Paper Static Elimination and Envelope Flattening Technology for Flexo Envelope Printing
This technical article solves two core pain points in
flexo envelope printing: paper static adhesion and uneven feeding caused by pre-folded envelope flaps, and optimizes feeding and register system for special folded paper substrates.
Flexo envelope printing targets finished pre-folded envelope paper with special three-dimensional flap structure, which is completely different from flat cardboard and roll paper substrates. Pre-folded envelope flaps cause uneven paper thickness during feeding, while dry envelope paper generates massive static electricity, leading to paper sheet adhesion, skewed feeding and pattern register deviation in sheet-fed flexo printing.
Static electricity accumulation mechanism of envelope printing paper. Envelope wood pulp paper has high insulation performance, and high-speed sheet friction generates static electricity that cannot be released quickly. Accumulated static electricity makes multiple envelope papers adhere together, causing double-sheet feeding fault and missing printing in sheet-fed flexo presses.
High Speed Flexo Printing Machine - Stack Flexo Flexo Printing Machine
Multi-stage static elimination system designed exclusively for envelope flexo presses. Contact static elimination rollers eliminate surface static directly before paper feeding; ion air blowers remove residual floating static electricity in paper transmission channel; ground wire modules release accumulated static charge to workshop ground. Combined three-level static elimination reduces paper adhesion fault rate close to zero.
Front-end envelope flap pre-flattening device for uniform feeding. The mechanical pre-flattening mechanism gently presses folded envelope flaps temporarily flat before printing station, eliminating paper thickness difference caused by raised flaps. After printing, the flaps rebound automatically to original state without damaging pre-folded creases, ensuring consistent printing pressure on whole envelope surface.
Fixed register mark positioning for envelope exclusive pattern. Envelopes have fixed printing areas avoiding flap bonding positions. The visual register system locks printing area boundary automatically, preventing patterns from covering envelope glue coating zones and affecting subsequent envelope sealing process.
Low-pressure printing parameter setting for thin envelope paper. Envelope paper is thinner than common folding carton cardboard, so excessive printing pressure will cause paper indentation and paper fiber damage. Reduced standard impression pressure by 15% guarantees clear ink transfer without destroying envelope paper surface integrity.
