Methods of Ink Testing for Commercial Printing

It’s no secret that traceable codes and markings are essential to modern commerce. Just one look around the grocery store will reveal just how many codes are required to appear on contemporary product packaging. Elements like expiration/packaged-on dates, lot codes, serial numbers, and more can all be found on products ranging from pharmaceuticals to pre-packaged food to electronics and beyond.

Required by both distribution networks and federal/state law, traceable codes and variable data markings are crucial packaging elements across many industries. As such, manufacturing operations and packaging facilities everywhere utilize industrial marking technologies like continuous inkjet printers and thermal inkjet printers to outfit their goods with the necessary information. 

Of course, no matter how good a printer is, applied codes won’t last if they aren’t made with an effective ink formula. To maintain code compliance, companies must create their traceable markings with ink formulas that are capable of remaining clear and legible throughout the entire product lifecycle. If the codes become unreadable or damaged over time, companies may end up performing recalls, paying fines, or facing other expensive penalties. 

Fortunately, trustworthy ink companies have their ways of verifying the effectiveness of their formulas before selling them. If you’re curious about modern methods of ink testing for commercial printing, here’s what you need to know.

The Importance of Ink Testing

Choosing an ink formula isn’t a task to be taken lightly. After all, to maintain compliance, traceable codes must maintain legibility and machine-readability from the initial processing stage until the product goes home with the consumer. In certain cases, code life must extend even further than this as well. 

Consider, for example, the coding specifications laid out by the MIL-STD-130M—the United States military’s set of requirements regarding the design, placement, and longevity of traceable codes placed on military equipment. According to MIL-STD-130M: 

[All] direct identification marking and identification plates, identification bands, identification tags, or identification labels used shall be as permanent as the normal life expectancy of the item and be capable of withstanding the environmental tests and cleaning procedures specified for the item to which it is affixed.

In other words, as long as the piece of equipment is in use, all traceable codes and markings must remain legible. This means that the codes must be able to withstand:

• Any humidity or dust present in the processing facility and field
• UV radiation
• Condensation presence during distribution
• Rough physical movements
• High heat

Although MIL-STD-130M sets a standard higher than most other industries, the need for long-lasting codes is shared everywhere from dairy production to electronics manufacturing. In particular, the codes applied to pharmaceutical and beverage products must be able to withstand condensation and the codes applied to canned foods must be able to withstand the heat used in the retort process.

To ensure that codes don’t blur, rub off, or fade away during a product’s lifecycle, manufacturers and packagers must know the specific properties of their inks before they apply them onto their goods. Important properties include:

• Dry time
• Levels of adhesion with different substrates
• Whether the formula can penetrate condensation
• Levels of resistance against heat, sun, alcohol, etc.

By carefully considering the properties of different inks, companies can discover a formula that is both compatible with their goods and capable of remaining legible throughout the product lifecycle. To uncover these properties, ink manufacturers subject their formulas to a few different industry-standard tests. 

Methods of Ink Testing for Commercial Printing

Although all ink developers have their own approach to formula testing, there are a few tests that are used across the industry. The most common methods of ink testing for commercial printing are patterned after techniques developed by the Paper Technology Foundation (PTS)—a German organization that’s been providing various testing services to the packaging field for decades. 

These tests enable companies to test the physical properties of their formulas to demonstrate exact drying times and levels of resistance against elements like moisture/water exposure, physical touch, high/low temperatures, sunlight, and more. Two common examples of such testing include:

• PTS-DF 103/2011: A drying time test developed for TIJ ink formulas, PTS-DF 103/2011 involves creating GS1 data matrix codes at 300 DPI and testing them with the aid of an automated wipe unit. At predetermined time intervals, the wipe unit swipes the barcodes to record how early they become smudged. Through this process, ink developers can record accurate data regarding drying times and degradation.
• ISO 18935: This test is used to determine water resistance. Like PTS-DF 103/2011, it begins with creating a series of GS1 data matrices at 300 DPI. Then, the codes are submerged in deionized water. After an hour of immersion, the codes are taken out of the water and dried on a glass plate. Once dry, the tester evaluates the quality of the coders with the help of a code reader. With this data, ink developers can verify how well a formula can resist moisture and water presence.

Tests similar to PTS-DF 103/2011 and ISO 18935 exist for several other elements as well, including levels of:

• Heat-resistance
• Alcohol-resistance
• Sunlight-resistance
• Thermochromic qualities
• Ink migration 

Unsure Which Ink Formula Will Work Best for Your Operation? InkJet, Inc. Is Here To Help

With the help of trusted testing techniques, ink developers can accurately assess the properties of their formulas and verify how well they work in certain situations. We would know—at InkJet, Inc., we have been manufacturing and selling ink for over 30 years. Over time, we’ve developed a diverse portfolio of printing consumables, ranging from thermal inkjet printer cartridges to aftermarket CIJ inks that are compatible with some of the most popular printer models in the industry. 

Whether you’re looking for an aftermarket alternative for a specific OEM formula or are simply unsure of which ink formula is right for you, InkJet, Inc. can help.

To learn more about the modern methods of ink testing for commercial printing, or to inquire about our ink products, contact us online today or call 1(800) 280-3245.