Small Batch Production Research Articles

Numerical and Experimental Study on the Influence of Low Frequency Vibration on Strains of Single Point Incremental Forming

Single point incremental forming (SPIF) is a decent potential procedure appropriate for small batch production. In addition to that, the formability of the material is expanded compared to the other sheet metal forming processes. Meanwhile, the more advanced SPIF process requires perfect comprehension of the material deformation technique. In this paper, the equipment of vibration - sheet metal forming was designed. Finite element model was used to demonstrate and analyze the effect of different frequencies of vibration on the strain distribution in single point incremental forming process. The results show that specific vibration parameters can decrease strain. Moreover, an experimental vibration system using single point incremental forming was designed. The numerical model is primarily supported by test results conclusions from a simple cone of Al1050 aluminum alloy.

In-process measurement of springback in tube rotary draw bending

Rotary draw bending of tubes allows repeatable and accurate manufacturing with narrow bending radii and high production rates, thanks to modern CNC controlled electrical machines. However, springback still represents one the main issues especially in small production batches or when the geometrical and mechanical properties of the raw profiles are not constant within the batch. In-process inertial measurements may allow the close-loop process control of the bending angle and, potentially, offer the possibility to compensate the springback by a real-time tuning of the bending. The paper focuses on a newly developed in-process measurement technique and presents an assessment of in-process inertial springback measurements. The springback of bent tubes is investigated as a function of the measurement gauge position and of the cross-section strain distribution along the bend.

Potentials of Bluetooth Low Energy Beacons for order tracing in single and small batch production

The quality of production planning and control in production companies largely depends on the accuracy of the database regarding the status quo of the production process, as well as the time required for each production step. Especially in single and small batch production, it is difficult to create a reliable database due to the large product spectrum and the variation in the production process. For this reason, this paper examines the potential of Bluetooth Low Energy (BLE) Beacons to create a low-cost real-time locating system (RTLS). In comparison to other existing RTLS solutions like RFID, BLE stands out through very low hardware costs and a high compatibility to almost every mobile device. Through a signal strength based approach in combination with probabilistic neural networks, the RTLS has been able to achieve a positioning accuracy with a mean absolute error of up to 0,74 m in an industry-like environment.

Investigation of the influence of incremental sheet forming process parameters using response surface methodology

New methods in metal forming are rapidly developing and several forming processes are used to optimize manufacturing components and to reduce cost production. Single Point Incremental Forming (SPIF) is a metal sheet forming process used for rapid prototyping applications and small batch production. This work is dedicated to the investigation of the profile geometry and thickness evolution of a truncated pyramid. The influence of process parameters during a SPIF process is also studied. A numerical response surface methodology with a Design of Experiments (DOE) is used to improve the thickness reduction and the effects of the springback. A set of 16 tests are performed by varying four parameters: tool diameter, forming angle, sheet thickness, and tool path. The Gurson-Tvergaard-Needleman (GTN) damage model is used to analyze the damage evolution during material deformation. It is found that the model can effectively predict the geometrical profile and thickness with an error of less than 4%. Furthermore, it is noticed that the forming angle is the most influential parameter on the thickness reduction and springback level. Finally, the damage evolution is demonstrated to be sensitive to the forming angle.

Production scheduling problem of automobile mixed model assembly line

Nowadays, the mode of production has changed from mass production to multi variety and small batch production, and mixed model assembly line has emerged. Mixed model assembly is widely used in automobile enterprises. This paper summarizes the theory and method of automobile mixed model assembly line scheduling, analyzes its characteristics and difficulties, summarizes the related optimization objectives, and introduces the related algorithms, so as to make the scheduling problem of mixed model assembly line more clear.

Transient Process Optimization for Dual-Arm Cluster Tools With Wafer Revisiting

In wafer fabrication, it is imperative to minimize the transient process of cluster tools for the sake of on-demand and preventive maintenance. Due to the trend of multi-type and small-batch production, transient processes appear more and more frequently. Thus, the optimization problems of transient processes have gained increasing attention from both industry and academia. The requirement for wafer revisiting tend to complicate this problem significantly. However, only a few studies take such a challenge for cluster tools with wafer revisiting. This paper focuses on the schedule optimization of transient processes for dual-arm cluster tools with wafer revisiting. To accelerate transient processes, including both start-up and close-down ones, we adopt a program evaluation and review technique to analyze and harness a cluster tool’s state evolution. We then propose computationally efficient algorithms to speed up transient processes. Finally, we provide illustrative examples to show their applications and validate their effectiveness.

