Gorenje (Slovenia)

This work investigates the evenness of fabric drying in a household heat pump tumble dryer. The evenness of drying was defined as the standard deviation of the fraction of water, evaporated from each fabric item. Drying experiments were performed according to the IEC 61121 standard, which was also followed to determine quantities and types of cotton fabric items (towels, pillowcases and sheets) within each load. Regression analysis was performed to develop models for evenness of drying as a function of load mass and drum speed. Similarities between the tumble dryer energy efficiency parameters and the evenness of drying were analyzed. A high level of agreement was determined between responses of energy efficiency, drying time and evenness of drying to changes in drum speed. Effects of load mass were however more complex and were reflected in a non-linear response of evenness of drying to changes in load mass – the best evenness of drying could be obtained at 2 kg load, followed by 6 kg and 4 kg load. Load composition was determined as an important factor affecting the evenness of drying. At larger loads, a sheet or a pillowcase in average contributed more to the un-evenness of drying than a towel. The presence of sheets and probably the ratio of sheets to other item types in the load were determined as the most probable factors that negatively affected the evenness of drying.

Remanufacturing can create opportunities for companies to become more sustainable while remaining profitable. However, not all companies will be able to profit from moving towards a closed-loop business model. This paper investigates the profitability of leasing and remanufacturing washing machines for a large white goods producer based on data provided by them. A simple analytical model is built to simultaneously estimate the costs for consumers and costs and profits for the manufacturer under the leasing system. The results are compared with the costs and profitability of the linear system where premium, economy, and budget washing machines are sold to consumers. A sensitivity analysis is conducted on important factors such as repair, administration and transport costs. Using the replacement chain method, we show that the consumer costs of budget washing machines in the sales system is significantly higher than the costs for premium washing machines. Consequently, those consumers would benefit most from a circular system in which premium washing machines are leased against acceptable fees. However, the additional costs for the manufacturer make it a challenge to generate the same level of profit as in the linear system. The research discusses important cost components companies will have to address when making a move towards a circular business model with leasing and remanufacturing.

Water stable, flexible and ecological acceptance composite films were prepared by the solvent casting process using native, dealuminated (treated with HCl to affect the surface chemistry and pore structure) and/or surface modified (coated with a cationic surfactant PDADM of different molecular weights) H-ZSM-5 type zeolite of different shapes (spherical vs. rod) and Si/Al ratios (P26 vs. P371) as adsorbents and cellulose nanofibrils (CNFs) as a networking matrix (in a weight ratio of 4:1). The films were tested for removal of the black anionic reactive dye with the highest bleeding effect at the first rinsing cycle of textile laundering. The effects of zeolite structure and surface chemistry on films dye’ removal kinetics from a standardised rinsing bath were investigated for up to 140 min at room temperature and using 0.1 g/l of dye concentration, depending on the film-to-bath weight-to-volume ratios (from 1:10 to 1:1000), thus simulating different rinsing conditions. The results show that up to 80 % of the dye was removed in the first 20 min in the lowest weight-to-volume ratio (1:10), fitting the Langmuir isotherm, and the process followed the pseudo-second order kinetic, yielding a multi-layer adsorption mechanism with a monolayer capacity of ~11 mg/g and ~21 vs. ~30 mg/g by films prepared from native or HCltreated and PDADMA100 vs. PDADMA400 coated P371 zeolites, respectively. Such efficacy was due to the more densely and fully surface-covered longitudinal P371 with PDADM400, given the huge electrostatic attraction sites for dye molecules, compared to the partly interpenetrated PDADM into relatively larger pore-sized (~450 nm vs. 220 nm) of P26. The filtration performance of the films was also examined, be used for the removal of the dye from the rinsing bath, released from the washing drum. An ultra-high flux rate (11.000 kL/m2 h MPa) with 45 % of dye removal efficacy and capacity of ~24 mg/g was provided by films prepared from spherical and aggregated P26PDADMA-400, showing its high potential also as a filter membrane.

Hard mineral scale fouling results in significant economic losses both industrially and domestically. Recently, attempts have been made to use ultrasound to mitigate scale formation and its removal based on the phenomena of cavitation. Cavitation erosion is the removal of material from a solid surface by pressure shock waves associated with the formation and collapse of bubbles. This paper reviews the literature on cavitation erosion of brittle crystalline materials in an attempt to better understand the relationship between the material properties of CaCO3 scale deposits and its potential removal by cavitation. The study finds that from a materials perspective cavitation erosion is intimately associated with both a material’s bulk properties and importantly to its microstructure. The situation is further complicated because the macro and micro-properties of CaCO3 scale are dependent on many factors relating to its depositional environment. The type of scale formed will affect how it is removed by cavitation.

Within industry, spring‐back is a problem which has to be considered during the manufacturing of tools. Over the last few years this has become an even bigger problem because of more complex drawn‐products and the discovery of new materials. The shapes of products depend significantly on the spring‐back effect, therefore an accurate prediction of the spring‐back effect plays a significant role during a product’s development process. Spring‐back in sheet‐metal forming can be described as the change in sheet‐metal’s shape compared with the shapes of the tools after the forming process. Using numerical computer analyses, spring‐back is a difficult problem to solve, especially when the tolerances of the component parts are very narrow. This research work presents the effects of different holding systems on the spring‐back effect in sheet metal deep‐drawing processes. A conventional holding system and a segmented holding system with distributed Blank holder forces (BHF) were evaluated. Analyses were carried out using computer finite element simulations, using the Pam‐Stamp software package for calculating. The results were compared and the conclusions given.

Abstract No abstract received.

HPTLC and HPLC-MS methods have been developed for quantitative determination of inulin in food products. Samples were applied to silica gel HPTLC plates and developed three times, twice with n -propanol-acetone-water, 45 + 30 + 25 ( v/v ), and the third time with n -propanol-acetone-water, 50 + 40 + 10 ( v/v ). Total development time was 150 min. Dried plates were dipped into DAP reagent for 10 s. After heating colored spots of the saccharides appeared. Quantitative evaluation of the colored spots was performed in transmission mode by means of a flatbed scanner and densitometer. The precision of measurements for the main inulin fractions was ±6.0%; the limit of quantitation ( LOQ ) varied from 0.1 to 1 µg per spot; and the 'linear' working range was between 0.5 and 4.0 µg per spot. The method was tested on real samples.