鸡蛋包装生产工艺的生命周期评价

鸡蛋包装多为一次性使用且消耗量很大,其材料一般为纸浆模塑和PVC等.基于生命周期评价(LCA)方法,利用eFootprint软件及数据库,对采用两种不同材料生产的鸡蛋包装分别建模,对二者的环境影响进行评价.研究选取的功能单位是可容装30枚鸡蛋的单个蛋托,尺寸为长292 mm、宽245 mm、高35 mm;系统边界包含该蛋托加工过程的主要工序,如包装材料加工、压制成型、分切、出厂包装等工艺过程.研究结果表明,评价对象在全球变暖潜值(GWP)、水资源消耗(WU)和初级能源消耗(PED)等环境影响方面贡献值较大,纸浆模塑蛋托这三类环境影响分别为90 g,0.17 kg,1.3 MJ,PVC蛋托这三类环境影响分别为720 g,4.27 kg,9.84 MJ.根据评价结果可知,纸浆模塑蛋托比PVC蛋托对环境产生的影响更小,故应优先选择纸浆模塑蛋托.建议在保证产品质量的前提下,优先选择对环境影响小的材料以及助剂进行产品设计、生产,并通过选择更高克重的PVC材料、修改蛋托结构设计等方式,降低包装产品对环境的影响.

Life Cycle Assessment of Egg Packaging Production Technology

The packaging for eggs is mostly disposable with great consumption. Its main materials are generally pulp molding and polyvinyl chloride, etc. Based on life cycle assessment (LCA) methodology, the environmental impacts of egg packaging with two different kinds of materials were built models and evaluated by using eFootprint software and database. The functional unit was based on a single egg packaging which could hold 30 eggs with the size of 292 mm in length, 245 mm in width and 35 mm in height. The setting of system boundary included the main processes of the egg packaging, such as packaging material processing, pressing, die cutting and packaging products etc. The results showed that the evaluation objects contributed a lot to GWP, WU and PED. The environmental impacts of pulp molded tray for eggs were 90 g, 0.17 kg, 1.3 MJ, while the polyvinyl chloride tray for eggs were 720 g, 4.27 kg, 9.84 MJ. According to the evaluation results, the influence on the environment from the pulp molded tray for eggs was smaller than that of the polyvinyl chloride tray, therefore, pulp molded tray for eggs should be preferred. On the premise of ensuring products quality, it was suggested to give priority to the materials and additives which had little impacts on the environment for product design and production, and reduce the impacts on the environment of packaging products by selecting PVC materials with higher gram weight and modifying the structure design of egg tray.