Iten Industries

What can Iten Politen® Pultrusions offer You?

The ITEN POLITEN� PULTRUSION Team is a highly educated, highly skilled, and highly motivated team, possessing more than 30 years of experience in Pultrusion engineering, design, process optimization and production manufacturing. Iten's Pultrusion Team is dedicated and devoted to providing unique custom solutions to the challenges and problems facing your use of pultruded profiles. Our rapid, low cost engineering, design, prototyping and optimization allows for the quick development of products in a cost effective way. Our process, "concept to reality and beyond," teamed with direct customer interaction, enables our customers a fast track to the market place with their newly developed products.

With ISO 9001 and lean manufacturing certifications, we offer a guarantee on quality deliveries on all on all predetermined commodity products that you expect and deserve. Our lean manufacturing certification guarantees Iten's commitment to focussing on cost savings opportunities for you and your custom products. Our "Concept to Reality and Beyond" philosophy, combined with personalized one on one customer interaction, guarantees your new products the pole position in the race to the market place.

Introduction to Pultrusion Process jump
Pultrusion Technology jump
Performance Properties jump
Market Opportunities jump
Comparable Materials jump
Summary of Benefits jump
Resources jump

What is the Pultrusion process? top

The pultrusion process is one of the most cost-effective methods for the production of composite materials. It is a continuous process that produces little waste material. Some what different than extrusion, where as material is forced through a die, in the pultrusion materials are pulled through the die. In the pultrusion process, fiber reinforcements are pulled through a resin impregnation area to coat the reinforcement with a thermoset resin. The material continues through preform plates that begin to shape the fiber/resin bundle, and through a heated die to cure the resin. A cured part in the desired shape that requires no further processing exits from the die. Although the process appears to be simple, numerous process variables such as pull speed, die temperature, quality of fiber/resin wet-out, and fiber volume can affect the quality of pultruded composites. In order to take full advantage of the pultrusion process, the effect each process variable has on mechanical properties must be completely understood. The highly skilled, highly educated and experienced Iten Pultrusion Team understands those variables and know what it takes to manufacture quality products.

Because it is a cost-effective method for the production of advanced composites, the pultrusion process has tremendous potential for traditional composite applications as well as a wide variety expanding applications.

A little about the technology top

What goes into the pultruded profile?

A pultruded composite consists of reinforcing materials, such as unidirectional glass fibers, other wise called rovings, continuos fiberglass mat and a thermoset resin that binds the composite together. A polyester surfacing veil to improve the external appearance of the composite, and chemical resistance or weatherability may also be added. A variety of ancillary materials may be added to the resin formulation, such as pigment for color, accelerators to speed the curing of the thermoset resin, internal release agents, and several various types of inert fillers, each having its own functionality. A pultruded profile can be uniquely designed to meet your custom application.

Process Technology

The most important ingredients in a successful pultrusion operation are the process technology, training and tooling. These are the key elements to producing quality parts at the best price. Our Politen Pultrusion team has 30 years of pultrusion experience behind them to provide you with the best price per value.

Process Control Systems

Accurate speed and pulling force control can be monitored by the operator continuously with visual reference of digital set points and operating modes, including purge cycles. Standard control systems include data reference to machine operation, computer controlled speed generation (closed loop) and data process collection and logging.

Infeed Tooling Module

The creel for continuous rovings generally consists of bookcase-type shelves with ceramic or polyethylene eyes located immediately above the packages. A mat rack is implemented for woven materials.

Resin Impregnation or wet out.

Impregnation of the fibers can be achieved with an open bath system or an injected die system, as dictated by product and process specifications.

In-Line Winder (Optional)

An in-line winder can be combined with the pultrusion process to add filament winding capability which allows for increase bi-axial strength.

Preformer Tooling

Custom forming guides are designed for each profile to orient the reinforcements at entry to the die. Iten Industries has built forming guides for products ranging from .062" diameter to 10"x30" wide profiles.

Die Spreader Station

The die/spreader table centers the die to the process centerline and heats the die for product exothermic curing. Dies are heated by electrical cartridges, controlled by state of the art processors.

Operator Control Station

Automatic or manual, control systems are state-of-the-art and give the operator precise control of the entire process.

