Lydall stock (US5240211029): Acquired by Unifrax in 2021

Lydall Inc, acquired by Unifrax in 2021, previously traded under ISIN US5240211029. US investors may track legacy holdings or filtration materials sector exposure via OTC markets.

Lydall Inc, a former US-listed company in advanced materials, was acquired by Unifrax in a deal completed in 2021. The transaction ended its independent public trading under ticker LDL on NYSE. This development marked the close of Lydall's chapter as a standalone equity for US retail investors.

As of: 14.05.2026

By the editorial team – specialized in equity coverage.

At a glance

• Name: Lydall Inc
• Sector/industry: Advanced materials and filtration
• Headquarters/country: United States
• Core markets: Industrial filtration, thermal acoustics, battery materials
• Key revenue drivers: Filtration media, sealing solutions
• Home exchange/listing venue: NYSE (LDL, pre-acquisition)
• Trading currency: USD

Lydall: core business model

Lydall specialized in manufacturing highly-engineered filtration media and advanced materials for critical applications. Its products served industries including transportation, industrial, and energy storage. Prior to acquisition, the company generated revenue through three main segments: Performance & Engineered Materials, Thermal/Acoustical Metals, and Filtration Products. These focused on nonwoven media for air, liquid, and fuel filtration.

Headquartered in Manchester, Connecticut, Lydall operated globally with facilities in North America, Europe, and Asia. Its business model emphasized innovation in sustainable materials, targeting growth in electric vehicles and clean energy. US investors valued its exposure to automotive and industrial sectors amid rising demand for efficient filtration solutions.

Main revenue and product drivers for Lydall

Filtration Products was Lydall's largest segment, contributing the majority of sales through specialized media for transportation and industrial uses. Key products included HEPA filters and pleated media for heavy-duty applications. Thermal/Acoustical Metals provided engineered solutions for noise reduction in vehicles and appliances, while Performance Materials targeted battery separators and medical applications.

In its final full year as public company, Lydall reported revenue driven by automotive OEMs and aftermarket suppliers. The firm's emphasis on lightweight, high-performance materials aligned with US market trends toward electrification and emissions control. Post-acquisition integration into Unifrax expanded these drivers into broader industrial applications.

Conclusion

Lydall's acquisition by Unifrax in 2021 transformed its market position, integrating its filtration expertise into a larger platform. US investors with prior exposure may monitor Unifrax developments or sector peers for similar opportunities. The legacy ISIN US5240211029 serves as a reference for historical tracking amid ongoing materials innovation.

Disclaimer: This article does not constitute investment advice. Stocks are volatile financial instruments.