• The Research Journal of the Costume Culture
• /
• v.23 no.6
• /
• pp.1082-1096
• /
• 2015

The purpose of this study was to examine laundry behavior according to the number of households and the type of washing machine that each household used. The data was obtained from questionnaires filled out by 417 households, which included college students living in Seoul and Gyeonggi province. The results of this study are as follows: first, according to the results of survey about the number of household members and type of washing machine that household had, one or two-person households accounted for 24.0%. Regarding the type of washing machine that each household used, there were more drum washers. In households comprised of three or more persons, a higher percentage had a machine with a pulsator. Second, with regard to the method of classifying the wash in doing the laundry, all families classified the wash according to color and textile material. Third, with regard to the amount of detergent in doing the laundry, 63.5% of households used the recommended amount of detergent while 28.3% of households used more detergent than the recommended amount. Fourth, with regard to the set temperature of water in doing the laundry, 36.2% of households used cold water; this was the highest percentage. Fifth, with regard to input sequence in doing the laundry, most households put the wash in the machine in advance, and then filled the washer with water; 56.1% of households added a rinsing process for all washing processes.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.3 no.2
• /
• pp.148-154
• /
• 2014

This paper describes problems of the sensorless starting of horizontal axis washing machines with direct drive and suggests solution, which was experimentally verified. Horizontal axis washing machines have very difficult conditions for the drive starting, especially at full load. Inertia of the tub and water, torque from the laundry make load torque at starting higher than rated one and sometimes even higher than the maximum torque of the motor, which makes sensorless starting extremely challenging task. This paper suggests modified open-loop starting, where control system is closed shortly after beginning at low speed and rotates the drum until laundry restructuring. To ensure proper work of the sensorless algorithm at low speed additional measures for increasing of the estimation algorithm performance have been taken. These measures include special algorithm for the drive parameters estimation, which has been developed and verified by the experimental results.

• The International Journal of Costume Culture
• /
• v.8 no.1
• /
• pp.23-31
• /
• 2005

Mechanical properties and hand evaluation of wool/acrylic(W/A) blend knits were conducted before and after repeated washing to get the optimum W/A blending ratio, which could help achieve the optimum mechanical and hand properties of the knits. The five test fabrics using the yarns with different W/A blending ratios($\%$), 100/0, 70/30, 50/50, 30/70, 0/100, were knitted. The fabrics were washed by a rotating drum type washing machine. Then, objective mechanical and hand properties were evaluated by KES-FB, Kawabata evalution system for fabric. The results are as follows: there was no change in the hand value of the knitted fabric with the W/A-blended yarn caused by the change in the blending ratio before washing. After washing, however, the increase of acrylic's blending rate caused the bending property to decrease proportionally, while the friction coefficient of the surface property increased. Furthermore, the study showed that W/A 50/50 possesses the most superior tensile property and shearing property, which could attain the optimum blending ratio. Similar results in hand value were derived in all the samples. After washing, however, the increase in acrylic's blending rate caused a proportional decrease in KOSHI and an increase in FUKURAMI. In addition, W/A 50/50 gained the biggest NUMERI value, again corresponding to the optimum blending ratio. Similar results in total hand value were derived in all the samples before washing. After washing, though, all the total hand values decreased, and, as the wool fabric's blending rate increased, the total hand values proportionally decreased further.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.11a
• /
• pp.295-296
• /
• 2008

• Journal of the Korean Society of Clothing and Textiles
• /
• v.30 no.2 s.150
• /
• pp.296-305
• /
• 2006

