Inkjet Printer for Plastic Bags: Will Codes Stick?

Last Updated: 2026-09-06

A code printed on a poly bag can wipe off with one pass of a thumb, and nobody notices until the customer does. An inkjet printer for plastic bags works, but plastic film is the hardest common substrate, because it is non-porous and often carries slip additives. Here is how to make codes stay.

The Short Answer

Plastic bags reject most inks for two reasons: the surface is non-porous, so there is nothing for the ink to soak into, and many films carry slip or anti-block additives that migrate to the surface and defeat adhesion. Codes stick when you address both: use an ink formulated for polyolefins, and give it a full cure before the bags are handled or stacked.

Continuous inkjet handles curved, moving bags well because of its short throw distance; thermal inkjet suits flatter, slower presentation. The choice follows your line, not the bag alone.

What to Know in Practice

Test adhesion the way bags actually travel: print, cure, then rub, flex, and stack the samples. A code that survives a thumb rub but fails after a night in a stacked pallet has not passed, and stacking pressure plus residual solvents is a common late failure.

Watch for surface treatment changes. Film suppliers alter slip additives and corona treatment without notice, and a formulation that worked reliably for a year can start failing on a new roll, which is why the sample habit matters more than any single ink choice. Keep a printed sample from each film lot, and re-test whenever the supplier or film grade changes.

About SHICAI

SHICAI builds industrial coding and marking equipment across inkjet and laser lines, for production and warehouse use. Machines ship with genuine components and tested consumables, and service and spares are arranged for export markets. The technical team answers directly rather than through a reseller chain.

Related Questions

Why does ink smear on plastic bags?

Usually a water-based ink on a non-porous surface, or handling before the ink has cured. Switch to a polyolefin-rated formulation and allow full cure time.

Can I print on both sides of a bag?

Yes, with two heads or a two-pass setup. Most plants print one side, because the code only needs to be readable once.

Is laser better for plastic bags?

For permanent codes on laminates and thicker films, laser avoids adhesion issues entirely. For thin PE bags, laser can burn through, so inkjet is usually safer.

Learn more about inkjet printing and ISO 9001 quality management.