• 고무기술
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• 제5권2호
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• pp.94-103
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• 2004

The present work describes modification of dual phase filler by electron beam irradiation in presence of multifunctional acrylates like trimethylol propane triacrylate (TMPTA) or silane coupling agent like bis (3-triethoxysilylpropyltetrasulphide) and in-fluence of the modified fillers on the physical properties of styrene-butadiene rubber (SBR) vulcanizates. Modulus at 300 % elongation increases whereas the tensile strength decreases with increase in radiation dose for the dual phase filler loaded styrene-butadiene rubber vulcanizates (SBR). However, modulus and tensile strength significantly increase, which is more, pronounced at higher filler loadings for TMPTA modified dual phase filler loaded SBR. These changes in properties are explained by the equilibrium swelling data and Kraus plot interpreting the polymer-filler interaction. Electron beam modification of the filler results in a reduction of tan ${\delta}$ at $70^{\circ}C$, a parameter for rolling resistance and increase in tan ${\delta}$ at $0^{\circ}C$, a parameter for wet skid resistance of the SBR vulcanizates. Finally, the influence of modified fillers on the properties like abrasion resistance, tear strength and fatigue failure and the improvement in the properties have been explained in terms of polymer-filler interaction.

• 펄프종이기술
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• 제42권3호
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• pp.50-57
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• 2010

A mill trial was performed in a kraft paper mill in order to evaluate the possibility of utilizing dual polymer dry strength aids system consisting of cationic PVAm and anionic PAM. It was found that the cationic PVAm - anionic PAM dry strength additives can improve paper strength without significantly disturbing the stability of the kraft papermaking process when virgin UKP was used as a furnish. Tensile strength (25.3% in machine direction, 48.4% in cross machine direction), elongation of paper (31.6%, 15.6%) and tensile energy absorption (48%, 54%) were improved. Air permeability of the kraft paper was improved as well (22%). Tear strength was decreased with PVAm dry strength aids system, but it can be compensated with decreasing refining degree. In addition, the mill trial results indicate that highly air permeable kraft sack paper can be produced by the addition of PVAm dry strength agents at the stock with reduced freeness.

• 접착 및 계면
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• 제9권2호
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• pp.24-31
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• 2008

본 연구에서는 EVA 에멀젼에 내수성 및 기계적 특성을 향상시키기 위하여 금속 이온 가교제인 calcium hydroxide 및 magnesium carbonate를 사용하여 이온성 가교결합을 도입하였다. EVA 에멀젼 필름의 가교밀도, 열적특성, 표면자유에너지 그리고 인장강도, 파단신율 및 인열강도 특성을 고찰하였다. 금속 이온 가교제 양이 증가함에 따라 EVA 에멀젼의 가교밀도는 증가하였고, 이에 내수성과 $T_g$ 값도 증가하였다. 그러나 EVA 에멀젼 필름의 표면에너지 및 기계적 특성들은 다소 다른 거동을 보였다. Calcium hydroxide 0.4% 그리고 magnesium carbonate 0.5%를 첨가한 경우가 EVA 에멀젼에 강한 이온성 가교결합이 형성되어 가장 높은 표면 자유에너지 값과 인장강도 및 인열강도를 보였다. 그러므로 본 연구에서 calcium hydroxide 및 magnesium carbonate와 같은 금속 이온 가교제가 EVA 에멀젼의 내수성과 기계적 물성을 향상시킴을 확인하였다.

