Last Updated on: 19 9 月, 2026

 

Polyurethane Pultrusion Profile Knowledge

 

In recent years, polyurethane resin has made its composite materials stand out due to its advantages such as good toughness, fast curing and no styrene fumes.

 

 

With the mastery of polyurethane molding technology and progress in controlling its reactivity to extend its shelf life, polyurethane has entered the field of composite materials, which has long been dominated by unsaturated polyester and vinyl ester resins. In the past, polyurethane composites were mainly used for automotive interior and exterior parts such as pickup truck boxes, floor pans, luggage racks, inner door panels, etc. (polyurethane is foamed) molded by structural reaction injection method (SRIM).

 

However, in recent years, polyurethane composites have developed technologies such as pultrusion, winding, vacuum infusion and long fiber injection, mainly using non-foamed polyurethane composites to manufacture window frames, bathtubs, light poles and large parts for trucks and off-road vehicles.

 

 

Polyurethane Pultrusion: Polyurethane pultrusion generally has low viscosity, moderate to high reactivity, good impact strength and toughness, and short beam shear properties.

 

 

 

Compared with other materials, polyurethane pultrusion can produce multiple benefits. It can increase the glass fiber content in the product and greatly improve the strength of the product. For example, the window frame obtained by pultruding glass fiber and polyurethane resin is 8 times stronger than PVC window frame, and its conductivity is 40 times lower than aluminum, so the insulation performance is much better.

 

At the same time, because polyurethane pultruded window frames are less brittle, they will not crack and are durable. High-performance polyurethane/glass fiber composite material is a high-strength, high-modulus, lightweight polymer composite material produced by continuous pultrusion process with high-hardness polyurethane elastomer as the matrix material and glass fiber as the reinforcement material.

 

 

Products made from polyurethane pultrusion technology not only have higher strength and better thermal insulation than traditional materials, but are also lighter and more environmentally friendly. Its application areas are very broad. From the original gorgeous bathtubs, to surfing and snowboards, to today’s innovative applications such as window frames and container floors, polyurethane composites have been integrated into all aspects of our daily lives.

 

It is reported that in the past few years, China’s demand for composite materials has shown a gradual growth trend. Composite materials are a high-tech material that integrates the characteristics of several materials into an all-round solution with excellent new performance.

 

It is precisely because of the unique properties of the material, such as light weight, high strength and rigidity, and the ability to help achieve higher cost efficiency and ecological responsibility, that polyurethane composite materials have attracted much attention from various industries. Especially in the construction and transportation industries, innovative technologies and applications have attracted much attention.

 

Performance Characteristics of Polyurethane/Glass Fiber Composite Materials

 

After several years of development, foreign polyurethane pultrusion molding has been commercialized. In the polyurethane pultrusion process, more reinforcing fibers can be used to greatly increase the strength of the product. At the same time, due to the excellent impact strength, tensile strength and interlaminar shear strength of polyurethane itself, the product can be made thinner and lighter.

 

For example, thinner I-beams can be made with less continuous filament mats and more untwisted rovings, reducing the thickness of the I-beam from 3.3mm to 2.6mm while maintaining its longitudinal stiffness. In this way, the product is 13% lighter and 7% more expensive. In addition, because pultruded polyurethane products are less brittle, they can be assembled in a conventional manner without cracking and breaking.

 

Specifically, the use of polyurethane pultrusion technology has the following obvious advantages: · When pultruding certain profiles with traditional resins, up to 4 or 5 different glass fiber mats may be required. These mats must be cut and shaped. With polyurethane pultrusion, glass fiber untwisted rovings can often be used instead of glass fiber mats. Eliminating glass fiber mats reduces the cost of raw materials and the labor cost of operating mats. Felts are also easy to break, and fragments may clog machines and affect production. Eliminating mats can increase production line speeds in many cases, thereby improving cost-effectiveness.

 

On the other hand, by replacing the mat with roving, the fiber volume content can be increased to about 80%, while the fiber content of most non-PU pultrusion products is 60%. In this way, the higher glass fiber content combined with the better performance resin creates a PU pultrusion profile with better strength and stiffness. · The higher strength performance of PU pultrusion products opens up some new applications.

 

These products can be used for purposes that polyester resins cannot perform, replacing steel and aluminum in the construction, infrastructure and transportation markets. · It is relatively simple, convenient and economical to convert the original pultrusion system to a PU pultrusion system without a large investment. The original die, heater and unit can still be used. · In addition to the above physical properties and molding advantages, PU pultrusion parts also have assembly advantages, especially easy fastening.

 

Due to the strength of PU, when installing screws in PU pultrusion products, no pre-drilling is required, which can save time and labor. Conversely, the force required to pull out the screws in PU pultrusion products is more than twice the force required to pull out the screws in polyester pultrusion products.

 

Under the same fiber structure, all properties of polyurethane/glass fiber pultrusion products are better than those of ordinary thermosetting resins, with similar bending modulus, greatly improved impact strength, high screw pull-out strength, good crack expansion resistance, excellent wear resistance, good secondary processing ability, and heat resistance above 240 degrees.

