1. Influence of cross-linkers on the wash resistance of chitosan-functionalized polyester fabricsTanja Pušić, Tea Bušac, Julija Volmajer Valh, 2024, original scientific article Abstract: This study investigates the wash resistance of polyester fabrics functionalized with chitosan,
a biopolymer known for its biocompatibility, non-toxicity, biodegradability and environmentally
friendly properties. The interaction of chitosan with synthetic polymers, such as polyester, often
requires surface treatment due to the weak natural affinity between the two materials. To improve
the interaction and stability of chitosan on polyester, alkaline hydrolysis of the polyester fabric was
used as a surface treatment method. The effectiveness of using cross-linking agents 1,2,3,4-butane
tetracarboxylic acid (BTCA) and hydroxyethyl methacrylate (HEMA) in combination with ammonium
persulphate (APS) to improve the stability of chitosan on polyester during washing was investigated.
The wash resistance of polyester fabrics functionalized with chitosan was tested after 1, 5 and
10 washes with a standard ECE detergent. Staining tests were carried out to evaluate the retention of
chitosan on the fabric. The results showed that polyester fabrics functionalized with chitosan without
cross-linkers exhibited better wash resistance than the fabrics treated with crosslinkers.
Keywords: polyster, functionalization, chitosan, cross-linkers, stability, washing
Published in DKUM: 10.09.2024; Views: 55; Downloads: 8
 Full text (17,25 MB)
This document has many files! More... |
2. Extending the protection ability and life cycle of medical masks through the washing processJulija Volmajer Valh, Tanja Pušić, Mirjana Čurlin, Ana Knežević, 2023, original scientific article Abstract: The reuse of decontaminated disposable medical face masks can contribute to reducing the environmental burden of discarded masks. This research is focused on the effect of household and laboratory washing at 50 °C on the quality and functionality of the nonwoven structure of polypropylene medical masks by varying the washing procedure, bath composition, disinfectant agent, and number of washing cycles as a basis for reusability. The barrier properties of the medical mask were analyzed before and after the first and fifth washing cycle indirectly by measuring the contact angle of the liquid droplets with the front and back surface of the mask, further by measuring air permeability and determining antimicrobial resistance. Additional analysis included FTIR, pH of the material surface and aqueous extract, as well as the determination of residual substances—surfactants—in the aqueous extract of washed versus unwashed medical masks, while their aesthetic aspect was examined by measuring their spectral characteristics. The results showed that household washing had a stronger impact on the change of some functional properties, primarily air permeability, than laboratory washing. The addition of the disinfectant agent, didecyldimethylammonium chloride, contributes to the protective ability and supports the idea that washing of medical masks under controlled conditions can preserve barrier properties and enable reusability.
Keywords: medical masks, washing, detergent, didecyldimethylammonium chloride, air permeability, antimicrobial activity, residuals
Published in DKUM: 15.03.2024; Views: 333; Downloads: 19
Full text (3,67 MB)
This document has many files! More... |
3. Sustainability-oriented surface modification of polyester knitted fabrics with chitosanTanja Pušić, Tea Bušac, Kristina Šimić, Mirjana Čurlin, Ana Šaravanja, Katia Grgić, Julija Volmajer Valh, 2024, original scientific article Abstract: The existing research deals with the process of modifying polyester knitted fabrics and polyester/cotton knitted fabrics with chitosan and the stability of functionalized surface with chitosan in the washing process according to a standard and an innovative washing procedure. The current research concept aims to evaluate the degree of progressivity and progressiveness: the modification of polyester knitted fabrics with chitosan and an innovative washing process. The polyester and polyester/cotton fabrics modified with chitosan were characterized by a staining test, microscopic analysis, zeta potential measurement, and pilling tendency of the knitted fabrics before and after five and ten washing cycles with reference detergent ECE A. The results of the zeta potential measurement of knitted fabrics functionalized with chitosan confirmed cationization of the polyester and polyester/cotton fabric with chitosan. The presence of chitosan on the washed knitted fabrics in reduced quantities is demonstrated by the staining test, the colour strength (K/S), and the zeta potential values. The staining test and surface charge of the tested knitted fabrics confirmed the research hypothesis regarding the degree of progressivity of the modification of polyester and polyester/cotton knitted fabrics with chitosan and the sustainability of the innovative washing process. The streaming potential proved to be a favorable method for monitoring the stability of chitosan in the washing process in combination with a staining test with the selected dye Remazol Red RB.