Pulling Section

The pulling section can be either a pair of reciprocating clamp pullers that can be synchronized for a continuous pull, or a single clamp for an intermittent pull. Optionally, Iten Industries also uses caterpillar pullers that are implemented for commodity profile manufacturing. This type of puller consists of a pair of continuous belts containing pads which engage the profile.

Flying Cut-Off Saw

A conventional flying cut-off saw is used to accurately section the profile to any length, and at any process speed ranging from 6 ipm to 14 feet per minute. Typically an abrasive or a continuous rim diamond blade is used, which gives a smooth consistent finished cut.

Pick Your Performance! top

You tell us how you want you product to perform. We are sure to have the materials you need for the performance you need.

POLITEN® PULTRUSIONS are formulated and manufactured from fiber reinforced thermosetting Phenolic, Epoxy, Vinylester and Polyester resins. Many grades are recognized by Underwriters Laboratories Inc.® and are formulated to meet:

GPO-1, NEMA GPO-1.- An economy priced, general purpose laminate or composite

GPO-2, NEMA GPO-2.- Highly flame resistant material UL 94 V-0

GPO-3 NEMA GPO-3. -UL recognized, flame resistant, arc and track resistant

High Temp ESP.- High heat resistance, excellent retention of physical and electrical properties at elevated temperatures.

Testing to ASTM, ANSI, Military, NEMA and customer specifications are performed in Iten's laboratories.

MATRIX CHOICE

The composite properties such as high-temperature performance, corrosion resistance, dielectric properties, flammability and thermal conductivity are determined exclusively by the properties of the resin matrix.

Unsaturated Polyester Resins are most commonly used in pultrusion Orthophthalic, isophthalic acids or anhydrides, in combination with maleic anhydride and various glycols, are the basic elements. Pultrusion polyester must have the ability to gel and cure rapidly to form the strong gel structure required for release at the die wall. Generally resins with the viscosities of 500 cP are used for pultrusion. Higher viscosity low-reactive monomer versions can be blended with additional styrene to suit the processing need. The styrene level must be properly maintained to achieve good cross-link structure without having residual (unreacted) styrene in the finished composite. Polyester resins exhibit good corrosion resistance to aliphatic hydrocarbons, water, dilute acidic & alkaline environments. They do not perform well when exposed to aromatic hydrocarbons, ketones, and concentrated acids. A high degree of unsaturation in polyester chain exhibits shrinkage up to 7% on curing. This level can be reduced using fillers and low-profile additives. Composite based on polyesters retains high percentage of their electrical insulation properties even if used continuously at temperature up to 200oC. Though polyester supports combustion without modification, hence backbone bromination or the use of additives greatly improves its flammability and smoke generation properties.

The electrical properties of polyesters make them suitable for use as primary insulators in many high-voltage applications. Retention of electrical properties even at elevated temperatures has made polyester insulators the materials of choice in many applications. The weatherability of polyester is fair to good. Additional protection is usually through a variety of ultraviolet absorption additives or using polyester surface veils and even painting (done after pultrusion)

Vinyl Ester Resins show better corrosion resistance and mechanical properties at elevated temperature, but are approximately 75% more expensive than polyester. These resins display greater toughness properties, such as inter laminar shear and impact strength. The chemical structure of vinyl ester resins is such that the reaction sites are at the end of each polymer chain rather than along the chain resulting in rigid segments along the polymer backbone. This leads to lower-link density and high-temperature capability of these materials.

Epoxy Resins are expensive materials. They are suitable for increased continuous-use temperatures up to about 150oC. They are used when physical properties of the highest level, as well as elevated temperature property retention, are required. Their excellent electrical properties & corrosion resistance also qualify them for use in many commercial applications requiring superior performance at elevated temperatures. Epoxy resins do provide increased flexural strengths and shear-strengths over polyester and Vinylester systems. Epoxy resins are cured by stepwise reaction hence their reaction rate is very slow, which affects the productivity of pultrusion process.

Other Resins - A variety of resin alternatives is also available for specific applications. The resins based on methyl methalcrylate although more expensive than polyesters could be used for their special properties i.e. improved physical properties, high filler loading due to low viscosity, rapid processing speeds, smooth profile surfaces and improved flame retardancy and weathering characteristics.

