This paper deals with the usage of the injection mould made from the plastic material. This technology is rapidly decreasing the time, necessary to the production of the prototype. This attribute takes nowadays a key role in the industry, especially in the automotive. Technology of using injection moulds from the plastic material (produced by additive technologies) has advantages in the decreasing of the time demands and cost reduction during the production of the prototype part. Unfortunately, plastic moulds have worse surface quality, lower lifetime of the mould (measured in number of produced parts) and more difficulties of moulding process regulation with respect to the metal moulds. This paper is focused on the injection process and it is describing the thermal distribution and specification of the comparable plastic specimen during injection into the metal and plastic mould. The results are the temperature and cycle-times comparisons. The effectivity of cooling is also compared in this work. It is obvious, that the plastic mould has worse results compared to the metal mould. However, this is clearly balanced by the speed of production and price of plastic mould. The prototype of the plastic mould was made from the material PA12GB with usage of 3D printer HP MJF4200

This paper deals with different ways of injection molding. A plastic part can be generally filled many ways. Use of more than one gate is common in a plastic industry. Cascade molding can affect the final properties of the product, especially by the number of gates, timing of closingopening and by the order of individual gates. A simple plastic box is used as a reference part in this paper. It is a longitudinal part with one side longer than the others. There are ribs on the bottom side of the box. The injection system is located on the bottom side of the box. The filling process is considering five individual gates. All possible filling variants are compared with respect to temperature, pressure and number of weld lines. Sequential filling from the central point of the box is the most suitable option.

In this paper, in order to achieve the required properties, several numerical simulations of pressure loading of the welded manhole cover are performed. The analysis of displacement and stress using the finite element method in the software NX Siemens 12 were conducted. Verification of numerical results was done by performing prototype testing consistion of the permanent deformation test and a loading capacity test. The loading capacity test was performed until the fracture occurred. The main goal of the paper is to determine the behaviour of the manhole cover under pressure load. The outcome of the analysis will be used for the design development of similar manhole covers.

Most injection-moulded plastics are injection moulded into moulds made from conventional materials such as steel or aluminium. The production costs of the mould are considerable. 3D printing from plastic can be used for injection moulds to save these costs. This article deals with injection moulding into a 3D-printed plastic mould. The injection insert was produced on a HP Multi Jet Fusion 4200 3D printer. The other part of the mould was made of aluminium. A custom injection mould was designed for the research. One insert was made from plastic, and one from aluminium. Both moulds were injected under the same injection conditions. A comparison of injection moulding into the plastic and aluminium inserts is made in this article. The difference when injection moulding into the plastic insert is explained using the different technological conditions. The part injected into the plastic insert was also different from the part injected into the aluminium insert. The difference is explained in this article. This article also looks at the interface between the injection-moulded part and the plastic insert using an electron microscope. The images taken clarify the differences between injection moulding into a plastic insert and an aluminium insert and the differences of the injection-moulded part from the plastic insert.

This work deals with the infill of 3D printed parts. The goal of this work is to provide recommendations on how much a part should be filled. The recommendation is supported by experiment. The selected load is tensile. Therefore, the geometry of the samples was based on the standard ČSN EN ISO 527-2. Five densities of infill were selected to determine an infill rate from 0 to 100%. In addition to the tensile strength values for each sample, the work also considers economic factors. Characteristic graphs for this issue were constructed at the end of the work. They give an overview of how tensile strength, as well as time, and the cost of 3D printing, change with increasing densities of infill.