• Journal of the Korean Wood Science and Technology
• /
• 제22권2호
• /
• pp.37-45
• /
• 1994

The possibility of reusing the paper sludge as a raw material of composition board mixed with cement was investigated. For the measurement of physical and mechanical properties, wood coment board and sludge combinend cement boards were fabricated with the three weigh ratios of paper sludge 10 % (SI), 20 % (S II) and 30 % (S III) to cement weight. For adding the cement hardning, $CaCl_2$ was also added to each mixed paste with the ratio of 1 %, 3 % and 5 % to cement weight, respectively. Crystal formation in paper sludge-, wood-cement composites was observed by scanning electron microscope. The results were summarized as follows. 1. Density and partial compressive strength of each specimens were relatively high in the order of sludge I, sludge II, Korean pine, Italian poplar and sludge III, sludge I, Korean pine, sludge II, Italian poplar and sludge III. 2. The mechanical properties of sludge-cement boards (S I and II) were higher than that of wood-cement boards prepared with Korean pine and Italian poplar. But the mechanical properties of wood-cement boards were improved by the adding of $CaCl_2$. 3. Water absorption and thickness swelling were increased with increase of sludge content to cement weight. 4. In SEM observation, sludge-cement composites showed sufficiently formed crystals but wood-cement composites showed poorly formed crystals.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
• /
• pp.326-330
• /
• 2005

Aircraft composite structure with honeycomb core experiences core crush problem in manufacturing. To prevent core crush additional processes are needed such as core stabilization and prepreg material tie-down and this is the cause of increasing cost. Recent study shows that high friction prepreg prevent core crush without additional process. This paper presents the analysis of high frictional material which attracts lots of interests through physical property, mechanical property and microscopic

• 한국재료학회지
• /
• 제31권6호
• /
• pp.339-344
• /
• 2021

Composite materials offer distinct and unique properties that are not naturally inherited in the individual materials that make them. One of the most attractive composites to manufacture is the aluminum alloy matrix composite, because it usually combines easiness of availability, light weight, strength, and other favorable properties. In the current work, Powder Metallurgy Method (PMM) is used to prepare Al2024 matrix composites reinforced with different mixing ratios of yttrium oxide (Y₂O₃) particles. The tests performed on the composites include physical, mechanical, and tribological, as well as microstructure analysis via optical microscope. The results show that the experimental density slightly decreases while the porosity increases when the reinforcement ratio increases within the selected range of 0 ~ 20 wt%. Besides this, the yield strength, tensile strength, and Vickers hardness increase up to a 10 wt% Y₂O₃ ratio, after which they decline. Moreover, the wear results show that the composite follows the same paradigm for strength and hardness. It is concluded that this composite is ideal for application when higher strength is required from aluminum composites, as well as lighter weight up to certain values of Y₂O₃ ratio.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
• /
• pp.39-40
• /
• 2003

This research surveys the effects of POY physical properties and processing conditions of belt texturing machine to the draw textured yarns. The various textured yarns are made with variation of 1st heater temperature, draw ratio and velocity ratio, and the physical properties of these specimens such as yarn linear density, tensile properties and wet and dry thermal shrinkages are measured and analyzed with POY physical properties and processing conditions of texturing machine. Especially yarn mechanical properties of DTY are analysed with the variation of untwisting tension (T$_2$) on the untwisting part in DTY process and thin and thick DTY yam model are proposed with surging phenomena in DTY process.

• 패션비즈니스
• /
• 제10권3호
• /
• pp.23-30
• /
• 2006

Various high-touch textile products have been developed recently including ultra-fine denier filament yarn fabrics. The touch or hand of high value-added products is of prime importance. Physical and mechanical properties of fabric specimens, ultra-fine denier filament yarn fabric specimen, 100% wool fabric and wool/polyester 50:50 fabric,were measured using the KES. Compressibility of the ultra-fine denier fabric is recommendable, possibly due to the good bulk property of the specimen. Overall, the THV of the ultra-fine denier fabric is positioned between those of the 100% wool fabric and wool/polyester 50:50 fabric. Observed differences in the physical and mechanical properties explain the fabric specimen characteristics reasonably.

• 펄프종이기술
• /
• 제35권3호
• /
• pp.59-65
• /
• 2003

This research was conducted to investigate the physical properties of Hanji made using maize, konyaku, and wheat powders at various concentrations. Regardless of the starch types, the most effective concentration to increase the physical properties of Hanji was 2 percent. They were significantly improved even at the treatment conditions of 0.1 percent. All the Hanji treated showed the increase of the breaking length, bust index, and tear index and the decrease of the folding number. The strength properties of the Hanji treated were markedly improved at 8 to 10 percent weight increase. The highest mechanical properties were found in the Hanji treated with konyaku powder.

