Pultex® is the registered trademark of Creative Pultrusions \(CP\) for

Chapter 1
Introduction to Pultrusion
Pultex® standard structural profiles are used in many highly-corrosive applications.
Creative Pultrusions, Inc. is The World’s Most Innovative Leader in the Fiber Reinforced Polymer
Composites Industry. Established in 1973, the company operates in two manufacturing locations: Alum
Bank, Pennsylvania (Corporate Headquarters) and Roswell, New Mexico; Technology Center: Pultrusion
Dynamics Division, Oakwood Village, Ohio; Creative Pultrusions International Ltd., United Kingdom;
and a complementary Worldwide Distribution Network. Pultex® is the registered trademark of Creative
Pultrusions, Inc. (CP) for products made by the pultrusion process. Pultex® profiles are Pultruded Fiber
Reinforced Polymer (FRP) components, manufactured from a wide variety of high performance
thermosetting resins and reinforcements, classifying pultrusion as a structural engineering material. As a
result, Pultex® profiles have been used extensively in many industries for construction, corrosionresistant, electrical/electronic, transportation, consumer and water/wastewater applications.
Within the last two decades, the pultrusion process has been used by the design engineer as having the
capability of manufacturing products that solve many modern problems. As a result, high-strength, lightweight and maintenance-free products and structures have been designed and built.
The New and Improved Pultex® Pultrusion Global Design Manual is developed to aid the design engineer
in understanding the pultrusion process and how various elements of the process and design affect the
performance and cost of the final product.
The information provided is the result of many years of participation with industries worldwide.
Applications vary from the development of new high-performance springs and bumpers for the
automotive industry to corrosion-resistant structural I-beams, channels and angles for the chemical
processing industry.
With The New and Improved Pultex® Pultrusion Global Design Manual, you, the design engineer, will
share in the knowledge and experience to assist in the design of your future pultrusion requirements.
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Bridges are easily installed in hard-to-access areas.
Fiberglass platform systems are ideal
in highly corrosive areas.
An integrated building system is lightweight, easy to erect and maintenance-free.
Pultex® Pultrusion Process
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Pultex® Pultrusion Process (cont’d)
Pultrusion is a continuous molding process using fiber reinforcement in polyester or other thermosetting
resin matrices.
Pre-selected reinforcement materials, such as fiberglass roving, mat or cloth, are drawn through a resin
bath in which all material is thoroughly impregnated with a liquid thermosetting resin.
The wet-out fiber is formed to the desired geometric shape and pulled into a heated steel die. Once inside
the die, the resin cure is initiated by controlling precise elevated temperatures. The laminate solidifies in
the exact cavity shape of the die, as it is continuously pulled by the pultrusion machine.
Process Advantages
The process provides maximum flexibility in the design of pultruded FRP profiles. Currently, profiles up
to 1.83 m wide and 0.53 m high are possible. Since the process is continuous, length variations are limited
to shipping capabilities.
Specific strength characteristics can be designed into the composite, optimizing laminate performance for
a particular application by strategic placement of high performance reinforcements. Color is uniform
throughout the cross section of the profile, eliminating the need for many painting requirements.
Processing capabilities include the production of both simple and complex profiles, eliminating the need
for much post-production assembly of components. Pultex® profiles can result in more satisfactory
performance of your finished products and structures.
Raw Materials Used in the Pultrusion Process
Each resin mix is formulated carefully to suit
application requirements.
Roving and mat are of major importance in
determining physical properties.
Resin
Selected high performance polyester resins are combined with suitable fillers, catalysts, UV
inhibitors and pigments to formulate the resinous matrix, binding the fibers together and providing
the structural corrosion resistance and other properties required. Although the vast majority of
applications can be serviced by the variety of polyester resins available, certain application
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requirements of higher strength or corrosion resistance can be satisfied with the selection of vinyl
ester.
Roving
Fiberglass roving provides the high longitudinal strength of pultruded products. The amount and
location of these reinforcements can be determined in the design stage and can alter the subsequent
physical properties of the finished product. Roving also provides the tensile strength needed to pull
the other reinforcements through the die; therefore, it is a necessary ingredient in the profile design.
Mat
Continuous strand mat provides the most economical method of obtaining a high degree of
transverse physical properties. The mats are layered with roving; this process forms the basic
composition found in most pultruded products. The ratio of mat to roving determines the
relationship of transverse to longitudinal physical properties.
Veil
Since pultrusion is a low-pressure process, fiberglass reinforcements normally appear close to the
surface of the product. These can affect the appearance, corrosion resistance or handling of the
products. Surface veils can be added to the laminate construction to displace the reinforcement
from the surface adding a resin-rich finish to the profile. The two most commonly used veils are
A-glass and polyester .
Pultex® Resin Systems
Resin mixtures, glass content and their combination can be altered to achieve special properties in a
profile due to the versatility of the pultrusion process. The specific resin formula may be adjusted for
each profile due to processing requirements.
Table 1-1 Available Resin Systems
Pultex®
Resin Series
1500
Polyesters
1525
Fire Retardant
Polyesters
1600
Vinyl esters
1625
Fire Retardant
Vinyl esters
2020
Low Profile Modified
Polyester Resin System
Characteristics
Good chemical resistance combined with high
mechanical and electrical properties.
A flame spread rating of 25 or less when tested
per ASTM E-84 plus the attributes of 1500
Series profiles. UL 94 VO rating also available
on request.
Excellent corrosion resistance, as well as,
improved physical properties and elevated
service temperature capabilities.
Same as Series 1600 plus the added bonus of a
25 or less rating per ASTM E84 and low
smoke generation.
Profiles requiring optimum surface finish
Typical
Applications
Standard Structurals used in
moderately corrosive environments
Crossing gate arms
Dunnage bars
Ladders
Fire retardant standard structurals
High performance standard structurals
High performance standard structurals
for severely corrosive environments
Transportation
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Table 1-1 Available Resin Systems (cont’d)
Pultex®
Resin Series
Characteristics
Halogen free, low flame and smoke.
3535
Modified Polyester
Typical
Applications
Mass Transit
Electrical
Reference The Pultex® Product Availability List for stocked items.
Other special resin systems are available; please contact the Engineering Department of Creative
Pultrusions, Inc.
Woven and Stitched Fabric
When the mix of required physical properties is not satisfied by conventional mat roving
construction, selected fabrics can be used to meet the end use requirements. Varieties of these
products can be used by themselves or in conjunction with the standard mat roving construction to
obtain the necessary results. The fiberglass fabrics are available in balanced, high longitudinal, high
transverse or ± 45° multi-ply construction. Since these materials are more costly, the composites
using these reinforcements are more expensive than standard construction pultrusion.
Other Reinforcing Material
Carbon and aramid fibers are also used in the pultrusion process in roving, woven fabric forms, or
in combination with fiberglass. These high modulus fibers add considerable stiffness to the
composite. Care must be taken when designing profiles with carbon and aramid fiber materials
since they are more costly. The composite should be designed for optimum performance.
Surfacing veils enhance the finished
profile and increase corrosion
resistance.
Woven/stitched goods increase transverse
properties of pultruded profiles.
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