Phenolic resins are also used in pultrusion owing to their high heat resistance and flame-retardancy/low-smoke characteristic.

A desire to improve toughness and post processing formability has lead to the use of thermoplastic resins. The engineering thermoplastic resins provide excellent heat distortion properties. The technology for impregnating fibers with thermoplastic resins includes hot-melt application and solvent solution impregnation.

Additives - By using various additives liquid resin systems can be made suitable to provide specific performance. Fillers constitute the greatest proportion of a formulation, second to the base resin. The most commonly used fillers are calcium carbonate, alumina silicate (clay), and alumina trihydrate. Calcium carbonate is primarily used as a volume extender to provide the lowest-cost-resin formulation in areas in which performance is not critical. Alumina trihydrate is filler that is used for its ability to suppress flame and smoke generation. Fillers can be incorporated into the resins in quantities up to 50% of the total resin formulation by weight (100 parts filler per 100 parts resin). The usual volume limitation is based on the development of usable viscosity, which depends on the particle size and the characteristics of the resin.

Special purpose additives include ultraviolet radiation screens for improved weatherability, antimony oxide for flame retardancy, pigments for coloration, and low-profile agents for surface smoothness and crack suppression characteristics. Mold release agents (metallic sterates or organic phosphate esters) are important for adequate release from the die wall to provide smooth surfaces and low processing friction.

An important characteristic pertains to the curing of thermoset resins. The polyester vinyl ester and methalcrylate systems are cured by the high-temperature initiation, followed by midrange accelerator and high-temperature completion. This contribution, which delivers the fastest processing speed, can also reduce resin pot life, especially in high ambient temperature.

REINFORCEMENT MATERIALS: One can use a wide variety of fibrous reinforcement and resin system to get a composite material with a broad spectrum of properties by pultrusion process. Since each fiber and resin material brings its own contribution to the composite, knowledge of raw material properties is the first step in designing a satisfactory composite product. The reinforcement provides mechanical properties such as stiffness, tension and impact strength and the resin system (matrix) provides physical properties including resistance to fire, weather, ultraviolet light and corrosive chemicals.

Reinforcement Types: Three characteristics must be considered when choosing reinforcements: first the fiber type (glass fiber, aramid and carbon); second the form (roving strands, mat & fabrics) and third the orientation. The glass fiber continues to be the most widely used reinforcement, because they are readily available and comparatively cheaper.

E-Glass Fibers, A borosilicate glass: the type most used for glass fibers for reinforced plastics, suitable for electrical laminates because of its high resistively, also called electrical glass, the most common, exhibits a tensile strength of approximately 345 Ksi and a tensile modulus of 6.8 Msi, but have relatively low elongation of 3 to 4%. A variety of fiber diameters and yields are available for specific applications. Surface sizing of glass fibers provides optimum impregnation and chemical bonding between the fibers and matrix resins, thus ensuring maximum strength development and retention.

S-Glass Fiber, A magnesia-alumina-silicate glass specifically designed to provide very high tensile-strength glass filaments. exhibits high tensile strength 490 Ksi & tensile modulus 12.5 Msi, and is used for high-performance applications.

A-Glass, A soda-lime glass similar to window or bottle glass with generally poorer chemical and water resistance. Used primary as surface mat

The Carbon Fibers made from an organic precursor by oxidation and carbonization and not having a graphitic structure. Primarily used in the Aerospace industry, exhibits tensile strength 550 Ksi , and tensile modulus at 33 Msi with elongation of 0.5 to 1.5%. Carbon fiber has various unique properties like electrical conductivity, high lubricity and low specific gravity (1.8 versus 2.60 for E-glass).

Organic Fibers such as aramids a generic classification for an aromatic polyamide (Kevlar and Nomex are examples of aramids) having high tensile strength 398 KSI and modulus 14 Msi along with elongation of up to 4%.

Polyester Fibers with appropriate binders have been used as a replacement for glass in applications that would benefit from increased toughness and impact resistance but where tensile and flexural strengths can be sacrificed.

Mechanical Properties

A broad spectrum of mechanical properties is provided by the selection of reinforcement types, style, form & proportion in combination with different matrix. The directionality of strength in a pultruded composite can be greatly influenced by substituting longitudinal reinforcement by random mat or directional fabrics. The absolute value of the specific property desired would depend on the fiber type chosen: glass, carbon, aramid, organic or natural fibers.

