In a series of three articles published in the peer-reviewed journalPackaging Technology and Science,来自Wageningen Food & Biobased Research, Biobased Products Business Unit,荷兰瓦赫宁根,研究了回收聚对苯二甲酸乙二酯(rPET)质量和回收含量水平对PET瓶性能的影响。

In第一部分,published on January 12, 2020, optical and mechanical properties, including haziness, color parameters, environmental stress cracking, and particle contamination were systematically studied in PET bottles containing 25-100% rPET of three different quality types. Particle contamination was studied by “dissolving bottle fragments and counting the insoluble particles.” Higher levels of particle contamination were found in rPET compared with virgin PET, as well as in rPET originating from co-collection systems compared with rPET from mono-collection systems. Particle contamination in turn directly correlated with the haziness and color parameters of PET bottles. The authors noted that “the acceptance of a hazy bottle depends on the color of the beverage and the marketing strategy of beverage company. Haziness could be more accepted by the consumers if they are aware that it indicates the use of recycled content in the bottles. Color and haze are marketing aspects and are not always regarded negatively.” In addition, some color parameters can be “largely influenced with additives.” The occurrence of environmental stress cracking did not correlate with the presence of rPET but was influenced by rPET processing parameters, and particularly by internal viscosity, which “can be ‘tuned’ during rPET production,” the authors explained.

In第二部分,发表于2020年8月3日,提供了迁移数据。作者总结说:“乙醛[(CAS 75-07-0)]和乙二醇[(CAS 107-21-1)]的迁移量符合食品接触材料(FCM)法规中给出的限值。”乙醛和乙二醇的缩合产物2-甲基-1,3-二氧戊环(CAS 497-26-7)的迁移浓度“低于限值”10µg/L,通常用于非故意添加的物质(NIA),不分类为“致癌”、“致突变”或“生殖毒性”(CMR)。“其他检测到的迁移物包括柠檬烯(CAS 138-86-3)、丙酮(CAS 67-64-1)、丁酮(CAS 78-93-3)、呋喃(CAS 110-00-9)、苯(CAS 71-43-2),苯乙烯(CAS号100-42-5)。作者解释说,柠檬烯是一种“天然香料”,而丙酮和丁酮“可能是小规模生产设施中用于清洁和保护霉菌的溶剂的残留物。”呋喃可能来源于“各种有机杂质”,因为这种物质是“已知的生物质热解产物,是由在热处理食品中,“苯和苯乙烯也被认为是由PET基体中的热诱导反应产生的,这涉及到污染物。”苯的形成尤其可以“归因于聚氯乙烯作为污染物,“苯乙烯”可能源于聚苯乙烯的热降解,聚苯乙烯是低质量PET中的一种聚合物污染物。“苯的迁移量被描述为“相对较小”,估计代表“风险管理的低优先级”。至于其他NIA,作者的结论是“根据潜在的数据和暴露场景,可以得出食品中不同的阈值限值,这仍然可以被认为是安全的。”。可能基于多种暴露情景,因此产生不同的结果,”在对含有rPET的瓶子提出最大回收含量建议之前,似乎有必要进行“进一步的风险评估”。作者进一步概述了有助于降低“rPET中的苯和其他NIAS”风险的两种策略,即“降低rPET中的氯浓度,并将注塑和吹瓶过程中暴露在高温下的时间限制在[最低限度]。”

In第二部分I,发表于2020年8月3日,给出了重复回收情景的建模结果。作者分析了在回收循环的不同步骤中颗粒和瓶子中存在的污染物,并提出了一个模型“一般描述在PET瓶子的闭环回收方案中这些污染物的累积”。发现收集系统的类型“极大地”影响这些污染物的累积PET瓶中的污染物,如单收集系统的瓶子比共收集系统的瓶子含有更少的污染物。因此,作者得出结论,“在使用单一收集系统的回收方案中,PET瓶比共收集系统含有更多的回收内容,而不会超过关键瓶性能的接受限值,如朦胧度、泛黄,利用所提出的模型可以计算出允许的回收物含量。

工具书类

Chacon,F.A.等人(2020年)。“回收率和rPET质量对PET瓶性能的影响,第一部分:光学和机械性能。Packaging Technology and Science内政部:10.1002/pts.2490

Thoden van Velzen,E.U.等人(2020年)。“Effect of recycled content and rPET quality on the properties of PET bottles, part II: Migration.Packaging Technology and Science内政部:10.1002/pts.2528

Brower,M.T.等人(2020年)。“回收物含量和rPET质量对PET瓶性能的影响,第三部分:重复回收的建模。Packaging Technology and ScienceDOI: 10.1002/pts.2489.

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