Maintaining a good impression is the only way to achieve the best print quality possible without sacrificing runability.
Good impression is established by first setting the correct distance of the plate and blanket cylinders and the blanket-to-blanket cylinders. These distances are specified by the press manufacturer and shouldn’t be changed without a thorough understanding of print impression.
Looking for ways to decrease your operating expenses on your press? Here are three areas that deserve your immdiate attention.
Brush your motor
Inspect the brushes on your DC press main drive motors. Whenever I conduct a press condition evaluation I always inspect the condition of the motor brushes. Brushes are often overlooked because their operating lives are so long. But brushes can become so short they can impact print register by causing press speeds to vary erratically. Additionally, if motor brushes become too short, they can damage the commutator on the motor’s arumature. And if the commutator is badly damaged, it can easily cost thousands of dollars to repair.
Ensuring excellent print register is more important than ever, especially in today’s competitive environment.
Replacing machine guards and machine covers can be aggravating. The guard may have been dropped, twisted or holes on the component could have been damaged. The frame of the machine could have even shifted.
A newspaper production manager called me this past month for some advice.
One of the motor controllers at his newspaper's press was down so the press had to be operated at a reduced speed to make sure the remaining motor was not overloaded. Curiously, the manager asked me if the electrician that he had hired to repair his downed controller had made the correct diagnosis.
Have you experienced tinting problems?
The problem can be localized or sometimes very severe. And the problem can stem from multiple sources: plates, plate chemicals, plate processor, light exposure to the plates, chemicals in the ink that attack the plate, press cleanliness, fountain solution and the condition of the water being used to process the printing plates and the water being used in the printing process.
The micrometric rollers on a Goss Urbanite and a Goss Community are installed on the press unit like a shish kabob. The removal of the micrometric rollers and components is like removing food from a skewer, and it’s done whenever the rollers become worn or grooved.
Are you prepared for a production stoppage? What have you prepared for? Is your backup plan complete?
Being prepared for any emergency is essential to the survival of the newspaper that you serve. If you don't have an emergency preparedness manual you should develop one. Then make sure all key personnel know about the manual, know what is in the manual, and how to use the manual well before any disaster arises.
Exercising your connection is whenever you move a connector back and forth over the pins it normally resides on, whether it's a PC board or wherever two connectors are plugged together.
Technology is the key for newspapers that have been cutting their press operations staff and reducing their training budgets.
I have seen the effects firsthand. As the industry continues to contract, I see fewer press operators. And for many newspapers, that means poorer print registration, poorer overall print quality and higher newsprint waste.
The delivery of ink onto the web occurs in a variety of ways. Here are the basics:
The press operator had complained that the iron-to-iron settings were misadjusted on one of the Goss Community units that he was operating.
It's not always possible to find a tool that will conveniently do the job at hand. But take care to ensure that if you do have to fabricate a tool, that it can remove and install parts without too much difficulty.
The top speed of your press is controlled by several factors that include base speed, field weakening speed (if your controller is equipped with this feature), the MOP (motor operated potentiometer) and the max speed, or top speed potentiometer. Modifying the pulleys or gearbox that drive the press can also control speed.
Web wrinkles can be difficult to eliminate, but with perseverance you can be successful.
Occasionally I receive parts that were not machined properly. This usually occurs with the inside dimensional hole of an eccentric used on a micrometric roller shaft. Perhaps the machinist or parts manufacturer that fabricated the part believed that if you are going to engineer a problem, it's better that the hole be too small rather than too large.
This past year I have been in several pressrooms staffed with workers who, on the surface, appear to lack the basic skills to efficiently operate a press.
It is normal to have some changes in ink density while the press is running, but how much is acceptable?
In a previous article I shared several ideas that would help press operators resolve press drive surging.
