Static Issue?
I’m running a Heidelberg Windmill 10x15 with the guides. Everything ran beautiful yesterday, but today the paper is being left behind in the press. As I run the press slowly by hand, the gripper picks up the stock and pulls it over towards the side guide and bottom guide. Just as the gripper releases the stock, you can literally see it jump back from the gripper bar about 1/4”, so that when the gripper closes again it leaves the stock behind in the press. From my 38 years of letterpress experience, this is a static issue, but does anybody have a quick fix? Some days this odd occurrence will happen and others it won’t. Usually my shop is kept at a constant 70 degrees and 45% humidity. Lately the temperature has been running around 75 degrees and the humidity around 35-40% I know from experience that once you fall below 40% is when static is most likely to crop up. I’m running 2 humidifiers, and the stock itself seems static free. Is there some way to ground the press to prevent static build-up, like that rubber strip on the bottom of the plastic shopping carts at Target? I only have one job that requires this close register running, and it always happens to come in during the winter months when static is a possibility.
Have you tried using a perfume mist er and spraying the packing with a little water and wiping it off quickly?
you are using a waxed or treated tympann sheet i assume and not some calendered art paper ?
Go to the grocery or supermarket; find a can of staticguard. Spray your packing and platen with it and wipe off with a fresh paper towel or shop rag. This should help. I keep the can handy near my presses, especially my C&P given the amount of static that thing can have during the winter…
Another thing some people use on other types of presses where there is a lot of rubbing going on is copper tinsel, though I don’t know where/how you could apply that here.
(I seem to recall having read that properly set gripper arms on a windmill will actually wipe the tympan paper as they pass over it?)
I have found that wiping the moving parts: grippers, feedboard and tympan with dryer sheets can reduce the static electricity.
Paul
Paul, great idea, dryer sheets, i never would have thought of them, thanks, another great tip, but if i’m caught stealing my wifes dryer sheets i’m telling her you put me up to it.
Don’t get caught!
RE STATIC Far Out maybe but just possibly worth a thought, along with many others and rising!!! playing and playing with VINYL record collection nobody gets more jarred off with static than we hence we use antistat spray (Team Diamond) etc . we spray antistat onto very very soft cloth (spectacle cleaner soft?) and rotate the vinyl under the pad, to remove inherent static and then spray a minute drop onto the soft brush that tracks across the grooves as the vinyl is turning. Knowing that many cylinders are equipped with soft brushes to keep the fed sheets in contact with the cylinder, WHY NOT instead of the quick fix, repetetive, wipe, adapt the vinyl record system, as above, and even take a very thin braided copper conductor, from the brush bar, to proper ground or earth, laugh if you will but here, in the U.K. it was a very common sight to see cars and especially space wagons, with the braided strap, conducting, static induced travel sickness, away to earth!!! Fall about with laughter if you will BUT just give it a tiny thought, possibly boring, quick fix every so often, versus in built semi-permanent answer???
re static-induced travel sickness and static electricity problems for printing:
It is thought that, in Australia, vehicle tyres (tires) are made so that they are conductive and static electricity is “grounded” (“earthed” in Australia).
Circa 1950s, a strap made of similar material was marketed for the same purpose. It was claimed that a local (my home town) family used a strap, but the most susceptible of the family became sick on one long trip; when they looked, they found that the strap had been tossed up and caught up in part of the vehicle so that it was no longer effective; it no longer contacted the roadway.
Circa 1930s, fuel tankers dragged a metal chain to overcome static electricity problems; not used now, probably because of conductive-tyre solution to problem.
If you look at desk-top home computer printers of the laser type (laser and powder) you may find some devices which are designed to discharge “static” (deliberate, it’s part of the process), strips with feathery conductors which brush the paper.
Before conductive tyres, toll-bridge fee collector personnel were sometimes “zapped”, so a line of flexible wires projecting upwards brushed the bottom of vehicles to discharge any static-electricity charge; I last heard of this problem about 50 years ago. Not a problem where I live, it’s a high humidity area.
But I talked to printers who worked on the bank of a large river, and their humidity changed according to direction of wind, so that multi-pass multi-coloured labels (printed multi-up) gave severe register problems due to change of dimensions of paper. I have not visited them for many years, it may be that they have enclosed the workplace, air-conditioned and stabilised humidity.
Humidity and static electricity may have been the cause of a problem at a weekly newspaper where I worked for a year; the stand-in printer got about 600 impressions out during 14 hours overnight, then things started to run OK and the machine turned over at 2000 per hour; I never heard if they solved the problem till they installed a web-fed press in place of the sheet-fed machine. But of course, that only side-stepped the problem, did not result in a solution?
In other words, taking steps to defeat static electricity may be worth a try, but how do you know if (perhaps) humidity has come to the rescue? Can you humidify the air at the workplace?
Alan.
P.S.: The instructions with the “Flying Doctor” radio read to connect the earth lead of the radio (transmitter and receiver) to a “good earth”; so the people on the cattle station (ranch) dug up some of the best soil from the flower garden, put it in a large earthenware plant-pot, and kept it watered well; but wondered why their wireless (radio) reception was not good. Sometimes a different antenna was used, one which used a counterpoise, which is good where the soil is not conductive; only now have I realised the necessity for good ground (soil) conductivity which gave me a problem during my primary-school days. — Alan.
Tried the water on the tympan and tried the static guard all to no avail. The problem I have is that the heating system is buggered up. The temperature is set to keep the top floor at 70 degrees, but the temperature on the bottom floor where the presses are located rises to 80 degrees. I know, heat rises right?? Anyroadup, I’ve got a guy coming in to correct the problem and then I should have no problem maintaining the humidity at 45-50% and temperature at 70 degrees up and down. But, oddly enough I have had the same issue during the summer when the humidity is 50%, so go figure! Ahh the joys of printing! I’m going to switch back and run the job without the gauges, but just run it slow to keep the register as tight as I can. What can you do? You gotta get the job out; can’t wait until things change. I’ll keep working on it until I find a solution. I’ve got a friend that’s a mechanical genius; maybe I’ll give him a call to see what he can come up with.