Showing papers on "Material flow published in 2001"

Visualization of the material flow in AA2195 friction-stir welds using a marker insert technique

Abstract: The material flow in solid-state, friction-stir, butt-welded AA2195-T8 was investigated using a marker insert technique (MIT). Markers made of AA5454-H32 were embedded in the path of the rotating friction stir welding (FSW) tool and their final position after welding was detected by metallographic means. Changes in material flow due to welding parameter and tool geometry variations were examined. The method provides a semiquantitative, three-dimensional view of the material transport in the welded zone. Because of the placement of markers at different positions at the weld centerline, the material transport in the longitudinal, transverse, and the vertical directions could be studied. Markers embedded in the path of the tool remain continuous after welding. The material transport, which is not symmetrical about the weld centerline, was such that the bulk of the material was transported to a position behind its original position. Superimposed on the primary motion of material in the horizontal plane of the weld is a circulation about the longitudinal axis of the weld. This circulation is found to increase with increasing weld energy.

Finite element simulation of material flow in friction stir welding

Abstract: A brief summary of recent finite element simulation results for the friction stir welding process is presented. The focus of the present study is on the characterisation of material flow around the rotating tool pin. Material flow patterns predicted by finite element simulations are found to compare favourably with experimental observations. The simulation results also reveal that material particles tend to pass and move behind the rotating pin from the trailing side, rather than both sides, of the pin. Possible variations in the material flow pattern due to variations in process parameters are discussed.

Achieving lean supply through agile manufacturing

Abstract: Drawing on results from supply chain modelling and dynamic simulation, presents four material flow principles which can be employed to reduce the bullwhip effect. A case study from the precision mechanical engineering sector is employed to illustrate the effect of rapid response manufacturing and supply chain integration. Analysis of six years of time‐series data indicates bullwhip reduction of up to 58 per cent. These results serve to validate the four material flow principles of selecting appropriate control systems, time‐compression, information transparency, and echelon elimination. They also raise interesting questions concerning the relationship between manufacturing agility and lean supply. For, by attenuating bullwhip the studied company was able to reduce their global inventory by 45 per cent. Thus, by viewing manufacturing in the context of the supply chain as a whole, it is possible to see how agile manufacturing can eliminate sources of variability induced waste; particularly inventory. In thi...

Material Flow Analyses of Noncircular-Shaped Granular Media Using Discrete Element Methods

Abstract: The mathematical development and application of two discrete element methods for analyzing the material flow of granular media is described. These two discrete element methods model the noncircular-shaped particles with analytical surface representations. 2D particles are modeled with a superquadric equation and 3D particles as ellipsoids. Two examples are then presented to illustrate the applicability of these techniques in engineering analysis. These examples include (1) flow of particulate media in a rotating drum; and (2) flow of ore material in an inclined ore pass system.

Thermomechanical oscillations in material flow during high-speed machining

Abstract: This paper presents a nonlinear dynamics approach for predicting the transition from continuous to shear–localized chip formation in machining. Experiments and a simplified one–dimensional model of the flow both show that, as cutting speed is increased, a transition takes place from continuous to shear–localized chip formation in the flowfield of the material being cut. Initially, the process appears to be somewhat disordered. With further increases in cutting speed, the average spacing between shear bands increases monotonically, and the spacing becomes more regular and asymptotically approaches a limiting value that is determined by the cutting conditions and the properties of the workpiece material.

Bulk material irradiation system and method

Abstract: A bulk material irradiation system includes an input for inserting bulk material A bulk material tube is connected to the input, forming a path for bulk material flow A pressurizing assembly is connected to the bulk material tube for forcing the bulk material to flow through the bulk material tube An irradiation assembly provides ionizing radiation to irradiate the bulk material passing adjacent to the irradiation assembly in the bulk material tube Irradiated bulk material exits the bulk material tube through an output

Optimal bidirectional spine layout for overhead material handling systems

Abstract: Overhead automated material handling systems have become the only material handling solution in semiconductor fabs to achieve zero footprint material handling in the expensive cleanroom floor. This paper provides two rectilinear layout configurations, single-spine and double-spine, for overhead track design. Given the locations of loadports and a pod from-to flow matrix, we determine the rectilinear layout of material flow systems with the objective of minimizing the total loaded travel distances. The optimal single-spine problem can be transformed to a known single-facility layout problem and solved with a linear-time algorithm. The optimal double-spine layout is obtained from the optimal single X-spine and Y-spine and is formulated as an allocation problem. We demonstrate the system designs by a numerical example. The resulting spine layouts are then compared with the Minimum Rectilinear Steiner Tree (MRST) and Shortest Rectilinear Flow Network (SRFN) layouts. MRST layout provides the shortest track length while the SRFN layout guarantees the shortest flow distances. The result shows that spine layout is a potential track layout pattern with respect to simplicity, track lengths and flow distances for overhead flow systems.

