DAGuide

Almost every direct-to-garment (dtg) manufacturer and distributor inform their customers to make sure that the room where the dtg printer is located remains within a 40% to 70% relative humidity for optimal printing.  However, very few of them will explain why this is important.  That is what this post is all about, but it is important to understand what humidity is.  www.Dictionary.com defines relative humidity as the amount of water vapor in the air, expressed as a percentage of the maximum amount that the air could hold at the given temperature.

Almost of the dtg printers on the market rely on a piezo print head (which is used in all Epson printers) to fire the ink on to the garment.  This type of print head uses electrical pulses to fire the ink through a thin metal plate at the bottom of the print head.  When a clog occurs, it happens in one of three places: 1) in the print head (usually right at the metal plate), 2) at the filter in the damper / cartridge and 3) in the ink line. 

When you have the printer in a room that has low humidity, it will increase the speed of the ink drying right at the metal plate and will lead to ink clogging.  This is just one of the reasons for ink starvation and banding for incurring.  Thus, it is highly recommended to keep the room where the printer is located between the recommended ranges of humidity to prevent the clogging from occurring.  Here is a picture of one type of hygrometer.

In order to monitor the humidity in the room, it is recommended that you get a hygrometer – an instrument used for measuring relative humidity.   However, I recommend that you find one that will allow you to recall the high / low readings so you can determine if the room remains at the same level of humidity at night.  You can purchase a hygrometer at several online stores and local home improvement / garden stores.

If the humidity level drops below the recommended minimum level, then you should purchase a humidifier that will add moisture in the air.  My recommendation is to purchase a humidifier that has a large enough reservoir (i.e. the water tank) that will allow you to keep the humidity in the recommended ranges for a period of three days.  This will allow you to set the humidifier at the end of business on Friday and last till you come back from the weekend on Monday.  Otherwise, the reservoir can run out before the end of the weekend and the humidity can drop below the recommended minimum range.

We hope this document answered the question thoroughly for you.  Feel free to continue a discussion about this question by clicking on the link(s) below.
a) http://www.t-shirtforums.com/fast-t-jet/t66578.html
b) http://www.t-shirtforums.com/anajet/t66884.html
c) http://www.t-shirtforums.com/direct-garment-dtg-inkjet-printing/t70345.html
d) http://www.t-shirtforums.com/direct-garment-dtg-inkjet-printing/t75177.html
e) http://www.t-shirtforums.com/anajet/t65763.html

Each dtg manufacturer should be able to provide you with a written list of what items need to be cleaned / maintained on a regular basis.  Usually this information can be found in an Owner’s Manual or on a user forum.  I recommend you create a schedule / signature log that requires the operator to sign off that the scheduled maintenance was done.  This log should have the daily, weekly and monthly maintenance procedures listed out and a place where someone can sign/date showing it was done.  This will help keep your business on track with keeping your machine in top printing shape.  In some cases, you will even find other users have created their own maintenance procedures that go beyond what the manufacturer recommends.  Here is an example of a post like this - http://www.t-shirtforums.com/direct-garment-dtg-inkjet-printing/t32835.html. 

Some dtg manufacturers have started incorporating some features into the dtg printers that help with the maintenance procedures.  For example, some dtg printers now have buttons on the side of the printer that allow you to run a cleaning cycle with the push of one button or where you can set it to run an automatic cleaning cycle every so many of hours / days.  Other printers have added features like an ink agitator to help prevent the ink from settling. 

 
White Ink Agitator from DTG Digital

Just make sure that you understand any cost associated with running these auto features (i.e. ink used during an auto cleaning cycle) and incorporate this into your pricing structure.

Common Maintenance Procedures
Below are some of the common maintenance procedures that are typically done to most dtg printers.  It is important that all dtg owners follow the instructions and recommendations of their dtg manufacturer as each printer might have some unique differences.
       Maintenance To Do List:
- Clean the maintenance station and wiper blade with cleaning solution.
- Use a cleaning swab to wipe around the nozzle plate under the print head.  Do not wipe over the nozzles of the print head.
- Clean both sides of the encoder strip with a lint-free pad
- Make sure that any items (i.e. rails,…) that need to be lubricated are done so on a regular basis.
- Check to make sure that the waste bottle is not full.
- Wipe up any ink splatter on the inside of the printer.

