Super barrier film for food packaging

The Italian packaging specialist Industria Termoplastica Pavese (ITP) and DuPont Performance Materials have jointly developed Clearpack F for food, a high barrier film for vacuum skin packaging (VSP) applications, which provides a multitude of benefits including perfect sealing at low processing temperatures, tamper evidence and appealing presentation of the packed food. These advantageous points make ITP’s new multilayer structure a premier choice for protecting fresh and processed food including meat with and without bones, sea-food or cheese on bottom trays made of polystyrene foam, rigid polyethylene terephthalate as well as PP and combinations of these with PE. Among the keys to these benefits are ITP’s skills in multilayer film coextrusion and a specially adjusted set of high performance packaging polymers from DuPont, including a Surlyn ionomer, a Bynel adhesive resin and an Appeel peelable sealant, as well as an EVOH layer providing a high barrier to oxygen and flavours.

“Currently available in thicknesses from 80 to 150 µm, our new Clearpack F for food provides a low sealing initiation temperature and low thermoforming temperatures of 130 to 150°C. Thus it allows for significant processing energy savings over traditional VSP solutions. Its softness and flexibility supports perfect forming around the food in the vacuum packaging line”, explains Massimo Centonze, CEO at ITP, who adds: “First users report an easy adaptability to their specific VSP machines and excellent results even when skin packaging chilled food (at 4 to 8°C), which is frequently required to preserve freshness, original quality and nutritional value”.

The high transparency of the Surlyn ionomer significantly contributes to the superior appearance of the food packages. Sealing through fatty and greasy contaminants, this ionomer helps reduce leakers, and its excellent toughness and puncture resistance support both high processing line speeds and flawless adaptation to the contours of the food on the tray during thermoforming. Surlyn also provides the low-temperature seal initiation of the structure as well as its excellent hot tack strength, and adds to its high vapor and moisture barrier. Of additional value are the secondary sealing and the surface adhesion achieved with Surlyn, forming a visually appealing second skin around the food and helping to minimize migration of liquids in the packaging for a clean, appetizing presentation.

ITP uses DuPont Appeel peelable sealant as an innovative solution in this application to combine the required hermetic sealing with a soft and uniform easy opening and a tamper evident stress-whitening effect under tension. The Bynel adhesive resins selected by ITP provide perfectly adjusted tie layers to achieve a non-delaminating structure built up with these high performance film components.

Massimo Centonze continues: “ITP is currently evaluating several options to further downgauging these peelable VSP barrier films without compromising performance of the final packaging. Beyond, we are in the process of extending our offering with grades for a greater variety of bottom substrates beyond foamed PS and rigid APET. We are confident that DuPont will again be able to provide the high performance packaging polymers needed to reach our goals”.