Sustainable cellulose bottle closures up-cycled from mixed waste paper with collagen coating
Novel biodegradable bottle closures made from up-cycled mixed waste paper and leather waste. Cellulose fibers are molded via heat press and coated with collagen hydrolysate for hydrophobic and barrier properties, offering a recyclable alternative to plastic closures.
Overview
This solution addresses the growing plastic waste crisis in the beverage packaging industry by transforming mixed waste paper and leather waste into high-performance, recyclable bottle closures. The approach combines cellulose fiber production from deinked and bleached waste paper with a collagen hydrolysate coating derived from leather waste, delivering a fully biodegradable and stream-recyclable alternative to conventional plastic closures. By up-cycling two significant waste streams simultaneously, the technology supports circular economy goals while reducing reliance on virgin pulp and petroleum-based plastics.
Technical specifications
- Cellulose fiber production: Waste paper is collected from offices and university departments, then processed through deinking, bleaching, and pulping to produce clean cellulose fibers suitable for molding.
- Heat press molding: Cellulose fibers are compression-molded using heat press techniques to form closures in multiple bottle sizes, increasing material density for enhanced tensile strength and improved air and oxygen barrier properties.
- Collagen hydrolysate coating: Collagen extracted from leather waste after dechroming is applied as a thin coating layer to impart hydrophobic properties. Laboratory results have demonstrated that a single-layer collagen coating reduces moisture permeability by approximately 2500%.
- Barrier performance: The combined cellulose substrate and collagen coating target dimensional stability, seal integrity, chemical resistance, moisture barrier, and oxygen barrier requirements for beverage closure applications.
- Recyclability: The cellulose-based construction allows the closure to be recycled through standard paper streams after use.
Technology readiness level
The technology is currently at an early-to-mid stage of development. Prior published research supports the use of cellulose fibers for packaging with strong mechanical and barrier properties, and internal laboratory validation has confirmed the dramatic improvement in moisture barrier performance from collagen hydrolysate coatings. Remaining validation steps include producing closures in multiple sizes, full mechanical and barrier characterization, and recyclability testing. Optimization for industrial-scale manufacturing is ongoing.
About University of Dhaka
Founded in 1921, the University of Dhaka is Bangladesh’s flagship comprehensive public research university, headquartered in the nation’s capital and serving a large, diverse academic and research community. Its city‑center location places faculty and facilities within close reach of government ministries, regulators, corporate headquarters, and development organizations, enabling timely collaboration and access to policy and market stakeholders. Companies engage through sponsored research and consultancy, shared laboratories for prototyping and analytical testing, executive education for managers, and talent pipelines supported by an extensive alumni network. Research is supported by national funding bodies and ministries as well as competitive international development and foundation grants. Dedicated industry engagement and IP support services help structure NDAs and MTAs, guide data use and compliance, and enable licensing and startup collaboration.
Inquire about this partnering listing
Looking for
Industry applications
delivered to your inbox.