應用實驗設計法改善食品外包材製程廢棄物量—以Y公司為例

Abstract

食品的包裝材料從早期的金屬、玻璃，發展至今的塑膠。由於PET塑膠瓶的出現，帶動了外包材-印刷收縮標籤的誕生。塑膠膜料的製造過程，從前段的製粒、抽料、分條，到中段的印刷製程、分條、合掌、複檢、切片，最後上機在顧客端之套標機台進行熱收縮套標。依據相關文獻及工程經驗，可知透明膜料原物料配方、膠粒乾燥處理參數對膜料品質具有關鍵性的影響，因此如何維持透明膜料製程的穩定性就成為膜料業界一個重要議題，忽視此類原物料的穩定性，將會衍生許多後續製程上品質的問題，進而造成重工、報廢、環保等問題。因此，本研究的主要目的是應用實驗設計手法，找出可提升環保材質PET透明膜料產品穩定性的機台參數最佳設定值及原物料配方。本研究係以台灣某透明膜料製造商為個案，利用本研究方法來降低顧客退回不良報廢品之數量，進而改善個案公司不可回收廢棄物之環保問題。Y公司經本研究方法改善後，顧客退貨率從20%降至5%內，相當於廢膜料量從每月36噸減少至10噸以內，即一年可減少支出約200萬，顯示本研究方法對個案公司改善效果顯著。

Materials for food package change from metal, glass to plastic bottles. Due to the development of PET plastic, the shrinkable label is also developed. The manufacturing process of the plastic film, starting from the granulation, strip material, extraction, then printing process and strip again, stack, quality review and slice. Finally, ship to clients using sleeve shrink machine for thermal shrinkage. Based on the previous studies and engineering experience, the crucial influences on the plastic film are raw-material formula and treatment of drying process. How to control the stability of the film manufacturing process has become the focus of the film industry. The unstability of the raw materials would cause many quality problems, such as rework, scrap and environmental issues. Therefore, the main purpose of this study is to apply the Design of Experiments(DOE) to find out the optimal parameter-setting of PET plastic films to reduce the amount of customer return. The customer return rate of the case study of Y company was 20% and is reduced to 5%. This is equivalent to reduce the amount of waste film from 36 tons per month to less than 10 tons. Consequently, it could reduce the expenditure of Y company about 2 million per month.