The use of additive technologies keeps growing. Increasingly, flammable powder materials are also used in additive technologies, and there is a risk of explosion or fire when using them. The current article deals with the determination of fire parameters of a powder sample of polyamide Sinterit PA12 Smoth in accordance with the EN 14034 and EN ISO/IEC 80079-20-2 standards. For that purpose, a sample at a median size of 27.5 µm and a humidity of 0% wt. was used. The measurements showed that the maximum explosion pressure of the PA12 polyamide sample was 6.78 bar and the value of the explosion constant K_st was 112.2 bar·m·s⁻¹. It was not possible to determine the MIT value of the settled dust, since the melting point of polyamide sample is low. The MIT of the dispersed dust was 450 °C. Based on the measured results, it can be stated that the powdered polyamide PA12 poses a risk in terms of explosions and fires. Therefore, when using polyamide PA12 in additive technologies, it is necessary to ensure an effective explosion prevention.

Polymers and their processing by engineering production technologies (injection, molding or additive manufacturing) are increasingly being used. Polymers used in engineering production technologies are constantly being developed and their properties are being improved. Granulometry, X-ray, FTIR and TGA were used to characterize polymer samples. Determination of the fire parameters of powder samples of polyamide (PA) 12, polypropylene, and ultra-high molecular weight (UHMW) polyethylene is the subject of the current article. An explosive atmosphere can be created by the powder form of these polymer materials, and introduction of preventive safeguards to ensure safety is required for their use. Although the fire parameters of these basic types of polymers are available in databases (e.g., GESTIS-DustEx), our results showed that one of the samples used (polypropylene) was not flammable and thus is safe for use in terms of explosiveness. Two samples were flammable and explosive. The lower explosive limit was 30 g·m⁻³ (PA12) and 60 g·m⁻³ (UHMW polyethylene). The maximum explosion pressure of the samples was 6.47 (UHMW polyethylene) and 6.76 bar (PA12). The explosion constant, K_st, of the samples was 116.6 bar·m·s⁻¹ (PA12) and 97.1 bar·m·s⁻¹ (UHMW polyethylene). Therefore, when using polymers in production technologies, it is necessary to know their fire parameters, and to design effective explosion prevention (e.g., ventilation, explosive-proof material, etc.) measures for flammable and explosive polymers.

Metalworking fluids (MWFs) are used during machining to prolong the life of the tool, carry away debris, and protect the surfaces of work pieces. During their lifetime they are prone to intensive microbial deterioration. Microbial contamination can be a problem, primarily because of potentional adverse effect to the operators health and effect on a fluid quality, performance and economics. Bactericides are added to control the growth of micro-organisms. The paper deals with possible utilization of ozone for sterilization of MWFs to avoid presence of biocides. There were tested 16 MWFs for their reaction to ozone application in extreme conditions (concentration of MWF 1% (v/v), ozone concentration 15 g hour^-1, application of ozone 4 hours). After, was realized pilot sanitation of selected in-use MWF for elimination of presence bacterias by applying lower concentration of O₃, there were measured few parameters to control the quality of treatment fluid.

The paper is focused on additive manufacturing (AM) which is the process of producing objects from a three-dimensional (3D) model by joining materials layer by layer, as opposed to the subtractive manufacturing methodologies [1], directly from raw material in powder, liquid, sheet, or a filament form without the need for moulds, tools, or dies. The article demonstrates potential environmental implications of additive manufacturing related to the key issues including energy use, occupational health, waste and lifecycle impact. AM provides a cost-effective and time-efficient way to fabricating products with complicated geometries, advanced material properties and functionality. Based on this review, we identified that additive manufacturing will have a significant societal impact in the near future. A critical technical review of the promises and potential issues of AM is beneficial for advancing its further development.

The exploration of 209 available Material safety data sheets of 85 straight oils, 46 emulsions, 51 semi-synthetics and 27 synthetics was carried out to provide a report on the most used components defined as dangerous substances. As many as 217 of different substances of which 15 were identified as biocides, 17 as corrosion inhibitors or neutralizing agent, 17 were lubricity improvers and 38 different base fluids, lubricity solvents or surfactants, while 93 substances were not identified specifically and 37 substances occurred only once. This article is focused on the list of biocides, neutralizing agents and corrosion inhibitors identified in all types of MWFs and their possible health effects.