UV Ink Primers for UV Inkjet Printers

Most substrates need a bit of help to achieve excellent adhesion. For this reason, primers are a vital addition to the printing process. Whether you’re printing on glass, plastic, metal, or tile, UV ink primers are essential to maximize durability, image quality, and abrasion resistance.

 

What is a UV Ink Primer?

A UV ink primer is a specialized coating applied as a preparatory coat to an object, to promote adhesion between UV curable ink and the surface being printed.

• Typically the first step in the printing process
• Often used after surface pretreatment (flame, plasma, or Pyrosil®)
• Strengthens the bond between the substrate and ultraviolet ink
• Especially useful for difficult materials like glass, polypropylene, or coated metals

 

When Should I use a UV Ink Primer?

The best way to ensure full adhesion is to cure the substrate with primers or by flame treatment prior to printing. Flame treatment is ideal for substrates that require a manipulation of surface tension, such as glass and polypropylene. An oxidized flame (should be blue in color) increases the movement of molecules on the surface of the substrate, thereby improving adhesion between the ink and substrate. 

The general rule of thumb when it comes to UV ink primers is that if you can get away with not using one, then don’t. Primers should only be used as needed. Skipping this step will save you time and money, but depending on your application, could result in a lower quality design.  

Superior adhesion depends on multiple factors such as the dyne levels of the ink and substrate, surface energy, coatings, and other bonding factors. Generally, the surface tension of the UV ink should be about 10 dynes less than the surface energy of the substrate. Since the range of 25-35 dyne is standard for UV inks on the market, we can expect a high-quality print to occur from printing on a product that has a surface energy between 35-45 dyne.  

 

How To Apply a UV Ink Primer 

UV ink primers can either be sprayed on or manually wiped on a substrate. Application methods include:

• Spray Application: For water-based or fine mist primers

• Manual Wipe-On: Using a lint-free towel when spraying isn’t suitable (e.g., due to low flash point)

• Automated Systems: Integrated machines for high-volume production lines

 

The Inkcups Solution

Inkcups provides many UV ink primer solutions for a variety of substances.

•  MagiCoat® – This pretreatment system for glass, is a breakthrough water-based inkjet ink primer that optimizes adhesion on glassware and other substrates. It features 8 rotating stations, 3 flaming stations, and a fine mist spraying system. The rotating stations include a vacuum to keep products firmly in place during pre-treatment. Next, the products are ready for the flaming stations and 6 flaming heads work to uniformly pre-treat the items. Flame treating eliminates any debris or other coatings already on the substrate that may inhibit adhesion. The fine mist spraying system ensures that each item gets evenly coated with water based MagiCoat® primer as part of the post-flame treatment. After the pre-treatment process, drinkware items have seen up to 600 industrial washes without image degradation. * 
• AutoFlame 360 Flame Treatment – This revolutionary machine automates the flame pretreatment process. It The machine features 8 rotating platens with vacuums to secure the objects. Once the product has been evenly treated with the optimal amount of flame, a built-in hydraulic system will lightly tap the finished product into a box. This easy load/unload system makes pretreatment part of the in-line printing process and helps to maintain a steady workflow.
• UV Inkjet Primers by Substrate – Some substrates have specific properties which inhibit full ink adhesion, and require adhesion promoters specially designed for each substrate. Inkcups offers 8 varieties of inkjet primers to ensure all substrates are covered, including glass, metal, plastic, tile, and more. Once your substrates are pretreated, continue to print as normal and expect better adhesion, increased durability, and improved abrasion resistance.

Choosing the Right UV Ink Primer

When it comes to decorating various substrates, a pretreatment and/or primer may be required for an overall high-quality print. Depending on the substrate and application, there is a primer that is right for you.

Inkcups encourages our customers to read through the technical data available for all of our products. Free adhesion testing is available upon request in order to determine the best primer for your product. Our expert ink technicians at Inkcups have worked  with a multitude of different substrates over many years. Our goal is to improve adhesion and increase abrasion resistance to ultimately create vibrant, durable products for satisfied customers.

If you have any further questions, don’t hesitate to contact us or visit the Inkcups Support Hub.

 

*Glass MUST be flame-treated prior to use of MagiCoat. Wash testing could be more (or less) depending on type of glassware used, detergent and temperature of wash.