• Composites Research
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• 제19권6호
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• pp.38-42
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• 2006

Wood Plastic Composite(WPC) has been introduced as a new constructional material in Europe and North America. The maintenance-free durability against weather was accepted by customers and the environment-friendly merits ignited the abrupt increase of market size. Domestic major companies have kicked off the WPC business at the market of outdoor constructional materials. Due to the high contents of natural wood fiber, the production equipments should be modified to remove the moisture, to prevent thermal degradation and to promote output rates. Materials including functional fillers play a critical role in rheological properties, which affects the physical and mechanical properties of the last products. More research might be performed for synergy effects combined by various academic fields from mechanical and chemical engineering to polymer process and material science.

• 한국산림과학회지
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• 제107권3호
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• pp.305-315
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• 2018

이 연구의 목적은 "목재의 지속가능한 이용에 관한 법률"에 근거하여 불법목재의 교역을 제한하는 제도 시행에 앞서 국내 목재시장에 미치는 영향을 분석하기 위하여 수행하였다. 시나리오 작성을 위해 부패인식지수를 활용하였고 이를 바탕으로 균형대체방정식 모형을 이용하여 정책실험을 수행하였다. 원목의 균형가격 변화율은 0.066%~0.071% 범위에서 상승할 것으로 분석되었다. 원목가격의 상승은 파생수요의 관계에 있는 제재목의 생산비에 반영되어 제재목의 공급량을 감소시킨다. 상품유형별로 대체효과에 의한 국산재 수요 확대와 국내 가격상승에 의한 공급량 확대를 감안하여 분석한 결과, 국산 제재목 가격 변화율의 범위는 0.885%~4.179%에서 증가하는 것으로 분석되었으며 이에 따라 국산 제재목의 공급량은 적어도 5.367% 증가될 것으로 나타났다.

• Journal of Forest and Environmental Science
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• 제30권4호
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• pp.362-369
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• 2014

This study investigated physical properties and combustion gas characteristics for 8 types of wood pellets (4 domestic and 4 imported products) distributed in the domestic market. Results showed that most pellet types were first-grade pellets in the wood pellet quality standards in Korea with the exception of 3 pellet types from K company (second-grade in mechanical durability), G company (off-grade in nitrogen content) and P company (second-grade in ash percentage). Mixed pellets which contained more lignin and sap content were higher in mechanical durability (%) than that of white pellets. From the combustion gas analysis results, NOx emitted from all pellets combustion was at acceptable levels for national emission standard of the Clean Air Conservation Act except for pellets from G company. In addition, CO levels from all types of wood pellets were acceptable except for pellets from D company and domestic pellets were higher CO levels than imported pellets. These results indicate the higher CO levels in domestic pellets due to the usage of forest thinning materials including logging debris which usually had the high content of bark.

• 한국산림과학회지
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• 제104권2호
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• pp.254-260
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• 2015

이 연구는 수입 목제품과 국산 목제품의 수요가 불완전 대체관계에 있다고 가정하고 아밍턴 대체 탄성치를 추정하였으며 이에 근거하여 수입 목제품의 관세 인하가 국내 목제품 생산에 미치는 영향을 분석한 것이다. 분석 대상 목제품은 합판, 섬유판, 파티클보드로 하였다. 분석결과, 국산 목제품과 수입 목제품은 완전 대체관계에 있지는 않은 것으로 나타났다. 합판과 섬유판에서 국산품과 수입품의 대체 탄성치가 높게 나타나 관세를 인하하였을 때 그 영향이 적지 않을 것으로 생각된다. 이에 비해 파티클보드 시장에서 국산품과 수입품은 차별화되어 있으며 대체 관계가 낮은 것으로 보인다. 섬유판은 국내 숲가꾸기 산물을 원료로 사용하고 있기 때문에 섬유판 생산의 위축은 국내 임업에도 부정적 영향을 미치게 될 것이다. 따라서, 시장개방에 대응하여 국내 목제품 산업의 경쟁력 강화를 위한 대책이 필요하다.

