Flexible film is lightweight, malleable, and versatile enough to be used in primary, secondary, and tertiary packaging processes, making it a popular choice for use in the manufacturing industry.  

For primary packaging, flexible film is used to produce resealable bags and pouches for a wide range of products, including food, medicine, and miscellaneous consumer goods. For secondary packaging, rolls of flexible film and shrink wrap are an easy way to bundle together bulk products like soda bottles, pre-packaged food, and books. Flexible film also plays a key role in maintaining pallet stability while products are in transit. 

Depending on how you’re using flexible film, there’s a good chance that it will need to be marked with some kind of product information. For example:

• Flexible bags of food require traceable codes to comply with distributor guidelines and possibly federal regulations.
• Shrink wrap-covered bottle packs often require batch codes to aid product recalls and inventory purposes.
• Pallets may require printed instructions to aid shipping and handling.

If this information isn’t printed clearly and correctly, it can cause a variety of issues, ranging from transportation difficulties to product recalls.

To help companies avoid marking complications, we’ve provided this quick list of flexible film printing best practices. By following these simple steps, you can improve your printing process and ensure marking success.

Use a Printing System That Meets Your Unique Coding Needs

Flexible film packaging is used by a wide variety of industries, ranging from food production to electronic manufacturing. With this variety comes a multitude of factors that determine whether a marking system is a viable option or not. 

For example, the coding requirements of a chip bag are vastly different from the coding needs of a medical device. While the chip bag will require a consistent lot code and likely an expiration date, the medical device will require a UDI (Unique Device Identification) code in two formats:

1. A high-contrast machine-scannable barcode, and
2. Human-readable plain text

To ensure the medical device complies with industry standards, all UDI codes must be applied at high DPI levels and be able to survive the entire product life cycle. Generally speaking, this requires a more powerful marking system than is needed for standard food items. 

In addition to DPI capabilities, other essential system considerations include:

• Whether the system is fast enough to meet production line quotas.
• How well the system can resist environmental issues like heat, humidity, and water presence.
• Investment cost and ongoing expenses.

Flexible Film Printing Success Hinges on Using the Right Ink

Once you have a printing system that can meet your production goals and remain operational in your facility, an ink formula must be chosen; it’s important to choose the right formula for flexible film printing.

When searching for ink, it’s essential to seek out a formula that is:

1. Compatible with flexible film.
2. Capable of withstanding any demanding product processing.
3. Able to maintain readability/scannability for the entire product life cycle.

As mentioned above, coding needs will vary based on factors like differing industry standards, output requirements, and facility environment. Similarly, ink effectiveness is affected by several elements beyond material compatibility. 

Today’s traceability standards require codes to remain readable and machine-scannable until the end of the product life cycle. Along the way, many issues can hinder code quality including:

• Sun and light exposure.
• Extreme temperatures (both low and high).
• Physical touch and movement.
• Humidity and moisture presence.
• Alcohol/chemical exposure.

For some industries, many of these elements are a part of product processing. For other, factors like light exposure and high-temperature exposure are experienced during transit or are a part of the product’s intended use setting. If a formula designed specifically to resist these issues isn't used, codes are likely to become faint, smudged, or otherwise damaged. 

Consequently, it’s important to consider all relevant environmental threats facing your product before investing in an ink formula. 

Is the Film Transparent? Outfit Your Line With the Appropriate Vision System

With a marking system and ink formula chosen, the last part of the flexible film printing process involves your production line. If you are using an opaque flexible film, you can likely use a standard through-beam photo eye to begin printing. However, if your film is transparent, you will likely need to make some adjustments to your line’s detection system. 

In broad terms, standard through-beam photo eyes will have trouble detecting the presence of transparent substrates. This is because through-beam systems are only able to detect materials if the material can successfully interrupt the through-beam. With opaque substrates, detection is essentially assured if the system is operating correctly. Comparatively, clear film is much less likely to trigger a reaction. 

To resolve this issue, make sure to use a vision system that is designed with clear material compatibility.

Want to learn more about flexible film printing? Stay connected to C&M Digest by subscribing to our newsletter. With information on hardware, formulas, and other important marking topics, our newsletter will keep you updated on the latest industry developments. To get in touch with us about possible collaborations or ideas for coverage, contact us today.