Physical Properties

Thermal conductivity of composites is affected by both matrix and fiber characteristics. Generally, the glass & organic fiber reinforced composites are excellent insulators for thermal and electrical environments. The use of conductive carbon fibers, however, results in composites that exhibit thermal and electrical conductivity to some extent; this reduces their effectiveness as insulators but creates opportunities because of their static charge and heat dissipation characteristics. Specific gravity is a key consideration when strength-to-weight ratios are important as in aircraft and aerospace applications. Carbon and aramid-reinforced composites excel because of their low specific gravities and high strength & stiffness characteristics.

The impact resistance of organic fiber reinforced composite is quite high, making them suitable for energy absorption applications. Fiber glass-reinforced composites are relatively poor in impact performance compared to organic fibers, but are superior to carbon-reinforced composites. Composites using carbon fiber rely on the toughness of the resin matrix for impact properties.

Chemical & Corrosion Resistance Characteristics

These characteristics of pultruded composites are attributed to the properties of resin used. Chemical & corrosion attack can occur at the product surface or at the end. The presence of a resin rich barrier layer on the surface provides greater degree of corrosion resistance. To achieve a resin-rich surface, a synthetic veil or mat, typically of polyester fiber, is used on the surface of the products when pultruded. The layer can range from 0.15 to 1.00 mm thick, depending on the thickness of the material used.

The end cut of the profile is particularly vulnerable to corrosion because fibers are exposed to the environment. Therefore, it is a common practice is to dip-coat the end cuts of pultruded profile to seal them from corrosive attack. If this is not done, the corrosion resistance of the fiber itself becomes an important consideration because the resin does not effectively protect the fiber from attack along the fiber-resin interface at open ends.

TYPICAL COUPON PROPERTIES

Below are test results for typical coupon properties of structural fiberglass profiles (Standard, Fire Retardant, & Vinylester shapes). Properties are derived per the ASTM test method shown. Synthetic surfacing veil and ultraviolet inhibitors are standard.


Mechanical Properties		ASTM		Units		Value

Tensile Stress, LW		D-638		Psi		30,000
Tensile Stress, CW		D-638		Psi		7,000
Tensile Modulus, LW		D-638		10⁶ psi	2.5
Tensile Modulus, CW		D-638		10⁶ psi	0.8
Compressive Stress, LW		D-695		Psi		30,000
Compressive Stress, CW		D-695		Psi		15,000
Compressive Modulus, LW 	D-695		10⁶ psi		2.5
Compressive Modulus, CW 	D-695		10⁶ psi		1.0
Flexural Stress, LW 		D-790		Psi		30,000
Flexural Stress, CW 		D-790		Psi		10,000
Flexural Modulus, LW		D-790		10⁶ psi	1.8
Flexural Modulus, CW		D-790		10⁶ psi	0.8
Modulus of Elasticity, E	Full Section 	10⁶ psi	2.8
Shear Modulus			----		10⁶ psi	0.450
Short Beam Shear		D-2344		Psi		4,500
Punch Shear			D-732		Psi		10,000
Notched Izod Impact, LW		D-256		ft-lbs/in	25
Notched Izod Impact, CW		D-256		ft-lbs/in	4

Physical Properties		ASTM		Units		Value

Barcol Hardness			D-2583		----		45
24 Hour Water Absorption	D-570		% max		0.45
Density				D-792		lbs./in.3	.062-.070
Coef.of Thermal Expansion, LW	D-696		10⁶ in/in/�C	8

Electrical Properties		ASTM		Units		Value

Arc Resistance, LW		D-495		Seconds		120
Dielectric Strength, LW 	D-149		kv./in.		35
Dielectric Strength, PF		D-149		volts/mil.	200
Dielectric Constant, PF		D-150		@60hz		5

Fire Retardant Polyester and Fire Retardant Vinylester Structural Profiles

Flammability Properties		ASTM		Units		Value

Tunnel Test			E-84		Flame Spread	25 max.
Flammability			D-635		----		Non-burning

Legend: LW = Lengthwise, CW = Crosswise, PF = Perpendicular to Laminate Face

Pick Your Markets top

Initial products made by the pultrusion process went into the recreational/sporting goods market (fishing rods) and into the electrical market (transformer spacer sticks). In the early stages the electrical market dominated the pultrusion business. The market applications since have increased. ITEN POLITEN� PULTRUSIONS will work with you and your customers to help plan prototype solve or resolve ideas and issues for you and your customers.