• Composites Research
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• 제20권2호
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• pp.32-38
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• 2007

Natural fibers can refer to all types of fibres only produced by nature. Their lengths vary from particles to long strands. Natural fibers are categorized roughly by six types, depending on the types of sources; base, leaf, seed, grasses, fruit and wood. Of these fibers, jute, flax, sisal and ramie are the most commonly used as reinforced materials in preparing polymer composites. In development and improvement of these composites, many studies have been implemented to overcome the drawbacks such as incompatibility, moisture problems and so on. The range of industry sectors of natural fiber-reinforced polymer composites becomes more extensive gradually and many of the companies all over the world are engaged in fabrications or applications. This paper mainly discussed the recent status of the domestic/overseas market and research issues of natural fiber-reinforced polymer composites. We made an exception of wood-polymer composites market which have played a great role because they had been often dealt with.

• Journal of the Korean Wood Science and Technology
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• 제39권6호
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• pp.521-530
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• 2011

구조용 집성재의 시장 수요가 확대되고 다양화되면서 교량이나 파고라와 같이 외기에 노출되는 조건에서 사용하기 위한 고 내구성 구조용 집성재에 대한 시장 요구가 증가할 것으로 예견된다. 따라서 본 연구는 국산 침엽수재로 제조되는 구조용 집성재에 적합한 방부처리 기술 및 기준을 개발하기 위한 목적으로 진행되었다. 본 연구에서는 방부처리된 국산 리기다소나무 제재목을 이용하여 구조용 집성재를 제조하고 제조 단계별 생산수율과 KS 품질기준 충족여부를 평가하였다. 방부집성재의 제조수율은 일반 집성재와 큰 차이를 나타내지 않았으며, 목재자원의 효율적인 활용을 위해서는 집성재 제조수율 향상방안과 함께 부산물에 대한 효율적 활용방안도 함께 검토되어야 한다. 리기다소나무 방부처리재의 경우 불균일한 방부약제 흡수량으로 인하여 구조용 집성재 제조용으로 적합하지 않은 것으로 확인되었으며, 집성재 제조 후에 유용성 방부제를 처리하는 방안에 대한 추가적인 검토가 요구되었다.

• Journal of the Korean Wood Science and Technology
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• 제39권5호
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• pp.429-436
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• 2011

The selected physical and mechanical properties of non-certificated LVL circulated in domestic lumber market were investigated and compared to relevant standards. The tested LVL passed the moisture content and the soaking delamination rate limit as per domestic (KS) and Japanese standard (JAS). The evaluated mechanical properties were flatwise/edgewise bending strength, modulus of elasticity (MOE), horizontal shear and compressive strength. The 30 mm-thick LVL showed significantly higher bending strength than that of the 25 mm-thick LVL. The modulus of elasticity (MOE) showed same tendency in the results of bending strength. The edgewise bending strength and MOE were higher than that of flatwise bending strength and MOE. The horizontal shear strength values were also showed similar results to bending strength values. The tested results were compared each other and each products were graded according to JAS 701 grade specification. The failure mode of LVL in bending test showed the similar failure mode of solidwood that failed in a simple tension manner (splintery tension). The glue line failure was severe in 25 mm-thick specimens due to concentration of shear stress in layer discontinuity containing small voids and starved glue lines. In horizontal shear strength test, failure mode of LVL showed the typical horizontal shear failure. Compressive specimens failed with fiber crushing in company with apparent delamination that splitted along the length of the specimens. From the results, the complete bonding between lamination and consistency in thin veneer layer were considered as a critical factor in the mechanical properties of LVL. Moreover, the standard test procedure and specification for non-certificated LVL should be required to check the performance of uncertificated materials.

