A method for representation of component geometry using discrete pin for reconfigurable moulds

Moulding plays a paramount role in our daily life. Traditional moulding is often dedicated and expensive. As the current market trend moves from mass production towards small batch and large variation production, the demand for a mould that can reconfigure itself for different components is greater than ever. The reconfiguration of mould is often realized through discrete pins. Previous research in that field had focused on the hardware of pin actuation in order to move pins up or down to represent different components and lock the pins at certain positions. Little research has been conducted into support software development that enables rapid reconfiguration of discrete pins to represent component geometry.This paper addresses a new method of software development for the reconfigurable mould utilising discrete pins. The overall aim of the method is to provide an interface for generic discrete pin tooling in order to enable quick reconfiguration of the mould to represent component geometry. The software is composed of three parts: part discretization, pin matrix construction and adjustment and pin matrix verification

The evolution of molds in manufacturing: from rigid to flexible

Abstract Nowadays, dynamic products life cycles and increase in the number of product variants have led to reduction in demand per variant. This modern trend is in contrast with the high production volume of manufacturing processes such as injection molding, since they are commonly employed for mass production due to their long changeover time. Traditional rigid molds do not seem to be able to cope with the current industrial and market challenges. Flexible and reconfigurable molding processes, such as the discrete pin tooling systems and changeable molds, appear to be a promising choice for achieving manufacturing economic sustainability. They represent an effective way to save resources and reduce labor costs and setup times. This paper explores the evolution of molds used in manufacturing, from the old models to the current reconfigurable ones through a state-of-the-art analysis of academic research and solutions implemented by industry. Conclusions and insights are presented

Development, modelling and analysis of Vacuum Assisted Multipoint Moulding for manufacturing fibre-reinforced plastic composites

Full version: Access restricted permanently due to 3rd party copyright restrictions. Restriction set on 12.11.2019 by SE, Doctoral CollegeMultipoint tooling is a mould making technology that enables the rapid reconfiguration of a mould to create individual components. It replaces the commonly used, elaborately designed, and costly manufactured solid die, with an array of individually adjustable pins. These pins can be set to represent a large variety of freeform surfaces. An elastic interpolation layer (IPL) is used to smoothen the pin array and forms the actual tooling surface. This technology is well established in sheet metal forming and other areas of manufacturing. However, only little research has been conducted in the area of fibre-reinforced plastic composites. In this thesis, a novel multipoint tooling technology is introduced, that is specifically designed for fibre-reinforced plastic (FRP) manufacturing. Different to existing solutions, this Vacuum Assisted Multipoint Moulding (VAMM) is capable of creating concave and convex geometries on a single sided mould. This enables the use of established FRP manufacturing processes without further adaptation. Two iterations of this technology are developed: A manually adjusted small-scale test bench is used to validate the VAMM concept and conduct experiments on, and a fully automated full scale manufacturing prototype then is used to demonstrate the feasibility of the technology for an industrial application. The elasticity of the IPL introduces two system immanent dimensional defects: the overall shape deviates due to the deformation of the IPL and the punctual support of the interpolation layer leads to a golf-ball-like surface effect. A process model was created to predict behaviour of the VAMM tool and the interpolation layer, and estimate the expected part quality. An iterative shape control algorithm was implemented, to improve the dimensional accuracy of the manufacturing process, by readjusting individual pins in the tool. On this model, a sensitivity analysis was conducted to quantify the influence of the process and pin array parameters on the dimpling of the tool surface. The most important parameters were identified and used in a Metamodel of Optimal Prognosis (MOP). This MOP enables the rapid estimation of the system behaviour. It was used to optimise the VAMM process and the interpolation layer in order to maximise the geometric part quality. With this method two IPL designs, one with a single, and one with two separate layers of silicone rubber, were evaluated. It turned out that the dual layer configuration can handle a 24 % higher process pressure, while using a 9 % thinner interpolation layer, to produce parts similar to the single layer configuration.Huber Kunststoff und Technik GmbHSGL Carbon SEPutzin Maschinenbau Gmb

