|Brown has been building thermoforming machinery for more than a half century, so their depth of knowledge of all the materials and processes used is extensive. Understanding these materials and their characteristics allows Brown to configure your equipment with the specific features and options required to maximize product quality and production.
Here is a glossary of the most commonly used materials in food packaging.
Polypropylene (PP) is a thermoplastic polymer made by the chemical industry from the monomer propylene (a flammable gas derived from petroleum hydrocarbon cracking). Polypropylene is reasonably economical, and is used in thermoformed food packaging applications for takeout and deli containers, as well as disposable cups and lids. Polypropylene is clearly a growth material for food packaging and disposable food packaging market segments.
Polyethylene terephthalate (commonly abbreviated PET, PETE) is a thermoplastic polymer resin of the polyester family. APET is popular because it offers two excellent attributes- clarity and rigidity. It is widely used in for fresh food clamshells, bakery goods, dairy and takeout containers. It’s also used for disposable food packaging products such as cups, and lids.
RPET (Recycled PET)
Clam-shell packaging is being manufactured from RPET, preventing tons of used PET materials from ending up in the landfills. Just like APET, RPET offers excellent clarity and rigidity for fresh food clamshells in bakery, dairy and takeout containers And just like APET, it’s also used for disposable cups and lids.
Polystyrene (PS) is an aromatic polymer made from the aromatic monomer styrene, a liquid hydrocarbon that is commercially manufactured from petroleum. Polystyrene is one of the most widely used kinds of plastic. Polystyrene can be transparent or can be made to take on various colors. Food packaging applications include deli, bakery, dairy and disposable cups, lids, plates, and bowls.
Polystyrene foams are good thermal insulators and therefore are often widely used in cooked take out food packaging and trays, egg cartons, and meat trays.
Oriented polystyrene (OPS) is produced by stretching extruded polystyrene film to improve its stiffness. Typical food packaging products are fresh food clamshells, bakery, and deli containers.
Polylactic acid or polylactide (PLA) is a biodegradable, thermoplastic, aliphatic polyester derived from renewable resources, such as corn starch in the U.S., or sugarcane abroad. Although PLA has been known for more than a century, it has only been of commercial interest in recent years, in light of its biodegradability. PLA is used for biodegradable and compostable disposable cups for cold beverages, deli containers and fresh food clamshells for food packaging.
Crystallized polyethylene terephthalate (CPET) is specially designed to resist temperature extremes and can be used safely in conventional gas, electric and microwave ovens from -40°C to 220°C. CPET containers are ideal for packaging a wide variety of food products from frozen and refrigerated, to pre-cooked and fresh foods. Convenience-seeking consumers are drawn to products packed in CPET, because preparation is as simple as heat and serve.
Multi-layer Barrier Materials
A barrier from oxygen and water vapor is often required in food packaging, so permeation is a critical factor in design. Some food packaging contains desiccants (oxygen absorbers) to help extend shelf life. Modified atmospheres or controlled atmospheres are also maintained in some food packages. Keeping the contents clean, fresh, sterile and safe for an extended shelf life is a primary reason to use barrier materials. Food packaging applications include shelf stable packaging and atmospheric packages for meat trays.
With today’s focus on manufacturing sustainability, new materials are being developed that are both thermoformable and biodegradable. Brown is working with a number of customers to discover new ways to configure equipment to meet parameters of these new materials.