Polyurethane Bushings
A polyurethane bushing is a friction reducing component that is placed between moving and stationary components as a replacement for lubricants. The use of polyurethane for the production of bushings is due to...
Please fill out the following form to submit a Request for Quote to any of the following companies listed on
This article gives detailed insights into polyurethane rollers. Read further to learn more about:
Polyurethane rollers are cylindrical rollers covered by a layer of elastomer material called polyurethane. Depending on the application, the inner roller core is prone to scratches, dents, corrosion, and other types of damage. The layer of polyurethane has intrinistic properties the inner roller core, such as abrasion resistance and impact strength. Polyurethane rollers are used in many manufacturing processes for performing operations such as:
Polyurethane is the most extensively used elastomer material for rollers. It is possible to make a variety of blends from different types and proportions of its compounding ingredients. Through blending, varying mechanical properties are obtained to suit a particular use. The most desirable properties of polyurethane are its toughness, high impingement resistance, shock absorption, and fatigue resistance.
Formulations of polyurethane can produce rollers that are hard and firm or soft and pliable. Polyurethane rollers are processed in hard to soft durometers depending on the requirements of an application. Polyurethane's durability and shock resistance make it one of the most popular types of roller compositions. In addition, polyurethane is an elastomer that can be thermoformed into any possible or conceivable shape.
Polyurethane and rubbers, such as nitrile and neoprene, belong to a family of materials called elastomers. Their elastic properties make them an ideal choice as roller-covering material. Polyurethane rollers have several advantages over ordinary rubber rollers. Their impressive mechanical properties make them more viable than other types. The many benefits of polyurethane rollers include:
Carbon Blacking – Rubber roller linings have carbon black added as a filler and reinforcing material. When rolled against a hard surface with sufficient force, they leave black streaks and marks damaging in applications such as finished goods handling and printing. Polyurethane rollers do not require carbon roller linings as extra support, which avoids the potential of carbon blacking.
Processing polyurethane does not require expensive and complicated equipment. A simple blending operation may only require a batch mixer (no heating equipment needed). This is in contrast with other rubber types, which employ equipment for mastication and heating.
Rubber roller linings typically have carbon black added as filler and reinforcing components. When rolled against a surface with sufficient force, they can leave marks that are unpleasant in applications such as finished goods handling and printing. Polyurethane rollers do not have this problem since they do not use carbon black.
Depending on the type of polymer system used, polyurethane can withstand water, oils, and other petroleum-based solvents. Water resistance is a required property for rollers under wet service or in environments with frequent washdown. Oil resistance is required for handling hydrocarbon-based solvents or chemicals such as inks.
Most of the engineering work for polyurethane rollers happens during the production of the elastomer lining. Four components make up the material: the polyol compound, the diisocyanate compound, the chain extender or curatives, and the additives.
The mixture of the polyol and the diisocyanate compounds forms the prepolymer resin. They combine to form a simple polymer chain from the reaction of a polyol component (a carbon-chained molecule with alcohol on both ends) with a diisocyanate component (a molecule with isocyanate on both ends). This results in a molecule with reactive alcohol on one end and a reactive isocyanate on the other. The alcohol end further links to another isocyanate end or terminal, while the isocyanate end of the same chain further reacts with chain extender compounds or curatives such as hydroxyl and amines. This process continues, making a long, chained polyurethane molecule.
The mechanical properties depend on the formulation of the prepolymer resin and the curatives. Additives are used to further improve the properties of the polyurethane, such as resin curing time, machinability, color, UV protection, and etc. Careful proportioning of additives relative to the amount of resin in the mixture is required since it can weaken the properties of the product.
The previous chapter briefly described how polyurethane is made and discussed the roles of the four different components. In this chapter, the focus is on the different chemicals used to make polyurethane and their implications on the final property of the product.
Like the polyols, diisocyanate compounds form the resin side of the polyurethane system. There are two main types of diisocyanate: aliphatic and aromatic.
Polyurethane is regarded as an engineering material because of its excellent properties. Most of which are attributed to its highly elastic nature. Below are some of the properties of polyurethane significant to roller applications.
Materials are graded according to their hardness relative to one another. For elastomers, hardness is characterized by the Shore Hardness Number. This is measured by a durometer. There are 12 different Shore Hardness Scales; each scale has its indenter configuration, profile, and force applied. The Shore scales used for polyurethanes are Shore A and D. Shore A scale measures the hardness of soft, semi-rigid polyurethanes, while Shore D measures hard rubbers and rigid polyurethanes. However, keep in mind that high hardness does not correspond with high rigidity or strength.
With impingement abrasion, the paths of the particles impacting the surface of a material can be perpendicular or at an angle. The attacks of the particles strike specific areas, causing high strain and breaking off small bits of the surface.
Regardless of the type of abrasion, polyurethane is highly capable of resisting both sliding and impingement. Since it has a low friction coefficient and high strength, it is unaffected by sliding abrasion. With impingement abrasion, it absorbs the energy from the particulate attacks, distributes the stress, and immediately recovers without any signs of damage.
