Shaping plastic packaging

An Industry Insight by Wim-Henk Stoppkotte, Promens

Over the years the technical properties of plastics have developed and become increasingly more suitable for use with food. Meanwhile many other materials like glass, tin and paper have been replaced by plastic especially in consumer packaging. Plastic foils, cups, flasks and trays are meanwhile well accepted as consumer packaging in combination with food.

“Frequent introduction of new products is essential to maintain our leading position in the market”
-Wim-Henk Stoppkotte

But the development of plastics has also had positive effects for other applications within the food supply chain. Different technical developments resulted in a wide range of plastic grades, each with their own specific set of properties. The possible applications have been broadened by improving for instance, impact resistance, temperature resistance, chemical resistance, different types of rigidity, transparency and approval for contact with food. On the other hand application of certain additives has improved characteristics of the plastic material such as detect ability or conductivity and made them more suitable for the food industry.

Rotational moulding
Rotational moulding is a process in which plastic is converted into hollow shaped products without any seam or welding. Seamless products are less likely to leak and easier to clean. The process allows the plastic to be transformed into various shapes without any internal stress in the product. Products will therefore be better impact resistant and have a longer lifetime. Double walled products can be created with an internal layer of insulation material. Moreover, the rotational moulding process creates a smoother surface on the inside of the product which makes it easier to empty the product and reduces the residues. And with that cleaning cost will also be reduced. Under certain conditions it is even possible to clean the container at 120 degrees Celsius, a true advantage for certain food applications. And, if desired, rotational moulding facilitates can create relatively thick walls to make a product stronger or able to carry loads. Therefore multi-trip applications are common fields of usage for rotomoulded products with a long lifetime. And given the combination of material and production process, the result is likely to outperform other materials, such as stainless steel or textiles (Big Bags) in many ways.

The Materials Handling Products division of Promens has proven for over 45 years that combining rotational moulding and plastics can lead to products with amazing product features. Next to a wide range of storage and transport products for the chemical industry, Promens has also developed materials handling products for several segments in the food industry. Their products are applied in the fishing industry and slaughterhouses, Many different types of food and food ingredients be transported such as mustard and mayonnaise, cereals and coffee but also yeast or flour. For every type of product there is a container that exists.

The Hopper
The Hopper is an example of what can be created by rotomoulding plastic. The design facilitates not only the use of the container but also supports the company image through its design and choice of colour. The coned outlet of 60 degrees allows even difficult flowing solids to be emptied swiftly. The choice of outlet sizes (50 and 80 mm horizontally and 300 mm vertically) sets no limits to the viscosity of the contents of the container. The 1000 and 1800 litre versions allow for optimal use of transport, dosing or storage capacity. And the all-plastic construction of this container is easy to clean, non-corrosive and light in weight. A dissipative version was introduced earlier this year for use in ATEX regulated areas.

“Frequent introduction of new products is essential to maintain our leading position in the market,” says Wim-Henk Stoppkotte, Director of Sales and Marketing Europe at Promens. “Later this year we will introduce a new 300 litre container on wheels. This container allows suppliers to serve customers efficiently with smaller quantities than the usual 500 – 600 litre quantities without having to handle a large quantity of cans or buckets. Customers of that size often do not work with fork lift trucks and therefore this new Cruzer will come in handy”.