# CleanFiber

> High-performance cellulose building insulation made from recycled corrugated cardboard.

## Why it is interesting

43North alum manufacturing climate materials in Buffalo — April 2024 Series B (~$28–33M equity) led by Spring Lane Capital plus $31.5M project finance, and later a $20M DOE MESC grant path for multi-state plant expansion.

## Profile

- **Stage:** series-b
- **Status:** private
- **Industries:** climate-tech, hardware-semiconductors
- **Coverage:** full
- **Last updated:** 2026-07-26

## Key facts

- 43North alumnus; HQ / manufacturing in Buffalo area (Lackawanna plant)
- Series B (Apr 2024): ~$28–33M equity led by Spring Lane Capital; $31.5M project financing facility
- Series B participants: Climate Innovation Capital, AXA IM Alts, Ahlström Invest, Tokyu Construction/Global Brain
- DOE MESC (Oct 2024): selected for $20M grant funding for additional plants
- Company has described cumulative capital >$100M including project finance / incentives; Inc. 5000 #1 fastest-growing manufacturing (2024, company claim)

## Investors in our directory

- https://venturecapitaltracker.com/fund/43north

## Related articles

- https://venturecapitaltracker.com/buffalo-startups-and-vc-firms-2026

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Source: https://venturecapitaltracker.com/startup/cleanfiber