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PL
Kartonowe opakowania wielomateriałowe (KOW), znane powszechnie jako opakowania Tetra Pak, stanowią fundamentalny element dzisiejszego przemysłu spożywczego. Choć mają one wiele zalet i zastosowań jako opakowania do żywności, to istotnym problemem jest ich późniejszy proces recyklingu, w którym udałoby się odzyskać wyjściowe surowce, w szczególności polietylen i folię aluminiową. Przedstawiono proces technologiczny przetwarzania laminatu LDPE-Al otrzymanego po procesie rozwłókniania opakowań KOW, opracowany przez naukowców na Politechnice Śląskiej, a następnie rozwinięty przez firmę Altempo Sp. z o.o. jako proces SolvtempoTM. Efektem prac było wybudowanie i uruchomienie instalacji pilotażowej na terenie zakładu o mocy przetwórczej powyżej 300 kg/h.
EN
R&D cooperation of the Silesian University of Technology and the Altempo company resulted in the implementation of the technol. for processing LDPE-Al laminate, obtained after the fiberization process of multi-material cardboard packaging. Altempo continued research to further develop the technology under the name Solvtempo™ process. The result of the work was the construction and launch of a pilot installation at the Altempo plant with a processing capacity of over 300 kg/h.
EN
The aim of this study was to determine the impact of additions of tungsten carbide and silicon carbide microparticles to the lubricant used in the burnishing process on the tribological properties of friction pairs. The cylinders made of AISI 1045 steel constituted a workpiece. Burnishing was made with a lubricant the SN150 base oil with addition of tungsten carbide and silicon carbide microparticles. The tested materials were burnished with forces of 1000 N and 1500 N. Before and after the burnishing process, the surface roughness and hardness of the tested materials were measured. The study also presents the results of tribological properties of friction pairs with the tested structural materials. It was found that the addition of tungsten carbide microparticles to the base oil in the burnishing process can result in improved surface quality and reduced surface roughness. The results also confirmed the effect of addition of tungsten carbide and silicon carbide to the lubricant used in the burnishing process on tribological properties.
PL
W artykule przedstawiono wyniki analiz porównawczych zachowania się dachów hal wielkopowierzchniowych poddanych niezamierzonym obciążeniom. W aspekcie bezpieczeństwa analizowano: wartość przenoszonego przez nośne elementy konstrukcyjne dachu dodatkowego obciążenia (ukrytego we współczynnikach obliczeniowych), poziom zapasu obciążenia zewnętrznego w funkcji wytężenia elementu, a także zachowanie konstrukcji w przypadku wystąpienia wysokiego obciążenia termicznego (sytuacja pożarowa). Uzyskane wyniki, zarówno stanu granicznego nośności (SGN), stanu granicznego użytkowania (SGU) jak i analizy w wyjątkowej sytuacji obliczeniowej, wskazują na większy poziom bezpieczeństwa w użytkowaniu hal dachów wielkopowierzchniowych wykonanych w technologii strunobetonowej w odniesieniu do dachów wykonanych z zastosowaniem kratownic stalowych, które potraktowano jako konstrukcyjne elementy porównawcze.
EN
The article presents the results of comparative analysis of the behavior of roofs of large-scale halls subjected to unintended design loads. In terms of safety, the following aspects were analyzed: the ability of the load-bearing structural elements of the roof to handle an additional loads (not taken into account at the design phase), the level of external load reserves as a function of the element’s effort, as well as the behavior of the structure in the situation of high thermal load (fire situation). The obtained results, both the ultimate limit state (ULS), the serviceability limit state (SLS) and the analysis in an exceptional situation, indicate a greater level of safety in the use of halls with large-area roofs constructed by using pre-stressed concrete technology, in comparison to roofs made using steel trusses, which were treated as comparative structural elements.
