Liniar and Whiteline Collaborate to Deliver a Smarter Flush Sash Sealing Solution

Collaboration that Starts with Fabricators

When fabricators feed directly into product development, the results tend to speak for themselves. That’s exactly what’s happened with the latest collaboration between Liniar and Whiteline Manufacturing - an initiative driven by a simple but important goal: to offer choice when it comes to sealing performance and fabrication efficiency on the 70mm flush sash window system.

Rather than accepting the status quo, Whiteline’s Product and Technical team approached Liniar with a practical idea for an alternative to traditional brush pile seals. What followed was a hands-on, joint development process focused on real-world fabrication and installation challenges.

Strong Foundations on Both Sides

Whiteline Manufacturing has built its reputation in the Southeast on delivering high-performance PVCu and aluminium systems to the trade, with a clear focus on precision and reliability. Liniar, meanwhile, continues to lead from the front in systems design and innovation, backed by in-house extrusion and a vertically integrated approach.

It’s a collaborative partnership that makes sense, combining shop-floor insight with system design expertise.

Turning an Idea into a Working Solution

The project began with a visit to Liniar’s Denby headquarters, where both teams sat down to explore the concept. Whiteline’s Head of Product & Technical, Leighton Baitup, brought detailed CAD drawings to the table, providing a solid starting point for development.

“From day one, it felt like a proper collaboration,” says Leighton. “We weren’t just handing over an idea, we were working together to refine it, challenge it, and make sure it would actually deliver on the fabrication floor and on-site.”

Working alongside Liniar’s technical and development teams, including Design & Fabrication Director Daryl Fradley, the concept was prototyped, tested, and refined. Input from Schlegel, Liniar’s sister company specialising in sealing solutions, added further depth to the process.

Daryl explains, “Having that direct input from a fabricator like Whiteline is invaluable. It keeps the focus on what really matters, how the product performs in practice, not just in theory.

“We also conducted market research to gather data from our wider customer base to ensure the project was feasible and scalable.” 

Designed for confidence across the supply-chain 

The result is a new Flush Sash Gasket and Corner Gasket system designed to address common pain points. The push-fit design simplifies fabrication, helping to reduce fitting time and potential errors. At the same time, improved seal integrity and cleaner shadow lines enhance both performance and aesthetics.

Crucially, the system has been engineered to accommodate expansion and contraction through seasonal temperature changes, supporting long-term reliability, adding peace of mind for installers and end users alike.

“It’s about making life easier,” Leighton adds. “If a product is quicker to fit, consistent to work with, and performs as expected, that’s a win for everyone across the supply chain.”

A Model for Future Development

This project underlines a wider industry point: meaningful collaboration between manufacturers and fabricators leads to better outcomes. By involving end users early, companies can avoid costly missteps and bring more practical, installer-friendly solutions to market.

As Daryl puts it, “The more we work closely with our customers, the better the end product becomes. That’s the direction the industry needs to keep moving in.”

For fabricators and installers alike, it’s a clear example of how shared expertise can translate into smarter, more efficient systems that benefit the full Liniar customer base.