PCT Engineered EB Finish Cure of UV Inks User Manual

♦

8700 Hillandale Road ♦ Davenport, Iowa 52806

Phone: [phone]

FAX: [phone] ♦ www.teampct.com

EB Pilot Line Test Report

EB Finish Cure of UV Inks

Background

PCT was asked to evaluate the potential to increase the line speed of a UV equipped web
offset press. The eight color press has been limited to a print speed of 600 fpm even though
it is designed for speeds up to 1200 fpm. The limiting factor has been the UV curing
capacity.

Purpose
PCT conducted tests to confirm that EB can provide complete cure of the same UV inks at
higher line speeds without the use of nitrogen for inerting the EB curing zone.

Test Procedure
The owner of the press ran sample material at a speed of 900 fpm with the existing UV
curing. This material was surface cured but testing showed that tape adhesion of the inks
was poor and the inks were severely affected by 10 to 15 MEK rubs.

We attached cut sheets of the printed material to a carrier web. The printed sheets were
EB cured IN AIR at the following conditions:

3.0 Mrads 100 fpm

3.5 Mards 100 fpm

4.0 Mrads 100 fpm

4.5 Mrads 100 fpm

3.0 Mrads 500 fpm

4.0 Mrads 500 fpm

Results
Our preliminary results show that after EB
exposure that all samples gave excellent tape
adhesion and a dramatic increase in MEK rub
resistance. This demonstrates that EB
exposure in air effectively completes the cure of
the UV inks and coatings.

Since our EB equipment can deliver 3600 Mrad
fpm (3 Mards @ 1200 ft/min or 4 Mrads @ 900
ft/min) it appears that the addition of an EB unit
to this press will provide effective high speed
curing without nitrogen inerting.