This study evaluate the effect of laundering on the deformation of knitted spandex/cotton fabrics compared with that of knitted cotton fabrics. Commercial knitted spandex/cotton and knitted cotton fabrics for T-shits were laundered in a drum-type washing machine and dried in a tumble dryer. Wale spirality, shrinkage, elastic recovery and surface contour of knitted fabrics were investigated under different laundering conditions: washing temperature, presoaking time and washing cycles. Knitted spandex/cotton fabrics had a lower angle of spirality than knitted cotton fabrics. After the first washing cycle, the angles of spirality of all the fabrics had decreased greatly. Knitted cotton fabric of low density deformed more than that of higher density. Knitted spandex/cotton. fabric of low density shrank less, because of the greater extension given during heat-set. Permanent elongation length at the 80$\%$ extension was longer than at the 50$\%$ extension, and the knitted spandex/cotton fabric which was expanded greatly during heat-set had a lower elastic recovery rate. The surface appearance of the knitted spandex/cotton fabrics was worsl~ than that of the knitted cotton fabrics before laundering and after repeated laundering, because of the much protruded cotton fibers from the yarns.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.19 no.3
• /
• pp.17-26
• /
• 2005

The random pulse width modulation(RPWM) in inverter-fed induction motor drive is presented. This paper describes a RPWM method based on space vector PWM strategy for shaping the switching noise spectrum in such a way it can merge with the natural system noise. To verify the validity of the proposed RPWM scheme, the experiment based on the DSP56F803 microprocessor was executed finally, the simulation and experimental results will be given to demonstrate the effectiveness of the unposed RPWM scheme.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.5
• /
• pp.132-139
• /
• 2008

To meet demand of big capacity and high speed rotation for washing machine, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Also, Vibration occurs due to the frequency of the rotating parts. But, shaft has various design factors such as diameter and distance between bearings according to configuration of shaft, the optimal values can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), which has several advantages such as less computing, high accuracy performance and usefulness, this study was performed investigating the interaction effect between the various design factor as well as the main effect of the each design factor under bending, twist and vibration and proposed optimum design using center composition method among response surface derived from regression equation of simulation-based DOE.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.8
• /
• pp.72-79
• /
• 2008

To meet demand of big capacity and high speed rotation for washing machine, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Shafting system is mainly divided into flange and shaft. Shaft and flange connected by inserting shaft serration into flange on the process of die casting. When the system is operating, the gap is formed between serration and flange. But, Serration has various design factors and the optimal values can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), this study was performed investigating the interaction effect between the various design factors as well as the main effect of the each design factor under bending, twist and vibration and proposed optimum design using box-behnken method among response surface derived from regression equation of simulation-based DOE.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.11
• /
• pp.1056-1063
• /
• 2007

Recently, there has been a growing consumer interest in the amount of noise produced by household electrical appliances. The designer of the product must identify the source of the noise, in order to reduce the noise. In the case of a household electric appliance such as the washing machine, there is consumer's complaint about the noise that is generated during the dehydrating condition. Because of several noise sources combined each other. It is difficult to identify the noise sources that contribute to the noise output. Multi-Dimensional Spectral Analysis (MDSA) is a method that can remove the correlation between different noise sources, and it expresses the key contributing factor as a unique output. This study utilized MDSA to analyze the contribution of each input in the noise output during the dehydrating condition.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.34 no.12
• /
• pp.2062-2072
• /
• 2010

This research evaluates the change of the water absorbency and drying speed of a quick-drying knit fabric by repeated laundering and laundering conditions and investigates the influence of laundering conditions on the functional properties of the knit fabric. Four factors of laundering conditions were studied: detergent, water hardness, water temperature, and frequency of rotation. Knit fabrics were washed for 25 laundering cycles in a drum-type washing machine with nine different laundering conditions derived from an orthogonal array. The properties of knit fabrics were measured with a drop absorption test, a strip test, and a drying time test. Relaxation shrinkage pointed to a change in the structural characteristics of the knit fabric. Wetting time was faster and wickability was greater in the knit fabrics that underwent 5 laundering cycles; in addition, there were no obvious changes in wetting time and wickability. The detergent was the most important factor in wetting time (40.4%) and wickability (60% or above). Water hardness, water temperature and RPM had less of an effect on wetting time and wickability. There were no significant differences between the levels of laundering conditions (except for detergent) on wetting time and wickability. Drying times with neutral and alkali were slower by repeated laundering; however, there was no obvious change in drying time. Hardness, water temperature and RPM had less of an impact on drying time.