Printing on Plastic Products: Choosing The Right Printer and Ink

Polyethylene terephthalate, high-density polyethylene, polyvinyl chloride—to most people, these names likely sound unfamiliar and possibly conjure up ideas of strange chemicals and science experiments. To those familiar with plastic packaging, on the other hand, these names likely bring to mind everyday household items such as water bottles, milk cartons, cereal liners, and detergent bottles. 

While plastics like polyethylene terephthalate (PET), high-density polyethylene (HDPE), and polyvinyl chloride (PVC) may not be readily recognized by their full names, the products made from them surround us every day. For example:

As you can see, many different industries rely on plastic to manufacture their products. From aerospace manufacturing to chemical development, plastic is versatile enough to both create durable goods and serve as long-lasting product packaging.

However, for any of these products to be sold in stores, they must comply with the labeling standards set by:

  • Governmental bodies
  • Retail outlets
  • Distribution networks 
  • Industry authorities 

To comply with these regulations and guidelines, many companies turn towards inkjet printing to directly mark their products with the required codes, text, and images. Of course, you can't just take a random inkjet printer and begin printing on plastic products—you need to have the right combination of hardware and ink to create legible, long-lasting codes. 

Here, we look at what it takes to find the perfect printer/ink combination to meet your plastic printing needs.

The Importance of Substrate Compatibility

The world of plastics is large, diverse, and populated with different plastic varieties that differ in chemical structure and physical properties. Thanks to this wide variety, plastics can be used to create a wide range of products, ranging from resealable bags to car parts. 

Today, seven major plastic varieties are found throughout the manufacturing field. They include:

  1. Polyethylene Terephthalate (PETE or PET), used to produce soda/water bottles, food/medicine jars, blister packs, and textiles.
  2. High-Density Polyethylene (HDPE), used to produce milk jugs, shampoo bottles, and cleaning chemical containers.
  3. Polyvinyl Chloride (PVC), used to produce pipes, tiles, window frames, and other construction materials.
  4. Low-Density Polyethylene (LDPE), used to produce flexible wraps and assorted food packaging.
  5. Polypropylene (PP), used to produce plastic food storage, cables, and long-lasting tools like rakes and ice scrapers.
  6. Polystyrene/Styrofoam (PS), used to produce disposable eating utensils, packing peanuts, and insulation.
  7. Miscellaneous Plastic Polymers, such as nylon and fiberglass, can be used for a variety of purposes. 

These diverse application possibilities are possible thanks to how all of these plastic varieties offer unique physical and chemical properties. At the same time, however, these differing properties affect how well certain ink formulas can adhere to product surfaces.

For instance, one may not use the same ink formula to mark PVC pipes as they would to mark flexible LDPE wrap because the substrates have different surface energies and properties. Consequently, code-compliance hinges on picking the best ink formula to fit your products’ unique material makeup. 

Choosing the Best Hardware and Ink Combination for Printing on Plastic Products

To accommodate the varying surface properties of plastic, ink producers today offer a wide range of formulas designed to meet the coding needs of specific plastic varieties. InkJet, Inc., for example, offers a variety of plastic-compatible formulas like DC-411 and DC-437 that take into account:

  • Unique substrate surface properties
  • Product shelf life
  • Particular production processes that require specialty properties like alcohol resistance and blacklight visibility

To use any of these formulas, however, you obviously need a printer—and like these inks—printer manufacturers offer a number of hardware options to fit different operational needs.

For larger operations, continuous inkjet printers, such as the DuraCode Touchscreen, provide users with the ability to mark products moving at hundreds of meters per minute with lasting codes and markings. Moreover, CIJ printers are able to maximize production uptime thanks to their ability to operate uninterrupted for up to 24 hours a day. 

For companies that don’t require the industrial speeds of a CIJ, thermal inkjet printers provide a more cost-effective alternative. Weighing only a few pounds, TIJ models like the Anser U2 Pro-S are well-suited for intermittent coding tasks and can print at speeds around 120 m/min. However, not all TIJ models are able to use plastic-compatible ink formulas, so it’s important to do your research before investing in a printer model. 

Could Laser Be Right for You?

Up until this point, we have only discussed plastic coding in relation to inkjet printing. 

While it’s true that inkjet printers have been used for decades to complete plastic coding applications, it’s important to note that they are not the only marking option on the market for this application. In recent years, for example, laser marking systems have become an increasingly popular choice for plastic coding applications. 

Like CIJ printers, laser marking systems are capable of completing industrial-speed marking applications with high accuracy and without interruption. However, they don’t require liquid ink to mark products, which both reduces ongoing costs and minimizes maintenance needs. Consequently, many large-scale companies have adopted laser solutions to complete their industrial plastic marking applications. 

At the same time, laser systems aren’t always an ideal option. For example:

  • Although they have fewer ongoing costs compared to CIJ systems, they cost significantly more upfront.
  • They often produce toxic fumes during operation and therefore require fume extractors to make the air safe for workers.
  • Not all plastic varieties are compatible with laser systems. 

Find out more about whether a laser marking system may be right for your plastic marking needs.

Need Help Printing on Plastic Products? Contact InkJet, Inc. Today To Find It

Although plastic is one of the most common manufacturing materials in the world, it’s not always easy to print on. To ensure codes are properly applied and legible, it’s essential to use a printer/ink combination that is:

  • Compatible with the specific type of plastic that your product is made from
  • Provides a readability-boosting level of contrast on the substrate’s surface
  • Capable of remaining legible throughout the product’s lifecycle

At InkJet, Inc. we can help you meet these goals in the most efficient way possible. 

For over 30 years, we have been developing ink formulas and selling printer hardware to industries of all backgrounds. Between our numerous inkjet printer options and diverse ink catalog, we can provide you with a printer/ink combination especially paired to fit your operational needs. Call us today to learn more. 

For personalized help printing on plastic products, contact us online today or call 1(800) 280-3245