Plastic Thermoforming versus Fiberglass (GRP/FRP)

Both plastic thermoforming and fiberglass molding can be used to make applications for a multitude of industries. However, blended polycarbonate and the plastic thermoforming process used to manufacture parts from this material have some very distinct advantages over fiberglass that should be considered for new and existing product designs.



Heavy weight is high cost. This has been a tenant in the aviation industry for a long time and is slowly being adopted by rest of the transportation and other industries as factors affecting operating costs and environmental impact are examined. Lighter weight offers savings in both fuel and energy consumption, and decreases carbon footprint and operating costs. For example, a reduction of 800 lbs (~360 kg) to an average city transit bus can equate to a 2-3% savings in fuel consumption, according to a 2010 study conducted by the U.S. National Highway Traffic Safety Administration. Additional benefits are a tangible increase in the life of vehicle components, such as brakes and propulsion systems.

Thermoformed plastic is lightweight and can offer a substantially reduced part weight when compared to fiberglass. Depending on the type of thermoplastic polycarbonate blended material used and a few other factors, the average thermoformed part is 30% lighter than their fiberglass equivalents. A fact reinforced by comparing specific gravity weights of raw material product on industry material provider websites from companies such as Covestro and SEKISUI SPI.

Overall Manufacturing Cost is Lower and Lead Times Faster

The manufacturing process of a fiberglass reinforced plastic part is relatively complex and labor intensive. Production often requires multiple tools to complete necessary production cycles of a single part. This increases both tooling and labor costs, and results in a relatively lengthy production time required to generate a finished piece.

The thermoforming process, on the other hand, is highly automated, relatively simple, and typically requires less labor. Most applications utilize only a single tool per part. Consequently, lead times tend to be shorter, and the tooling and labor costs are reduced when compared to the fiberglass molding process. From a purely process perspective, thermoforming is often both faster and cheaper than the fiberglass counterpart in smaller production volumes of 250-3000 parts annually.

Greater Design Freedom and Aesthetic Flexibility

One of the unique characteristics of the thermoforming process and material is its ability to produce extremely detailed and complex parts. Diverse surface texturing options, precise tolerances for mated parts, and complex geometry design are just a few of the possible applications that are otherwise difficult or costly to fabricate with fiberglass. The availability of colored plastic raw material can, in most cases, also remove the additional cost and time associated with the secondary process of part gel coating or painting. These advantages give designers the freedom to create complex modern designs that are more aesthetically pleasing and functional.

Environmentally Friendly and Industry Compliant

As companies and passengers become more eco conscious and industry standards and government regulations increase, thermoplastic material providers have responded by creating products able to meet the challenging demands of regulated industries, such as mass transit and aviation markets. Thermoplastic raw material providers have a variety of blended polycarbonate and other thermoplastic options that are compliant with U.S. and European industry standards. Thermoplastic materials are also recyclable and VOC free, a trait generally not shared in fiberglass processing.

Extremely Durable

Thermoplastic polycarbonate blends are, on average, 4 times more impact resistant than traditional fiberglass. The flexible and durable nature of thermoformed plastic material allows impact forces to be deflected over the materials surface, allowing the material to recover from impacts that would otherwise crack the more rigid and unyielding material of a fiberglass part. The benefits are an increase in part life and a reduction in part replacement and maintenance costs. Most thermoplastic is also highly resistance to stains, chemical cleaners, and graffiti.

With many material options and manufacturing processes available, each with their own set of pros and cons, there is no shortage of choice when it comes to your application. While thermoformed polycarbonate blends may not be the answer for every product, it quite clearly provides solutions for many markets that other materials and manufacturing processes are hard pressed to match.

Productive Plastics is top contract manufacturer for heavy gauge thermoforming, including vacuum forming and pressure forming. Contact us or request our complimentary thermoforming design guide for more information.

Please contact Productive Plastics for more information on the thermoforming process
Please download our complimentary thermoforming design guide for more information on the thermoforming process

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