Towards an integrated description of product, process and supply chain

Abstract: This paper draws upon learning from the aerospace, automotive and retail sectors to provide a framework for the modelling and simulation of supply chains, the processes that occur within them and the products that flow along them. The framework allows an integrated description of products and processes in a supply chain. Such a description could be used to support analyses and simulations that take account of the supply chain and its constituent products and processes. The framework itself is based on a data model that uses a single pattern for the representation of structured data. This pattern is used three times for supply chain, process and product. The descriptive capability of the framework is demonstrated through a case study that is taken from the packaging industry.

Method apparatus for separating unwanted matter from granular material

Abstract: In a method of separating unwanted fine matter from heavier granular matter a flow of the material is produced under vacuum firstly through alternating expansion and contraction passages and then against impact surfaces to cause multiple redirections of the material and separation of the heavier granular material from the material flow

Method of manufacturing a flowmeter for the precision measurement of an ultra-pure material flow

Abstract: A method of manufacturing a Coriolis flowmeter for the measurement of a process material requiring an ultra high level of purity. This is achieved by forming the entire flow path of the Coriolis flow meter from a PFA plastic material that does not transfer ions from the Coriolis flowmeter to the process material flowing through the flowmeter.

Laminated distribution manifold plate system

Abstract: A hot melt adhesive material flow control system comprises an input manifold for receiving a supply of adhesive material, a plurality of flow control valves from which the adhesive material is discharged, an output manifold for heating the adhesive material and conducting the hot melt adhesive material to the flow control valves, a pair of multiple outlet pumps for supplying the adhesive material to the flow control valves, and a recirculation pump for recirculating adhesive material back from the flow control valves to the pair of multiple outlet pumps. A distribution plate and a recirculation plate are interposed between the input and output manifolds and have separate and independent fluid circuits or flow paths defined upon opposite surfaces thereof. In this manner, the number of plates required to define the flow paths is significantly reduced. In addition, the output manifold, the flow control valves, the recirculation pump, and the multiple outlet pumps are independently mounted upon the input manifold so as to simply disassembly and reassembly of the components in connection with maintenance, cleaning, replacement, or repair operations.

Determination of flow stress properties of machinable materials with help of simple compression and orthogonal machining test

Abstract: This paper describes a possible method for predicting values of orthogonal metal cutting properties such as shear angle, cutting force etc., on a basis of the well known Hollomon equation, using a simple compression test in order to avoid any cutting experiments. There are two possibilities: the flow stress properties can be obtained from an independent material test; or by measuring the active and passive cutting forces from the orthogonal machining test itself. This paper is concerned with a material flow stress equation, including the effects of strain (ϵ), strain rate ( ϵ ) and temperature (T), which is one of the five equations that have to be solved in simulation analysis with the finite element method. In finding a solution for those five equations, it is necessary to dispose of flow stress properties by rearrangement of the Hollomon equation and so making it usable for cutting process investigation. The rearrangement is described in this paper.

Modeling continuous flow with discrete-event simulation

Abstract: The paper describes the application of discrete everit simulation to study continuous material flow. Logistics is an integrated part of most manufacturing companies. The purpose of the study is to determine the required logistics operations to allow continuous operations of a chemical manufacturing plant. The application has been used to provide critical decision support.

Design of Components and Layout of Machines for Material Handling

Abstract: Efficient material handling can reduce the amount of work in manufacturing operations. This paper discusses the design of components and the layout of machines from a material handling perspective. A way to reduce the material handling cost without compromising the component functionality is to choose satisfactory design options. The relationships between the design of the components and material handling are analysed to reduce the flow of material in a manufacturing system. In Model I, component routes are selected for a potential manufacturing system when only limited information regarding the layout of the machines is available. The selection of component routes is integrated with the determination of machine locations, the layout of single-row machines, and the layout of multi-row machines with equal areas, respectively, in Model II. Each problem is mathematically formulated and two algorithms are presented with illustrative examples.

Integriertes Controlling für Aufbau, Betrieb und Anpassung von Supply Chains

Abstract: Supply chain management (SCM) stands for the integrated coordination of inter-organizational value chains. Current approaches focus on the integration of material flows based on the positive effects of integrated information systems. The effects of an integrated cash flow management are not considered so far. The paper shows that the integration of material and cash flow management is the next logical step towards the integrated management of supply chain processes. A controlling approach for supply chain cash flows is developed and based on an IS architecture it is shown how the integration of material and cash flow management can be realized.