Polyurethane is blended to produce a low coefficient of friction, high tear strength, and elasticity, properties that help it withstand abrasion. The composition of its resin produces its exceptional abrasion resistance. Among the polyol compounds for making polyurethane, polyesters have the best tear and abrasion resistance.
Polyurethane tear strength is measured in pounds per inch of thickness. The testing for tear strength is dependent on the application for which the polyurethane will be used. Tear strength tests have been established by the American Society for Testing Materials (ASTM). There are three ASTM tests used to determine the tear strength of polyurethane, which are:
Polyurethane exhibits good thermal aging resistance when formulated with certain compounds such as PPDI and CHDI. Typical polyurethanes have a maximum operating temperature of about 90 to 100°F (32 to 37.7°C). Special but more expensive formulations can reach 302° F (150°C).
The manufacture of a polyurethane roller is a straightforward process that involves the fabrication of the roller core, balancing, polyurethane blending, bonding, building, curing, machining, and quality testing. The fabrication process is similar to that of other rubber roller types. The main difference is cover building since the polyurethane resin is in liquid form.
Polyurethane rollers have a solid core or a keyway and space for bearings, which are designed for one or both ends of the roller. Bearings reduce friction against the static and rotating parts. The configuration, mounting, and type of bearing can vary depending on the design of the roller.
All dimensions of a polyurethane roller must be accurate to attain the required diameter, roundness, and balance of the roller. After fabrication, the roller core is subjected to secondary processes such as blasting, lapping, and cleaning to remove any traces of corrosion and contaminants.
The formulation can be done through different processes. These are known as the single shot, prepolymer, and quasi-prepolymer processes.
The single-shot process involves having all components in separate chambers. These will then be blended by a mixing head and poured or injected into the mold.
The second option is the prepolymer process. This process is carried out by mixing the polyols and diisocyanates before pouring them into the mold. This process helps dissipate the heat produced from the exothermic reaction of the compounds.
Last is the quasi-prepolymer process. Quasi-prepolymers consist of polyols partially reacted with the diisocyanate compounds. This simplifies the formulation process since the quasi-prepolymers are less viscous and require low processing temperature.
Other rubber compounds used for roller linings are in the form of calendered sheets and strips. They are joined to the roller core by plying and extrusion. Polyurethane formulations are available as liquid mixtures. Thus, the processes of building polyurethane are casting and injection molding. Both of these methods use liquid resins.
Casting involves placing the roller core into a mold where the polyurethane polymer is poured. The process of casting is an economical method for manufacturing polyurethane rollers and is much less expensive than injection molding.
Injection molding requires expensive dies that must be machined and configured to the shape of the desired polyurethane roller. It involves a great deal of time and the use of expensive machinery and equipment.
Other polyurethane systems employ an additional curing process known as post-curing. Post-curing further improves the mechanical properties of the cast, as well as its temperature aging resistance.
There are many machines available to produce polyurethane rollers in the United States and Canada. These machines are essential in today's society as they enable the mass production of polyurethane rollers, which are used in various industries such as manufacturing, transportation, and material handling, contributing to improved efficiency and productivity in these sectors. We provide information on many of the leading polyurethane roller producing machines below.
Characteristics: The SC3000 is a high-precision spin-casting machine that offers efficient and accurate production of polyurethane rollers. It ensures uniform distribution of the material and excellent surface finish.
Characteristics: The E-DM series is designed specifically for polyurethane injection molding, enabling the production of rollers with intricate designs and consistent quality.
Characteristics: The XJL-120 is an extrusion machine tailored for polyurethane rollers, capable of continuous production with customizable dimensions and hardness levels.
Characteristics: The Linden Polyurethane Casting Machine Series offers precise control over material mixing ratios, temperature, and curing time, ensuring consistent quality in the production of polyurethane rollers. These machines are designed for versatility, enabling the creation of various roller sizes and hardness levels to meet specific industry requirements.
Characteristics: The Delta Engineering PU Extruder DX Series is optimized for continuous extrusion of polyurethane, making it ideal for high-volume production of polyurethane rollers. The machines feature advanced temperature and pressure controls, allowing manufacturers to achieve precise roller dimensions, uniform density, and excellent surface finish. They are also equipped with easy-to-use interfaces for efficient operation and maintenance.
Please note that it's essential to verify the current availability and popularity of these specific models and their manufacturers as the information might have changed since this update. For the most up-to-date information regarding polyurethane roller producing machinery, it is recommended you reach out to the manufacturers directly or consult with industry suppliers in the field of polyurethane roller equipment production.
The choice of polyurethane rollers for an industrial application is mainly based on their durability and wide range of durometers. While tooling for manufacturing rubber rollers is expensive and time-consuming, polyurethane casting uses aluminum molds that are easily formed and shaped to the proper dimensions of the designed roller.
Although polyurethane rollers are easily produced, they have exceptional durability, are resistant to abrasion damage, and come in sizes to fit all types of roller applications.