Rapid manufacturing of vacuum forming components utilising reconfigurable screw pin tooling

Current market trends are moving from large quantity production towards small batch production and mass customization. This has led to the high demand for the flexibility and adaptability of manufacturing technology and systems. Several reconfigurable pin type tooling systems have been proposed and developed to satisfy such demands. However, these reconfigurable tooling systems still suffer from several drawbacks, including difficulties associated with positioning and locking the pins and problems of uneven “staircase” surface effects from relying on discrete finite size pins. The main focus of this research is on building a hybrid vacuum-forming machine system (HAVES) based on reconfigurable screw-pin tooling (SPT)as a test bed for understanding the processes involved in developing this technology and to examine the feasibility of implementing such technology in an industrial system. The SPT used is composed of identical screw pins,which are engaged with each other in an array pattern. By adjusting vertical displacement of the screw pins, a wide variety of component geometry can be formed. The adjustment methodology of the SPT is formulated mathematically in order to help construction of the SPT be parametrical thus enabling automatic CNC G-code generation. The HAVES test bed development involves full machine design and hardware and software integration. The hardware integration task included a CNC controller, drive motors, encoders, milling and screw adjustment heads, SPT, vacuum forming system. The software integration task involved the processing of three-dimensional CAD geometry to automatically generate post processed G codes in order to adjust the screw-pin to the required component geometry and subsequent surface machining for driving the final die geometry and minimize operator intervention. The completed HAVES test bed has been tested for accuracy, repeatability and functionalities with quality good results. An economic analysis has been also conducted to verify the economic feasibility of the HAVES test bed by comparing the cost of making vacuum forming components using a dedicated mould versus using the HAVES test bed

Development of a Fabrication Technique for Soft Planar Inflatable Composites

Soft robotics is a rapidly growing field in robotics that combines aspects of biologically inspired characteristics to unorthodox methods capable of conforming and/or adapting to unknown tasks or environments that would otherwise be improbable or complex with conventional robotic technologies. The field of soft robotics has grown rapidly over the past decade with increasing popularity and relevance to real-world applications. However, the means of fabricating these soft, compliant and intricate robots still poses a fundamental challenge, due to the liberal use of soft materials that are difficult to manipulate in their original state such as elastomers and fabric. These material properties rely on informal design approaches and bespoke fabrication methods to build soft systems. As such, there are a limited variety of fabrication techniques used to develop soft robots which hinders the scalability of robots and the time to manufacture, thus limiting their development. This research focuses towards developing a novel fabrication method for constructing soft planar inflatable composites. The fundamental method is based on a sub-set of additive manufacturing known as composite layering. The approach is designed from a planar manner and takes layers of elastomeric materials, embedded strain-limiting and mask layers. These components are then built up through a layer-by-layer fabrication method with the use of a bespoke film applicator set-up. This enables the fabrication of millimetre-scale soft inflatable composites with complex integrated masks and/or strain-limiting layers. These inflatable composites can then be cut into a desired shape via laser cutting or ablation. A design approach was also developed to expand the functionality of these inflatable composites through modelling and simulation via finite element analysis. Proof of concept prototypes were designed and fabricated to enable pneumatic driven actuation in the form of bending soft actuators, adjustable stiffness sensor, and planar shape change. This technique highlights the feasibility of the fabrication method and the value of its use in creating multi-material composite soft actuators which are thin, compact, flexible, and stretchable and can be applicable towards real-world application

Fabricate

Bringing together pioneers in design and making within architecture, construction, engineering, manufacturing, materials technology and computation, Fabricate is a triennial international conference, now in its third year (ICD, University of Stuttgart, April 2017). Each year it produces a supporting publication, to date the only one of its kind specialising in Digital Fabrication. The 2017 edition features 32 illustrated articles on built projects and works in progress from academia and practice, including contributions from leading practices such as Foster + Partners, Zaha Hadid Architects, Arup, and Ron Arad, and from world-renowned institutions including ICD Stuttgart, Harvard, Yale, MIT, Princeton University, The Bartlett School of Architecture (UCL) and the Architectural Association