• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.5
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• pp.80-84
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• 2015

Softness is considered one of the most important attributes of hygiene paper such as tissue and towel. Being subjective in nature, however, softness attribute has been generally believed to be impossible to evaluate using objective methods. Hallmark in his pioneering work proposed that tissue subjective softness should be mainly consisted of the bulk softness component and surface softness component. The bulk softness component can be determined by tensile stiffness; the surface softness component by surface tester. The surface friction turns out far more important than the surface roughness in determining the surface softness component. It cannot be too much emphasized that both results of the tensile stiffness and the surface friction should depend on measuring conditions such as an instrument used, sample sizes (e.g., basis weight, length, and width) and operating conditions of the instrument (e.g., gauge length, cross-head speed, size of stylus, and its scanning speed). This indicates that a direct comparison of the test results would be impossible or misleading unless they have been tested under the identical conditions. This may explain why the standard objective test method for tissue softness has not been available at present.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.4
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• pp.30-36
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• 2002

This research was conducted to investigate the feasibility of using deinked pulp of white ledger(DIP) for the manufacture of high quality premium tissue. The three types of tissues were prepared using the softener treated bleached DIP, softener treated mixed pulp of unbleached DIP and virgin pulp, and untreated mixed pulp of bleached DIP and virgin pulp, respectively, and their tensile index. softness, and brightness were measured and compared. The bulk and surface softness increased only slightly by the addition of softener(0.2% mineral oil) into the bleached DIP. The tensile index was decreased by 15∼30%, and the brightness was the range of 86% to 87% ISO. The softener(0.2∼0.8% mineral oil or dialkyl imidazoline) treatment of mixed pulp of unbleached DIP and virgin pulp Improved the bulk and surface of tissue considerably. However, the brightness was low as 85% ISO or below. Although the softness of the tissue made from bleached DIP blended with virgin pulp was the lowest among three types of tissues evaluated, its tensile index was the highest and brightness was 87∼88% ISO. Based on the results, it may be predicted that the bleached DIP blended with virgin pulp is the best raw material for the manufacture of high quality premium tissue if softener treatment is applied to mixed pulp, because the softness can be improved by the addition of softener. In general, the softness of tissue was improved with the increase in the amount of softener: However, the tensile index inversely proportional to the amount of softener added. Dialkyl imidazoline was more effective than mineral oil with respect to the improvement in softness, even though the loss in tensile index was severe with the treatment of dialkyl imidazoline.

• Fibers and Polymers
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• v.7 no.3
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• pp.295-304
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• 2006

High-bulk worsted yams with different shrinkable and non-shrinkable acrylic fibers blend ratios are produced and then single jersey weft knitted fabrics with three different structures and loop lengths are constructed. The physical properties of produced yams and compression properties of produced fabrics at eight pressure values (50, 100, 200, 500, 1000, 1500 and $2000 g/cm^2$) were measured using a conventional fabric thickness tester. Then, weft-knitted fabric compression behavior was analyzed using a two parameters model. It is found that at 40 % shrinkable fibre blending ratio the maximum yam bulk, shrinkage, abrasion resistance and minimum yarn strength are obtained. It is also shown that high-bulk acrylic yarn has the highest elongation at 20 % shrinkable fibre blend ratio. The statistical regression analysis revealed that the compression behavior of acrylic weft-knitted fabrics is highly closed to two parameter model proposed for woven fabrics. It is also shown that for weft-knitted structure, there is an incompressible layer (V') which resists against high compression load. Acrylic weft-knitted fabrics with knit-tuck structure exhibit higher compression rigidity and lower softness than the plain and knit-miss structures. In addition, at 20 % shrinkable fibre blend ratio, the high-bulk acrylic weft-knitted fabrics are highly compressible.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.311-316
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• 2006

The role of short fibre pulp - Mixed Harwood, Eucalyptus, Aspen, Birch, etc for the manufacture of different grades of paper is very well recognized. At the same time, lots of efforts are in progress to maximize the advantages while preserving their own special property. Bleached Acacia Kraft Pulp (BAKP) is comparatively new entry but gained quick recognition. BAKP was introduced to the world market by South East Asian suppliers in the late 1990's. This paper discusses in detail the role and opportunities of use of short fibre pulps. A logical technical comparison has been made between BAKP and another short fibre grades. BAKP being a short, thin-walled fibre shows several similarities with Eucalyptus pulp in terms of good bulk and stiffness. Refining energy and strength properties are very similar, but the shorter fibres and thinner cell walls give an outstanding opacity and formation compared to other commercial short fibre pulps. The collapsed and band-shaped nature gives a matchless smoothness, enabling less calendaring and exceptional printing properties. BAKP is shown to give several advantages to fine paper manufactures, compared with a number of established short fibre pulps such as Brazilian and Chilean Eucalyptus, Canadian Aspen and Indonesian Mixed Hardwood. It is important to consider refining and calendaring conditions to achieve optimum performance. For outer layers of multiply board, Acacia gives excellent coverage due to its high opacity and uniform fibre distribution. Its low roughness property gives improved printability. For tissue products, Acacia gives unique property of superior softness both in terms of hand feel and bulk softness. The high fibre population gives an impression of much higher quality due to the higher opacity and good formation.

