The chances are, you, just like me, have an inkjet printer at home. The chances are you use the printer occasionally to print several pages of text or a bunch of photos. The chances are next time you going to use the printer, it won’t work for the printhead are clogged.

Of course, the best way to get rid of clogged jets is to prevent them. Some say you should print regularly (daily/weekly or else), some would advise you to get a laser printer instead. But when you’ve already got this problem, how to troubleshoot the cloged printer?

There is a way to bring your inkjet printer back to life.

The essence of problem with clogged printhead is that ink dries inside the printhead jets, letting no liquid ink from cartridge tank to go out. Given that, the essence of unclogging a printhead lies in dissolving that dried ink.

There are arguments about what is the best solvent to clean inkjet heads. People naming this or that solvent are both right and wrong. The thing is there no best solvent, there is one that dissolves the particular type of ink.

Understanding printer ink

Before we start, there is something to know about printer inks. In one of previous posts I cited one good article titled “Debunking the Myths of Digital Inks” by Tony Martin. If somehow you have not read the article yet, I will brief you on it.

In general, in any printer using water based inks, whether they are dye, pigment or hybrid colorants, they tend to have similar formulations.

They use mainly water, a colorant or mixture of colorants, dye, or pigment or both, a wetting agent like glycerin that allows the liquid to flow and allow the ink to enter the paper surface, a product to slow down drying on the heads like glycol, and often an alcohol to speed drying on the paper surface. Some inks with pigments require an adhesive to attach the particles to the paper surface, so they use a resin, usually acrylic.

This all gives us the idea of what reagents to use for dissolution (at least I strongly hope it does.)

Selecting a solvent

How would one know what exact solvent is suitable for his or her case? That’s pretty easy to figure out.

Usually there’s decent amounts of ink spilled everywhere in these situations. Instead of risking your potentially expensive heads, try your various solvents on dried ink outside of printing head. If you don’t already have spills to clean up, then intentionally make one. Let it dry and then clean it up… with “whatever” you’re contemplating running through the printer.

If it doesn’t work outside the printer, neither will it unclog the head from inside. If it dissolves the ink, then you have a much better chance of success.

A troubleshooting advice

To help you dissolve dried ink in printhead, here is a receipt that should work on the majority of water based inkjet printer inks.

The mixture uses either ammoniated window cleaner (which uses glycol, alcohol, water and ammonia) with extra isopropyl alcohol, or in places where ammoniated window cleaner isn’t available, use ammonia mixed to about 1% concentration, and adding the isopropyl.

However, there are some inks that use different technologies and may not work with these solvents.

Hewlett-Packard is boosting its effort to effectively recycle used inkjet printer cartridges, Wednesday introducing a new process that manufactures new cartridges from recycled cartridges that are separated and rebuilt from scratch.

The “closed loop” process gives used HP inkjet cartridges a sustainable end-of-life value and puts the material back to good use while being environmentally friendly.

The process first breaks down plastic in printer cartridges made of PET (polyethylene terephthalate), after which additives including fibers and resins are used to strengthen and regenerate the plastic. The remolded plastic is then used to manufacture new HP inkjet cartridges.

The plastics or cartridges are not melted, refilled, resold or sent to a landfill, HP said. The process also applies to other products, like PET water bottles.

The process, which went into pilot in 2005, has already resulted in HP manufacturing 200 million printer cartridges. The process will go into full manufacturing now.

Each inkjet cartridge contains 70 percent to 100 percent recycled material. Users will find the process beneficial as cartridges with new material perform better than used or refilled cartridges.

HP allows users to return inkjet cartridges worldwide for free in most cases through its recycling program, said Ken Fleming, marketing director of supplies for HP. In some cases, a postage-paid return envelope is provided by HP with the inkjet print cartridge box.

The process will apply only to HP cartridges, the company said. No external inkjet cartridge brand is being put through the new recycling process.

Before the implementation of the new process, not all plastic recovered went into making new cartridges. They were used by others to manufacture products including auto parts and toys.

The inkjet cartridge recycling initiative is the latest in HP’s broad effort to be environmentally friendly. HP recently announced that it would implement more energy-efficient technologies across its PC lines to reduce computer energy use by 25 percent in 2010.

One of the important aspects to think of when choosing a printer or buying a replacement cartridge, is how much ink or toner that cartridge actually contains. Amount of ink or toner in cartridge is usually called cartridge yield or page yield.

