Startup profile · funding coverage
CleanFiber funding, valuation and investors
High-performance cellulose building insulation made from recycled corrugated cardboard.
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Funding, valuation & investors
Answer-first snapshotLatest funding
Series B
~$28–33M equity + $31.5M project finance · April 2024
Latest known valuation
Not publicly disclosed
Total disclosed equity funding
$10M
Excludes debt, grants, acquisitions, secondaries, and IPO proceeds.
Current status
private
series b · Buffalo, NY
Investors in latest funding
Lead: Spring Lane Capital
Other: Climate Innovation Capital , AXA IM Alts , Ahlström Invest , Tokyu Construction / Global Brain
Latest tracked event: DOE MESC grant selection (October 2024). It is shown separately because it is not counted as disclosed equity funding.
Overview
CleanFiber manufactures environmentally friendly cellulose insulation from recycled cardboard boxes using a patented chemical treatment process. Based in Buffalo / Lackawanna, NY (founded 2013 as UltraCell Insulation by Jonathan Strimling), the company is a 43North alumnus that scaled a regional plant into a national expansion story.
In April 2024 CleanFiber closed a Series B led by Spring Lane Capital — reported as $28M equity in contemporaneous coverage, with the company later citing a $33M Series B — alongside a $31.5M project financing facility from Spring Lane. Participants included Climate Innovation Capital, AXA IM Alts, Ahlström Invest, and Tokyu Construction/Global Brain. In October 2024 CleanFiber announced selection for $20M in U.S.
Department of Energy MESC grant funding to support additional production facilities. The company has claimed cumulative capital well above $100M when including project finance, tax credits, and related facilities.
Why CleanFiber 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.
Product & use cases
Manufactured cellulose insulation produced from recycled cardboard, sold into building insulation channels as a climate-oriented alternative to fiberglass and foam products.
- Residential new construction and retrofit insulation
- Builders seeking recycled-content cellulose products
- Regional and national insulation distributors sourcing plant-made cellulose
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)
Funding history (newest first)
DOE MESC grant selection
2024-10 $20MSource: Read source · cleanfiber.com
Series B
2024-04 ~$28–33M equity + $31.5M project finance- Spring Lane Capital (lead)
- Climate Innovation Capital (participant)
- AXA IM Alts (participant)
- Ahlström Invest (participant)
- Tokyu Construction / Global Brain (participant)
Source: Read source · techcrunch.com
Series A
2022 $10MSource: Read source · techcrunch.com
Investors in our directory
Funds linked from CleanFiber's profile — open a fund page for stage focus and related deal articles.
Competitive landscape
Edge: Cardboard-to-cellulose manufacturing at industrial scale in Buffalo, paired with project-finance-friendly expansion rather than only software-style equity rounds.
Building insulation is an incumbent-heavy materials market. CleanFiber competes on recycled cardboard feedstock and manufacturing scale-out, using project finance and public grants alongside venture equity.
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Fiberglass insulation majors (Owens Corning, CertainTeed, etc.) incumbent
Dominant residential insulation share.
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Other cellulose insulation producers direct
Traditional cellulose often from newsprint; feedstock and process differ.
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Spray foam insulation adjacent
Different install method and performance/cost tradeoffs.
Notable stories
- Spring Lane Capital had watched the company for over a decade before leading the 2024 Series B and project facility (TechCrunch, Apr 2024).
Industries
Market / IPO context
Editorial / static context — not a live quote.
FAQs about CleanFiber
Practical answers founders, operators, and investors typically search for.
Last updated:
Editorial note: AI tools assisted with research, structure, or drafting. Venture Capital Tracker retains human editorial responsibility for factual accuracy, relevance, and source quality before publication.