Integrated scheduling algorithm for multiple complex products with due date constraints

A new scheduling algorithm based on improved genetic algorithm is presented to solve integrated scheduling problems in small batches of multiple complex products with different manufacturing and due dates. This algorithm virtualizes the schedule of multiple complex products into a single scheduling of one product by establishing a relationship matrix of operation of multiple products to facilitate complete optimization. In addition, novel coding, crossover, mutation, and encoding are designed for the improved genetic algorithm. The proposed integrated scheduling algorithm is tested by existing examples. Experimental results validate the effectiveness and superiority of the proposed integrated scheduling algorithm.

A Research on The Formability of PVC Sheet in Single Point Incremental Forming (SPIF) Technology

Nowadays Single Point Incremental Forming (SPIF) is really a new technology of forming metal sheet after its formation and long development in about five decades. Although it was invented in, 1967 by Leszak, an American inventor, but the applications of the innovative technology have just been popular from 1990 because of the advance of controlling technology. This technology is especially adapted to small batch, unique or single productions. In almost all cases, the workpiece material sheets are metal such as aluminum alloys, bronze, mild steel, stainless steel and even Titanium with lot of researches, papers and thesis... Nonmetal sheets are rarely applied in this technology because of rare application. Nowadays, on the rise of the development of composite materials such as, PVC, thermoplastic resins... that have been a lot of applications on living life and technology. In this paper, we dedicate all of our work in the examination some parameters of forming that influence on the deformable ability of PVC plastic by empirical method under the support of DOE and Minitab software. This paper also provides our own experiences in forming PVC sheet that we had performed in the recent decade.

Design and Implementation of MES for Discrete Manufacturing Workshop of an Aerospace Enterprise

MES belongs to the production execution system of manufacturing enterprises. When applied to the production process, MES can effectively promote the construction of enterprise information and improve the market competitiveness of enterprises. This paper takes the discrete manufacturing workshop of an aerospace company as the research object, aiming at the characteristics of its multi-variety, small batch, and discrete production, combining the current production management status of the workshop and the functional requirements of information business, guided by advanced concepts such as lean production Thought, proposed the MES system architecture design plan, built an aerospace enterprise discrete manufacturing workshop MES. The system mainly includes process management, material management, equipment management, plan management, special process management, quality management, data collection and other functions. The system opens up the production process data link, realizes process visualization, material life cycle management, and fine production equipment management, production planning process control, special process monitoring and tracking, process quality data analysis, and automatic collection of generated equipment data. And the system have formed a digital analysis platform suitable for aerospace discrete manufacturing workshops, solving the actual production management problems of aerospace enterprises’ discrete manufacturing workshops and improving It improves the information management level and production efficiency of the workshop, and provides ideas for the leap-forward improvement and development of the production and manufacturing capacity of the enterprise.

Research on economical sawing equipment for auto roll-forming frame part adapted to fast switching of multiple varieties

Precise angle sawing is an important process to ensure the auto roll-forming frame parts be assembled and welded accurately. Large enterprises can adopt special sawing machine and fixture to meet the requirements. However, this method is not suitable for small enterprises due to its large investment and insufficient flexibility of the manufacturing system. Considering the multi-varieties and small batches production characteristics, economical sawing equipment based on the general cutting machine platform equipped with quick change fixture is introduced. By changing the fixture position on the platform, and replacing a few necessary elements, this equipment can accomplish different angle precise sawing for various auto roll-forming frame parts. Finally the economical technology renovation purpose is realized.

Modular milling cutter with inner-cooling network

The big sized milling cutters are expensive tools and are not appropriate for small batches production. Making these tools more versatile, able to fit to different kinds of processes and shapes of the parts to be machined is a must. As well, cooling the cutting area is very important. The existing end-mill cutters are designed to feed internally with coolant only the teeth on the front side. The paper presents a concept of a modular tool, made of elementary disk cutters, able to be reconfigured to get different shapes and sizes. The main element of novelty the paper claims is the inner cooling system of the complex tool. The special design of the elementary milling cutters and of the shaft they are mounted on make the tool able to lead jets of coolant to every insert, no matter where they are placed, on the cylindrical or on the front side of the milling cutter. A network of channels drilled in the shaft and in the body of elementary milling cutters make this possible. The capability to splash with coolant under high pressure all the cutting edges do not depend on the number of teeth of the tool. Being delivered from inside the cutting tool, the coolant splashes directly on the contact surface between the inserts and workpiece, which makes cooling more efficient.