• Journal of the Korean Wood Science and Technology
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• 제41권3호
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• pp.258-268
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• 2013

목재산업은 녹색성장과 더불어 한국의 차세대 성장동력으로써 주목받고 있다. 또한, 지속적인 목재의 이용과 목재산업의 활성화를 위하여 "목재의 지속가능한 이용에 관한 법률"이 2012년 제정되었다. 자연으로부터 얻어진 목재자원의 가치를 향상시키고 선순환 구조를 지닌 목재제품이용의 확대를 통해 지속적인 성장을 동반하기 위해서는 목재제품 품질관리가 필요하다. 이 논문에서는 국내외 목재제품의 규격 품질표시제도를 살펴보고 국내 목재산업에의 적용을 위한 방안을 모색해 보고자 하였다. 제재목을 중심으로 미국, 캐나다, 뉴질랜드와 일본의 규격 품질표시제도의 운영현황에 대하여 조사하였으며 목재제품에 대한 규격 품질표시제도는 시스템 진화를 통해 생산자의 자발적 참여로 운영되는 제3자 인증제도로 발전됨을 확인할 수 있었다. 국내 목재제품의 규격 품질표시제도의 활성화를 위해서는 도입기에는 산림청 중심으로 일원화 시스템을 구축하여 조기정착을 유도하고 성장기 및 성숙기를 통해 인식구조 개선과 생산자의 자발적 참여를 위한 인센티브 개발 등의 기반을 마련하여 제3자 인증제도로 발전시켜야 할 것이다.

• Journal of the Korean Wood Science and Technology
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• 제35권2호
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• pp.61-68
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• 2007

The applicable scope of adhesives in the current society is broad and currently, several types of PVAc resin are sold in the market for adhesives. PVAc resin is primarily used for wood works and paper adhesion. However, the PVAc resin itself has the disadvantages that its viscosity is highly temperature- dependent and the work condition and viscosity get worse at the low temperature in the winter seasons. Although phthalate-based plasticizer is used to complement these disadvantages, adhesion strength and heat-resistance are weakened by adding the phthalate-based plasticizer and in the winter period, the amount of quantity should be increased. Also in a high-density product, it worsens the work condition by causing a rise of viscosity and delays curing and in a low-density product, it worsens the storage stability by causing separate precipitation. In addition to these, the phthalate-based plasticizer as a material of causing environmental hormones is currently restricted in the advanced countries for its amount of use and also in the domestic market, it is necessary to prepare for the situation. This study has not only eliminated the disadvantages of PVAc resin emulsion without adding a phthalate-based plasticizer of causing these problems, but also synthesized the PVAc resin for timber adhesion that is excellent in woodwork, thermal-resistance, water-resistance, storage stability, and adhesion performance. As the result, it has proven an excellent performance in thermal resistance, water resistance, storage stability, and minimum film forming temperature.

• Journal of the Korean Wood Science and Technology
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• 제46권4호
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• pp.323-337
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• 2018

Merkusii pine wood (Pinus merkusii) was extensively planted throughout Indonesia, where it is only indigenous in northern Sumatera, by the Dutch during colonial times. The demand for this wood species, especially in the domestic market, has increased notably, despite its limited durability regarding decay resistance. The purpose of this study was to investigate the occurrence of juvenile and mature wood on merkusii pine and to analyze its radial features from pith to bark based on density, shrinkage, static bending in modulus of rupture and modulus of elasticity, fiber length, microfibril angle, and durability. A segmented modeling approach was used to find the juvenile-mature transition. The graveyard test was performed to characterize the termite resistance from pith to bark of merkusii pine. The maturations were estimated to start at radial increments of 15 cm from the pith by fiber length and of 12 cm from the pith by microfibril angle. The projected figures for the proportion of juvenile wood at breast height were around 65%. The results also indicate that the pine wood was $0.52g/cm^3$ in density, 1.45 in coefficient of anisotropy, which indicates its good stability, 7597 MPa in modulus of elasticity, and 63 MPa in modulus of rupture. Natural durability against subterranean termite of the merkusii pine wood was rated to be grade 4 to 0 from pith to bark. However, after being treated by Entiblu and Enborer preservatives, its rating increased to grade 10 to 9.