Sustainability is no longer just a buzzword—it’s a global imperative.

Governments, consumers, and OEMs are demanding more sustainable products and manufacturing processes. In the plastics industry, this means reducing environmental impact by minimizing waste, lowering energy usage, and increasing the use of post-consumer recycled (PCR) and post-industrial recycled (PIR) materials.

Regulations such as the European Union’s Circular Economy Action Plan, the U.S. Plastics Pact, and California’s SB 54 law are setting aggressive targets for recycled content, landfill diversion, and product recyclability. Brands that fail to adapt face potential financial penalties, product restrictions, or lost business with eco-conscious customers.

Yet the road to sustainability is not simple—especially for injection molders.

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The Challenge of Using Recycled Materials in Injection Molding  

Recycled plastics present a major challenge for injection molders due to their inconsistent material properties. Unlike virgin resin, which offers predictable viscosity, melt flow, and mechanical strength, recycled materials can vary significantly between batches. These inconsistencies come from:

• Varying source polymers (even within the same resin type)
• Degradation from multiple heat histories
• Unknown or inconsistent filler and additive content
• Contaminants such as moisture or incompatible plastics
• Wide molecular weight distribution

As a result, molding with recycled content using traditional process setups can lead to:

• Higher scrap rates
• Flash and short shots
• Dimensional inconsistencies
• Warped or brittle parts
• Increased downtime for adjustments

This makes many molders hesitant to adopt recycled materials—even when customers demand it.

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Cavity Pressure: The Key to Sustainable Injection Molding  

Cavity pressure sensors provide the real-time feedback molders need to confidently process recycled materials. Rather than relying solely on machine settings (like injection pressure or screw position), cavity pressure sensors measure exactly what’s happening inside the mold cavity.

By doing so, they allow processors to compensate for material variation and ensure consistent part quality—regardless of resin source or batch.

1. Ensuring Proper Fill and Pack  

Cavity pressure data allows processors to identify when a cavity is fully filled and packed correctly. Even if recycled material viscosity varies, the CoPilot® system detects deviations in real time, alarms or sorts suspect parts, and—when connected for control—can trigger velocity-to-pressure transfer based on cavity pressure.

2. Reducing Scrap and Increasing Repeatability  

Using pressure thresholds to define part acceptance helps avoid overpacking, underfilling, or flashing. This reduces rework, cuts material waste, and makes it easier to meet customer quality specs using recycled resin.

3. Supporting DECOUPLED Molding®  

RJG’s DECOUPLED Molding® methodology enhances the benefits of cavity pressure control by separating the injection process into three distinct phases—filling, packing, and holding. This allows molders to:

• Control shear and velocity during fill for optimal flow
• Precisely manage pack pressure for dimensional stability
• Maintain consistent hold pressure to ensure part integrity

These scientific molding techniques are critical for dealing with recycled material variability and improving process capability.

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Sustainability Regulations Are Accelerating Change  

The pressure to move toward sustainable plastics processing is intensifying. Consider these recent developments:

• EU (Green Deal / PPWR): Policy direction is that all packaging placed on the EU market must be reusable or recyclable in an economically viable way by 2030. (The separate PPWD recycling-rate target for plastic packaging is 55% by 2030.)
• U.S. Plastics Pact: The original pledge targeted 100% of plastic packaging reusable/recyclable/compostable by 2025; Roadmap 2.0 now extends unfinished targets to 2030.
• OEM mandates: Automotive and consumer-goods brands increasingly specify recycled content and carbon goals (e.g., industry guidance for measuring recycled content in automotive supply chains).
• Retailer scorecards & certification: Programs like Amazon SIPP/FFP/SIOC and Walmart’s Sustainable Packaging Playbook and ESG initiatives set packaging/recyclability expectations and influence supplier ratings and chargebacks.

These pressures are transforming sustainability from a “nice to have” into a competitive necessity.

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RJG: Helping Molders Turn Recycled Plastics into Reliable, Profitable Parts  

RJG’s technology empowers manufacturers to mold with recycled materials while maintaining high part quality and throughput. The CoPilot® system with cavity pressure sensors enables precise control, faster troubleshooting, and real-time process insight—even when resin properties fluctuate.

Benefits include:

• Reduced scrap and downtime
• Improved first-pass yield
• Lower material costs with higher recycled content
• Support for corporate ESG goals
• Future-proofing against upcoming regulations and OEM demands

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A More Sustainable and Profitable Future  

Using recycled materials no longer means sacrificing quality or predictability. With the right technology and process knowledge, molders can produce high-performance parts, reduce environmental impact, and meet evolving market demands.

RJG is leading the charge in sustainable injection molding—helping manufacturers worldwide adopt eco-friendly practices without compromising performance or profitability. This includes the newest, cutting-edge developments in Autonomous Process Control.

See how industry leaders are using RJG technology to reduce waste, improve efficiency, and mold with recycled materials—visit our Sustainability Use Case page to learn more.

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