WEB PRINTING

DO NOT INSTALL A 4 oz. RESERVOIR INK CARTRIDGE AT THIS TIME. The coder is designed to print using the ink contained in the pre-inked ink roll. Since a freshly saturated Ink Roll was just installed on the coder, the system will have plenty of ink. Installing a 4 oz. Reservoir Ink Cartridge immediately will result in over saturation of the ink roll and flooding of the Inking System. The 4 oz. Reservoir Ink Cartridge should not be installed until most of the ink is consumed from the ink roll and the print quality shows signs that more ink is needed.

SPECIAL WEB PRINTING APPLICATIONS

In applications where the web material is too narrow for both friction drive bearers to contact the surface of the web, contact with one friction bearer is acceptable. When the web is too narrow for even one friction bearer to contact the web and still position the print as necessary, a custom made guide roller can often be utilized.

PRINT

DRUM

FRICTION

BEARER

NARROW

AL

 

WEB MATERIAL

 

GROOVE

FIGURE 36

MODIFIED GUIDE ROLLER

PRINTING ON NARROW WEB MATERIALS

Using this approach, the guide roll must be machined with a groove which will not only accurately guide the web mate- rial and drive the guide roll but it must also keep the surface of the web material flush with the surface of the guide roll where the friction bearers make contact. (See Figure 36.)

This method of mounting is generally more appropriate when the web material is extruded rubber or some similar mate- rial which has a high coefficient of friction since it must drive both the guide roll and the print drum. Using a custom guide roller which is driven by an external power source is cer- tainly acceptable but it is generally rather costly since the surface speed of the guide roller must precisely match the speed of the web or smeared prints will result.

PRINTING DIRECTLY ON MASTER ROLLS

Universal Non-Porous Conveyor Line Printers can also be mounted on custom designed extension arms which will enable them to print directly on the surface of a master roll of web material as it is unwound. This technique is fre- quently used when conveniently positioned idler rolls are not available. In these applications, as the master roll of web material decreases in size, the mounting arm pivots and keeps the print drum in constant contact with the sur- face of the roll as shown in Figure 37. In these installa- tions, the weight of the coder is used to supply printing pressure and typically the standard spring tension mecha- nism and mounting column are removed. Custom mount- ing brackets and extension arms should be carefully de- signed to keep the coder in an acceptable attitude when printing on a full roll of film all the way down to the smaller diameter of the core. For more details on custom mount- ing systems, contact our engineering department.

 

EXTENSION ARM

PIVOT

CODER

POST

 

CODER

 

TRAVEL

 

 

MASTER

 

ROLL

FIGURE 37

21

Page 21
Image 21
Universal Laser Systems CLP-100NI-NPRT manual Special WEB Printing Applications