An analysis of chemical properties of flexible packaging

Polymers and films: Evaluating their properties

Medical devices, pharmaceuticals, food/drink, cosmetics, and industrial sectors use flexible packaging that is made up of films and polymers. Alternative suppliers, recyclable raw material streams, changing regulatory climates, and managing manufacturing and customer demands can all present challenges when using these materials. These priorities can be balanced by combining standardized testing and custom approaches.

Film properties and chemistry must be considered when testing flexible packaging. By using a variety of probe gases, chemicals, and water, permeation properties are evaluated in a single layer or engineered multilayer films. Permeation and migration of liquids/vapors, oxygen transmittance, water vapor transmission, and probe gases are evaluated. A packaging solution can be tailored to meet the end-user's needs by relating these properties to the chemical make-up and film structure.

It is possible to determine the bulk composition of a film, the chemical and thickness composition of multilayer films, the surface treatment, and chemistry of polymers, as well as the molecular weight of polymers using film composition analysis methods. Cross-section and Raman mapping allow for the evaluation of the multi-layer film.

Criterion Scientific is a US base Chemical Testing lab that can also test any type of flexible packaging materials

Polymer type and glass transition temperature (Tg) can be determined using Fourier-transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). A technique called X-ray photoelectron spectroscopy (XPS) can be used to evaluate surface chemistry or treatment. It can also be used to identify polymer exemption classification under laws such as the US Toxic Substances Control Act (TSCA) by using gel permeation chromatography (GPC). During processing, volatile organic chemicals (VOCs) can also be released, which may pose a risk to workers from monomers, solvents, or other additives. For an industrial hygiene assessment, TD-GCMS has the capability of both identifying and quantifying these species.

Tests can be used to evaluate heat seal adhesion failures, compatibility failures, and in-use failures. To detect particles and gel impurities on sealing surfaces, we use FTIR microscopy and confocal Raman. Molecular weight changes can be assessed through GPC and DSC, Raman, and scanning electron microscope-energy dispersive x-ray spectroscopy (SEM-EDS).

For food contact or packaging compatibility studies, assessing chemical migration properties is helpful. The method evaluates the compatibility of additives and contaminants with food or cosmetic product using techniques such as Raman mapping, liquid chromatography-mass spectrometry (LC/LCMS), and gas chromatography-mass spectrometry (GC/GCMS), and inductively coupled plasma mass spectrometry (ICP-MS).

Learn more about evaluating flexible packaging and Thermal Conductivity Testing Lab