this study, a fast synthesis technique for silica aerogel powder was proposed that reduces the length of the tedious surface modification and solvent exchange processes. Spherical silica aerogel powder could be fabricated by an emulsion polymerization method from water glass and n‐hexane. A stable water glass‐in‐hexane emulsion with a water glass to hexane ratio of 5:5 was fabricated using the surfactant, sorbitan monooleate (Span80). It was found that acetic acid and isopropanol catalysts for the hydrolysis and condensation of water glass droplets dispersed in the emulsion were crucial for the synthesis of the spherical silica aerogel powder with a narrow particle size distribution and for reducing production time. In addition, the particle size of the spherical silica aerogel could be controlled by changing the water glass droplet size.

IBS: An economic perspective on mechanisation and automation

Incorporating mechanisation and automation in the construction process is necessary to reduce production time and costs, improve working conditions, avoiding dangerous works, allow work to be performed where people cannot do, and eventually will increase performance, and product quality. This paper discusses a preliminary study on enhancing the quality of life by adopting Industrialised Building System (IBS) focusing on the economic perspective on the use of mechanisation and automation. The sustainability principles in the IBS have always maintained the harmony between environment and construction, improve human self-respect and encourage economic development to strive for a better quality of life.

Structural Model for Fibre‐Reinforced Precast Concrete Sandwich Panels

Fibre‐reinforced concrete (FRC) has been used in numerous types of precast elements around the world, as has been shown that reductions in production costs and time can be obtained; however, there is little experience of this material in Uruguay. Therefore, our study analysed the feasibility of its utilisation in this country. This paper reports on the development of a simple analysis model that is useful for the design of FRC precast elements. The model efficiency was evaluated through its application to a practical case study—vertical precast concrete sandwich panel systems tested by bending. Three different types of reinforcement were analysed: synthetic fibres, metal fibres, and steel mesh. With the developed model, the cost‐efficiency of different panel geometries and amounts of reinforcement were evaluated. The model allowed consideration of the contribution of the fibres to withstand internal tensile forces of the panels and therefore be able to substitute for the steel mesh in the panel wythes. It was found that it was possible to optimise panel reinforcement and geometry, thereby reducing wythe thickness. Besides the reduction in production time, it was possible to achieve cost savings of up to 10% by replacing steel mesh with fibres and of more than 20% if the geometry was also modified.

Experimental study of the use of refrigeration systems as cooling and heating systems in the production process of the VCO

Coconut oil extracted from the coconut milk obtained from fresh coconuts s often called virgin coconut oil (VCO). VCO is beneficial to health as an anti-oxidant and can lower HDL cholesterol in the blood while increasing blood LDL levels. In Indonesia most of VCO being produced on a small scale of home industries. Its production capacity still needs to be increased by improving production processes and implementing an appropriate technology accordingly. This research aims to conduct a study on making small-scale production machinery needed to produce VCO with reduced production time and improved quality of VCO in accordance with ISO 7381 quality criteria. The experimental results of the VCO machine has been develop and tested show good Coefficient of Performance of the system in amount of 3.93 and 2.8 for heating and cooling system respectively. Temperature of the VCO cooling chamber can be maintained in the range of 8°C to 10°C, as well as for heating, the reactor temperature can be maintained from 39°C to 42°C. The expected goal of this research developing a prototype of VCO production machine was done with ability to provide more efficient production process able to increase volume of VCO result by 23%.

Performance analysis of a FLP problem using AHP-TOPSIS and FAHP-FTOPSIS

To meet the ever-increasing demands of manufactured product and rising competition among rival industries; well-organised, inexpensive, efficient and effective facility layout plan (FLP) needs to be equipped. FLP decision problem entails to assignment of departments, positioning of machine equipments, material handling decisions, design as well as planning of production operations, required for higher productivity with better quality and improved efficiency. It is estimated that 70% of the total production cost is due to material handling (including equipments, direct-indirect labour costs, etc.), within a facility layout however, better facility placement can contribute to up to 30% less operating expenses. ABC Pvt. Limited was considered for FLP problem because of improper material flow through shop floor and extended transportation time for material transfer. The objective of this research is to analyse and compare the performance of existing Front Axle Division Layout of ABC Pvt. Limited with the four proposed design alternatives using AHP-TOPSIS and FAHP-FTOPSIS, thereby reducing production time, material handling distance and material handling cost (MHC). The management of the case study company has adopted the analysis results as the basis to their future layout planning problem. The practical contribution of this research can, thus, be justified.

Performance Analysis of a FLP Problem using AHP-TOPSIS and FAHP-FTOPSIS

To meet the ever-increasing demands of manufactured product and rising competition among rival industries; well-organised, inexpensive, efficient and effective facility layout plan (FLP) needs to be equipped. FLP decision problem entails to assignment of departments, positioning of machine equipments, material handling decisions, design as well as planning of production operations, required for higher productivity with better quality and improved efficiency. It is estimated that 70% of the total production cost is due to material handling (including equipments, direct-indirect labour costs, etc.), within a facility layout however, better facility placement can contribute to up to 30% less operating expenses. ABC Pvt. Limited was considered for FLP problem because of improper material flow through shop floor and extended transportation time for material transfer. The objective of this research is to analyse and compare the performance of existing Front Axle Division Layout of ABC Pvt. Limited with the four proposed design alternatives using AHP-TOPSIS and FAHP-FTOPSIS, thereby reducing production time, material handling distance and material handling cost (MHC). The management of the case study company has adopted the analysis results as the basis to their future layout planning problem. The practical contribution of this research can, thus, be justified.

A compact and scalable fabrication method for robust thin film composite membranes

A compact and scalable membrane fabrication method proposes an environmentally friendly process intensification in terms of efficiently reduced production time, chemical consumption, and wastewater generation, resulting in a robust membrane.