Study on Manufacture of Korean Paper(Hanji) Sludge-Wood Fiber Composite Boards I. Physical Properties of Korean Paper(Hanji) Sludge-Wood Fiber Composite Boards

한지슬러지-목재섬유 복합보드의 제조연구 I. 한지슬러지-목재섬유 복합보드의 물리적 성질

This study was carried out to develop the Korean paper(Hanji) sludge-wood fiber composite boards utilizing the relinquished sludges occurring from the making process of Korean classic paper Hanji. The bark of paper mulberry(Broussonetia kazinoki Sieb.) has been used as a raw material since past hundreds and thousands years. Korean paper(Hanji) sludge was divided into two kinds, the one was the white sludge from the first stage and the other was the black sludge occurring from the final stage of Korean paper(Hanji) making. Four levels of the mixed ratio of each white or black sludge to wood fiber(10:90, 20:80, 30:70 and 40:60), three levels of the resin adhesives(PMDI, urea and phenol resin) and three levels of the density(0.60, 0.75 and 0.90) were designed to investigate the physical properties of Korean paper(Hanji) sludge-wood fiber composite boards. From the results and discussion, it could be concluded as follows : 1. In the white sludge-wood fiber composite board, the thickness swelling was not affected by the specific gravity and sludge additive of composite boards, but among the resin adhesives PMDI resin showed the best dimensional stability. Water absorption was superior in urea resin, secondly PMDI resin and very poor in phenol resin. 2. In the black sludge-wood fiber composite board, thickness swelling was superior in PMDI resin but very poor in phenol resin. In water absorption, PMDI and urea resin showed good results, regardless of specific gravity or sludge additive, but phenol resin showed poor results. 3. From the results and discussion of physical properties it is suggested that the white sludge-wood fiber composite boards bonded with PMDI or black sludge-wood fiber composite boards bonded with urea resin were made possibly with similar or better properties. compared with general fiberboard until the addition of 20% sludge into wood fiber.

한지제지 공정 중에서 발생하는 백색슬러지와 흑색슬러지를 각각 일정비율(10:90, 20:80, 30:70, 40:60)로 목재 섬유와 혼합하고 PMDI, 요소 및 폐지수지를 이용하여 목표비중 0.60, 0.75, 0.90 별로 복합보드를 제조한 결과 전반적으로 볼 때 백색슬러지를 20% 정도까지 혼합하고 PMDI 수지를 적용하면 통상적인 보드와 유사하거나 오히려 더 좋은 치수안정성을 가지는 것으로 판단된다. 또한 흑색슬러지의 경우는 요소수지를 사용하거나 PMDI 수지의 첨가량을 증가시켜 조절한다면 20%의 슬러지 첨가량까지는 치수안정성 면에서 통상적인 보드와 큰 차이가 없는 보드를 제조할 수 있다고 믿어진다.