The consumer/recreational and electrical markets have dominated the pultrusion business since the mid 70's. The latter has continued to expand and the list below contains opportunities for pultrusions in electrical applications. Typically these are the largest users of fiberglass reinforced plastics (FRP) pultruded shapes.

Applications:

Industries:

Aerospace				Military
Automotive				Off shore
Chemical Processing			Oil & Gas
Construction				Petrochemical
Electrical/Utility			Pulp & Paper
Food & Beverage				Recreation

ELECTRICAL APPLICATIONS FOR PULTRUDED SHAPES

1. Transformer air duct spacer sticks
2. Pole line hardware
3. Ladders
4. Bus bar supports
5. Motor top sticks
6. Cable support trays
7. U-shaped motor stator wedges
8. Service truck booms
9. Switch actuators
10. Fuse tubes

CONSUMER/RECREATIONAL APPLICATIONS FOR PULTRUDED SHAPES

1. Sail battens
2. Tent poles
3. CB antennas
4. Skate boards
5. Tool handles
6. Ski poles
7. Hockey sticks
8. Fence posts
9. Bike flags
10. Paddle shafts
11. Bows and Arrows
12. Crossbows
13. Golf shafts
14. Flag poles
15. Pole vault poles
16. Xylophone bars
17. Umbrella shafts
18. Snowmobile track stiffeners

CORROSION RESISTANT USES OF PULTRUDED SHAPES

1. Bridges and platforms
2. Floor gratings
3. Hand rails
4. Ladder cages
5. Pipe supports
6. Stairs
7. Structural supports
8. Pipes and tubes
9. Wear plates
10. Slide guides
11. Sucker rods for oil wells
12. Internal tank supports
13. Demister blades
14. Structural shapes
15. Wet scrubbers for power industry
16. Cable support trays

TRANSPORTATION USES OF PULTRUDED SHAPES

1. Lading bars in trucks and railcars
2. Kick plates
3. Trailer jamb posts
4. Subway contact rail covers
5. Bus luggage racks
6. Seating
7. Flat sheets for refrigerated trucks
8. Leaf springs

CONSTRUCTION USES FOR PULTRUDED SHAPES (This area is much more developed in Europe.)

1. Portable work platforms,
2. Sign posts
3. Lamp posts
4. Roof trim (Europe)
5. Gutters
6. Glazing systems (Europe)
7. Green house structures
8. Building panel sections
9. Reinforcing Rod (Rebar)
10. Sign support posts
11. Signs
12. Highway delineator markers

MISCELLANEOUS USES FOR PULTRUDED SHAPES

1. Heat shields on Xerox copiers
2. Slats for hog pens
3. Farm wagons
4. Pallets for food processing plants

Pultrusions Versus Structural Timber top

Pultruded glass fiber reinforced structural shapes and plate have a number of significant advantages over timber in many structural applications. Pultruded fiberglass will not rot or decay and is not susceptible to insect attack. Unlike wood, fiberglass requires no environmentally unfriendly preservatives or repellants, does not absorb any significant amount of water and is consistent in strength and appearance piece-to-piece (no culling). Pultruded fiberglass is stronger, more rigid and lighter weight than structural timber. Is pultruded fiberglass a better choice for your application? Consider the point-for-point comparison below.

NOTE: Properties shown for pultruded fiberglass structural shapes are approximate for typical off-the-shelf structural pultrusions.

