New resins cut material use, ups productivity, claims manufacturer

Reducing packaging weight not only reduces material and transportation costs, but also helps a company to meet the tougher recycling requirements in place today. Basell said the new PP resins -- marketed under the trade names Adstif HA740J, Higran RS1684 and Moplen EP310K, can be used to replace traditional material such as polyethylene terephthalate (PET) or glass. "Competitive trends in the packaging industry to improve productivity and reduce weight and cost are driving the development of innovative PP resins increasingly replacing more traditional material such as PET or glass,"​ said Rainer Mantel, a Basell spokesperson. "We are seeing new customer requirements for improved barrier properties and aesthetics with low odour and taste, as well as the right balance of rigidity and impact resistance."​ AdstifHA740J is designed for those requiring preformed multi-layer barrier food packaging. The new resin is a nucleated, high-crystalline PP material for use in sheet extrusion and thermoforming processes. The resin offers improved processing, high transparency and stiffness without loss of impact resistance, the company claims. Adstif HA740J has the potential for thermoformers to incorporate regrind into clear PP applications without compromising transparency, the company claimed. Basell cited tests showing sheet containing ethylene-vinyl alcohol copolymer (EVOH) and a tie layer exhibited no visible signs of degradation or yellowness, even after recycling numerous times. The company also cited customer trials showing that the product's processability leads to better wall thickness distribution in thermoformed packaging. "Our new Adstif resin may provide additional value to customers', as a well-balanced wall thickness in thin-wall packaging can improve failure rates and result in the use of less material,"​ claimed Michael Luetke, a Basell project manager. The Adstif HA740J resin exhibits higher stiffness, providing good dimensional stability in thinner gauges even after sterilization, hot-filling or microwave reheating, the company claimed. Basell is targeting the material at the multi-layer barrier food packaging market. Luetke said food companies have been showing a "lot of interest" in using transparent barrier PP resins in food packaging to replace glass jars and metal cans. ​"We believe that weight reduction of up to 30 per cent is feasible in small portion barrier PP packaging compared to these traditional materials, resulting in substantial cost savings,"​ claimed Luetke. The Higran RS1684 resin is designed to replace existing materials used in foamed food tray applications, the company said. The new resin is produced using Basell's Spherizone PP technology. It is being marketed as a high melt strength PP grade that can be used to make foamed food trays used in the packaging of fresh fruits, vegetables and meat. The polypropylene resin has all of the typical food-contact benefits of polyolefins, said Cees Besems, a Basell manager. Food can be packed 'in-line', which can minimise the risk of tray contamination during transfer from line to line, he said. The fine-cell structure of foamed PP can produce packaging that is aesthetically attractive and comfortable to the touch. "For certain producers, the resin can be used in foamed food tray production that utilises chemical foaming agents up to 0.60 densities,"​ he said. "The resin can produce trays that are considerably less brittle than competing polymer foams, needs no seal layer and has good resistance to oils and fats.​" Higran can also be used in form-fill-seal lines, surpassing polystyrene performance in foamed packaging, as it provides high dimensional stability during hot filling and microwave reheat-ability, he claimed. In addition to foamed tray applications, Basell's new Higran RS1684 grade can be used for blown film extrusion. Tests show that the new resin can enhance bubble stability, thereby increasing production line output, the company claimed. The Moplen EP310K resin is marketed as a medium flow heterophasic copolymer for use in cast film applications such as retortable pouches. The resin contains no slip or anti-blocking agents and can be used in customer food contact applications, the company said. Bernd Hoecker, another Basell managerl, said the company's tests show that Moplen EP310K has impact resistance, stiffness, processability, transparency and a low gel content. "Good film stiffness with deep-freeze impact resistance, together with high heat resistance, results in packaging that can withstand a broad temperature range, allowing refrigerator to microwave use,"​ he stated. "In addition, the exceptionally good sealing properties can expand food's shelf life."​ Moplen EP310K's other features include improved scratch resistance and reduced shrinkage combined with easy processing and low stress whitening, the company claimed.