BEKUM: economical alternatives in the materials used for extrusion blow moulding

Of crucial importance are the current machine and system solutions for the economic and ecological production of bottles, containers, cans, drums and IBCs made of plastic. On the material side, the focus lies on three aspects: the newly developed EPET IV materials, the processing of calcium carbonate (chalk) and the resource-saving recycling of materials. A further highlight at the trade fair will be on the importance of spiral distributor blow head technology to increase performance.

Fully transparent EPET packaging with handle function

The high transparency of glass-clear EPET IV container convincing at the point of sale (photo: BEKUM)

A key concept in the packaging industry is product differentiation. Accordingly, suppliers are constantly looking for innovative or recyclable materials for new product ideas. The fully transparent, newly introduced EPET class IV material, capable of being extrusion blow moulded, is an interesting candidate. This material has sufficient stability for extrusion blow moulding. The parameters of the improved class IV are higher than the 1.0 PET recycling stream launched on the market. The typical challenges of PET blow moulding are exceptionally well mastered by the high-quality EPET class IV materials. EPET IV has a comparatively high resistance to wear. The material can be completely melted in the extrusion unit without causing excessive wear. In respect of the machine, special requirements must be met to provide a robust, reliable, fully automatic production in a 3-layer operation. Blow-moulding machines from BEKUM, such as the HYBLOW 407 D, have been specially designed for high performance in these demanding EPET applications.

The HYBLOW 407 D (photo: BEKUM)

The HYBLOW 407 D allows the reliable production of EPET bottles with flash removal and directed bottle transfer integrated into the machine. The current 07 series of machines with the C-frame clamping unit, patented by BEKUM, is perfect for EPET processing due to the high closing force per cavity, uniform force distribution and extremely quick force generation. Michael Mehnert: "BEKUM has numerous references in extrusion blow moulding of the most demanding PET and co-polyester materials. Customers accordingly have access to a comprehensive knowledge base on blow moulding PET materials. This is particularly true in respect of attractive handle containers made of transparent EPET IV for innovative new product ideas for our global customers."

Two options for reducing the cost of materials

In order to reduce the cost of materials, two methods are available to the packaging manufacturer. The use of calcium carbonate (CaCO3 = chalk) and recycled material as a substitute in the middle layer. The proven multilayer co-extrusion technology from BEKUM provides the flexibility required and also offers advantages in the processing of both material strategies. Even the combined introduction of chalk and PCR material as a multilayer system is possible and has already been successfully implemented by BEKUM.

Calcium carbonate for effectively cutting costs

The use of calcium carbonate (chalk) displays excellent barrier properties. The improved UV protection function is also attractive for packaging manufacturers. However, it is in respect of its extremely high cost effectiveness that the use of calcium carbonate (chalk) is decisive. Michael Mehnert: "With a 20 l canister for the packaging of cooking oil, 24% of
the HDPE, based on a total weight of only 900 g, could be replaced by chalk at a far lower price. The cost difference between HDPE and chalk in this specific case was about USD 1,000 per tonne. At a machine output of 210 items per hour and 6,000 production hours per year, this results in possible savings of more than USD 270,000 per year. These are very exciting prospects for a packaging manufacturer."

Substitution by recycled material

The use of recycled materials (PCR = post consumer recycled) as a substitute in the middle layer is the other ideal route. The tri-extrusion technology from BEKUM is the  solution for the smooth and efficient production of multilayer systems. It provides the opportunity of including inexpensive, but varied, recycled polymers (old plastics) and their different rheology in the processing between the material layers of the new material. This option was presented to professionals in the industry as part of the launch of the new electric blow-moulding machine EBLOW 37 at the K 2016. A three-layer 20 l canister with a combined material layer distribution made of chalk and PCR was shown. The production parameters in figures: an output of 240 20 l canisters/h (918 g net weight, 1,188 g gross weight) has a flash waste of 23%. The potential savings for packaging manufacturers are enormous. The flash waste generated during the production process is 100% reused in the production and processing. In addition, 20% of the HDPE new material can be replaced by the less expensive combination with chalk. There are also advantages when adding colour. The 2% proportion of colour pigments in a single-layer design can be reduced to 0.5%.
The more expensive colour pigments (master batches) only need to be applied to the outer
layers. The hidden core no longer needs to be coloured.

High extrusion quality with high-tech spiral distributor blow heads

More performance in extrusion blow moulding due to spiral distributor blow heads from BEKUM (photo: BEKUM)

At the Interpack 2017, the focus of BEKUM will once again be on the spiral distributor blow head technology. The unique spiral distributor blow heads are characterised by an excellent, uniform wall thickness distribution in the parison and in the end product. This results in a significant potential for packaging manufacturers to optimise the single-layer parison quality. However, the spiral distributor blow heads from BEKUM are even more impressive in respect of items with a multilayer structure. In this regard, manufacturers of packaging products do not need to dispense with user friendliness. The heads can be easily adjusted by the operator from the front of the machine. In addition, the head design enables faster colour changing times than conventional designs. The consequent significant increase in machine productivity is of enormous interest to packaging manufacturers in regard to flexibility and profitability. The consumption of change material for cleaning can also be reduced to a minimum by means of spiral distributor blow head technology. The compact design of the spiral distribution blow heads is a further advantage. Their smaller surfaces mean considerably less energy is required to heat them. All in all, the high-tech spiral distributor blow heads from BEKUM provide packaging manufacturers with interesting options to increase the quality of the items, save time and costs during production and a general improvement in adding value.