Issue
I am not sure what inkjet is best for my application. Now, you tell me that you sell 2 types of DOD, the HP (GT-Jet 36) or Spectra (GT-Jet 72 and GT-Jet 64). Add all continuous inkjet (CIJ) on the market and you’ll understand I’m lost.
Which one should I take?
Short-circuit Decision Helper
If you absolutely want a system
• $10k, buy an HP with cheap driving software, no support.
• that prints 2”, is fast, and needs no dryer, buy a Bitjet from Domino or BX600 from Videojet for around $80k.
• that prints addresses on paper envelopes at medium speeds, buy an HP or a GT-Jet SG 256.
• that print on webs at 1,000 fpm, buy a Scitex CIJ for $220k.
• that prints on cards at 250 fpm, 30’000 p/h, buy a GT-Jet for $35k.
• that prints one line of text or numbers, buy an A400 or Excel, or a valve jet for $8k.
Unfortunately, as always, choosing the right solution is not that easy; technology changes, your customer has new requirements, need more efficiency or higher speeds, different substrates and inks, have to train people on one platform only if possible, etc. Behind all these aspects hides a powerful controller: least and always forgotten ! that you can scale up and add different inkjets and applications using the same User Interface to avoid lengthy learning curves as you grow, buy the right controller, an MIC. For more on the MIC, please see www.graph-tech.ch.
If you want more facts about both HP and Spectra technology, please continue reading.
Strengths and weaknesses of HP cartridge based systems
Strengths (Important, Good, Nice to have):
a) Cheap investment(I)
b) Nice print at native 600 dpi vertical resolution. 200-300 dpi in horizontal.
c) Various inks (blackness, color, etc) but most water based.
d) Serviceability. Cartridge bad, just replace it at low cost (I)
e) Limited down-time (I)
f) Better with bulk tank (G)
g) Installed in no time (N)
Weaknesses (Show-stopper, Bad, Not so nice):
a) The investment is low but the running costs are high
b) Jet burn-out: thermo process kills jets with time. Jet burn-outs begin to appear after 2-3 replenishment of cartridges, extended burn-out after 400 ml of ink. Not bad for address printing but expensive when printing barcodes (S/B)
c) Jetouts 1: after couple minutes of no print, bad print for 2 books (B)
d) Speed relatively slow. “safe speed” of 60 m/min (197 fpm) at 300 dpi. (B)
e) Substrate and speeds always an issue limited because of ink that can be used. Best on paper. (S)
f) Has to be very close (around ½ mm or 2/100”) to substrate to print high quality. No problem on webs but bad on other transports. (S/B)
g) ½” cartridges. Painful alignment. You always see the stitching between the cartridges.
h) Needs IR dryer (around $5,000). Spectra needs dryer too but solvent CIJ not. (N)
Price per cartridge is around $25 for regular inks (at 42 ml per cartridge that is $590 per liter !) , around $50 for new solvent/UV (That is 1,190 per liter) of 42 ml, that makes . A bulk tank makes inks about 60% cheaper but the cartridge burn-out still the same.
Strengths and weaknesses of Spectra Jetting Assemblies based systems
Strengths (Important, Good, Nice to have):
a) Longevity: treated right, a jetting assembly lasts many thousands hours (I)
b) Ink type versatility: solvent based, UV based, oil-based, wax based. (I)
c) Easy to exchange when broken: not as easy as HP but most are repaired in 1-2 hours (G)
d) Distance to substrate is 2-3 times better than HP: 1 to 1.5 mm.
e) Realistically attainable speeds is about 2-3 times more than HP, 5 times if drying is the bottle neck.
f) More “industrial” than HP.
Weaknesses (Show-stopper, Bad, Not so nice):
a) Jetouts: much better than HP if treated right but high cost of replacement, just a jetting assembly costs between $500 and $1,000 (B)
b) Distance to substrate still quite close for many machines, especially compared to CIJ (5-8 mm).
c) Needs UV or IR dryer (around $5,000), much better now with LED curing. Spectra needs dryer too but solvent CIJ not. (N)