In my last post we discussed the possibility of implementing process controls in reclaim to recapture ink before it becomes waste. You can say the same thing about emulsion. If you can’t produce a usable screen and need to expose a second time, you have lost time, which is money, and throws you off your production schedule. One of the biggest time suckers that causes these issue is pinholes. This blog will be broken down into smaller snippets because of the many ways that people can produce pinholes. This is not a blame game, but when you see how existing processes can cause what are called pinholes, you might have a few AH-AH!! moments.
First and foremost, I have actually seen a real pinhole. This is caused by a printer taking a needle and puncturing the mesh for the sole purpose of getting something (usually a fleck of hardened emulsion) out of the image area. Two things happen here: one, the integrity of the mesh has been compromised and you will see a rip in that area soon. And two, as the hole expands it will affect your next job. So that, ladies and gentlemen, is a real pinhole.
Other voids in the mesh that are the size of pinhead are a different animal and the causes are many. If you are going to figure out where in the prepress process the voids are being created, a loop-magnifying glass is absolutely a necessary tool. It actually allows you to look into the center of the void to determine the cause. Everyone who has access to the screen before it is coated, when its coated, and after the emulsion is dry should have one in their possession.
My all-time favorite cause of “pinholes” is also the main culprit at the end of reclaim. When I convert someone to Easiway Products, either in a manual application process, or to a Dip Tank process. Most, if not all, of our screen washes and emulsion removers have built in degreasers. With that said I always explain to the customer that the final rinse is with weight of water, flood rinse, no pressure. I make an emphatic point to make sure that we are all on the same page with the final water rinse. I leave and not a day later I get the “I’ve got pinholes like you can’t believe” call. After we step back from the edge of the cliff, I ask if the reclaim person, who was there and cleaned screens with me yesterday is ‘flood rinsing’ like I demonstrated with weight of water, I get one of two answers: 1-He/she isn’t in today; we have a new person in reclaim. Or, “how would I know, I’m on a press!” I understand the frustration level so I just start all over again with how to flood rinse both sides of the entire screen and call me back. Eighty-five percent of the time that usually fixes the issue. In the few instances that it does not, it becomes a 911 visit to the customer.
This is where reclaim creativity causes chaos. I enter the screen room and ask someone to reclaim a screen, usually following the manual that I left there. When it comes to the final water flood rinse, most times the reclaim person will take one giant step backward and use the pressure washer to ‘flood rinse’. When I interject that the use of the pressure washer for the final rinse is not really flooding the mesh with water, its more like blowing the leftover degreaser either up and down or left and right inside the mesh openings, I let them finish the screen their way. Then I take the next screen and do an actual flood rinse with weight of water and mark both screens. We let the screens dry and then coat both of them. When the screens are coated the results are very obvious. The screen that was properly flood rinsed looks like glass and the ‘high pressure’ flood rinse looks like the Hayden Planetarium! Again, all it takes is an additional 15-25 seconds at the very end of reclaim with a weight of water rinse and this step will save you a massive amount of time, either having to recoat a screen or worse when the screen gets out on the press and you have down time to fix ‘pinholes’.
Written By: Frank Ventimiglia | Easiway Systems | Senior Regional Manager East Coast
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