When you turn to see what the yield of a cartridge is, you will see a number of pages the cartridge is enough to print. For instance, IBM 28P2008 toner cartridge has a declared yield of 30,000 pages, while HP C6657AN ink cartridge capable of printing 400 pages. For a reason that is beyond me, ink cartridges are less capacious.

But printed pages differ from one another. One time you print a to-do list, next time it’s 10-page report.

For the purpose of cartridge yield measure, almost all printer manufacturers base their black ink/toner cartridge yields on 5% coverage. This means only 5% of the whole page is covered with ink or toner. 5% coverage implies basic type with no bold characters, no graphics and no pictures.

CMYK toners for color laser printers and copiers base their cartridges yields on 20% to 35% coverage (5% to 7% per color). In reality, if a document had a 100% fill, there would be 400% coverage. Tri-color inkjet/toner cartridges base their page yield on 15% coverage (5% per color).

Now take the last two paragraphs above and place them on a Letter-sized sheet of paper. Congratulations! You have created a sample 5% coverage page:

Let me ask you how often, if ever, you print pages like that? Who would ever need 400 or even 30,000 such pages?

Filling up the page, I managed to repeat the two paragraphs as many as 6 times, which gives us 30% coverage. This seems more like a commonly printed page:

I wonder why they don’t measure ink/toner cartridge yield in 30% coverage pages as more realistic. It’s clear that given a definite amount of ink in a cartridge, this would mean fewer pages to be printed and demonstrated.

On the other hand, I would know how many printed pages I’d have with maximum use of ink, i.e. I would be aware of the worst possible state of thing. Hence, if I print not that much text and graphics per page, I get more printed pages.

Wouldn’t it be more fair and realistic information for us, customers? I believe it would.

Whatever is the reason for using 5% coverage as industry standard, now you know what it is like and can approximate it for real-life prints.

Previously on ”How to Detect and Fix Problems with Laser Monochrome Printing” we examined toner cartridge components and reviewed several possible reasons of printing problems. Today we shall pick up from where we left last time.

3. Magnetic Roller

This roller in HP printer is a metal cylinder covered with special coating with a magnetized bar inside. This part rarely gets out of order. For most part dirty print is caused by toner dosing.

The dirt “gives” a stripe to magnetic roller, thus, “taking away” a stripe from image on prints:

One of the signs of incorrect toner dosing is spilling of toner into the split between the metering blade and the magnetic roller:

Toner is spilled onto magnetic roller, which transfers the toner on photo drum. Photo drum, in turn, transfers the toner on paper, just like it should. This is how those needless stripes occur along the length of the page. The stripes may be black, if the split is wider than necessary for toner dosing, or they may be light, when the dosing is hindered due to dirt-clogged split.

In the office, anything may qualify as dirt, even a fly.

 Again, the problem is fixed by reassembling the cartridge or by replacing it with new.

4. Waste Toner Hopper

As we mentioned at the beginning, a cartridge contains a wiper blade that cleans unused toner. Such toner is collected into special container, waste hopper, and then is cleaned out during remanufacturing and refilling. Alas, sometimes low quality toner or carelessness of labor may lead to unpredictable results.

The prints clearly show that overrun waste hopper makes the toner spill over.

To fix this problem you should empty the waste hopper or replace the cartridge.

It’s worth mentioning that printing artifacts are not always due to faulty parts. For most users, a printer is a mere box that prints. However, for all technical service engineers printer is a piece of art, even if it’s a simple desktop monochrome printer. So, before blaming it all on printing consumables, one should make sure it is cartridge that’s guilty.

An exotic deviations in hardware of Hewlett-Packard LaserJet 1300: failed changes of thermofilm caused ripples around letters:

To determine which part of the printer is guilty of bad printing, it is necessary to have some knowledge of printing technologies and how they work.

Certainly, looking for most common cartridge breakings we can consider 5-7 more situations of bad printing. But it’s very often that the cartridge was used for 2-3 or even 10 times. Such a prolonged use results in critical worn-out and subsequent replacement of this and that parts of the cartridge. To avoid these unexpected troubles, use only quality printing consumables. The trick is not to get confused with everyday situation when looking for some extraordinary breaking:

This cartridge is simply running out of toner:

Cartridges won’t fail if you regularly replace them and use quality toner for refills. Remember, saving on savings may cost you a pretty penny.

That’s how prints should look like, regardless printer brand or model. They are all crisp and contrast, without a single mark. Making the right decision on printing supplies and refilling and remanufacturing company, will save time and money and spare you of headache. This is a fact proven by time and numerous companies.