Corex: Increased Efficiency and Reduced Scrap in the Production with Recycled Polymers

Corex Plastics (Australia) Pty Ltd is a leading manufacturer of twin wall profile Fluteboard® and Corflute® sheet and solid sheet extrusions. The company’s closed loop philosophy forms an integral part of its business, but also posed some challenges for the company. With the recycling business growing, there was an enhanced need for adequately sorting feed streams and controlling quality of recycled resins. Thermal analysis instrumentation from NETZSCH is the solution to their problems.

About Corex Plastics & Recycling

Corex Plastics (Australia) Pty Ltd, established in 1985, is a leading manufacturer of twin wall profile Fluteboard® and Corflute® sheet and solid sheet extrusions. In 2011, Corex identified the need to adopt and implement environmentally sustainable practices and strategies in a customer-centric approach. The Corex Recycling Division emerged to manage its ‘closed loop program’ to provide a socially responsible, ‘cradle to cradle’, resource solution service with their customers. This philosophy now forms an integral part of Corex’s business, but also posed some challenges for the company.

Challenge 1: Sorting feed streams into polymer categories

Due to an increasing demand for recycled plastics, Corex Recycling began recycling their own waste streams and sourcing post-industrial scrap from external suppliers. The change to using waste plastic as feedstock required the purchase of an FT-IR with ATR accessory to quickly identify and sort the different feed streams into polymer categories.

While the FT-IR has been very helpful to Corex’s quality control requirements, many feed stream contamination problems still occurred, which were attributed to the above-mentioned technique not being able to distinguish multi-layers in feedstock like films.

Figure 1: Contaminated injection molded part
Figure 2: Compatibilized injection molded part

Challenge 2: Quality control and assurance of recycled resins

A few years into Corex recycling journey, the company experienced exponential growth in their external recycled resin supply business. This growth has lead the business to focus increasingly on robust quality control and assurance methods.

The NETZSCH DSC 214 Polyma was the best choice

In 2017, Corex acquired the DSC 214 Polyma from NETZSCH Analyzing & Testing after an exhaustive search for the best instrument in the market to meet its needs. The Proteus® software SmartMode and Identify features allow Corex process operators without a background in polymer science to use the instrument and obtain usable and precise results, without the presence of a laboratory technician. This was extremely helpful given the 24/7 nature of their business.

As a recycling company, Corex have increasingly become specialists in developing resins with the same properties as the virgin products currently used by customers. For this application, the company uses DSC analyses to check the materials for melting and crystallization temperatures and carries out oxidative stability tests (OIT) to compare the thermal stability of the incumbent products against Corex Recycling’s products. All of this data was unattainable before the arrival of the NETZSCH DSC 214 Polyma.

“Over the last few years our customers have often complemented our materials as market leading in quality and this has a lot to do with the appropriate use of our DSC facility.”

– Cameron Janky, Polymer Engineer, Corex Plastics

Due to the use of DSC, Corex recycling has been able to offer a more comprehensive QA/QC analysis including detailed data sheets that show the constituents and their quantity within a manufactured end product.

“The DSC 214 Polyma has allowed us to improve our production efficiency by greatly reducing the amount of scrap material and helped increase throughput by reducing the amount of screen changes the recycling machine requires due to removal of impure feed streams.”

– Matt Nettleton, General Manager, Corex Recycling

Learn more about the NETZSCH DSC 214 Polyma and the software features of Proteus®.

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