Printing Process on the Melco G3 Garment Printer

customerAugust 22, 2018

Initial Powering Up of the Printer


Caution!

Before powering up the printer, make sure that:

  • All safety/shipping fixtures have been removed.
  • The tray is inside, but not all the way back.
  • No objects or tools are placed on the tray.
  • The cartridges are filled with ink and properly inserted into their respective bays.
  • White inks must be shaken for 3-5 seconds.

  1. Shake the white ink cartridges for 3-5 seconds.
  2. Press the power button.
    pc_power.png
  3. After powering up, an automatic ink charge will be initiated. Do not do anything with the printer until the initial ink charge is completed.
  4. After the initial ink charge, perform a nozzle check to confirm that all the ink channels were filled correctly. See the nozzle check section for instructions.

If the automatic ink charge is not initiated after start up, you must manually charge the inks by completing at least 3 power cleans from the printer control panel. After the power cleans, perform a nozzle check. If the nozzle check is not perfect, perform one or two more power cleans until the nozzle check is perfect. 

Selecting a Garment

Selection of a garment is mostly a matter of personal preference. However, it is important to keep in mind that you will be printing with water based inks. This means that the garment must be able to absorb water.

  • We recommend garments made with natural fibers.
  • Water sealed garments that have received a treatment with water repelling liquids will produce poor results. This is because the garment must be able to absorb the ink allowing the ink to seep into the fabric itself. Water repellent or treated garments do not take ink well.
  • Old garments that have been worn multiple times and washed multiple times prior to printing may also yield poor results because the textile itself may have deteriorated due to use as well as residues from detergent and fabric softeners.
  • It is important to remember that while printing on textiles the condition of the textile will impact the quality of the print. The surface of the garment will also affect the quality of the print. Printing on a fuzzy surface will often lead to a blurry or fuzzy print.
  • Garments with buttons, seams or any object that creates an uneven surface when laid flat will impact printing. Table shape or height may need to be changed.
  • Some garments by nature of their construction will interfere with the laser obstruction sensor no matter what you do. This also includes garments that will not fit into the print bay.

Your garment selection will directly determine the finished look of the design on the garment. For example, printing on a pink shirt with white ink versus printing on pink shirt with no white ink will give very different results. To learn more about how the color of a garment can impact the finished print, take a look at the graphics section of this document.

Fabric Texture

Keep in mind that all textiles have some amount of fuzz or lint on their surface. Also, as all textiles are an interlacing of fabric (of some kind), the surface of the garment has many valleys and gaps (even if you cannot see them). The ink that is being applied to the garment is being done on a very small scale, meaning that the ink droplets themselves can fall into those imperfections on the textile creating a less than quality printed image to the naked eye. This is why prints on paper can appear so photo realistic while a print on a wool blanket would not retain the same level of crisp clarity that the same print would on a smooth surface (piece of paper). This is due to the nature of the material itself and it's overall surface properties when ink sits on top of it and drys. In addition to the indentations in fabric (the valleys and gaps due to the weave of the fabric) it is also possible that the fuzz from the textile itself may sit on top of the garment creating little mountains of fuzz. This can create that same distorted effect when printing.

Pretreatment

The purpose of pretreatment is to create a flat smooth surface on your garment so that ink can be applied to and adhere to the garment. Being made of a different composition than the color inks, white ink requires pretreatment to stay on the surface of the material.

The key to pretreatment is:

  • Apply an evenly distributed amount of pre-treatment solution using an synthetic roller.
  • Use the pretreatment and roller to flatten and smooth the surface of the garment.
  • Roll in one direction preferably with the grain of the fabric to ensure no textile fuzz or imperfections in the weave of the fabric stick up.

Pretreatment is generally used in dark garment printing. The color of the material that you are printing on will impact the final appearance of the print because direct to garment printing use translucent inks. This means that in order to obtain the crispest colors possible on a dark garment, you need to create a white background on the garment.

All textiles have imperfections in their surface where ink can fall. In order to minimize this you need to create both a smooth surface to print your white background on and a surface with some additional adhesive qualities. The solution is to use pre-treatment in your dark garment printing process.

Pretreatment Technique

You should have a well ventilated room, a large flat surface for prep, and a container for your pretreatment solution. Lightly apply the pre-treatment solution to the shirt using the roller provided. Make sure that the print area becomes visibly damp, but not overly saturated. As long as total coverage is achieved, less pre-treatment is better for wash fastness and color vibrancy than too much pre-treatment.

  1. Make sure the heat press is set at the following settings:
    1. 330°F
    2. 45 seconds
    3. High Pressure (80psi) or the number 7, 8 or 9 displayed on the automatic heat presses. Reduce the pressure if the pretreat does not wash out.
  2. Heat set the blank shirt for 10 seconds; this will remove excess moisture and flatten the fibers while assisting with a smooth re-treatment application. Use a fresh sheet of silicone coated parchment or kraft paper.
  3. The shirt collar should be to the front; the fibers lay down from top to bottom (collar to bottom of shirt).
  4. Shake the pretreatment solution well to counteract settling. Make sure the cap is on tight before you begin.
  5. Pour enough pretreatment into a paint pan.
  6. Soak roller (do not over saturate).
  7. Apply the pretreatment by rolling in one direction from neck to bottom of shirt or desired coverage area (one direction only; do not roll forward and backward); apply a medium pressure to ensure that the pretreatment is getting into the fiber.
  8. Slightly overlap the roll. Dip the roller into pretreatment solution as needed.
  9. Hover the heat press over the shirt for 10 seconds.
  10. Cover the shirt with coated Kraft or parchment paper and close press.
  11. Remove shirt after 45 seconds or when the steam disappears
  12.  Re-press for another 10 to 15 seconds if the shirt is still wet; this means you are applying too much pretreatment.

