RDM Test urges packaging converters to test for residual solvents inhouse

As the EU's Packaging and Packaging Waste Regulation begins to apply from 12 August, RDM Test Equipment is urging flexible packaging converters to reconsider where, and how often, they test for residual solvents.

The packaging performance specialist argues that the shift towards sustainability-first materials now under way makes the industry's long-standing once-a-run sampling convention increasingly difficult to rely on, and that the answer is to bring testing onto the production floor.

PPWR is accelerating a concerted move towards mono-material, downgauged, and higher recycled-content structures, as converters and brand owners redesign packaging for recyclability. These materials are a defensible response to the regulation, but they also behave differently in the drying tunnel from the laminates they replace.

Examples, RDM Test says, include heat-sensitive polyolefin structures that may not tolerate the dryer temperatures a mixed laminate absorbed, films with higher recycled content varying more between deliveries, and downgauged webs running differently at speed. The result is a solvent-removal process running closer to its limit, with variables that are harder to predict than they were.

The way most converters test has not moved with the materials. Conventional laboratory gas chromatography takes up to 50 minutes per sample, in a controlled environment, run by trained analysts. At that cost per test, sampling once per production run has long been close to the practical maximum. As those structures change and run lengths shorten, RDM Test argues, a single end-of-run sample has become inefficient and impractical.

With no room for compromise on line speed, the company's position is that residual solvent testing should move to where the material is actually made. On-floor analysis lets production teams test often enough to see a drying or airflow problem develop and adjust process parameters before non-conforming material reaches slitting, pouching, or dispatch.

To meet that need, RDM Test has now added the Neptune 803 gas chromatograph, manufactured by N.I.R.A., to its residual solvent testing range. Returning results in as little as seven minutes, it is built for deployment directly on the production floor, including harsh, solvent-affected environments, removing the need to transport samples to and from a laboratory. A front-access measurement cell and minimal sample handling, with no vial sealing required, mean it can be operated by trained production or QA personnel rather than dedicated laboratory staff.

Phil Neal, Managing Director at RDM Test Equipment, said: "The instinct when a new material won't behave is to treat it as a one-off, then retest, adjust, and move on. What converters are now telling us is that it's stopped being a one-off. The polyolefin and recycled-content structures coming through for PPWR are less forgiving in the dryer, and they're arriving faster than the test regime around them was ever designed for.

"A sample taken at the end of a run tells you what left the line, not what's happening on it. Once you accept that, the question isn't really about the instrument, but about location. Testing belongs where the decisions get made, which is the production floor, not a lab in a different part of the building. That's the shift we think this regulation forces, and it's the one we'd encourage converters to make before a customer makes it for them."