Metallized Barrier Sealants


Reducing material and carbon footprints with metallised barrier sealants

Packaging Films 1-2013 One of the most common flexible packaging formats is the stand-up barrier pouch. This structure typically consists of three layers as shown in figure 1. These structures include a PET/print/adhesive/metallised PET/adhesive/ sealant or PET/print/adhesive/metallised OPP/sealant, with each of these layers playing a functional role in the overall structure. Figure 1: Comparison of 3-ply vs. 2-ply structures for stand- up pouches. The printed PET provides a surface for excellent printability and adds stiffness to the structure. The metallised layer provides an oxygen and moisture barrier in case of metallised PET or moisture barrier in the case of metallised OPP, and also improves stiffness. Metallised films in general provide good aesthetic value and allow for eye-catching graphics, which may be a brand owner requirement in some finished structures. Lastly, the sealant layer provides sealing for the pouch which must also have good COF (coefficient of friction), HSIT (heat-seal initiation temperature), and seal strength, which are critical to downstream processing and performance. Metallised sealants allow converters and brand owners to improve their carbon footprint by reducing material and energy usage when transitioning from a 3-ply structure to a 2-ply structure with- out compromising barrier perform- ance or other key performance cri- teria such as COF and HSIT, which are critical in downstream process- ing (figure 1 and table 1). Based on the […]


AIMCAL Sustainability Award: Celplast O2 Barrier Metallized Sealants

Cel-Met and O2 Barrier metallized sealants from Celplast permit down-gauging of approximately 25% without compromising the barrier properties or performance of the barrier laminate. The Cel-Met sealant replaces metallized oriented polypropylene to reduce a three-ply structure to two plies while providing an oxygen transmission rate (OTR) of 4.0 cubic centimeters per 100 square inches per day and a water vapor transmission rate (WVTR) of 0.08 grams per 100 square inches per day. The O2 Barrier sealant replaces metallized polyethylene terephthalate to convert a three-ply structure to a two-ply and provides even higher barrier properties: 0.04 cubic centimeters per 100 square inches per day OTR and 0.05 grams per 100 square inches per day WVTR. Eliminating the need for a second pass in the lamination process also conserves adhesive and reduces energy requirements 31% for solvent-based structures and 11% for solvent-less. Carbon dioxide emissions also drop: 34% for solvent-based laminating and 30% for solvent-less. Applications include stand-up and peg-display pouches. Judges Comments The judges noted the metallized sealants reduce steps in the process and achieve a significant source reduction. “It’s a new way of looking at structures and definitely a step in the right direction,” concluded one member of the panel. A detailed article on these Barrier Sealants is available on Converting Quarterly Magazine 2011 Quarter 2 p 56.