Keywords: knitted fabrics, polyester, polyester/cotton, chitosan, washing, surfaces
Published in DKUM: 05.02.2024; Views: 285; Downloads: 21
Full text (47,17 MB)
This document has many files! More... |
4. The influence of physico-chemical parameters on water scale precipitation on washing machines' heatersDanijela Urbancl, Darko Goričanec, Jurij Krope, 2007, professional article Abstract: The paper presents the results of analysis of physico - chemical parameters influence on the intensity of water scale precipitation on washing machines heaters. Washing machines of the same producer were, to this end, modified to an endless cycle of washing with the same amount of cotton fabric at the same conditions. On the basis of various experiments it was determined that water hardness, the amount of exceeded carbon dioxide, water turbulence around the heater, the amount of cotton fibres in water exceeded from fabrics, and heater specific heat strength have the key role in water scale building up in washing machines heaters.
Keywords: magnetic water treatment, magnetic hydrodynamics, water scale, calcium carbonate, scale prevention, washing machine, electrical heater
Published in DKUM: 21.12.2015; Views: 1882; Downloads: 130
Full text (544,97 KB)
This document has many files! More... |
5. An integrity analysis of washing machine holdersNenad Gubeljak, Matej Mejač, Jožef Predan, 2007, original scientific article Abstract: The paper deals with structure integrity analysis of the holder for the carrying cross of a washing machine drum. Premature fracture of the holder occurred between mechanical sustainable tests of washing machine in the factory. In order to prevent fracture, the task was to determine the reasons for premature fracture of the holder and to estimate the suitability of the new design of the holder cross. Input data for structure integriry analysis were obtained by material by mechanical testing of used materials. Stress and strain analysis of holder limit load was performed by finite element modeling of holder. Dynamic tests of holders with two different thicknesses were done on a servo-hydraulic machine in order to find dynamical strength and endurance of holder. Fracture behaviour of holders is defined as initiation and propagation of crack. The obtained behaviour confirmed that the new design of holders reduces stress concentration in the critical region. Consequently, the new holder subjected to the same dynamic load can endure a higher number of cycles until breakage. The total number of cycles overcomes industrial testing requirements.
Keywords: lomna mehanika, visokociklično utrujanje, preizkušanje lomne žilavosti, nosilci kadi pralnega stroja, mejna obremenitev, ocena celovitosti konstrukcije, fracture mechanics, high cycle fatigue, fracture toughness testing, washing machine holders, washing machine drums, structure integrity assessment, limit load
Published in DKUM: 10.07.2015; Views: 1856; Downloads: 113
Full text (517,04 KB)
This document has many files! More... |
6. Implementing hygiene monitoring systems in hospital laundries in order to reduce microbial contamination of hospital textilesSabina Fijan, Sonja Šostar-Turk, Avrelija Cencič, 2005, original scientific article Abstract: As textiles sent to hospital laundries contain many types of pathogenic organisms, it is important that laundering not only has an appropriate cleaning effect but also has a satisfactory disinfecting effect. Critical to this process is the maintenance of an appropriate hygiene level in the clean area of laundries in order to prevent recontamination of textiles from manual handling when ironing, folding, packing etc. The aims of this study were to evaluate the hygienic state of a hospital laundry, to introduce continuous sanitary measures, and to introduce a continuous hygiene monitoring system with an infection control programme. Two systems for evaluating hospital laundry hygiene were combined: HACCP principles (hazard analysis and critical control points) and RAL-GZ 992 standards (quality assurance standard for textile care of hospital laundry). Evaluation of the hygienic state of the hospital laundry was carried out by evaluating the number and types of micro-organisms present at the critical control points throughout the whole laundering process, using RODAC agar plates for surface sampling and the pour plate method for investigating water samples. The initial examination showed that the sanitary condition of the laundry did not reach the required hygiene level. Therefore, fundamental sanitation measures were instituted and the examination was repeated. Results were then satisfactory. The most important critical control point was the chemothermal laundering efficiency of the laundering process. To prevent micro-organisms spreading into the entire cleanworking area, it is important that, in addition to regular sanitary measures such as cleaning/disinfecting all working areas, technical equipment and storage shelves etc., regular education sessions for laundry employees on proper hand hygiene is undertaken and effective separation of the clean and dirty working areas is achieved.
