Fox River Associates is a leading North American supplier of high-quality release liners used throughout the composites industry, including in prepreg manufacturing for aerospace, automotive, sporting goods, and industrial applications. With over 35 years of experience serving customers that rely on consistent release liner performance, Fox River Associates provides tailored solutions that help manufacturers and converters maintain efficiency and profitability.
Our release liners are engineered for use in both unidirectional (UD)/fabric prepreg processes and drum winder (tape winding) processes — two distinct but critical methods for composite part manufacturing. Whether you’re making airplane wings, floor panels, luggage compartments, or high-performance sporting goods like pickleball paddles and golf club shafts, Fox River Associates offers the right release liner for your resin system and process requirements.
Call Fox River Associates today at 1-800-647-6579 or use the form on this page. Our experienced technical composites team is ready to work with you.
What Is the Role of a Release Liner in Composite Prepreg Manufacturing?
In the composites market, release liners serve as temporary supports and protective layers during resin coating, handling, storage, and curing. They maintain the surface quality of the prepreg and allow for clean removal before layup or curing.
Fox River Associates supplies film and paper release liners designed to handle tacky resins, temperature fluctuations, and demanding mechanical requirements found in both hot melt and solvated prepreg processes.
- Hot melt prepreg process: Involves melting the resin and coating it onto fibers or fabric, requiring release liners that can withstand high heat and still peel cleanly without distorting the resin layer.
- Solvated prepreg process: Uses a resin dissolved in solvent, which is later evaporated. Liners in this process must be compatible with the solvent system and resist chemical attack while maintaining dimensional stability.
By understanding these process differences, Fox River Associates can help customers select the most appropriate silicone-coated or non-silicone release liner for their prepreg resin chemistry and production method.
Unidirectional (UD) and Fabric Prepreg Applications
Unidirectional (UD) and woven-fabric prepregs are typically produced as flat sheets or wide rolls. In these applications, the release liner provides:
- Dimensional stability across wide widths
- Smooth resin release and protection against resin transfer or surface imprinting
- Reliable peel performance under varying humidity and thermal conditions
Common liner types for UD/fabric prepregs include:
| Liner Type | Base Material | Coating Type | Key Benefits |
| Silicone-coated PET film | Polyester (PET) | Platinum or solventless silicone | Excellent release, thermal stability |
| Polypropylene (PP) film liner | Polypropylene | Silicone | Flexible, chemical resistant |
| Silicone-coated kraft or glassine paper | Paper | Solvent or emulsion silicone | Breathable, cost-effective |
| Non-silicone coated PET film | PET | Fluoropolymer or specialty coating | Silicone-free systems |
Fox River Associates offers all these release liner types — available in a variety of substrate thicknesses and release levels — to ensure smooth coating and handling during prepreg manufacture.
Drum Winder / Tape Winder Prepreg Applications
Drum winding (or tape winding) processes require release liners with different mechanical and surface properties. The tape is wound continuously onto a rotating mandrel at high speed, which means the liner must:
- Unwind consistently with low friction
- Resist stretching, tearing, or wrinkling
- Maintain release stability under tension and temperature
For these applications, Fox River Associates supplies strong silicone-coated PET or polypropylene films engineered for consistent performance during continuous winding. High-temperature films are also available for advanced thermoset and thermoplastic resin systems.
These release liners are ideal for applications like:
- Pressure vessels and composite pipes
- Aerospace spars and structural tubes
- Golf club shafts and hockey sticks
- Composite drive shafts and sporting goods cores
Why Choose Fox River Associates for Composite Release Liners?
At Fox River Associates release liners are our only business. That focus means you gain access to one of the most experienced technical teams in the industry. Our specialists understand the nuances of resin coating, tack level, cure cycles, and liner unwind characteristics — and how those details affect your process performance.
Customers count on us because:
- We’re ISO 9001:2015 certified, ensuring consistent quality and traceability. This level of process control is crucial not just for composites, but also for medical tape and critical adhesive markets where cleanliness and consistency matter.
- We have the shortest lead times in the industry, with small minimum order quantities to serve small and mid-size manufacturers as well as large-scale producers.
- We carry ample inventory and operate regional warehouses and converting facilities in Atlanta, GA; Chicago, IL; Dallas, TX; and Los Angeles, CA — ensuring quick, reliable delivery across North America.
- We provide responsive, personal service. Our experienced team works closely with each customer to understand resin types, tack levels, and process needs before recommending a liner.
Selecting the Right Release Liner — Questions to Ask
When choosing a composite release liner, consider these key factors:
- What is the resin chemistry and cure temperature? (Hot melt or solvated; epoxy, phenolic, or thermoplastic)
- What is the process type? (Wide-width unidirectional/fabric vs. drum/tape winding)
- What tack level or peel force is required?
- Will the release liner need to handle vacuum bagging, temperature fluctuations, or autoclave cure?
- What are the roll width, tension, and core requirements?
By sharing this information with Fox River Associates, our technical team can recommend the appropriate film or paper release liner — whether it’s silicone-coated PET, HDPE, LDPE, or non-silicone fluoropolymer-coated film.
Where Composite Prepreg Release Liners Are Used
Fox River Associates’ liners are found in a wide range of end-use composite products, including:
- Aerospace: airplane wings, interior panels, floor systems, luggage compartments
- Sporting Goods: pickleball paddles, skateboards, golf shafts, bicycle frames, hockey sticks
- Automotive and Transportation: body panels, hoods, and structural reinforcements
- Industrial: pressure vessels, pipes, wind turbine blades, and tooling boards
Whether your prepreg line runs carbon fiber, fiberglass, or aramid, the high quality release liners from Fox River Associates will help ensure clean release, dimensional accuracy, and efficient throughput.
Why North American Composites Companies Choose Fox River Associates
Companies across North America partner with Fox River Associates because we offer a unique combination of technical expertise, responsiveness, and supply reliability. We’re a stable, focused company that has specialized exclusively in release liners for more than three decades, helping manufacturers in aerospace, industrial, medical, and tape markets stay competitive and efficient.
Our commitment is simple:
- Deliver the highest-quality release liners available.
- Provide technical support and customer service that exceeds expectations.
- Ensure you always have what you need — when you need it.
Get Started Today
If you’re developing or producing composite prepregs and need a trusted partner who understands both unidirectional/fabric and drum winder applications, contact Fox River Associates today.
Call Fox River Associates today at 1-800-647-6579 or use the contact form on this page to connect with our team. We’ll help you identify the most appropriate release liner for your resin system, process, and performance goals — ensuring reliability, efficiency, and success in your composite manufacturing operation.