HP Designjet H45000 HP Designjet H35000 and H45000 Printer Series - Headstrike - Page 3

1. Each jetting orifice is punched through, creating small but very sharp projections. 2. When printing under ordinary circumstances, the jets are 0.085" from the surface of the media. 3. When a headstrike occurs, those sharp orifice projections scrape printed ink and media particles and drive the particles into the orifices themselves. Uncured, Liquid Ink Partially Cured Ink 4. The ink scraped from the media by the headstrike has already been exposed to some UV light, so it is partially cured and is looking for other ink molecules to bind with. Inside the orifice, the partially-cured ink finds the unexposed, liquid ink and initiates curing with those molecules. 5. If the partially-cured ink is not cleaned promptly, the curing process will continue, ultimately rendering the affected nozzles permanently blocked by cured ink. Other Lingering Effects The blocked nozzles described and illustrated on the previous pages are one lasting effect of a headstrike. Others include the following: 3