Reuse food packaging

The commercial potential for recycling post-consumer PET is not limited by lack of depolymerizing technology. Many options are available with varying degrees of capital intensity. The technologies most probable to provide satisfactory quality product, suitable for reuse in food packaging, are likely to cost US 1.00/kg or more and require capacities of over 20000 annual tonnes. 

One approach to reduce the contaminant levels consists in reusing the wasted plastic as the core of the new material. Residues of pesticides or harmful contaminants may limit recycling of plastics as a result of their potential toxicity. Utilisation of post-consumer plastics for pharmaceutical or food-contact applications is forbidden, and multilayer food packaging materials manufactured using functional barriers are subjected to strict regulations [9, 40, 41]. 

Franz R and Welle F, 1999, Analytical screening and evaluation of post-consumer PET recyclate materials from the market with respect to reuse for food packaging application. Deutsche Lebensm.-Rdsch. 95 (3). 94-100. 

L. CASTLE, Recycled and reused plastics for food packaging Packaging Technology and Science, 1994, 7, 291-297. 

It has been suggested that formed plastic containers, used for carry-out foods, should not be reused for microwaving as such containers, if heated, may be subjected to conditions other than those for which they had been safety tested. The authors recommend that for all take-away food packaging, if it has not been tested for repeat use, then labelling should clearly indicate that the foodstuff should not be re-heated in the packaging. 

Retortable food packages using EvOH as the oxygen barrier are multilayer structures which are formed by coextrusion. The number of different layers in a the structure can vary a representative five-layer structure is shown in Figure 3. Often one or more layers are added to reuse scrap and regrind in the package. There is a wide range of possible combinations of layer thicknesses which can be used in this type of structure. 

Large-scale production of snack food is done in deep fat fryers. These are either batch or continuous fryers. In a batch fryer, the food is added into a large pan of hot oil. The oil is heated either directly from under the fryer or in an external heater. In the latter case, the oil is continuously recirculated into the pan and it is stirred with a stirrer. Formerly, manual stirring was common but modern kettles are generally equipped with mechanical stirrers. Fried product is removed and spun through a centrifugal device to remove the excess oil from the surface. The product is seasoned and packaged. The recovered oil is reused. 

PETE can be used to make shatterproof plastic bottles, such as those used for soft drinks. However, these bottles cannot be recycled and reused directly because they cannot withstand the high temperatures required to sterilize them. PETE can t be used for any foods, such as jellies, that must be packaged at high temperatures. Eor these uses, a new plastic, PEN, or polyethylene naphthalate, is used. 

---