Case Study: Circular Innovation with PC4 in Carpet Manufacturing Overview

Bentley Mills, a California-based commercial carpet manufacturer, has become the first in the U.S. to standardize the use of post-consumer calcium carbonate (PC4)—reclaimed from discarded carpet backing—across all its carpet backing systems. This initiative marks a significant milestone in sustainable manufacturing and circular economy practices within the flooring industry.  

Background 

Carpet backing traditionally contains calcium carbonate as a filler to provide weight and stability. Most of this material ends up in landfills after carpets are discarded. PC4 refers to calcium carbonate recovered from post-consumer carpet waste, offering a sustainable alternative to virgin mineral fillers.  After nearly two years of research and development, PC4 was standardized in February 2025 across all of Bentley’s backing systems.This initiative, supported by the Carpet America Recovery Effort (CARE) and in partnership with Circular Polymers by Ascend, marks a transformative shift in how carpet waste is repurposed, contributing to both environmental sustainability and regulatory compliance.  

Recent Policy Context  

The National Stewardship Action Council (NSAC) is a national nonprofit advocacy organization advancing a circular economy that is good for people, the planet, and fair markets. NSAC proudly sponsored California’s AB 863, a model circular economy law and Extended Producer Responsibility (EPR) solution requiring carpet-to-carpet recycled content. While Bentley’s adoption of PC4 came before the law’s deadlines, this leadership demonstrates how forward-thinking manufacturers can set the pace—and how policy ensures broader industry adoption. AB 863, advanced by NSAC, provides the clear market signals needed for other manufacturers to follow Bentley’s example and invest in circular supply chain innovation. 

Implementation Strategy  

• Material Recovery: PC4 is extracted through a proprietary mechanical process that isolates and purifies calcium carbonate from reclaimed carpet backing, reducing the presence of residual fibers or latex.  

• Standardization: Bentley incorporated PC4 into every running-line backing system without requiring customer opt-in or premium pricing. 

• Recycled Content Certification: The recycled material is vetted and certified by SCS Global, ensuring accurate reporting for post-consumer recycled content claims. 

• Material Health Certification:  The PC4 passed testing for legacy chemicals in accordance with Cradle to Cradle v4.0 Silver requirements. 

• Regulatory Alignment: Supports California’s AB 863, which mandates at least 5% carpet-to-carpet recycled content by 2028.

Sustainability Impacts Waste Reduction

Diverts significant volumes of carpet waste from landfills. 

• Carbon Footprint: Reduces lifecycle CO₂ emissions by replacing virgin fillers with mechanically recycled PC4. 

• Circular Economy: Reinforces closed-loop manufacturing by reintroducing reclaimed carpet materials into new carpet products. 

• LEED Credits: Enhances eligibility for LEED® certification through recycled content and environmental declarations. 

Outcomes 

• Performance: Bentley reports a slight decrease in tensile strength, but no compromise in final product performance or durability. 

• Customer Benefit: The change is seamless for customers, with no added cost or change in product specifications. 

• Cost-effectiveness: PC4 is a cost-neutral alternative to virgin calcium carbonate due to subsidies offered to the reclamation facility through the CARE program. 

• Industry Leadership: Sets a precedent for other manufacturers to adopt circular practices. This success demonstrates the power of policy leadership (NSAC’s sponsorship of AB 863) combined with industry leadership (Bentley’s proactive adoption).   

With the launch of a National Textile Working Group, NSAC invites others to join us in advancing a circular economy for carpet, textiles, and other valuable materials, bringing producers, local governments and states, retailers, and recyclers to the table to pursue similar solutions. To honor this milestone and national achievement, NSAC will recognize Bentley’s California and national leadership with a Circular Economy Leadership Award in early 2026 highlighting Bentley as a model for how innovation and policy together can transform industries. 

Conclusion 

Bentley Mills’ integration of PC4 into carpet backing exemplifies how policy, innovation, sustainability, and regulatory foresight can converge to transform waste into a valuable resource, fully unlocking economic, environmental, and public health benefits.This case study highlights the potential for reclaimed materials to become standard components in high-performance products, advancing both environmental and economic goals. 

NSAC invites interested companies, communities, states, and organizations to partner with us in advancing similar circular economy policies and practices and looks forward to celebrating leaders like Bentley who demonstrate what’s possible. 

Join the Textile Working Group

Carpet tiles and rolls produced by Bentley Mills using PC4 recycled content.