纸基复合包装中铝塑分离的湿法工艺条件研究

纸基复合包装中的纸基部分通过水力碎浆分离后可直接用于生产再生纸. 其铝塑部分由1层0.02～0.03 mm厚的铝箔和2层0.03～0.08 mm厚的低密度聚乙烯膜层压复合而成，主要对铝塑的湿法分离进行研究.比较了甲酸、乙酸、盐酸3种剥离剂的分离效果; 用甲酸作为铝塑剥离剂时, 考察了剥离剂的浓度、反应温度、液固比及破碎尺寸对铝塑分离的影响; 根据铝塑分离时间、分离率、铝的损失率等指标，通过正交试验及方差分析优化铝塑分离的工艺条件. 结果表明，甲酸分离铝塑的最优条件: 剥离剂浓度为4 mol/L, 反应温度为60 ℃,液固比为60 L/kg, 破碎尺寸为5 cm×5 cm. 在该条件下, 铝塑的分离率达到100%. 

Research on the Wet Process Conditions of the Separation of Aluminum and Plastic in Post-Consumer Aseptic Packages

The paper part of post-consumer aseptic packaging can be used to produce recycled paper, while the aluminium and plastic parts are composed of low-density polyethylene (LDPE, 0.03-0.08 mm) and aluminum foil (0.02-0.03 mm). This study focused on the separation of aluminum and plastic in post-consumer asepticpackages using a wet process, and compared the different separation degree by methanoic acid, acetic acid and hydrochloric acid. The major variables when methanoic acid was used as the Al-PE separation reagent, such as the separation reagent concentration, reaction temperature, liquid to solid ratio and solid size, were studied. Separation conditions were optimized by experimenting with orthogonaldesign and variance analysis based on evaluating indicators of separation time,separation rate and mass loss rate of Al. The results showed that the optimum separation conditions of aluminum and LDPE using methanoic acid as a separation reagent were: 4 mol/L of methanoic acid concentration, 60 ℃ of reaction temperature, 60 L/kg of liquid to solid ratio and 5 cm×5 cm of solid size. The separation rate reached 100% under these conditions.