EN
This paper describes findings in the surface topography of Ti6Al4V alloy after finish turning process under dry and MQL (minimum quantity lubrication) machining. The research was fulfilled in the range of variable feeds per revolution of 0.005-0.25 mm/rev and cutting speeds of 40-100 m/min using the depth of cut of 0.25 mm that fits finish processing conditions. The test plan was developed on the way to use the Parameter Space Investigation (PSI) method. The topography features were measured by a Sensofar S Neox optical profilometer using the Imaging Confocal Microscopy technique. Ra parameters and surface roughness profiles as well as 2D images and contour maps were analyzed. Under the studied machining conditions, lower Ra roughness parameters are obtained in the feed rate of 0.005-0.1 mm/rev and cutting speeds of 40-60 m/min. In comparison with dry machining, up to 17% reduction in Ra parameter values was obtained using the MQL method and vc = 70 m/min and f = 0.127 mm/rev as well as vc = 47.5 m/min and f = 0.22 mm/rev. Depending on the machining conditions, peaks and pits as well as feed marks typical for the turning process are observed on the machined surfaces.
EN
Titanium alloys belong to the group of difficult-to-cut materials, machining of which leads to a number of challenges including large thermal loads on the cutting inserts and difficulties in obtaining a high quality machined surface. Great cutting forces, in turn, result in increased energy consumption. Therefore, it becomes important to attempt to reduce the amount of power consumed during machining, which can be achieved, among other things, by reducing the value of the coefficient of friction in the cutting zone. This paper presents a study on the influence of the size as well as the Cu nanoparticle concentration added to cutting fluid in MQL method on the power grid parameters while turning of Ti6Al4V titanium alloy. In this research, nanoparticles of 22 nm and 65 nm at concentrations of 0.5 wt% and 0.75 wt% were used. Turning process was carried out with constant cutting parameters and variable aerosol formation parameters, i.e. mass flow rate of nanofluid and volumetric flow rate of air. Based on the study, the use of 22 nm nanoparticles at 0.5 wt% concentration is recommended to achieve the smallest monitored values of the power grid parameters. The statistical analysis revealed that, out of the aerosol formation parameters considered, both the air flow rate and nanofluid flow rate do not significantly affect the values of the analysed power network parameters. However, the most significant factor is the variable nanoparticle size.
EN
The paper presents evaluation of the surface topography obtained after turning of AISI 1045 steel with the use of cemented carbide tools diversified in terms of applied titanium-based coatings. During the research, three types of coatings deposited with the PVD method on a P25 sintered carbide insert were compared: nitride-titanium TiN, nitride-aluminum-titanium TiAlN and carbon-titanium TiC in a wide range of variable cutting speeds 125 - 325 m/min and variable feeds 0.05 - 0.25 mm/rev. The quality of the machined surface was assessed on the Sensofar S neox System optical profile meter using the confocal method. The paper presents the results of 3D parameters, contour maps, isometric views and material ratio curves. The surface topography analysis showed that for the TiAlN coated insert, lower surface roughness parameters were observed in the range of lower cutting speeds and higher feeds, while for higher cutting speeds, lower values of the selected 3D parameters were found for the insert with TiC coating. For the insert with TiC coating, the most even distribution of the valleys and ridges of the machined surface roughness was also observed. The research results determined the range of cutting parameters that allow the selection of the appropriate type of titanium-based coating when machining AISI 1045 steel.
12
Content available remote Projektowanie płyt warstwowych poddanych skręcaniu
PL
W artykule przedstawiono efekty skręcania występujące w płytach warstwowych ściennych montowanych w układzie poziomym. Przedstawiono wzory pozwalające na wyznaczenie sił wewnętrznych w płycie oraz obliczenie naprężeń. Wzory zilustrowano przykładem obliczeniowym. W ostatniej części artykułu omówiono sposób weryfikacji stanów granicznych nośności płyty.
EN
The paper presents the torsion effect occurring in wall sandwich panels installed in a horizontal arrangement. The presented formulas enable determining internal forces in a panel and calculating stresses. The formulas are illustrated by a calculation example. The last part of the article discusses a method of verifying ultimate limit states of a panel.
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