Recycling system for the FDM/FFF method material designed for small and medium-sized production batches

With fast growing industry in the field of additive technology, possibilities of DIY (Do It Yourself) projects grow as well. This also gives the opportunity for non-expert's users to project and develop some complex products on their own. The reaction was global overflow of the 3D printer's sale worldwide. If we look in the long term, environmental pollution caused by their disposed polymer is their biggest flaw. Recycling process sometimes can be very expensive, and in certain cases unavailable for some users. In this paper, low-cost recycling system for materials that are most commonly used for FDM/FFF method is presented. The main goal was to reduce environmental pollution and 3D printing costs by presenting the possibility of making its own polymer made of scrape plastic. Moreover, this allows users to make their own recipe by mixing different types of scrape polymer, or adding reinforcing material such as chopped dry fibre, metal powder, etc.

Effects of process variables optimization on the quality of parts processed in high speed single point incremental sheet metal forming by ranking algorithm

Single point Incremental shaping (SPIF) is a metal forming process which rose to unambiguous quality toward the commencement of the 1990 s. ISF is an exceptionally limited twisting procedure in which a device, modified to take after in a specific direction, moves over a sheet metal and structures the coveted shape and a prosperous process to manufacture sheet metal parts that is well adapted for prototypes or small batch production. On contrast with the traditional sheet forming technologies this is relatively a slow process and is only profitable for the above mentioned production types but it can be used in different applications in automotive and aircraft industries, in architecture engineering and in medical aids manufacturing. SPIF is a die less method of forming which offers high formability. In this study the SPIF, process parameters such as the spindle Speed 1000/1500/2000 (Rpm), Feed 100/300/500 (mm/min), Tool Diameter 8/10/12 (mm) and step down 0.2/0.4/0.6 (mm) at the specimen interface greatly influence in the Cone shaped Mechanical quality such as Maximum Thinning rate (%), Surface roughness (µm), spring back (%) & formability of Forming for Aluminium alloy AA 8011. The aim of the present work is to study these parameters to build up a cone quality, formed by VMC and to carry out a detailed study of these parameters, experiments were conducted by using the L9 orthogonal array. The output parameters such as affecting mechanical and forming quality were analyzed by TOPSIS and ranking was analyzed.

Manufacture of an aerospace component with hybrid incremental forming methodology

Single point incremental forming is a promising sheet metal forming technique for small batch production. However, the technique is unable to manufacture vertical walls without significant thickness variation and geometrical errors. Two-point incremental forming has the capability of manufacturing vertical walls but requires actuators and intricate rig designs. This paper presents a design facilitating vertical wall manufacturing using a die similar to that used for two-point incremental forming but without actuators. The geometry is created in six passes with a toolpath that can be generated on any leading computer-aided manufacturing software. Manufacturing with this technique reduces geometrical errors in critical areas and improves thickness distribution. This research will be of interest to anyone looking to manufacture prototypes with flat-based geometries in a cost-effective manner.

Inkjet-/3D-/4D-Printed Perpetual Electronics and Modules: RF and mm-Wave Devices for 5G+, IoT, Smart Agriculture, and Smart Cities Applications

With the revolutionary developments in the fields of millimeter-wave (mm-wave) and Internet of Things (IoT) technologies and the billion devices promised to be implemented by the end of the decade, the realization of inexpensive, low-power, and intelligent systems is highly desirable. Additive manufacturing (AM) is a technology seeing widespread adoption due to its ability to enable rapid prototyping for iterative design; its reduced setup costs, facilitating economic small-batch production; and its ability to significantly reduce waste by-products, resulting in both environmental benefits as well as lower manufacturing costs. On the other hand, current lithography-based manufacturing technologies-a huge contributor to the growing RF and 5G wireless electronics industry-require extensive design verification, have longer turnaround times, and produce harmful byproducts. Although AM can offer time and cost benefits under the correct conditions, among the more impactful demonstrations of the manufacturing technology are the novel topologies enabled by design rules that allow feature sets, including nonorthogonal planes, conformal surfaces, multimaterial deposition, simultaneous thick- and thin-film deposition [1], complex 3D structures, integrated voids, and gradient index materials.

Organizational factors for manufacturing defects reduction in small batch production

The study is devoted to the defects organizational causes analysis in the machine building products production process. The companies with the small batch production were taken into consideration. Factors related to the time norms fulfilling percentage, the work rhythm, the consolidation of operations at one workplace, the new technologies introduction and equipment failures were chosen. A preliminary factors selection according to independence criteria allowed us to build a reliable regression model for the defects rate calculating. The main factors influencing the defects rate in small batch production are the time norms fulfilling percentage, the rate of consolidation of operations at one workplace, and the number of new technological processes introduced. This allowed us to offer recommendations on the machining sites work organization. The final operations and productswhich are made from expensive metals should be carried out at workplaces with a low rate of operations consolidation. Also, it is important that the wage system should not contribute to over-fulfillment of norms. The maintenance and repair system should prevent malfunctions during operations fulfilment.

