As trailer manufacturers continue searching for stronger, lighter, and more durable materials, many are moving beyond traditional aluminum and wood-based construction methods. Today’s enclosed trailers, cargo trailers, toy haulers, and specialty vehicles demand materials that not only improve long-term performance, but also deliver a cleaner appearance and lower maintenance requirements.

That shift has led many trailer manufacturers to adopt advanced composite solutions like PolyCor AP for trailer siding and structural panel applications. Designed as a high-performance trailer aluminum replacement, PolyCor AP helps reduce common issues associated with traditional trailer materials, including oil canning, moisture damage, and long-term panel deterioration. Its lightweight composite construction supports improved durability while maintaining the smooth, professional finish manufacturers and end users expect.

Unlike conventional aluminum trailer siding or wood-backed panels, PolyCor AP features a wood-free composite design engineered specifically for demanding trailer applications. The material helps manufacturers build quieter, longer-lasting trailers with improved dimensional stability and reduced maintenance concerns over time.

Beyond exterior trailer siding, the PolyCor product family also supports interior trailer construction through solutions like PolyCor™ HL for trailer ceilings and headliners. Together, these PolyCor composite panels help trailer manufacturers create more reliable, modern trailer designs built for long-term performance.

The Growing Demand for Better Trailer Building Materials

Modern trailer manufacturers face several major obstacles, including:

• Eliminating siding distortion (oil canning)

• Reducing trailer weight

• Improving fuel efficiency

• Preventing water damage

• Reducing long-term maintenance

• Improving durability for enclosed trailers and specialty vehicles

As customer expectations continue to evolve, many traditional trailer building materials no longer meet the performance demands of modern trailer manufacturing. Wood-based products can absorb moisture over time, leading to swelling, rot, warping, and material deterioration. Meanwhile, aluminum trailer siding is often susceptible to oil canning, which creates a wavy or uneven appearance that can reduce overall trailer aesthetics.

To address these challenges, many trailer manufacturers and trailer builders are turning to advanced composite solutions like PolyCor AP, which provide improved durability, dimensional stability, and long-term reliability for enclosed trailers and specialty vehicles.

What Is PolyCor AP?

PolyCor AP is a proprietary composite sheet developed specifically for trailer siding and specialty vehicle applications. Designed and sold exclusively by Piedmont Plastics, PolyCor AP provides trailer manufacturers with a lightweight, durable, and dimensionally stable alternative to traditional aluminum and wood-based trailer building materials.

Compared to many conventional trailer building materials, PolyCor AP offers several performance advantages, including:

• Wood-free construction

• Waterproof performance

• Lightweight design

• Dimensional stability

• Resistant to oil canning

• Outdoor durability

• Printing compatibility

These characteristics make PolyCor AP an ideal solution for enclosed trailers, cargo trailers, toy haulers, and a wide range of specialty vehicle applications where appearance, durability, and long-term performance are essential.

Why Trailer Manufacturers Are Using PolyCor AP

The Need To Eliminate Oil Canning

Oil canning is a frequent issue with aluminum trailer siding, especially on large trailer panels. It appears as visible waviness or distortion across the surface of the trailer and is commonly caused by temperature fluctuations, vibration, and stress placed on the panel during travel. As aluminum expands and contracts, the siding can develop an uneven appearance that affects the overall look of the trailer.

For trailer manufacturers and builders, oil canning can lead to several concerns, including reduced visual appeal, distorted graphics, lower perceived quality, customer complaints, and potential warranty issues.

How PolyCor AP Helps Eliminate Oil Canning

PolyCor AP was engineered to provide excellent dimensional stability in changing temperatures and demanding road conditions. Unlike traditional aluminum trailer siding, PolyCor AP resists the expansion and contraction that often causes oil canning. This allows trailer manufacturers to achieve a smoother, flatter trailer siding surface that maintains a cleaner appearance over time.

This advantage is especially valuable for enclosed trailers and specialty vehicles featuring large exterior side panels, vehicle wraps, printed graphics, custom branding, and painted finishes. A smooth trailer surface not only enhances appearance but also creates a better foundation for graphics, wraps, and paint applications.