Here is a link to post that goes over some of the things a dtg owner should think about when it comes to maintenance - http://www.t-shirtforums.com/direct-garment-dtg-inkjet-printing/t41796.html.

Advanced Maintenance Procedures
Throughout the internet, you will find information about how some dtg owners have been able to do some unique cleaning methods (i.e. soaking a print head, putting dampers through an ultra sonic cleaning,…) to get their machine working properly.  I strongly encourage you speak with your dtg manufacturer first to make sure that you don’t cause additional harm to your dtg printer before trying any advanced maintenance procedures.  Here is a link to a post that talks about some of these procedures - http://www.t-shirtforums.com/direct-garment-dtg-inkjet-printing/t25918.html.

The general rule for most dtg printers about dtg ink is “Let it sit and it will clog.”  With any Epson-based dtg printer, the particles that make up the dtg inks are much larger than the particles of ink that the printer was designed for.  Thus if the printer sits idle for a couple of days, you may get a clog in the ink lines and/or the print head.  Thus, it is important to keep the ink flowing through the lines and print head in order to prevent wasting the ink during a cleaning cycle.  In addition, most dtg manufacturers recommend that you agitate the white ink to keep the TiO2 from settling to the bottom of the container.  This includes the ink in your bulk feed system or cartridges – as well as the ink you have in inventory.

PRINTING TIP:  I recommend you print one sample every business day at a minimum to help keep the ink in the lines and the print head moving properly.  By printing a sample, you create marketing material to help promote the fact that your business can now produce short-run decorated apparel.  Otherwise, you will probably land up wasting as much ink running head cleanings to remove the blockage. 

MAINTENANCE TIP:  Some dtg printers will come with built-in maintenance programs that will run a periodic head clean or nozzle check based on a schedule the user sets.  Also, as previously mentioned, there is a software program called Printer Jockey (www.printerjockey.com) that provides you the ability to flush a single channel of ink that a nozzle check shows is clogged.  This will save you the ink that is used by running a head cleaning on the channels of ink that are not clogged.  For videos on this software, click on the player below:

Here are some links that talk more about why head clogs occur and how much ink is used during the cleaning cycles:
- http://www.inkjetgarmentprinters.com/forums/viewtopic.php?p=25092#25092
- http://www.inkjetgarmentprinters.com/forums/viewtopic.php?t=1817

When using a dtg printer, you should understand that your environmental elements (i.e. temperature, humidity,…) can play a role in how your printer performs.  For example, shops with low temperatures or low humidity might experience more clogged nozzles.  Also, areas that have a high level of dust will tend to receive a higher amount of errors associated with a dirty encoder strip.  If you plan on taking your printer on the road to do event production, you will want to check out the weather forecast in advance and prepare for the climate at that location. 

MAINTENANCE TIP:  A good trick to help keeping the nozzles in the print head from drying up at night is to put a damp towel under the platen, load the platen directly below the print head and place a low-nap or lint-free towel covering up the top of the printer / platen.  This will create a closed in area of humidity below the print head and will keep the nozzles moist.

I recommend that every dtg owner have a small digital temperature gauge to keep track of these items.  Most dtg printers will operate efficiently when there is approximately 50% humidity. 

 
Digital Humidity Gauge

Some shops may need to purchase a small humidifier to compensate for low humidity levels – especially during the winter months when heaters are used.  When looking at a humidifier, you will want one that can last through the evening - so a large tank would be recommended.

Please contact your dtg manufacturer for the recommended level of humidity for your specific printer.  Here are a couple of links to posts that talk about how the environment has affected some printers:
*  http://www.inkjetgarmentprinters.com/forums/viewtopic.php?t=4116
*  http://www.inkjetgarmentprinters.com/forums/viewtopic.php?t=4188