The choice of polyurethane rollers as conveyor rollers is due to their noise abatement and abrasion and solvent resistance. In packaging and shipping, conveying systems are the foundation of efficient and smooth operations. Materials have to move quickly without being damaged or mishandled. Polyurethane rollers are an important part of the effortless conveyance of parts, tools, customer orders, and equipment. Their noise suppression properties assist in keeping the work environment stress free for workers.
An essential part of a conveyor roller system is idler rollers, which perform different functions to assist in the movement of materials along a conveying belt. The two types of idler rollers are carrying and return, with carrying rollers moving materials while return rollers support the conveying belt during its return.
On the return side, flat return idlers are used to support the return of the conveyor belt. They have a steel support rod and lifting brackets to keep the belt from stretching, deforming, and slacking.
Industrial polyurethane coated casters are a rugged, durable, tough, and strong type of caster capable of carrying up to five tons. They have a higher capacity than rubber wheels and are made of high density thick polyurethane. These polyurethane casters are chosen because they can carry exceptionally heavy loads without damaging floors or other surfaces.
As with polyurethane rollers used on conveying systems, industrial polyurethane casters operate noiselessly and have a larger footprint, which reduces stress on the floor. The longevity of polyurethane industrial casters is due to their elasticity, which provides ergonomic benefits.
A polyurethane bushing is a friction reducing component that is placed between moving and stationary components as a replacement for lubricants. The use of polyurethane for the production of bushings is due to...
Polyurethane molding is the process of fabricating or manufacturing plastic parts by introducing a urethane polymer system into a tool or mold and allowing it to cure. Like any other type of plastic, the excellent processability...
Urethane casting is the process of injecting polyurethane and additive resins into a soft mold usually made of silicone elastomer. The casting process is similar to injection molding; injection molding differs by using hard, metal molds...
Urethane wheels are wheels made of molded urethane, also known as polyurethane. Urethane is an elastomer that comprises urethane carbamate linkages and is a portmanteau phrase for elastic polymer...
Blow molding is a type of plastic forming process for creating hollow plastic products made from thermoplastic materials. The process involves heating and inflating a plastic tube known as a parison or preform. The parison is placed between two dies that contain the desired shape of the product...
Molding is a manufacturing process that uses a mold - the latter being a solid container used to give shape to a piece of material. It is a forming process. The form is transferred from the mold to the material by...
Fiberglass molding is a method for forming complex and intricate parts using fiberglass resin. Though there are several reasons for producing parts and components from fiberglass, the most pressing reasons are the...
Fiberglass is a plastic reinforced material where glass fiber is used as reinforcement, and the glass fiber is flattened into a sheet. It is also known as glass fiber reinforced plastic or glass reinforced plastic...
Many of the products used daily are made possible by producers and suppliers of rubber and plastic. These substances are robust, adaptable, and capable of practically any shape required for various industrial purposes. Several varieties are...
Plastic bottles are bottles made of high or low-density plastic, such as polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polycarbonate (PC), or polyvinyl chloride (PVC). Each of the materials mentioned has...
Plastic caps and plugs are two distinct ways for sealing the ends, tops, and openings of tubes and containers. Caps are placed over the opening, and plugs are placed in the opening. Due to the many varieties of...
Plastic coating is the application of liquid polymers or plastic on the surface of a workpiece by dipping or immersion. The result is a thick plastic finish for protective and decorative purposes. This gives the material additional resistance against...
Plastic injection molding, or commonly referred to as injection molding, is a manufacturing process used in the mass fabrication of plastic parts. It involves an injection of molten plastic material into the mold where it cools and...
Plastic overmolding has a long and interesting history, dating back to the early 1900s. The first overmolding process was developed by German chemist Leo Baekeland, who invented Bakelite, the first synthetic plastic. Baekeland used a...
Rotational molding, commonly referred to as "rotomolding", is a plastic casting technique used to produce hollow, seamless, and double-walled parts. It uses a hollow mold tool wherein the thermoplastic powdered resin is heated while being rotated and cooled to solidify...
Rubber injection molding is when uncured rubber is transformed into a usable product by injecting raw rubber material into a mold cavity made of metal. The applied pressure produces a chemical reaction like...
Rubber molding is a process of transforming uncured rubber or an elastomer into a usable product by transferring, compressing, or injecting raw rubber material into a metal mold cavity...
There are several methods to perform rubber overmolding, and each method has its own unique advantages and disadvantages. The choice of method typically depends on the design and material requirements of the product being...
Silicone rubber molding is a method for shaping, forming, and fabricating silicone rubber parts and products using a heated mold. The process involves compressing or injecting silicone rubber into a mold...
Thermoplastic molding is a manufacturing process that works to create fully functional parts by injecting plastic resin into a pre-made mold. Thermoplastic polymers are more widely used than thermosetting...
A grommet edging is a flexible rubber or plastic strip that covers rough and sharp surfaces found in openings and edges of panel walls to protect the passing electrical cables, wires, and other sensitive components...