本研究目的為改善凹版塗佈的膜厚穩定性，因膜厚為影響客戶端印刷品質的重要因子，但凹版塗佈塗層乾燥後僅20nm~3µm，生產速度高達280m/min，目前市面上無測量系統可直接並即時量測塗層厚度，故期望透過生產中塗料料槽的重量損失、塗料的密度與固成分差異、有機溶劑揮發的控制…等，其他可量測的項目去推算膜厚，實測驗證其正確性，找出影響膜厚的因子並加以改善。
為達到此目的，須先建立即時的濕塗量監看系統，並設法測得塗料的密度與固成分，結合濕塗量與固成分推算膜厚。本研究透過實驗法以PDCA (Plan-Do-Check-Act)管理循環，添購設備改善現有系統，讓濕塗量與膜厚可即時監看，再經由製程改善與優化品檢手法降低變異，期望達到改善效果。
研究發現，主要影響膜厚的原因是塗料的有機溶劑揮發造成固成分變化，進而影響膜厚，溶劑揮發的影響主要原因有兩個：
1. 生產不同幅寬產品時溶劑揮發量不同，單位時間揮發量與產品生產寬度成反比。
2. 當塗料的單位時間揮發量固定時，當迴流桶的塗料量越少時，揮發量對固成分的影響越大，固成分會急遽上升。
針對第一點，透過製程的改善，依不同生產幅寬建立不同滴定量，可有效平衡其揮發量，並讓即時濕塗量達到穩定。第二點為建立自動補料系統，讓回流桶的塗料穩定維持在30~50kg之間，可有效穩定固成分。比對改善前後各120筆資料，乾量的Cpk由0.41提升至0.95，乾量超標率由12.5%降低至0%，表示上述的對策是有效的。

關鍵字：凹版塗佈,膜厚,有機溶劑揮發,固成分

The purpose of this study is to improve the film thickness stability of gravure coating. A well-known manufacturer of decorative films in Taiwan is used as an example, and the PDCA (Plan-Do-Check-Act) management cycle is used to improve the existing system by purchasing equipment, and then the variation is reduced by process improvement and optimization of quality inspection practices. It was found that the main reason that affects the film thickness is that the organic solvent volatilization of the coating causes the change of solid content, which in turn affects the film thickness. There are two main reasons for the influence of solvent volatilization:
1. The amount of solvent volatilization is different when producing products with different widths, and the volatilization amount per unit time is inversely proportional to the production width of the product.
2. When the volatilization amount of the paint per unit time is fixed, the less the amount of paint in the trough, the greater the effect of volatilization on the solid content, and the solid content will rise sharply.
After improving the above problems, comparing 120 pieces of data before and after the change, the Cpk of the film thickness was increased from 0.41 to 0.95, and the over-standard rate was reduced from 12.5% to 0%.

Keywords：Gravure , Solvent volatilization , Solid content

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