Lightweight Trailer Construction Without Compromising Strength

Weight reduction remains a major priority in trailer manufacturing, but manufacturers still require materials that can withstand long-term use and demanding environments. PolyCor AP helps trailer builders balance lightweight construction with dependable durability.

Lighter enclosed trailers and specialty vehicles can offer improved fuel efficiency, easier towing, increased payload capacity, better handling, and reduced stress on suspension systems. At the same time, trailer siding materials must endure constant road vibration, moisture exposure, outdoor weather conditions, temperature changes, debris impact, and daily wear.

PolyCor AP delivers a combination of lightweight performance and structural durability, making it a strong solution for enclosed trailers, cargo trailers, toy haulers, and specialty vehicle applications.

Reduced Noise and Vibration in Enclosed Trailers

Another key benefit of PolyCor materials is improved sound dampening. Traditional aluminum and wood-based trailer materials can transfer road vibration and outside noise directly into the trailer interior. Over time, deteriorating fiberboard materials may also create openings that allow additional sound penetration.

PolyCor AP helps reduce these issues by minimizing vibration transfer and supporting quieter trailer construction. A quieter trailer interior can improve comfort and usability for applications such as toy haulers, recreational trailers, mobile workspaces, specialty vehicles, mobile medical units, and command centers. By helping reduce vibration and supporting insulated trailer designs, PolyCor AP contributes to a more comfortable and quieter enclosed trailer environment.

Better Trailer Graphics and Branding With PolyCor AP

Trailer appearance plays a major role in many enclosed trailer applications, particularly for trailers used in business advertising, motorsports, mobile services, recreational applications, and brand promotion.

For this purpose, PolyCor AP provides a smooth, stable surface that works well for:

• Vinyl graphics

• Vehicle wraps

• Printed branding

• Painted finishes

• Custom trailer designs

Because PolyCor AP resists oil canning, graphics maintain a cleaner, more professional appearance over time. This allows trailer manufacturers to produce enclosed trailers and specialty vehicles that look premium both on the lot and on the road.

PolyCor HL for Trailer Headliners and Ceilings

While PolyCor AP is widely recognized for trailer siding and exterior trailer applications, the PolyCor product family also supports interior trailer construction. PolyCor™ HL was specifically developed for trailer headliners and ceiling applications, giving trailer manufacturers a lightweight, water-resistant alternative to traditional fiber-based ceiling materials.

Engineered for enclosed trailers, toy haulers, and specialty vehicles, PolyCor HL helps improve interior durability, minimize moisture-related damage, and support quieter, longer-lasting trailer interiors.

Challenges With Traditional Trailer Ceiling Materials

Many enclosed trailers and toy haulers still rely on fiber-based ceiling materials that can absorb moisture and deteriorate over time. These traditional materials are prone to water absorption, sagging, mold, and mildew growth. As these materials degrade, trailer manufacturers and owners may face costly repairs, reduced durability, and shortened trailer lifespan.

Benefits of PolyCor HL

PolyCor HL offers trailer builders a water-resistant ceiling solution designed for long-term performance in demanding trailer environments. Key advantages of PolyCor HL include:

• Lightweight construction

• Washable surfaces

• Chemical resistance

• Improved durability

• Sound dampening properties

• Long-term moisture resistance

Its fluted rib structure also helps increase panel strength while reducing sound transmission throughout the trailer interior. For trailer manufacturers focused on durability, reduced maintenance, and improved interior performance, PolyCor HL provides a significant upgrade over traditional fiberboard ceiling materials.

Applications for PolyCor Products

PolyCor materials are used throughout the trailer manufacturing industry across a variety of enclosed trailer and specialty vehicle applications.

Why Trailer Manufacturers Choose PolyCor

Trailer manufacturers need more than just materials. They rely upon a supply partner that understands the challenges of trailer building and specialty vehicle manufacturing.

As the exclusive distributor of the PolyCor product line, Piedmont Plastics works closely with trailer builders to help identify the right materials for trailer siding panels, ceilings, interiors, and specialty vehicle applications. Learn more by connecting with our material experts!