The research on the levelling process of thick slabs based on the electric motor parameters monitoring

For the leveling machines in conditions of a small batch production which is typical for manufacturing sheets of non-ferrous alloys, in particular, titanium, the rollers heating is very influential. In order to expand the technological possibilities of the main equipment in non-stationary thermal working conditions of rollers that is an actual new scientific problem the experimental study of the loading in the hot leveling of slabs made from hardly-deformed titanium alloys was carried out on the 9-roll leveling machine. To achieve this goal the methodology of the complex experimental study of the actual loading definition of the leveling machine drive was developed. The experimental study was carried out for alloys Ti6Al4V (Vt-6s) and PT-3V with the initial heating temperature of the rolled product from 750 to 850°C. The slab leveling process was logged for slabs with the thickness from 20 to 68 mm, the width from 985 to 1720 mm by the number of passes through the leveling machine from 2 to 8. The treatment and analysis of experimental data was conducted on the basis of which the summary of permissibility of assortment expansion of leveling slabs has been formulated.

A Research of Optimization of the Forming Parameters to the Minimum Radial Dimension Error when Forming Sheet by HOTSPIF Technology

Single Point Incremental Forming (SPIF) technology has become popular and familiar for forming sheet, especially in single, small and prototype batch production in many fields such as medicine, aviation, automobile... However, sheet materials with high hardness and durability are difficult to deform and shape because of their high properties. In that case, if we determine a set of logical suitable technological parameters such as temperature T (°C), speed of forming Vxy (mm/min), vertical tool feed z (mm) and tool diameter D (mm) for single point incremental forming at high temperature (Hot SPIF) technology we will get high precision dimension product. The paper presents a study to optimize the main technological parameters when processing non-alloy Titanium sheet materials by HOT SPIF technology to get the smallest error in the radial direction of the product.

Effects of time and temperature during melanging on the volatile profile of dark chocolate

Chocolate made from small-batch production is known for distinct sensory properties that differentiate its products from large-scale production. Specifically, small-batch processing includes a melanging step, a chocolate refining (a process involving time and temperature to refine texture and flavor) process that occurs in a stone wet-grinder. Chocolatiers understand that melanging is essential to flavor and overall quality, however the influence of melanging on the aroma chemistry of the finished chocolate is anecdotal and largely uncharacterized. Here, we evaluated the effects of time and temperature of melanging on the volatile chemistry of the finished chocolate. Specifically, chocolate aroma was profiled using HS/SPME–GC–MS for three different time and temperature combinations. A total of 88 compounds were annotated by mass spectrometry and included a diverse set of chemical classes such as pyrazines, aldehydes, terpenes, alcohols, esters, and ketones. Analysis of variance (ANOVA), principal component analysis (PCA), and partial least squares analysis (PLS) revealed that the overall aroma profile was influenced by the type of melanging, and time had a greater effect than temperature. Example compounds affected by time include 2-methylpropanal, dimethyl sulfide, and benzaldehyde. Particle size was also measured for each sample. Majority particle size was found to be below 25 microns generally at all time points beyond 8 h. Analysis showed significant p-values for the temperature variable for several compounds, but significant p-values for the time variable were apparent for a greater number of compounds. For compounds which showed dependency on both time and temperature, the p-value for the time variable was much smaller in most cases. Both PCA and OPLS analyses suggested the same trends. These data support that time is a critical factor in determining the aroma chemistry of chocolate and affects a diverse set of known flavor active compounds.

The influence of self-lubricating coating during incremental sheet forming of TA1 sheet

Incremental sheet forming (ISF) is an advanced sheet forming process featured with great flexibility, enhanced formability, and high efficiency especially for small batch production. However, the poor surface finish and the large forming load are the main shortages of ISF, especially for the difficult-to-form materials such as titanium sheets. In the present work, a self-lubricating coating was successfully prepared on pure titanium substrates by the atmospheric plasma spraying (APS) process before the forming process for improving the lubrication condition. It was found that the friction is significantly reduced during the forming process when using the self-lubricating coating compared with that with traditional mineral oil as the lubricant. In addition, the wear rate suggests that components’ surface has self-lubrication coating after forming due to excellent wear resistance of the coating. Furthermore, a better external surface quality can be obtained when the friction resistance is lower since the friction plays a crucial role in material deformation. The tensile test suggests that the effect of heating on sheet mechanical properties is opposite to coating on that. Finally, the effects of coating on mechanical properties of the TA1 sheet were investigated and the appropriate parameters for spraying the self-lubricating coating were determined. The present work provides a novel method for enhancing the product quality in ISF through lubrication condition improvement.