- Post by: Bill Hood
- August 11, 2021
- Comments off
Registration can be one of the most nerve wreaking tasks in the screenprinting technologies for anyone who has to print multiple colors or produce a print that must register on the substrate perfectly with each print. Some may be surprised by the downtime experienced trying to line up that job that did not want to cooperate is really not necessary. With a little knowledge and taking the right steps, can all but eliminate registration problems.
But, wait, there’s more! While attempting to register for that job, there was a lot more going on that was causing even more financial loss. The very things that caused the registration problem are decreasing not only productivity but also a loss of quality. There may have an increase of dot gain or dot loss that will rampant from one substrate to another. The ink deposit will be uneven across the image plane and will result in a loss of color consistency.
The most likely problem causing misregistration is that it could be that the press is out of parallel. Many printers, if not most, suffer from this same problem. All of this can go away. Hard work is not needed to achieve excellent quality and increased productivity. All that is needed is to gain knowledge and put that knowledge to work.
The most important solution is to bring the press into parallel and geometric plane. While many of the variables we are faced with are unavoidable or simply beyond what we can fix given the constraints of time and money, bringing the press into a parallel and geometric plane is certainly within anyone’s reach.
For anyone having registration problems, first look at several variables, and decide which are causing the issue. Once it is known where the problem lies, then fix that problem, so that the continuous plague with problems disappear.
Here are 7 Steps to Resolving Registration Problems
1. Obviously, begin with films that are in register with one another. If printing with roll film, registration could be an issue caused by drag from the weight of the roll. Heat and humidity could be creating a shift in the film positive.
2. Sufficient tension on the mesh that it won’t move during printing. Tension to the mesh manufacturers suggested minimum tension level.
3. The exposure unit glass must be flat. The heat from the exposure will cause the glass to sag in the middle and if so, it should be replaced. Check it with thread stretched from one corner to the opposite corner.
4. The press must be capable of holding the screens tightly in place. Side clamps on a manual press are always a necessity for properly securing frames in place.
5. The print head must be held tightly at the registration gate. It can usually be adjusted or the Teflon rollers may need to be replaced.
6. All platens should be on a plane with one another. If someone touches the platen with a slight force, it could be tilted to one side. This causes the image on that screen to travel further to reach the platen on that corner and thus creates a problem. While there, check the plane of each platen individually. Any platen that is bowled or bowed should be replaced immediately.
7. Since screenprinting is an off-contact method of printing, the mesh must be moved down to touch the substrate. If the screen is not on a geometric plane with the platens, then the mesh will be moved more in the direction in which it is further from the platen. This will throw the registration in that color off.
There is more to registration than explained in an article, and that is why I wrote the book, Parallelism and Geometric Plane and created the Parallelism and Geometric Plane Test, both available at http://screenprintbooks.com online. I hope this helps those with registration problems come to a quicker solution.