Oscillating roller-recomended frequence?

[nosefo]

We have a 1994 mod. narrow web press (52cm) from the manufacture Castagnoli Form Consulta: Evolution VS650. We have stuggled with stripes or ghosting on the printed surface. This stripes is caused by the negative printing area mostly. The extra color that have built up on the rollers because of this negative field, will on the next turn of the roller be printed with almost double density. Our oscillating rollers have the ratio of 12:1. That means that the oscillating roller turns 12 times before it has moved the whole movement. Is that ratio normal?

We have now also tried out a gearbox with ratio 7:1. the oscillating roller sutanly move faster, but i didnt gave the result we expected. Any Idea how to solve/reduce this problem?

More info:
We have 3 oscillating roller in every print tower. Nr.1 is almost on top with the ink fountain, the nr. 2 next to the roller for ink/water-plate. And nr. 3 is shared between the two form rollers.
Our cirmferencial is 24"- 61cm
We use color from Coates Lorrilux- UV, Fountain solution is: Swego soft 2000, IPA:9%, PH around 4

 

[xpquickprint]

Yes you have an idea but you aren't sharing it acceptprint?

 

[nosefo]

What do you mean?