How many times have you requested a box of this or a sample of that and had a winner right away? When testing a new product, the chances of success go way up with a little communication between the customer and the supplier. It’s no different with doctor blades. Like other parts of the printing process, investing a little time and effort in a doctor blade trial vs. sampling will improve your odds of finding the best blade for your application.
Sampling vs. Trialing
There are two ways to test a new doctor blade: a sample and a doctor blade trial. The critical difference is the information that is exchanged between you and your doctor blade supplier. While both offer the chance for you to try something new, a trial greatly increases your probability of success.
Sampling
If you’ve ever requested a doctor blade sample, you probably submitted your request through the company’s website, waited several days, and received your new blade samples in the mail. They may have sat on your desk for a while until you were reminded of the reason you requested the samples in the first place and installed them in your press. If you were lucky, the blades worked well and you proceeded with your first order.
If you’re like most companies, however, several rounds of sampling are needed to find a good fit. This requires sustained effort and patience on your part. With doctor blades, a different blade material, thickness or tip may be needed, and you keep your fingers crossed that you will eventually happen upon a winning combination.
Trialing
An alternative to sampling a new blade is a doctor blade trial. When you perform a blade trial, your odds of finding the right product go up significantly. Through communication and participation in a production run, the supplier acquires key information about your process. This information is used to zero in on the ideal product for your application and shortens your path to finding the right doctor blade.
Doctor Blade Trial Process:
1. Initiation of Blade Trial – You request a blade trial from your doctor blade supplier. The supplier will take the time to learn about your process and ask questions regarding your press and application:
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- Press type
- Press speed
- Run length
- Print type
- Anilox line screen
- Chamber type
- Substrate
- Ink type
- Problems with ink lay-down
The supplier will then make a recommendation and supply doctor blades for a production run.
Doctor blade supplier assisting with a blade trial
2. Production Run – The blade supplier should be very involved during the production run. He will confirm all of the information gathered about the application, verify that the blades have been installed correctly, make sure there is proper chamber alignment and help make adjustments if necessary. The results of the run will be documented along with any challenges faced by the press operators.
3. Analysis and Evaluation – Following the production run, the used blades are returned to the supplier’s facility where the engineering department is engaged to do a complete evaluation. The engineering team will assess the worn blades and look at how much wear has occurred, the contact length of the worn area and the contact angle of the blade. These findings will reveal how the blade performed on press. By looking at the wear patterns, the engineers can also determine whether the chamber was aligned to the anilox roll, if the blades were positioned properly and if there was too much pressure on the chamber. A complete report containing these results is provided to you. These results may be used to make improvements to your current process.
4. Feedback and Recommendation – After the blades are analyzed by the engineering department, the blade supplier will either confirm that the blades were successful in the application or recommend a different blade based on the results (such as different blade material, thickness or tip configuration). Having taken the time to gather all important information about the press and application, the supplier will be able to provide the doctor blade that maximizes press efficiency and resolves any issues he was experiencing.
For people willing to roll the dice and be patient until finding the right product, sampling is a reasonable way to search for a better doctor blade. However, to shorten the process of finding the best blade for your application, taking the time to conduct a doctor blade trial is the way to go. For a small commitment of time and resources up front, the payoff is substantial in terms of saving time and money in the long run.