• Elastomers and Composites
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• 제40권1호
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• pp.12-21
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• 2005

본 연구에서는 CSM 에멀젼의 물성을 향상시키고자 금속성 가교제인 magnesium carbonate 및 calcium hydroxide를 첨가하여 가교밀도, 열적특성, 표면자유에너지 그리고 인장강도, 파단신율 및 인열강도 특성을 고찰하였다, 금속성 가교제인 magnesium carbonate 및 calcium hyroxide 양이 증가함에 따라 CSM 에멀젼 필름은 가교밀도는 증가하였고, 이에 내수성과 $T_g$ 값도 증가하였다. 금속성 가교제로 magnesium carbonate를 첨가하였을 때 calcium hydroxide에 비해서 다소 높은 가교밀도와 $T_g$ 값을 보였다. 하지만 CSM 에멀젼 필름의 표면에너지 및 기계적 특성들은 다소 다른 거동을 보였다. Magnesium carbonate 0.75% 그리고 calcium hydroxide 1.0% 첨가한 경우가 가장 높은 표면 자유에너지 값과 인장강도 및 인열강도를 보였으나, 그 이상의 양을 첨가하였을 경우에는 오히려 감소함을 확인하였다. 그러므로 본 연구에서 CSM 에멀젼의 물성을 향상시키는데 적용되는 금속성 가교제로서 calcium hydroxide 보다 magnesium carbonate가 더 적당하며, 0.75% 첨가하였을 때 보다 향상된 물성을 얻을 수 있었다.

• Elastomers and Composites
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• 제46권2호
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• pp.138-143
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• 2011

EPDM에 카본블랙과 더불어 무기 충전제인 탈크, 탄산칼슘, 혹은 클레이를 함께 혼합하여 EPDM 배합물과 가황물을 제조하여, 무기 충전제가 EPDM 배합물과 가황물의 특성에 미치는 영향을 조사하였다. 무기 충전제를 추가해도 결합 고무 함량(bound rubber content)에는 큰 차이가 없었다. 무기 충전제 함량이 높을수록 큰 입자로 존재함을 확인하였다. 무기 충전제를 추가하면 가교 시간은 전반적으로 증가하는 경향을 보였으며, 델타 토크(delta torque)는 감소하였다. 무기 충전제를 추가하면 모듈러스는 전반적으로 감소하였으나, 신율과 인장강도 그리고 인열강도는 증가하였다. 모듈러스의 감소와 신율의 증가는 가교밀도의 감소로 설명하였으며, 인장강도와 인열강도의 증가는 신율의 증가로 설명하였다. 무기 충전제의 첨가에 의해 보강성은 증가하지 않았고 가교밀도는 감소하였다.

• 한국의류산업학회지
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• 제14권4호
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• pp.635-640
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• 2012

In this study, thermoplastic urethane (TPU) coating yarns were prepared at various extruding temperatures. The fine structure and mechanical properties of resultant TPU coating yarns examined by the wide angle X-ray diffractometer (WAXD), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and tensile test. TPU coating yarns (prepared at extruding temperatures at $175^{\circ}C$) were confirmed as a stable fine structure that obtained excellent tensile strength and flexibility. The C samples prepared by optimized conditions made by TPU woven floor mat. The structure of the woven mat is $4{\times}4$ basket weave and have laminated with the EVA foam to obtained final TPU woven floor mat products. The resultant TPU woven floor mat was obtained to 1.5MN of tensile strength, 22% of the elongation, and 0.2MN of tear strength. The weight loss abrasion and the resilience by the ball rebound of the TPU-woven floor mat was prior to those of the PVC subsequently, we were able to develop a woven floor mat with TPU coating yarn and produce an eco-friendly high valuable woven floor mat using an interior product.

• 한국의류학회지
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• 제38권3호
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• pp.397-403
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• 2014

In this study, various types of Jumchi Hanji were made to develop shroud materials as a new use for Hanji. The properties of Hanji (basis weight, thickness, apparent density, bulk, tensile strength, wet tensile strength, elongation ratio, tear strength, bursting strength, and folding endurance) are measured. In all cases, Jumchi Hanji had a higher thickness, lower apparent density and higher bulk than Hanji because pores in the intervals of mulberry fiber are composed of bulk. So, it is considered to carry a value as a textile material. As for the results of the strength analysis of Jumchi Hanji, Jumchi technique enhances 25% of elongation ratio, which is regarded the most important role in textiles and 35% of bulk. Moreover, it was shown that it enhanced overall strength. In conclusion, it implies the possibility of applying it as a shroud material. Jumchi Hanji is thought to have enough potential to be developed as a material to carry the characteristics of Hanji in the textile market.

