• Journal of the Korean Home Economics Association
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• v.50 no.2
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• pp.85-92
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• 2012

This was a study examining the fatliquoring of natural dyed cow skin with Coptis chinensis Franch. The K/S according to optimal dyeing condition, mordants and mordanting method was measured. And the surface, sections, tensile strength, elongation, stiffness and colorfastness according to post-dyeing fatliquoring were observed. The optimal conditions include 300%(o.w.f.), $50^{\circ}C$, 30 minites. Fe-simmordanting showed the highest dyeability. Coptis chinensis Franch showed a yellow color regardless of mordants and mordanting methods. Tensile strength and elongation increased in the case of simmordanting compared with untreated and the process of fatliquoring further increased. The softness significantly increased when fatliquored. Shrinkage was slightly reduced when dyed, but showed almost no change with fatliquoring. Lastly, color fastness increased overall with mordanting and partly increased with fatliquoring. The rubbing and light fastness were excellent Cu- mordanting, and drycleaning fastness also improved with Cr-mordanting.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.325-336
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• 2010

In this study, we experimented that how to synthesis waterborne urethane-epoxy hybrid resin for leather garment coatings. First of all, We had analyzed datas by FT-IR, SEM and TGA for the machanical properties. By instruments analysis measurement we confirmed that synthesis of urethane and epoxy. In this experiment we knew that polyurethane and urethane-epoxy hybrid resin have 4~5 grades of solvent resistance. Tensile strength measured in the urethane-epoxy resin(epoxy 12%, 2.033$kg_f/mm^2$) had the most strong strength than polyurethane(1.833 $kg_f/mm^2$) emulsion samples. Also urethane-epoxy hybrid resin had better result than polyurethane in acid resistance and abrasion test. As hight proportion of epoxy in hybid resin, we obtained low elongation and low flexibility. In this result, the mechanical properties of waterborne polyurethane-epoxy hybrid resin showed that how effect in leather coating by ratio of epoxy emulsion.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.11
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• pp.63-68
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• 2019

The dimensional quality of flexible foams is often difficult to be evaluated through general machine vision inspection methods due to the free deformation of the outer shape. For the evaluation of the dimensions of flexible foams, methods of estimating the size of the product through the expansion rate of the product surface are evaluated. Specimens with various dimensions and surface gratings are prepared, and the degree of surface expansion is measured through machine vision. The correlation, between the measured surface grid size and the actual size of test specimens, is analyzed. We further analyze the correlation between the size of test specimens and the position of the surface grid. This study provides a basis for estimating the actual dimensions of specimens by measuring the surface expansion of flexible foams.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1619-1626
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• 2020

In this study, the physical properties of water-dispersible polyurethane resins synthesized with polyammonium phosphate and HMDI were studied by coating film samples and full-grain surfaces. Solvent resistance was found to be unchanged in all samples, and in terms of tensile strength, DPU-AP3 (1.887 kgf/㎟) containing the most ammonium polyphosphate showed the lowest physical properties. The elongation rate was measured as 54 8% in the sample containing a large amount of ammonium polyphosphate. Abrasion resistance was measured as 548 mg.loss of a sample containing a lot of ammonium polyphosphate, and it was confirmed that the physical properties of the blended resin of ammonium polyphosphate and water-dispersible polyurethane were changed.

• Textile Coloration and Finishing
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• v.32 no.4
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• pp.274-280
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• 2020

This study compared the mechanical properties of bamboo fiber composites and kenaf fiber composites through physical treatment (ultrasonic treatment). Kenaf, a composite of PP reinforced with bamboo fiber, was made using injection molding technology. PP was used as a binder and the ultrasonic treatment time of bamboo and kenaf was increased by 30 minutes to compare and study various mechanical properties of bamboo and kenaf composites through physical treatment. Interfacial properties such as internal cracks and internal structure of the wave cross section were confirmed using a scanning electron microscope (SEM). As a result of the ultrasonic treatment, most of the characteristics were fragile as the ultrasonic treatment time was increased, and it was confirmed that the natural characteristics of the twisted fibers had a great influence on the characteristics of the composite material.

• Journal of the Korean Applied Science and Technology
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• v.38 no.1
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• pp.178-185
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• 2021

In this study, polyvinyl alcohol (PVA) and polypropylene glycol (PPG)-based polyurethane dispersion resin for wound coating was synthesized. And the physical properties of the sample were coated on the surface of the film sample and the leather (Full-Grain) to study the physical properties change. In the case of tensile strength, PUD-PA1, which reacted with the least amount of PVA, showed the highest resistance at 2.00 kgf/㎟. Likewise, the rate of elongation was measured as high as 554% for PUD-PA1, which reacted with the least amount of PVA. The abrasion resistance measurement result showed that as the PVA response increased, the strength of the surface decreased to 36.77 mg.loss.