Modelling and Simulation of a Material Flow System

Abstract: Modern production control systems, e.g. a factory for cars or any other complex industrial good face two major problems. First, the systems need to become more decentralised to increase their availability. Second, the markets force the demand of smaller lot sizes and more flexibility to produce different goods in parallel. Nowadays, re-configuration of production control systems consists of two parallel tasks, i.e. the hardware reconstruction and the software development. However, the software is tested on the real hardware and this raises long down times of the whole system. These down times are the main problem of a re-configuration, because they produce the highest costs. To reduce the testing phase costs, we present an approach to simulate the control software of a production control system beforehand. We illustrate our approach on a model of an existing material flow system, which is a major part of a production control system. Our emphasis in this paper relies on the simulation facilities of the modelled system, whereas our modelling approach is discussed in previous work. We introduce a generic layer architecture and a process oriented simulation kernel for certain hardware properties to get a realistic simulation.

Material flow and inventory control applications: modeling continuous flow with discrete-event simulation

Abstract: This paper describes the application of discrete event simulation to study continuous material flow. Logistics is an integrated part of most manufacturing companies. The purpose of this study is to determine the required logistics operations to allow continuous operations of a chemical manufacturing plant. The application has been used to provide critical decision support.

Measuring material cycling in industrial systems

Abstract: As the negative environmental implications of a modern industrial economy have begun to be recognized, a growing comprehension of the key role of material flows in industrial systems has developed. To this end, several indices characterizing material cycling have been developed. Current indices of material cycling for industrial systems, however, do not effectively measure cycling due to the lack of consideration of both direct and indirect flows in a system. A physical flow modeling approach from ecology, input-output flow analysis, is used in this study to develop cycling indices to address the limited scope of existing measures. The input-output cycling metrics, by definition, measure the percent of flows in a system or in a particular process that are cycled. The input-output cycling indices are compared to traditional industrial cycling metrics in this paper with a set of hypothetical cases. From these comparisons, the traditional cycling metrics are shown to not effectively measure cycling in complex material flow systems.

Gyroscopic mass flowmeter

Abstract: A mass flowmeter having a first embodiment (1500) that uses gyroscopic forces rather than Coriolis forces to determine material flow information, such as mass flow rates, for a material flow. The interior of the flow tube (400) defines a helix element (300) that imparts a spin to the material flow within the flow tube. The flow tube is vibrated transversely by a driver (D). The transverse vibrations and the spin imparted to the material flow together generate gyroscopic forces within the flow tube. The magnitude of the flow tube deflection that results from the gyroscopic forces is related to the magnitude of the material flow within the flowmeter and is measured to determine material flow information. A second embodiment (1600) of the flowmeter further functions to detect the Coriolis forces on the vibrating flow tube and generates material flow information from the detected Coriolis forces. The Coriolis based material flow information and the gyroscopic based material flow information are both applied to associated meter electronics which uses the two sets of information for comparison and error checking and other purposes such as compensation.

Granular podwer bunker with functions of breaking arch, blocking free and adjustable flow

Abstract: The utility model relates to a granular powder storage bin with functions of breaking arch, avoiding block and adjusting flow, which comprises a gear box which is composed of an arch breaker, a sector wheel, a flow control board, a flow controller, a drive device, etc, and forms a storage bin with a charging hopper and a charging barrel When the drive device is started up, the arch breaker, the sector wheel, and the flow control board are rotated, and materials flow out from the storage bin When the flow controller is switched on, material flow can be adjusted The utility model is an environmental protection granular powder storage bin, which combines functions that an arch is broken inside the bin, a blanking hole is blocking free, a level of blanking material is even, and material flow can be remotely controlled and regulated into a whole; besides, the utility model has the advantages of less investment, no noise, no dust pollution, reliable operation, and safe operation, and thus, the utility model is worth being popularized

Pressure molding thermoplastic sheets, e.g. for vehicle components, includes control of local thickness by inducing material flow from other areas

Abstract: A three-dimensional shape (21) is molded from a heated thermoplastic sheet with a punch while held at the edges in a die. The thickness of the article (22) is increased by inducing material flow from an adjacent section (23) by releasing the holding force on it. The adjacent section (23) is eventually cut off as waste. The process can also be used for vacuum forming. Independent claims are also included for the following: (a) the punch is fitted with a cutter that puts a cut into the material in the adjacent section (23), to produce material flow towards the article (22) as the cut opens out into a hole (52); (b) inducing material flow by means of a clamping mechanism for the sheet that locally releases its grip during the forming process.

Apparatus and method for measuring the viscosity of plastic materials

Abstract: In an apparatus for measuring the viscosity of plastic materials including a heatable housing structure, enclosing a controllable material pump for generating a certain material flow, a plurality of capillaries, a melt distributor is provided in the supply line of the material from the material pump to the capillaries with which the material can be directed to either of the plurality of capillaries and each capillary is provided with a pressure and a material temperature sensor providing the values needed for determining the viscosity of the material.