• 펄프종이기술
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• 제30권2호
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• pp.47-54
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• 1998

Refining is one of the most important processes of fiber treatment that provides optical and physical properties of final paper products. The evaluation method of refining progress is usually freeness (CSF) or wetness (SR) test because of its rapidity and convenience. However, there are some deficiencies in using freeness or wetness test to evaluate pulp fibers accurately because its results are more influenced by fines contents than extent of fibers treatment. The objective of this study is to show the deficiency of wetness in evaluating the refining process. For this, beating is done by varying the beating load. Handsheets are made after beating until 25 and $32^{\circ}C$ SR, and then paper properties are measured. Refined fibers are analyzed by fiber length, fines contents, curl, kink, WRV, and zero-span tensile strength. The results show that longer beating time is required to reach the same wetness at lower beating load. There are differences in the average fiber length, distribution curve of fiber length, fines contents, curl, kink, WRV of long fiber fraction, drainage time, and zero-span tensile strength of rewetted sample at different beating load. At the low beating load in the same wetness, apparent density, breaking length, burst strength, and tear strength are higher, while opacity and air permeability are lower than those of the high beating load. Using Page s equation, which shows the relationship among tensile strength, intrinsic fiber strength, and interfiber bonding strength, interfiber bonding strength is calculated and analyzed to explain final paper properties. At $25^{\circ}C$ SR, interfiber bonding strength is only slightly higher at 2.5kgf beating load, while the intrinsic fiber strength is substantially higher. At $32^{\circ}C$ SR, intrinsic fiber strength is a little bit higher at 2.5kgf beating load, and interfiber bonding strength is remarkably higher than those of 5.6kgf beating load. These results can be used to explain the different properties of the final paper at selected beating loads.

• 펄프종이기술
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• 제35권4호
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• pp.75-80
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• 2003

The purpose of this study was to design wedding dress by using Korean paper(Hanji). The Korean paper showed the good(excellent) properties of durability, softness, and tensile strength was 3.7Kg, tear index was 6 mN$.$$m_2$/g and folding numbers was 466. The appreance of Hanji was widely varied by blending(mixing) with other materials and various effects, pleating, crumpling, twisting and so on were achieved. The dress silhouette and form transformation of Hanji was very easy. Detailed points those are frill, pleats, gather, bow, paper casting, pin tuck for wedding dress were able to express easily. Hanji wedding dress has the natural texture because of natural properties of Hanji and that is echo friendly products.

• 펄프종이기술
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• 제38권5호
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• pp.9-15
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• 2006

Wet compaction test (WCT) is a fiber evaluation method where wet fibers are compressed at one side of a cylinder and water drains out from the other side. The consistency of the fiber furnishes and their pressures are recorded during the test. In the previous study we found that WCT results always gave better coefficients of determination in fiber furnish drainage, and paper properties (density, tensile, tear, and burst strength) than those of WRV (water retention value). Fiber freeness and fiber length correlated well with drainage and tear strength of the furnishes, respectively; however, their correlations were very much improved by combining the WCT results. In this study, we used the WCT test for fractionated fiber furnishes to see whether improvement of the WCT is possible. We found that strength properties such as breaking length and burst index were correlated better with the fractionated long fiber furnishes. Drainage was greatly affected by the presence of short fiber furnishes. We used bleached chemical pulps (SwBKP, HwBKP), recycled pulp (OCC), and mechanical pulp (BCTMP) as fiber furnishes in this study. Fiber fractionation can be performed on-line in these days by using multifractor and WCT can be used as an on-line test in papermachine in the future.