Compare	Pultruded Fiberglass Structural Shapes	Structural TimberDouglas Fir
CORROSION RESISTANCE	Superior resistance to a broad range of chemicals. Unaffected by moisture or immersion in water if ends are properly sealed. Surfacing veil and UV additives create excellent weatherability.	Can warp, rot and decay from exposure to moisture, water and chemicals. Coatings or preservatives required to increase corrosion or rot resistance can create hazardous waste and/or high maintenance.
INSECT RESISTANCE	Unaffected by insects.	Susceptible to insect attack (marine borers, termites, etc.). Coatings to increase resistance to insects can be environmentally hazardous.
STRENGTH	Pultruded fiberglass is stronger, and has higher flexural strength than timber. Ultimate flexural strength (Fu) LW = 30,000 psi, CW = 10,000 psi. Compression strength is 30,000 psi.	Extreme fiber bending = up to 2800 psi.* Compression parallel to grain = up to 1800 psi.*
STIFFNESS	Pultruded fiberglass is approximately 1-1/2 times as rigid as wood. Modulus of elasticity LW = 2.5 x 10⁶ psi, CW = .8 x 10⁶ psi.	Modulus of elasticity = up to 1.8 x 10⁶ psi.*
ELECTRICAL CONDUCTIVITY	Non-conductive - high dielectric capability.	Timber can be conductive when it is wet.
WEIGHT	Specific gravity = 1.7 Pultruded fiberglass has significantly higher strength-to-weight ratio.	Specific gravity = .51 (oven dried).*
FINISHING AND COLOR	Pigments added to the resin provide color throughout the part. Special colors available. Composite design can be customized for required finishes.	Must be primed and painted for colors. To maintain color, repainting may be required.
COST	Lower maintenance, longer product life often equals lower overall costs.	Lower initial cost.

Pultrusions Versus Steel top

Unlike Steel which will rust when exposed to weathering and chemicals, fiberglass structural shapes are highly corrosion resistant. Features of both pultrusions and steel structural shapes are compared on a point-for-point basis below.

NOTE: Properties shown for pultruded fiberglass structural shapes are approximate for typical off-the-shelf structural pultrusions.

Compare	Pultruded Fiberglass Structural Shapes	Steel A-36 Carbon
CORROSION RESISTANCE	Pultrusions are available in either polyester or vinyl ester resin for resistance to a broad range of chemicals. Painting required only when exposed to direct sunlight.	Subject to oxidation and corrosion. Requires painting or galvanizing for many applications.
WEIGHT	Lightweight - weighs 75% less than steel. 1/2" thick plate = 4.7 lbs./sq. ft.	Could require lifting equipment to move and place. 1/2" thick plate = 20.4 lbs./sq. ft.
CONDUCTIVITY	Does not conduct electricity. Low Thermal Conductivity 4 (BTU/SF/HR/F°/IN).	Conducts electricity. Grounding potential. Thermal Conductivity 260-460 (BTU/SF/HR/F°/IN).
STRENGTH	Pultrusions have a high strength-to-weight ratio, and pound-for-pound are stronger than steel in the lengthwise direction. Ultimate flexural strength (Fu) LW = 30 ksi CW = 10 ksi	Homogeneous material. Yield strength (Fy) 36 ksi
STIFFNESS	Modulus of elasticity LW = 2.5 x 10⁶ psi CW = .8 x 10⁶ psi Will not permanently deform under working load.	Modulus of elasticity 29 x 10⁶ psi
IMPACT RESISTANCE	Glass mat in pultruded parts, distributes impact load to prevent surface damage even in sub-zero temperatures. Will not permanently deform under impact.	Can permanently deform under impact.
EMI/RFI TRANSPARENCY	Transparent to EMI/RFI transmissions.	Can interfere with EMI/RFI transmissions.
VERSATILITY	Pigments added to the resin provide color throughout the part. Special colors available.	Must be painted for color. To maintain color and corrosion resistance, repainting may be required.
EASY FIELD FABRICATION	Pultruded fiberglass can be field fabricated using simple carpenter tools with carbon or diamond tip blades. Lightweight for easier erection and installation.	Often requires welding and cutting torches. Heavier material requires special handling equipment to erect and install.
COST	Lower installation and maintenance costs in industrial applications often equals lower lifecycle costs.	Lower initial material cost.

Pultrusions Versus Aluminumtop

Pultruded glass fiber reinforced structural shapes and plate have a number of significant advantages over aluminum extrusions. Pultrusions are electrically and thermally non-conductive, impact resistant, highly corrosion resistant and EMI/RFI transparent. Is pultruded fiberglass the best material choice to meet the needs or requirements of your application? Features of both pultruded fiberglass structural shapes and aluminum extruded shapes are compared on a point-for-point basis below.

