Flexo Printing∣Common problems of flexo plate in flexographic printing#1
|The Common Issue of Flexo Plate #1|
Text, lines and patterns are too thin on flexo plate (photopolymer plate).
After flexo plate making process, small characters and independent dots fall off from the flexographic plate.
|What are the main causes of the issues relating to Flexo Plates?|
1. The exposure time of the flexo plate is insufficient.
2. The film has small contrast, fog and unclearness.
3. Improper baking and thermal curing for flexo plate (photopolymer plate).
4. The water temperature is low when brushing flexo plates, the washing out time is long.
5. The brush is too hard and the brushing is too deep.
6. Excessive pressure during flexo printing on the machine and improper adjustment.
|How to solve this Flexo Plate issue?|
Control the exposure time properly in flexo plate making process when the flexo plate has small text, lines, patterns and independent dots. The 3kw iodine gallium lamp has an exposure time of about 20 minutes. It must adjust longer than normal situation to make sure the above images won't fall off.
Due to the longer exposure time, the well-prepared flexo plate has a relatively small slope (about 70°) on the textured side and the flexo graphic base is firm.
Under normal circumstances, the oven temperature should be controlled at around 60-65 °C when baking , drying and thermal curing for flexo plates(photopolymer plate). The purpose is to evaporate the moisture on the flexo plate but if the drying temperature is too high then the flexo plates are easily to get bubbles.
The processing film for flexo plate should be without fog and make sure text and lines are smooth and clean, no lack of broken strokes.
When making flexo plates, whether it automatically processes on machines or manual brushing flexo plates, the water temperature should be controlled at 50-60°C and rinse until the base is exposed.
When brushing the flexo plates, please rotate the brush as brushing on one side is easy to brush the side and slope which causes the small lines to bend and fall off from flexo plates.
When brushing the flexo plate, choose soft and suitable brushes. If the brushes are too hard, it will cause small text is broken and damaged.Also, pay attention to the depth as it does not have to be washed to see the base.
If brushing too deeply, the text, lines, and patterns on the flexo plates will be brushed off. In addition, do not take too long for the flexo plates to be washed.
When the flexo plate is ready to print on the machine, please adjust the pressure on ink roller and the flexo plate, as well as the flexo plate and the impression cylinder.
Adjusting the pressure of flexo plates should be smaller than adjusting the copper-zinc plate and the movable-type printing plates. The ink roller and impression cylinder will crush the fine lines on the flexo plate under excessive pressure which will also affect its printing run length.
|MAXMA Flexo Plate Solution!|
MAXMA also supplys quality-oriented flexographic plates to let you replace Dupont flexo plates(Cyrel series), Flint flexo plates(Nyloflex series) and Macdermid photopolymer plates(LUX ITP series and Digital series) for saving your costs.
Please directly contact MAXMA for further solutions.
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