Making Polymer Blow Molding More Sustainable

The plastics industry has made progress in answering the sustainability call.

Evolving resins, part design, and technologies have enabled converters to consume less energy and raw materials during production, while still ensuring structurally sound products with appealing designs that are able to draw shoppers’ attention.2

A reliable polymer resin supplier with the right infrastructure and expertise can help converters test and optimize production processes so that they can rise to meet the growing call for sustainable offerings and practices.

The ways in which converters are able to respond to shifting sustainability sentiments and the growing number of related regulations in countries around the world vary based on specific production processes, product lines, buyers, supply chains, and other factors.

Let’s explore some of the ways blow molders have responded to the ongoing sustainability trend and its inherent opportunities and hurdles.

Converters Are Using More Recycled Polyethylene

It’s important to understand that blow molders working to achieve sustainability goals are already off to a good start.

Many of them are already using polyethylene, one of the most recyclable (and popular) polymers.3

Polyethylene, specifically high-density polyethylene (HDPE Resin), is the most widely used polymer in blow molding applications, with key end markets including packaging and consumer goods.4

Polyethylene’s popularity with converters also stems from its ease of processing, versatility and cost-effectiveness.

Blow molders are increasingly layering in recycled resins, including recycled polyethylene, with virgin plastic during the production process.

Such increases in recycled content stem from a combination of converters’ own sustainability commitments as well as various market demands, such as those created by major brands like Coca-Cola Co. and Unilever to increase recycled content in their products.1

Designing for Recyclability Enables Sustainability

To optimize sustainability in a practical manner, converters can do more than simply use PE made from recycled products through an integrated mass balance system. They can also leverage certain types of PE and applications that are easier to recycle after consumer use. For instance, monomaterial type applications that are fully recyclable after they’re used.

Shell Polymers is working with converters to design for commoditization, meaning our resin is easily processable for converters to use in their applications and easier to recycle, post-consumer. 

Sustainable Plastic Packaging: Less Resin, Less Energy

While polymer films get much of the attention when it comes to the sustainability benefits of lightweight food packaging, blow molders, too, are contributing to the trend.

Modern design simulators and technology have helped converters to ensure proper part design, enabling further lightweighting.

Meanwhile, newer blow molding production machines have improved electric drives and control systems, and use less energy overall during production, while still producing 500 to 1,500 pieces per hour.2 3

Using less resin and less energy in the converter production process promotes sustainability and benefits converter bottom lines.

For Suppliers Like Shell, Reducing Pellet Loss is Just the Start

Aside from using less electricity and resin, converters and suppliers alike are also focused on eliminating resin waste in blow molding applications and other production processes.

At Shell Polymers, we’re committed to reducing waste in the overall resin production process, through training and procedures to prevent pellet loss. Our new Pennsylvania polyethylene plant is also designed with sustainability in mind.

Shell is aiming to achieve “zero-waste” company-wide by reducing waste generated and increasing reuse and recycling in its business and supply chains. The company will set goals for those initiatives by the end of 2022.

Shell has also pledged to use one million tonnes of plastic waste a year in our global chemicals plants by 2025, and to increase the amount of recycled plastic in our packaging to 30% by 2030.

For Converters, Sustainability Switches Not Always Simple

While the potential benefits of transitioning to more sustainable production methods are many, the process can be challenging for converters and their customers, including consumer goods providers and retailers. Innovative, sustainable products to date have generally been less cost-effective, less efficient, and less convenient than incumbent packaging.

Transforming a packaging portfolio also requires brands to grapple with complex and sometimes conflicting trade-offs between various sustainability metrics, such as increasing a product’s recyclability versus reducing its carbon footprint.

Meanwhile, realistic options for making a product differently can be limited, due to slim profit margins and branding challenges, all of which can vary by geographic region.4

Shell’s Polymer Pioneers and Pros, including Blow Molding Technical Service Engineer Michael Misco, can draw on deep technical and industry expertise to help converters – including those working to produce more sustainable blow molding applications – understand and address sustainability demands and other production challenges or opportunities that emerge.

At our new polyethylene plant in Monaca, Pennsylvania, we will work collaboratively to address fluctuations in a customers’ supply needs, such as increased resin demand stemming from new or growing product lines.

Our plant’s Innovation Center, which includes our analytical lab and other testing and quality control facilities, was built as a collaborative space for Shell and converter customers to address product and long-term growth needs.

Learn More About Industry Sustainability

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