NOTE: Properties shown for pultruded fiberglass structural shapes are approximate for typical off-the-shelf structural pultrusions.

Compare	Pultruded Fiberglass Structural Shapes	Aluminum Extruded Shapes
CORROSION RESISTANCE	Superior resistance to a broad range of chemicals. Surfacing veil and UV additives improve weatherability.	Can cause galvanic corrosion. Corrosion resistance can be increased through anodizing or other coatings.
WEIGHT	Very lightweight - about 70% the weight of aluminum on a density basis.	Lightweight - about 1/3 that of copper or steel.
ELECTRICAL CONDUCTIVITY	Non-conductive - high dielectric capability.	Conducts electricity - grounding potential.
THERMAL CONDUCTIVITY	Insulates - low thermal conductivity, 4 (BTU/SF/HR/F°/IN); low thermal coefficient of expansion 4.4 (IN/IN/F°)10⁶.	Heat conductor - high thermal conductivity. 150 (BTU/SF/HR/F°/IN); thermal coefficient of expansion 11-13 (IN/IN/F°)10⁶.
STRENGTH	Ultimate flexural strength (Fu) LW = 30 ksi CW = 10 ksi. Pultruded fiberglass has 86% of the yield strength of aluminum and, pound-for-pound's, stronger than aluminum in the lengthwise direction.	Flexural strength (Fu) 35 ksi. Homogeneous material.
FINISHING AND COLOR	Pigments added to the resin provide color throughout the part. Special colors available. Composite design can be customized for required finishes.	Silver color. Other colors require prefinishes, anodic coatings and paints. Mechanical, chemical and electroplated finishes can be applied.
EMI/RFI TRANSPARENCY	Transparent to radio waves, EMI/RFI transmissions; used for radar and antennae enclosures and supports.	Highly reflective.
FABRICATION	Easy field fabrication with simple carpenter tools - utilizes adhesive bonding and/or mechanical joining. No torches or welding.	Good machinability - welding, brazing, soldering or mechanical joining.
COST	Slightly higher tooling costs; price per lineal foot marginally higher.	Extrusion tooling is relatively inexpensive. Part price comparable or slightly lower.
IMPACT RESISTANCE	Glass mat in pultruded fiberglass distributes impact load to prevent surface damage even in sub-zero temperatures. Will not permanently deform under impact.	Easily deforms under impact.

Products & Process: Features of Pultruded Products top

HIGH STRENGTH Stronger than structural steel on a pound-for-pound basis. Has been used to form the superstructures of multistory buildings, walkways, sub-floors and platforms.

LIGHTWEIGHT Pultrusions are 20-25% the weight of steel and 70% the weight of aluminum. Pultruded products are easily transported, handled and lifted into place. Total structures can often be pre-assembled and shipped to the job site ready for installation.

CORROSION/ROT RESISTANT Pultruded products will not rot and are impervious to a broad range of corrosive elements. This feature makes pultrusions a natural selection for indoor or outdoor structures in pulp and paper mills, chemical plants, water and sewage treatment plants, structures near salt water and other corrosive environments.

NON-CONDUCTIVE Glass reinforced pultrusions have low thermal conductivity and are electrically non-conductive.

ELECTRO-MAGNETIC TRANSPARENCY Pultruded products are transparent to radio waves, microwaves and other electromagnetic frequencies.

DIMENSIONAL STABILITY The coefficient of thermal expansion of pultruded products is slightly less than steel and significantly less than aluminum.

PARTS CONSOLIDATION Custom designed pultrusions allow multiple discrete parts to be designed and fabricated into a single part thus reducing the number of fabricated parts and the need to join these parts together.

LOW TEMPERATURE CAPABILITIES Glass fiber reinforced pultrusions exhibit excellent mechanical properties at very low temperatures, even -70�F. Tensile strength and impact strengths are greater at -70�F than at +80�F.

AESTHETICS Pultruded profiles are pigmented throughout the thickness of the part and can be made to virtually any desired custom color. Special surfacing veils are also available to create special surface appearances such as wood grain, marble, granite, etc.

Plant 3 Politen® Pultrusions