 

Comparison of the performance of main thermosetting resin/glass fiber composite materials

 

 

Pure polyurethane/glass fiber is the best pultruded composite material at present. The material has a complex cross-section, a smooth surface, a fast pultrusion speed, the best water, acid, alkali and salt resistance, good flame retardancy, can be painted, aliphatic polyurethane system, solvent-free, styrene-free, and environmentally friendly.

 

Main uses of Polyurethane/Glass Fiber Composite Materials

 

Used in Building Materials

In recent years, building energy conservation has become an important part of China’s sustainable development. In buildings, doors and windows, exterior walls, roofs and floors are the four major parts of building energy consumption, and doors and windows have the worst insulation.

 

It is estimated that for typical enclosure components in my country, the energy consumption of doors and windows is about 4 times that of walls, 5 times that of roofs, and more than 20 times that of floors, accounting for about 40% to 50% of the total energy consumption of enclosure components.

 

Therefore, enhancing the thermal insulation performance of doors and windows and reducing the energy consumption of doors and windows are important links in improving the quality of indoor thermal environment and improving the energy conservation level of buildings. The rise of composite materials in applications has brought us new ideas, making it possible to apply them to the transformation of building energy-saving doors and windows.

 

Compared with traditional materials, polyurethane pultruded window frames have stronger dimensional stability, higher lateral mechanical properties, higher specific strength and rigidity, and better thermal insulation effects.

 

 

In addition, the unique pultrusion process of polyurethane material technology does not contain volatile organic compounds (VOC), so it is also very environmentally friendly. Glass fiber reinforced polyurethane pultruded door and window profiles are made of glass fiber as a reinforcing material and polyurethane as a matrix, and are produced through an advanced injection and dipping pultrusion process.

 

The development of GRPU door and window profiles is to provide energy-saving window solutions with a total heat transfer coefficient of K ≤ 2.0 W / (m • K) for high-rise buildings.

 

 

Polyurethane (PU) has inherent heat-insulating capabilities and has long been used to make foam sealants, sealing strips, and insulation strips in the energy-saving door and window industry. Using polyurethane to make the entire window frame of energy-saving windows is a domestic first.

 

 

The advantages of GRPU window frames are determined by the performance characteristics of GRPU materials themselves. As a new type of composite material, GRPU window frames are a new growth point. Using this resin, larger, thinner and strong enough profiles can be made for large window frames and even curtain walls. This window frame is said to be much better than aluminum, wood and plastic window frames. It has excellent expansion and contraction properties and can withstand various climatic conditions, from the Arctic cold to the desert heat and the humidity of the seaside. It can be painted or post-processed to form a wooden appearance.

 

Polyurethane Composite Window Frames have the Following Basic Characteristics:

 

High Thermal Insulation

GRPU profiles, like solid wood and PVC, have a very low thermal conductivity of 0.22 W/m•K at room temperature, which is only about 1/700 of aluminum alloy, and is an excellent thermal insulation material.

 

Low Thermal Expansion

GRPU has a linear thermal expansion coefficient of about 7×10-6/K, which is much lower than that of aluminum alloy and is similar to that of the wall; therefore, when the temperature changes, the GRPU frame will not have a gap with the wall, and the sealing is good, while ensuring the thermal insulation of the entire window in an environment with a large temperature difference.

 

Corrosion Resistance

GRPU profiles have strong corrosion resistance to most acids, alkalis, salts, organic matter, as well as seawater and humid air; and they are rust-proof and immortal, and their corrosion resistance is better than other material door and window profiles. It is especially suitable for coastal, corrosive and generally humid places.

 

Good Electrical Properties

GRPU profiles are good insulating materials, are not affected by electromagnetic waves, and do not reflect radio waves; they have special uses for the construction of communication systems.

 

Polyurethane/Glass Fiber Composite Materials for Container Floors

 

Lighter and More Durable Containers

 

Due to the high pultrusion efficiency, high strength and rigidity of the material, as well as excellent impact resistance and wear resistance, it has added a lot of color to the container transportation industry.

 

 

After years of research and development by researchers, this composite reinforcement material is considered to have at least five advantages:

 

First, it is low weight, which can reduce the amount of energy in transportation;

 

Second, it has a complete resistance to all types of products (water, oil, odor, microorganisms);

 

Third, the overall energy required for production is very low;

 

Fourth, it increases the service life of the container;

 

Fifth, it has a reusable and recyclable floor.

 

The new container is particularly particular about the materials used. A 40-foot container can reduce the weight by 550 kilograms, thereby reducing the energy required for transportation. Compared with traditional wood-based materials, materials using polyurethane extrusion technology will reduce the weight by 22%, and the fuel consumption and transportation costs of the entire ship and truck container will be greatly reduced.

 

While being lightweight, it also maintains sufficient toughness. This feature also reduces maintenance costs and increases the service life of the container. The service life of traditional container wood floors is only 5 to 10 years, while the service life of polyurethane pultruded floors can exceed 20 years.

