The paper describes the mechanical qualities of thermoset – epoxy resin filled with recycled rubber in the form of micro-particles. Such an application of waste can be regarded as material usage which should be preferred to other ways of waste handling. Micro-particles of recycled rubber affect the mechanical qualities of polymer in which they are dispersed. The paper quantifies cohesive and adhesive properties of the filled epoxy resin. Filling polymers – thermosets with waste fillers saves costs, it does not burden the environment, and it is inexpensive. The results described in this paper can lead to enlarging the application areas of recycled rubbers. As the filler, recycled rubber gained by the process of an ecological disposal of tyres by Gumoeko, s.r.o. (private limited company) was used.
This article analyses the optimization of technological and machining parameters when processing thermosets. These parameters were optimized by various tests, e.g. cooking and pressure test. The reason for using the cooking test is that thermosets are low molecular weight compounds and this test provides a picture of their ability to absorb the liquid. The importance of optimizing the parameters is in the fact that after moulding of thermosets, it is not possible to melt and mould them again. Therefore, every moulded piece that does not satisfy the quality conditions is a reject and loss for the company [1,2]. The article shows limiting parameters and contains proposed optimizations for moulding in order to avoid rejects and damage to machines. The three main technological parameters of moulding are examined, namely compaction pressure, mould temperature and moulding time. The external parameter is thermoset temperature [3,4,5].
1 March 2020 in Management Systems in Production Engineering
This article deals with the adjustment of a 3D printer for laser engraving and material cutting. The print head can be fitted with a solid laser diode module, which achieves a compact size while retaining its useful power. Two paths lead to the use of such a concept. It is possible to equip the existing print head with a module, which also brings a number of disadvantages such as, for example, the reduction of the printing space or the need for a suitable mounting design. A more elegant solution is to consider this in the design of a 3D printer and design a system to exchange the print heads for 3D printing and laser engraving. Such a solution allows full utilization of the workspace and simple installation of the effector for the required type of work. According to the installed power of the laser diode, it is possible not only to engrave but also cut material such as thin wood, veneer or acrylic glass. The use of such a machine is not only for graphic elements but for the creation of various stencils, boxes or simple models, which can be made up of plastic-burning pieces. The laser module is controlled by a driver, which is designed for the device. This is connected to a 3D printer control board. It is, therefore, necessary for the control board to have at least two pins, which can be controlled after adjusting the control firmware. Most laser modules are normally equipped with an adjustable lens, which is used to concentrate the focus of a laser for the given distance against the worktop. Thus, the modified 3D printer can perform its function as a multi-purpose CNC machine, while a basic platform similar for both devices is used.
This contribution focuses on hole drilling into grey cast iron and steel 11 523. The most used method of hole machining is the one using a screw drill HSS to reach the accuracy class from IT 11 up to IT 14. Surface roughness ranging between Ra 3.2 μm and Ra 6.3 μm depends on the parameters of the drill used and drilled material. An emphasis is put on the accuracy of shape and dimension as well as on meeting the tolerance limits of holes [1,2,3,4,5]. In most cases, it is possible to reach those conditions using the common methods of hole drilling. Finishing such as roughing, reaming and countersinking is used for meeting high-quality requirements [6,7,8,9].
19 January 2018 in Management Systems in Production Engineering
Increase in the number of orders, the increasing quality requirements and the speed of order preparation require implementation of new solutions and improvement of logistics processes. Any disruption that occurs during execution of an order often leads to customer dissatisfaction, as well as loss of his/her confidence. The article presents a case study of the use of quality engineering methods and tools to improve the e-commerce logistic process. This made it possible to identify and prioritize key issues, identify their causes, and formulate improvement and prevention measures.
This contribution focuses on solving a customer complaint accepted by an organization for manufacturing of automobile seats. The occurrence of nonconformity and causes of undetected nonconformity in the manufacturing process of automobile seats is solved by seven new quality management tools. Causes, effects, activities leading to elimination of the problem, remedies and precautions for possible problems within solution implementation, and time schedule with individual reserves are defined. Results lead to solving the issue both on the part of supplier and on the part of the organization for manufacturing of automobile seats