• 한국세라믹학회지
• /
• 제37권7호
• /
• pp.645-650
• /
• 2000

Effects of the chemical composition and sintering atmosphere on the formation of reaction phases and physical properties of reactive hot-pressed TiB2-AlN-BN composites were investigated. At N2 atmosphere, TiN was formed by the reaction between Ti and N2, which inhibited the densification and results in inferior mechanical-and electrical properties of the composites. However, at Ar atmosphere, enhanced densification and physical properties of composites were obtained due to that the TiN formation reaction was excluded. Densification of the composites was also hindered by BN, therefore, inferior mechanical-and electrical properties of composites were obtained with amount of BN in the starting materials. At Ar atmosphere, TiB2-AlN-BN composites having 318 MPa of flexural strength, 3.5 MPa.m1/2 of fracture toughness and 276$\mu$Ω.cm of electrical resistivity were fabricated from mole ratio 1:2:1.6 of Ti-Al-BN mixtures.

• 한국세라믹학회지
• /
• 제40권3호
• /
• pp.273-278
• /
• 2003

다공질 세라믹스 흡음재료의 흡음특성과 물리.기계적 특성에 미치는 하수슬러지 슬래그 첨가량과 입경 효과에 대하여 조사하였다. 시편의 물리.기계적 특성은 슬래그 입경과 관계 없이 소성온도가 증가하고 슬래그 함량이 감소함에 따라 증가하였으며, 슬래그의 함량이 일정한 시편은 물유리 첨가량이 증가하고 슬래그 입경이 감소함에 따라 증가하였다. 1~3mm 크기의 슬래그를 약 77~89 wt% 함유하고 1,05$0^{\circ}C$에서 2시간 소성한 시편의 부피비중은 1.48~1.71, 압축강도 85~163 kgf/$\textrm{cm}^2$을 나타내었으며, 1~3mm의 슬래그를 이용한 시편은 저주파영역, 슬래그 입경이 1 mm이하인 시편은 고주파영역의 흡음특성이 향상되었으며, 시편의 두께가 증가함에 따라 저주파영역의 흡음특성이 향상되었다.

• 한국가구학회지
• /
• 제13권2호
• /
• pp.19-28
• /
• 2002

This study was carried out to investigate the wood properties for efficient utilization of warm temperate tree species. The tested species were Actinodaphne lancifolia Meisn. grown in Korea. Fundamental wood properties such as anatomical, physical and mechanical properties and chemical components were examined. This species was diffuse porous, straight grained and fine textured wood. The heartwoods of this species was not distinguished clearly to the sapwoods. This species had moderate specific gravity, shrinkage, and mechanical properties. And this species had high content of the extractives by organic solvent.

• 임산에너지
• /
• 제22권2호
• /
• pp.26-35
• /
• 2003

Bamboo strand board (BSB) was made with Phyllostachys banbusoides growing in Damyang district. Physical and mechanical properties of this BSB were summarized as follows; The specific gravity of BSB was 0.63∼0.79. Specific gravity decreased slightly with the thickness and length of BSB. Moisture content of BSB manufactured was 5.8∼6.9%. The absorption ate of BSB (42∼48%) did not show any relationship with the thickness and length of BSB. The thickness swelling rate of BSB was 13.9∼17.0%, relatively higher than any other panel products. Thickness swelling rate increased with the thickness of BSB, showing the strand thickness influenced much more on the rate of thickness swelling of BSB than the length of strand. The 3-point bending strength of BSB was 98∼126kgf/$\textrm{cm}^2$. Bending strength of showed the tendency of increase with the increased length of BSB, but with the decreased thickness. In particular, the length of BSB showed more effect on the increase of bending strength of BSB than the thickness of BSB. The compression strength perpendicular to BSB surface was 411 ∼ 465 kgf/$\textrm{cm}^2$, and the optimal length of strand for the 1mm- and 2mm-thickness of strand was 40mm and 60mm, respectively. Compression strength paralleled to BSD was 160∼221kgf/$\textrm{cm}^2$ and the optimal length of strand for the 2mm-thickness of strand appeared to be 60mm. The present work showed that appearance, physical and mechanical strength of BSB appeared quite positive in terms of board qualities, suggesting that bamboo would be appropriate for the production of board materials. In addition, our work showed that the crucial factor for determining the mechanical characteristics of BSB was the dimension of strand.