HP Designjet H35000 and H45000 Printer Series - Tips and Tricks for Corrugated Plastic

Corrugated plastic or ﬂ uted polypropylene, known commonly by its brand-names Coroplast™, IntePro

, Plasticor

Cor-X

, and others, is a popular media for UV-curable inkjet printing applications. This document describes a number

of recommended techniques to get the most out of your UV printer and this media type.

Media Selection

There are many suppliers and many product variations of corrugated plastic. Not all products are identical in how

well they work with UV-curable inkjet printing. We have experienced poor performance with media from one supplier

and markedly improved performance with media from a different source, with no other changes to the printer, work-

ﬂ ow, or environment. If the media you have obtained from one source is not performing well, investigate an alternate

product or supplier. Test a small quantity ﬁ rst to ensure that you have located a superior product.

Media Preparation

Like many synthetic materials, corrugated plastic is prone to problems with static electricity. Static causes two issues

with the media. First, the static charge attracts dust particles to the media prior to printing. When ink is applied to the

dirty media, the ink adheres to the particles on the surface of the media rather than the media itself. This ultimately

leads to the appearance of “pinholes” or other defects when the particles are wiped away. The second problem with

static is that the electrical charge attracts the ink droplets away from their intended targets and causes the droplets to

land in the wrong place. The typical end result is a “haze” or “ghosting” of faint ink around the desired print area.

To avoid these problems, wipe down the media prior to printing using isopropyl alcohol. Other methods can be used

to reduce static in the general printer environment, but wiping down each sheet of media is recommended regardless

of other anti-static methods.

Server Conﬁ guration

Best results on corrugated plastic are obtained when the smallest quantity of ink is used. Every media has a prop-

erty known as adhesion, or how well the cured ink attaches to the media surface. Adhesion can be quantitatively

measured. When too much ink is used, poor adhesion can result, and corrugated plastic is one of the most sensitive

medias to this effect.

When conﬁ guring your server, use color management settings that will process and print the image with the smallest

amount of ink. Indications that your software is putting down more ink then desirable are enhanced swath to swath

or “lawn mower” banding and/or an “orange peel” or wrinkling effect in areas of heavy coverage followed by a

loss of adhesion in these same areas.

HP Software RIP

HP print server products include a color transform or proﬁ le named “Generic Low Ink Coverage”. This color proﬁ le

will apply the smallest amount of ink and is recommended for use with corrugated plastic. Alternatively, the RIP trans-

form speciﬁ cally named for “Coroplast” may also be used.

Onyx RIP Products

Users of the Onyx print server products (RIP Queue, Poster Shop, Production House) will ﬁ nd that the “out of the box”

color proﬁ les supplied by Onyx tend to lay down heavier coverage of ink until the proﬁ le has been calibrated to your

own printer. Since no current third-party RIPs support the use of the printer’s on-board color sensor, an external device

is required to perform this calibration. External device support varies depending on the software used. The semi-

transparent nature of most ﬂ uted polypropylene media can compound the difﬁ culty of taking accurate color readings

with any device.