The Dyeing Properties of Woody Fiber Regenerated from Waste MDF by Reactive Dyes

This study aims to review the relations between the dyeing conditions (i.e., dye concentration, addition amounts of salt and alkali, and dyeing temperature) and dyeing properties and color fastness to light for identifying the optimal dyeing conditions when dyed regenerated woody fibers were obtained through the defibration of waste medium density fiberboard (MDF) using reactive Red H-E3B (Bis-monochlorotriazine (MCT)/MCT type) and reactive Red RB133% (Bis-MCT/Vinyl sulphone type). The dyeing yield (K/S) obtained using two types of reactive dyes increased as the dye concentration increased by 1-10% (on the weight of fiber (OWF)). In addition, the K/S of H-E3B was higher than that of RB133% irrespective of the dye concentration. The color difference of H-E3B after ultraviolet (UV) radiation was lower than that of RB133%, denoting good resistance to discoloration by UV. As the amount of sodium sulfate increased, the color difference and K/S also increased, and the adequate salt content was determined to be 50-70 g/L. Further, the color difference and K/S significantly increased only the addition of 2 g/L of sodium carbonate; however, almost no difference was observed when more than 2 g/L of sodium carbonate was added. The addition amount of sodium carbonate was adequate 5-10 g/L to dyeing the fiber and the pH at this addition level was 10. The dyeing yield of H-E3B increased when the dyeing temperature increased; however, it subsequently decreased after the dyeing temperature became $80^{\circ}C$. The dyeing yield of RB133% was almost the same up to $60-70^{\circ}C$ but declined subsequently. Thus, the adequate temperatures were $80^{\circ}C$ and $60^{\circ}C$ for H-E3B and RB133%, respectively. If the waste MDF woody fiber was dyed under the aforementioned optimal conditions, dyed regenerated woody fiber can be obtained having the following colors: 1.5 to 2.0R with the H-E3B dye and 9.6 to 10.0 PR with RB133%.

반응성염료에 의한 폐MDF 재생 목질섬유의 염색특성

폐MDF로부터 해섬하여 얻은 재생섬유를 Reactive Red H-E3B (Bis-monochlorotriazine(MCT)/MCT type)와 Reactive Red RB 133%(bis-monochlorotriazine/Vinyl sulphone type)로 염색할 때 최적의 염색조건을 구명하기 위하여 염색조건(염료 농도, 염과 알칼리 첨가량, 염색온도)과 염색특성 및 일광견뢰도와의 관계를 검토하였다. 2종의 반응성염료 모두 염료농도가 1~10(%,OWF)로 증가함에 따라 염착량(K/S)은 증가하였다. 또한, H-E3B가 RB 133%보다 염료 농도에 관계없이 K/S는 높았으며, 자외선 조사에 따른 색차는 낮아 자외선에 의한 변색 저항성이 양호하였다. 황산나트륨의 첨가량이 증가할수록 색차 및 K/S도 증가하였으며, 염의 첨가량은 50~70 g/L가 적절하였다. 2 g/L의 탄산나트륨 첨가에 의해 색차 및 K/S가 크게 증가하였으나 그 이상의 첨가량 증가에서는 거의 차이가 없었다. 탄산나트륨의 첨가량은 pH 10을 유지하는 5~10 g/L가 적절할 것으로 생각된다. H-E3B 염료는 염색 온도가 높아짐에 따라 염착량이 증가하다가 $80^{\circ}C$에서 다시 감소한 반면 RB 133%는 $60{\sim}70^{\circ}C$까지는 거의 동일한 염착량을 나타냈으나, 이후 감소하였다. 따라서 H-E3B는 $80^{\circ}C$, RB 133%는 $60^{\circ}C$가 적정한 것으로 판단된다. 이상의 최적조건에서 폐MDF 목질섬유를 염색처리하면 H-E3B염료는 1.5~2.0R, RB 133%염료는 9.6~10.0 PR의 색상을 가지는 염색 재생 목질섬유의 제조가 가능하였다.