• Korean journal of food and cookery science
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• v.29 no.5
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• pp.469-478
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• 2013

The effects of tapioca starch (TS) and tapioca modified starch (TMS) as additives on the quality characteristics of rice cookies were investigated in this study. The amounts of TS and TMS replaced were 5, 10 and 15%(w/w) based on 100 g of rice flour. At the result of rapid viscosity analyser (RVA) properties of rice flour added with starches, peak, trough, and final viscosity of rice flour added with TMS decreased significantly(p<0.05). Hardness of dough and cookies as measured by Texture analyzer (TA) significantly decreased upon addition of TMS, and hardness of cookies significantly decreased upon addition of TS, hardness of cookies TMS lower than TS. L value of dough and cookies increased upon addition of TMS, whereas a value decreased upon addition of TMS. Spreadability of cookies increased upon addition of TMS, 10% TMS is the highest. Bulk density of dough decreased upon addition of TMS, bulk density of cookies decreased upon addition of TS and TMS, and bulk density of TMS cookie lower than TS cookie. In sensory evaluation, 10% TS added rice cookies showed the highest score in overall acceptability, hardness, brittleness, color, softness, taste and flavor, and 15% TS added rice cookies showed the highest score in appearance. And 15% TMS added rice cookies showed the highest score in overall acceptability, taste, brittleness, flavor, and 10% TMS added rice cookies showed the highest score in hardness, flavor, taste and color. It is indicated that the quality characteristics and sensory characteristics of the rice cookie can be improved by adding TS and TMS.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1426-1432
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• 2013

Changes in the textural properties of rice cookies as a result of using roasted soybean flour (RSF) as an additive were investigated in this study. RSF was replaced as 3, 6, 9, 12, 15 and 20% of 100 g of rice flour. The addition of RSF increased the hardness of dough and cookies as measured by texture analyzer (TA), whereas moisture content of dough and cookies decreased upon addition of RSF. Further, the addition of RSF led to an increase in the L value of dough and cookies, but to a decrease in the a and b values. In addition, the bulk density of cookies decreased upon addition of RSF, whereas bulk density of dough also declined when compared to control. The spreadability of cookies was found to be lower in comparison to control. The values of ${\Delta}bulk$ densities (BD) and ${\Delta}hardness$ of cookies also increased upon addition of RSF. From the point of view of sensory evaluation, addition of 9% RSF to rice cookies showed the highest score in terms of overall acceptability and softness. A 12% RSF addition to rice cookies led to the highest score in sandiness. As a result, we conclude that the crispy texture of the rice cookie can be improved by adding RSF.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1096-1099
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• 2001

The basic design structure of RC-GCTs (Reserve-Conducting Gate-Commutated Thyristors) is firstly given in this paper. The bulk of wafer is punch-through (PT) type with high resistivity and narrow N-base width. The photo-mask was designed upon the turn-off characteristics of GCT and solution of separation between GCT and diode part. The center part of Si wafer is free-wheeling diode (FWD) and outer is GCT part which has 240 fingers totally. The switching performance of GCT was investigated by Dessis of ISE. The basic manufacture process of 2500V-4500V RC-GCTs was given in this work. Additionally, the local carrier lifetime control by 5Mev proton irradiation was adopted so as to not only to have the softness of reverse recovering for FWD but for reduction of turn-off losses of GCT as well.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1277-1282
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• 2013

The effects of pregelatinized rice flour (PRF) as an additive on the textural properties of rice cookies were investigated in this study. PRF was used at 10, 20, 30, 40, 50, and 60% per 100 g of rice flour. The hardness of dough and cookies, as measured by a texture analyzer, increased upon the addition of PRF. In contrast, the moisture content of the dough and cookies decreased upon the addition of PRF. The L value of the dough and cookies decreased upon the addition of PRF, whereas the a value increased upon the addition of PRF. The bulk density of the cookies increased upon the addition of PRF. In addition, the spreadability of the cookies was lower than the control. In the sensory evaluation, rice cookies with 50% PRF showed the highest scores for hardness, brittleness, softness, and moisture. Rice cookies with 60% PRF showed the highest scores for sandiness. Our results suggest that the texture of the rice cookies can be improved by adding PRF.

• Journal of Korean Society of Forest Science
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• v.113 no.1
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• pp.14-30
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• 2024

This study characterized areas at risk of land creep by focusing on a site that has undergone this phenomenon in Ulju-gun, South Korea. Land creep in the area of interest was catalyzed by road expansion work conducted in 2022. The site was examined on the basis of its geological features, topography, effective soil depth, soil hardness, electrical resistivity, and subsurface profile. It consists of a slope covered with sparse vegetation and a concave top that retains rainwater during rainfall. Compositionally, land creep affected the shale, sandstone, and conglomerate formations on the site, which had little silt and more sand and clay compared with areas that were unaffected by land creep. An electrical resistivity survey enabled us to detect a groundwater zone at the site, which explains the softness of the soil. Finally, the effective soil depth at the land creep-affected area was 30.4 cm on average, indicating deep colluvial deposits. In contrast, unaffected sites had an effective soil depth of 24.7 cm on average. These results should facilitate the creation of systems for monitoring and preemptively responding to land creep, significantly mitigating the socioeconomic losses associated with this phenomenon.