• Textile Coloration and Finishing
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• v.35 no.1
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• pp.42-65
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• 2023

Leather is widely used in human lives and many industries, and the market size continues to grow. In terms of quality and durability, natural leather is still being used as the most luxurious product. And synthetic leather, made of polyvinyl chloride (PVC) and polyurethane (PU), were developed and being widely have been used as alternative materials for natural leather. Processes, properties and issues of these leather were reviewed. Then silicone leather was reviewed why they can be good candidates for leather. Properties of general silicone polymers and silicone rubber coating agents were reviewed such as eco-friendliness, human-friendliness, stain resistances, resistance to uv light and ozone, heat stability and so on. Papers and patents related to silicone leather were studied to understand current status of development and commercialization of silicone leather. Finally direction of development was described how to improve deficient performances of current silicone leather, such as formulation of silicone, combination with organic materials and manufacturing processes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.3
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• pp.239-247
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• 2008

Low back disorders (LBDs) have been the most common musculoskeletal problem in Korean workplaces. It affects many workers, and is associated with high costs to many companies as well as the individual, which can negatively influence even the quality of life of workers. The _evaluation of low back disorder risk associated with manual materials handling tasks can be performed using variety of ergonomic assessment tools such as National Institute for Occupational Safety and Health (NIOSH) Revised Lifting Equation (NLE), the Washington Administrative Code 296-62-0517 (WAC), the Snook Tables etc. But most of these tools provide limited information for choosing the most appropriate assessment method for a particular job and in finding out advantage and disadvantage of the methods, and few have been assessed for their predictive ability. The focus of this study was to _evaluate spinal loads in real time with lifting and pulling heavy cow leathers in variety of postures. Data for estimating mean trunk motions were collected as employees did their work at the job site, using the Lumbar Motion Monitor. Eight employees (2 males, 6 females) were selected in this study, in which the load weight and the vertical start and destination heights of the activity remained constant throughout the task. Variance components (three dimensional spaces) of mean trunk kinematic measures were estimated in a hierarchical design. They were used to compute velocity and acceleration of multiple employees performing the same task and to repetitive movements within a task. Therefore, a results of this study could be used as a quantitative, objective measure to design the workplace so that the risk of occupationally related low back disorder should be minimized.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.52-52
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• 2011

나노필라멘트는 단면직경이 수백 나노미터에서 수십 나노미터 수준인 초극세 장섬유를 말하며, 해도형 복합방사로 얻어진 섬유를 알칼리 감량을 통해 해성분을 용출하여 도성분에 해당하는 나노필라멘트를 얻는다. 이러한 나노필라멘트사는 초극세와 마찬가지로 단위중량당 표면적이 크고, 작은 굴곡반경 및 낮은 굴곡 반발성으로 인하여 일반 합성섬유에 비하여 고가성 및 새로운 기능성을 부여하는 제품에 응용 될 수 있다. 특히 나노필라멘트를 이용한 편물제품으로 경편물은 wiping cloth 등 산업용도에 적용되며, 환편물은 인조피혁 등 의류용으로 사용된다. 나노필라멘트 편물은 원사섬도, 편물의 조직, 밀도 및 중량 등에 따라 분할율과 용출 특성이 상이하므로 후가공 공정에 있어서 감량공정은 매우 중요하다. 또한 나노필라멘트와 같은 세사의 경우 일반사보다 비표면적이 증가하여 동일한 염색조건에서 옅은 색상을 나타낸다. 이로 인해 같은 색상을 위하여 보다 많은 염료를 투입해야 하며, 결과적으로 견뢰도 문제가 발생할 우려가 있다. 이 연구에서는 해도형 나노필라멘트 PET 원사와 일반 PET사를 복합한 2종의 편물을 이용하여 알칼리감량특성 및 3가지 분산염료에 대한 염색성과 견뢰도를 조사하였다. 알칼리 처리조건에 따른 감량률을 측정함으로써 각 편물의 이론 감량률에 도달하는 지점을 확인하고, SEM사진 분석을 통하여 해도사의 감량정도 및 분할특성을 확인하였다. 나노필라멘트 편성물은 염료농도가 증가함에 따라 지속적으로 K/S 값이 증가하였으나, 전체적으로 낮은 K/S값을 얻었다. 또한 염색온도가 110에서 $100^{\circ}C$로 증가함에 따라 K/S값이 감소하였는데, 이는 고온에서 분산염료가 나노필라멘트로부터 일반 PET사로 이염이 더 많이 발생하였기 때문이라고 생각된다. 세탁견뢰도의 경우 양호 또는 우수하였으나, 일광견뢰도의 경우 1등급으로 매우 낮아 이를 개선하기 위한 노력이 향후 진행되어야 할 것이다.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.238-245
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• 2014

Objectives: It was known that workers in synthetic leather company are mainly co-exposed to dimethylformamide(DMF) with methyl ethyl ketone(MEK) or toluene(TOL) instead of a single dimethylformamide. This study was examined to the physico-chemical properties in single DMF and binary mixture DMF with MEK or TOL. Materials: Physico-chemical properties were measured by Korean and American Standard Test Methods. Results: Boiling point, specific gravity and flash point in single DMF were significantly higher than binary mixture DMF with MEK or TOL and such difference was dependent on the mixing ratio of MEK and TOL, and low explosion limit in binary mixture DMF with TOL was only significantly lower than single DMF. However, Reid vapor pressure had significantly higher in binary mixture DMF with MEK or TOL compared with single DMF. Conclusions: Our results demonstrate that the binary mixture DMF with MEK or TOL synergistically increases volatilization of DMF. It was concluded that the interaction between DMF and MEK and/or TOL might play a key role in the volatilization process of DMF under environmental conditions of workplace.