Analisis Pengaruh Opasitas Tinta Putih Terhadap Cacat Bubble Pada Proses Cetak Rotogravure Kemasan Flexible

Penelitian ini bertujuan menganalisis pengaruh opasitas tinta putih terhadap cacat bubble pada proses cetak rotogravure kemasan fleksibel di PT XYZ. Penelitian dilatarbelakangi belum diterapkannya parameter opasitas pada prosedur incoming inspection tinta sehingga variasi karakteristik tinta dari tiga pemasok berpotensi memengaruhi kualitas hasil cetak. Penelitian menggunakan metode kuantitatif dengan pendekatan eksperimen dan analisis deskriptif. Pengujian dilakukan terhadap tinta putih menggunakan parameter opasitas, viskositas, dan densitas pada substrat OPP. Opasitas diukur menggunakan X-Rite Spectrodensitometer dengan metode contrast ratio, sedangkan data dianalisis menggunakan regresi linear sederhana. Hasil penelitian menunjukkan bahwa peningkatan opasitas cenderung meningkatkan viskositas dan densitas tinta sehingga pelepasan udara selama proses pencetakan kurang optimal dan jumlah cacat bubble meningkat. Sebaliknya, opasitas yang terlalu rendah menghasilkan daya tutup yang kurang baik. Rentang opasitas sekitar 50-60% memberikan keseimbangan terbaik antara daya tutup dan rendahnya cacat bubble, sehingga dapat dijadikan parameter penting dalam pengendalian mutu tinta dan proses pencetakan.

This study aims to analyze the effect of white ink opacity on bubble defects in the rotogravure printing process of flexible packaging at PT XYZ. The study was motivated by the absence of opacity as a parameter in the incoming ink inspection procedure, allowing variations in ink characteristics from three suppliers to affect print quality. A quantitative experimental approach with descriptive analysis was employed. White ink samples were evaluated based on opacity, viscosity, and density using OPP film as the substrate. Opacity was measured using an X-Rite Spectrodensitometer based on the contrast ratio method, while the data were analyzed using simple linear regression. The results indicate that higher opacity tends to increase ink viscosity and density, reducing air release during printing and consequently increasing bubble defects. Conversely, excessively low opacity decreases hiding power. An opacity range of approximately 50-60% provides the best balance between adequate hiding power and minimal bubble defects, making opacity an important quality control parameter for incoming ink inspection and rotogravure printing.