 

Railway Sleepers

 

In Europe, railway builders are increasingly looking at pultruded FFU (fiber reinforced foam polyurethane) sleepers to replace wooden or concrete sleepers.

 

 

After several successful applications, a line system was recently installed in the German chemical park of Leverkusen, using a total of 136 FFU sleepers. It is said that this sleeper looks like wood and combines all the advantages of natural products and modern design. It can be sawed, planed, nailed, screwed and glued with ordinary woodworking tools. Its thermal expansion coefficient and thermal conductivity are very low.

 

Due to fiber reinforcement, it has high compressive, tensile and bending strengths, and its service life is more than 3 times longer than that of traditional sleepers. Due to its closed-cell structure, it absorbs very little water even in heavy rain, which does not affect its excellent electrical insulation properties. The material is also resistant to hydrolysis, grease, seawater, frost and deicing salts, and remains stable under long-term climatic conditions.

 

Its weight and on-site processing performance are much better than concrete, and it can be made into any length without the need to make a separate mold for each length. Its ecological performance is also a major advantage. No solvents are used during manufacturing and it can be recycled after use. Due to these advantages, FFU sleepers are particularly suitable for use in tunnels and bridges.

 

In Japan, more than 90,000 polyurethane sleepers are laid every year, and now more than 1.3 million are in use. This type of sleeper is used in the rails of Japan’s famous high-speed train “Shinkansen”.

 

Other uses

 

Polyurethane pultrusion products include profiles, rods and plates, such as ladder rods, tool handles, pole crossarms, poles, hockey sticks, dock piles, container plates, etc.

 

Raw materials and equipment for polyurethane composite material production

 

Main Materials

 

Polyurethane materials (including polyols, isocyanates, catalysts, defoamers, lubricants, release agents, etc.) and glass fibers, of which glass fibers account for 80%-85%.

 

Main Equipment:

 

Glass fiber guide frame, polyurethane casting machine, molding traction machine, cutting machine, etc. The cost of pultrusion equipment is about 200,000 yuan (20 tons of traction force), and polyurethane equipment is 100,000-150,000 yuan.

 

Polyurethane Composite Material Production Process

 

Process Flow:

 

 

Production Efficiency:

Depending on different specifications, the pultrusion speed varies from 1.2 to 3 m/min. The width is greater than 50 cm.

Source: Internet

 

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Company Profile

Xi’an Yongxing Technology Development Co., Ltd. was established in 2004. It is a comprehensive enterprise integrating R&D, manufacturing, processing (OEM), international trade and services, facing the industries of petroleum, wind power, electricity, environmental engineering, clean energy, etc. The company is located at No. 2, South Section of Caotan 9th Road, Caotan Industrial Park, Xi’an Economic and Technological Development Zone, China, with a registered capital of 51.68 million yuan, covering an area of ​​80,000 square meters and more than 100 employees.

 

Mainly engaged in the research and development, design and manufacturing of glass fiber composite materials, carbon fiber composite materials, aramid fiber composite materials, basalt fiber composite materials and their products.

 

The Resin Bases Involved are: unsaturated resin, vinyl resin, epoxy resin, phenolic resin and polyurethane resin. At the same time, we also develop and produce chemical additives related to composite materials.

 

The Company’s Main Products:

Composite pultruded beams for wind turbine blades

Composite embedded UD stays for wind turbine blades

FRP composite molded grilles

FRP composite grille covers

FRP composite platforms

FRP composite guardrails

FRP composite stair handrails

FRP composite power fences

FRP composite cable trays

FRP composite ladders

FRP composite cage ladders

FRP composite pultruded profiles

FRP composite pultruded channels

FRP composite pultruded angles

FRP composite pultruded square tubes

FRP composite pultruded round tubes

FRP composite pultruded T-profiles

FRP composite pultruded rectangular tubes

FRP composite pultruded I-beams

FRP composite pultruded profiles

Polyurethane pultruded rods

Polyurethane pultruded tubes

Polyurethane pultruded profiles, etc.

 

Widely used in various fields such as petroleum, petrochemicals, chemicals, ports, electricity, transportation, papermaking, medicine, steel, food, municipal administration, real estate, photovoltaic solar energy, and clean energy.

 

It is suitable for working corridors, chemical work platforms, tunnels, offshore oil drilling platforms, ladders and pedals for oil drilling rigs, and electric dust collectors in power plants, which are prone to rust, pollution, and high temperature and flammability.

 

The products and markets are mainly concentrated in North America, Europe and Southeast Asia; currently, they have been exported to the United States, France, Britain, Germany, Mexico, Brazil, Japan, Italy, Russia, Kazakhstan, Brazil, Armenia, Singapore, Malaysia, Vietnam, the Philippines, Hong Kong, Taiwan and other countries and regions, and have been recognized by domestic and foreign customers for their excellent quality, fast delivery and excellent service, and have gradually established long-term and stable partnerships with customers, and have won unanimous praise from customers.