Note - Excess pretreatment will come out after the shirt is washed.

Staining on certain color shirts

Some color garments such as bright orange, lime green and hot pink have dyes that react with heat and pressure. This reaction can cause a bluish/reddish stain to be seen after the shirt is cured.

To prevent this, you need to follow the following steps:

  1. Do not preheat garment.
  2. Spray the shirt down with distilled water.
  3. Apply pretreatment as described above.
  4. Hover for 10 seconds.
  5. Place parchment paper over garment and close heat press.
  6. Use the curing parameters settings for the pretreatment above, but extend the time to 60 seconds.

Loading a Garment

  1. Move table to the load position.
    Move the table to the "load" position (shown below) by pressing the "Eject" button on the table control panel. If using the standard (framed) table, raise the platen frame.

    g3 nozzlecheck 1

  2. Load the garment on the table.
    Place the garment on the table by laying it flat against the platen with the head of the garment positioned at the front of the platen (closest to you). If the garment is not flat, the printer “obstruction sensor laser” will detect an obstruction and the platen will stop moving until the obstruction is cleared. The garment should be centered on the platen using the area of the garment to be printed upon as your point of reference for center.

    loading a garment

  3. Tuck garment under the platen.
    If using the standard (framed) table, carefully close the platen frame over the garment. This frame provides a gripping surface that prevents the garment from sliding on the platen. It also helps to eliminate wrinkles on the garment. Tuck any loose portion of the garment under the platen but above the print tray being careful not to leave any part of the garment hanging in a place where it may catch on the printer during platen movement.

    tuck shirt

Table Height Adjustment

Table height (platen height) is adjustable and should be set for each type of garment on which you are going to print. The purpose of adjusting the height of the table (platen) is to ensure that the garment you is the optimal distance from the print head, ensuring the best possible quality of print. The distance that the print head is from the garment has a significant impact on print quality. Since the print head cannot be moved up and down, the garment will need to be moved closer to or farther from the print head by adjusting table height.

While it is possible to adjust the table height when the table is in any position, you should only adjust the table height while it is in the "load" position. This is because it is possible, depending on the thickness of the garment you are printing on, to contact the print head. This must be avoided at as this can damage the print head beyond use.

The printer is equipped with a laser sensor that will alert you if you move a garment too high.

To automatically set table/platen height:

  1. Start with the garment loaded on the table and the table in the load position. If not there, press the "Out" button on the table control panel.

    g3 tableheight 1

    Note - When the table is in the load position, the printer display panel will display. This is a normal display message and will go away when the table is in the print position.

    g3 tableheight 2

  2. Press the "Auto" button on the table control panel. The table will move in and self-adjust to the appropriate height. It will then eject itself.

    g3 tableheight 3

  3. Occasionally, the auto-adjust will be slightly too high for the edge of the table. Pressing the "Home" button will send the table to the print position. If the limit LED lights, the down button must be pressed.

    g3 tableheight 4

If the garment it is too far from the nozzle plate, the print quality will suffer and ink over spray will be visible. If the garment is too close to the nozzle plate, there is risk of the print head touching the garment which could make the print head unusable.

Remove Garment

Caution - The ink on your garment is wet after printing, be careful not to touch the wet ink or allow the garment to touch the wet ink. This will smear the print.

Once the print job has completed the table will move out to the load position providing you with access to remove the garment. Gently lift the platen frame (if using it) to gain access to the garment. When you remove the garment it is recommended that, with your back to the printer, you grab the garment at the shoulders using two hands and slide it from the printing table in a smooth and even motion to avoid wrinkling or bunching the print.

You should end up with the print on your garment facing you.

remove shirt

Heat Press Settings

Printing inks require heat treatment after printing. The most common method is using a heat press because of size, cost and efficiency.

To fix the ink onto the garment with heat treatment, place the garment on a heat press with the printed side up. Spread it flat on the heat press, minding not to touch the wet ink or allow the garment to fold over on itself (touching the wet ink). Cover it with a sheet of heat press paper being careful not to drag the paper or smudge the wet ink. There are three types of heat press paper:

  • Treated parchment paper for a matte finish
  • Coated craft paper for matte finish
  • Teflon paper for a shiny finish

If you reduce the heat press temperature, you must increase the time. If you are using a textile oven or conveyor dryer, you can set the temperature lower but you will have to increase the time. Settings and results vary depending on the manufacturer and brand of your conveyor dryer, see manufacturer recommendations.. Heat treatment below 300ºF is not recommended.

Curing Dark Colored Shirts (white ink underlay)

  1. Make sure the heat press is set at the following settings:
    1. 330°F - 340°F
    2. 90 seconds
    3. Light pressure (10 - 12 psi or the number 3 displayed on the automatic heat presses)
  2. Hover the heat press over the shirt for 10 seconds; this will help cure the inks before applying pressure (this is similar to the flash technique used in screen printing).
  3. Carefully cover the ink with parchment or kraft paper and close the press. Do not slide the paper into place as that will smear the inks.

Curing White/Light Colored Shirts (no white ink)

  1. Make sure the heat press is set at the following settings:
    1. 360°F to 370°F (use a temperature in this range that does not scorch the garment)
    2. 25 seconds
    3. Medium pressure (40psi) the number 4 or 5 displayed on the new automatic heat presses)
  2. You do not need to hover since this is only 1 layer of ink (CMYK)
  3. Carefully cover the ink with unbleached paper and close the press. Do not slide the paper into place as that will smear the inks.

Teflon sheets will cause the final product to have a shiny look; transfer paper will give the image a matte look.

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