Keywords: textile care, hospital laundry, laundry hygiene, micro-organisms, washing quality parameters, sanitary microbiological parameters, hospital-acquired disease prevention, sanitary measures
Published in DKUM: 01.06.2012; Views: 2974; Downloads: 95
 Link to full text |
7. Laundry wastewater treatment using coagulation and membrane filtrationSonja Šostar-Turk, Irena Petrinić, Marjana Simonič, 2005, original scientific article Abstract: This paper presents the results obtained from laundry wastewater treatment using conventional methods namely precipitation/coagulation and the flocculation process with adsorption on granular-activated carbon (GAC) and an alternative method, membrane filtrations, namely ultrafiltration (UF) and reverse osmosis (RO). Chemical analyses showed that parameter values of untreated wastewater like temperature, pH, sediment substances, total nitrogen and phosphorous, COD, BOD5, and the amount of anion surfactants had been exceeded in regard to Slovenian regulation. These regulations can be used as requirements for wastewater reuse and make treated wastewater an available source for the existing water supply. The study of conventional treatment was based on a flocculation with Al2(SO4)3 18H2O and adsorption on GAC. Membrane filtrations were studied on a pilot wastewater treatment plant: ultrafiltration (UF) and reverse osmosis (RO) units. The membranes used in this experiment were ceramic UF membrane and spiral wounded - polyethersulfone- RO membranes. The quality of the wastewater was improved by both methods and the specifications of a concentration limit for emission into water were confirmed. The disadvantage of GAC is that there is no possibility of any kind of selection, which is essential for recycling and re-use, while permeate coming from RO met the required regulation as well as requirements for reusing in washing process. However, the economical analyses showed that the membrane filtrations are more expensive compared to the GAC treatment process.
Keywords: laundries, washing of textiles, waste waters, advanced oxidation processes, membrane technology, membrane filtration, coagulation
Published in DKUM: 01.06.2012; Views: 2938; Downloads: 120
Link to full text |
8. Analysis of product development on large-scale production with multi-criteria approachTomaž Kostanjevec, Jože Balič, Matej Rajh, 2009, original scientific article Abstract: The multi-criteria (MC) method is applied to the development of a large-scale product in the case of mid-price range washing machines using MC approach. The concept represents the method for developing a new product in the production process. The development of a large-scale product on the basis of MC analysis provides more accurate forecasting of the most important parameters in the centrefold of a multidimensional (MD) character in the way of customer demands, and important production and development restrictions areset in this MD environment with aid of MC analysis. The production parameters are identified and through this, there is a possibility of reducing production costs. A forecasting method of production demands as possible result is powerful tool for achieving strategically and concurrent advantage.
Keywords: product development, multi-criteria analysis, forecasting, washing machines
Published in DKUM: 31.05.2012; Views: 2198; Downloads: 47
Link to full text |
9. Hygiene monitoring systems for hospital textile launderingSabina Fijan, Sonja Šostar-Turk, 2007, professional article Abstract: The main aim of washing laundry is to remove soils and microorganisms from infected and dirty textiles and achieve clean, fresh and disinfected textiles ready for use. Textiles undergo laundering processes, which include: soil removal with special laundering agents; bleaching; disinfecting; and finally neutralising and rinsing. Because textiles from hospitals may contain many kinds of pathogenic -bacteria, fungi and viruses, it is essential that the laundering process has not only a cleaning effect but also an antimicrobial one. Since users of hospital textiles are often patients with a weakened immune -system, it is recommended that best practice and common sense be employed when washing and -disinfecting hospital textiles. Most people assume that the laundry returned to them is in fact clean and, therefore, safe. Experience encourages all infection control teams to take laundering very seriously. (1-15) Inappropriately disinfected textiles are one of the possible sources of nosocomial infections for patients. There are reports of hospital textiles being the source of nosocomial infection with streptococci, enterococci, Bacillus cereus, staphylococci and coliforms.(5-9) There are some documented cases where staff in hospital wards and laundries have been infected with scabies, fungi, salmonellas, gastroenteritis viruses, hepatitis A viruses and coxiellas after treating dirty laundry.
Keywords: textile care, hospital laundry, laundry hygiene, micro-organisms, washing quality parameters, sanitary microbiological parameters, hospital-acquired disease prevention, sanitary measures
Published in DKUM: 31.05.2012; Views: 3178; Downloads: 44
Link to full text |
10. Modifikacija pralnega stroja glede porabe vode : diplomsko deloUroš Ljubojević, 2008, undergraduate thesis Keywords: pralni stroj, doziranje vode, poraba vode, hidrostat, eng, washing machine, laundry machine, water filling, water consumption, pressure switch
Published in DKUM: 04.02.2009; Views: 3116; Downloads: 435
Full text (11,94 MB) |
