#polyurethane rollers

Polyurethane materials with hardness around 70 to 90 have good abrasion resistance and it often use to cover for metal rollers.

Polyurethane rollers

The term durometer refers specifically to an object’s hardness measured by its indentation properties, which are defined by an object’s resistance to permanent indentation. Often times the word durometer is referred to as both the measurement of hardness and the durometer instrument which was created by Albert Ferdinand Shore in the 1920s to determine scales of Shore hardness.

While the origins of both hardness scales and the coining of the term durometer trace back a significant number of years before the Shore hardness scale was invented, the vast majority of modern science practices rely on its scales in one form or another.

There are several different types of durometer scales used to properly measure the hardness properties of materials, but the two most common scales are the ASTM D2240 type A and D scales. Scale A is designed to measure the hardness of softer plastic materials, like out urethane rollers which have a durometer hardness of 55 and 70, while Scale D is designed to measure the hardness of harder plastics.

The largest and most interesting difference between Scale A and Scale D originates from the physical size of the hardened steel rod performing the durometer. With the hardened steel rod in Scale A, the foot measures 1.1mm-1.4mm in diameter with a 30°. In Scale D, the hardened steel rod measures the same 1.1mm-1.4mm diameter but differs in that its radius has a narrower tip and has a 30° conical point instead.

The ASTM D2240 recognizes ten other different durometer scales, all differentiating in accordance to the types of material they measure. Some of these difference include diameter, extension, and spring force.

To put things into perspective, the durometer has measured properties of hardness in common objects which you may see or use daily, such as the bicycle seat, chewing gum, rubber band, door seal, skateboard wheels and much more. Each of these materials in ranked in a scale ranging from 0-100, where higher values indicate harder materials and lower values indicate softer materials.

Can you guess which materials ranked where? Check out some of the durometer values below on common objects.

• Bicycle seat: 15-30 • Chewing gum: 20 • Rubber band: 25 • Door seal: 55 • Skateboard wheel: 98

The twelve durometer types are A, C, D, B, M, E, O, OO, DO, OOO, and OOO-S. The bicycle seat and the chewing gum fit within the OO Scale, for example, while the skateboard wheel, rubber band, and door seal fit within the A Scale.

All in all, it’s intriguing to sometimes stop and wonder about how a scale might have been originally constructed to accurately describe the hardness properties of all different types of materials around you. Among even the most modern science ideologies today, the Shore hardness scales are as solidified a concept as some of the hardest objects measured to date.

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from Polydrive http://www.polydrive.com/discussion-of-durameter-scales/

Polyurethanes are known as reaction polymers formed by synthesizing urethane links. The component polymers are isocyanates and polyols. The physical properties of urethanes which are specified by ASTM are dependent upon the specific classification for urethanes. These classifications include:

Microcellular urethane

Urethane coatings

Flexible cellular materials such as molded, bonded and slab urethane foams

ASTM tests each of these classifications of urethanes differently and also with different testing classifications. For example, ASTM D2370 – 98(2010) tested the tensile properties of urethane coatings. These properties include:

Elasticity

Elongation

Tensile strength

(Ref. https://www.astm.org/Standards/D2370.htm)

In testing microcellular urethane, ASTM D3489 – 11, the properties included plasticity, specific gravity (SpG) and density.

In ASTM testing of flexible cellular materials, the properties included hardness with a range of 20A to 75D, density, specific gravity and viscosity.

It should be noted that due to the fact that urethanes are used in a number of common products for industrial uses (ex:  urethane rollers) and home use (ex: polyurethane coated flooring), testing of the physical properties follow ASTM’s guidelines for plastics. As such, it can be expected that these diverse uses would also require physical property differentials. For example, thermoplastic polyurethane’s physical properties include resistance to oil and grease, as well as elasticity and transparency.

As an elastomer, the properties of urethane or polyurethane are resiliency and elasticity. The physical properties for urethane coatings for wood flooring would necessitate durability and resiliency. These properties are also found in thermal insulation used in homes and buildings to protect the interior from drafts and to reduce the cost of energy.

How the Physical Properties and ASTM Figure into Urethane Uses

ASTM relies on standardization to produce testing results that reflect a specified classification for each material tested. For example, when ASTM tests urethane for hardness, the results allow the producers of products to rely on the findings of ASTM’s standards as a guide to how to produce a broad range of urethane products with varying levels of hardness. This is also true for urethane coatings. Flooring designers and manufacturers rely on the durability of urethane used to produce flooring materials.

Density is another physical property of urethane that affects manufactured materials like coatings for window lineals and siding for buildings. Since urethane is used in end products, the physical properties as outlined by ASTM provide reasonable design, manufacture and buyer confidence children’s car seats, vehicle body parts and sports gear.

Generalized Urethane Roller Industry Tests

It is important to note that even though there are many tests available to test polyurethanes and urethane’s, the urethane roller industry utilizes a general set of tests (the specific testing method may vary):

Hardness – ASTM D2240

Tensile strength – ASTM D412

Elongation – ASTM D412

Tensile Stress 100%, 200% & 300% Modulus – ASTM D412

Tear strength – ASTM D624

Split tear –  ASTM D470

Rebound – ASTM D2632

Compression set – ASTM D395

Do You Have Specific Needs?

If you have further questions about your roller application, or you require assistance in creating a custom roller, contact us toll free at:

800-563-3381

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from Polydrive http://www.polydrive.com/physical-properties-urethanes-specified-astm/

Steel mills work with steel in varying states from raw metal to liquid metal. One of the processes that most steel mills have to complete is a transportation method for heated steel across the plant. Many factories use runout tables to transport the hot metal from one side of the factory to the other. These units use rollers to move the metal from one place to another, like a heat-proof conveyor system.

The problem with this roller design, is that metal pieces often have a difficult time transferring motor power to the rollers with a high level of efficiency. The misalignment and chemical contaminants that are often involved with the process can reduce the efficiency of the rollers significantly.

Luckily, factories have the option of using urethane rollers couplings that help manage the distribution of the motor power while remaining aligned and prevent corrosion even with daily contamination and use.

Urethane rollers are capable of keeping up with the transport of over 8,000 tons of hot steel each day. It is vital for a factory to be able to rely on the metal transportation methods to prevent the production from slowing or halting during business hours. This could cause a factory to lose money and even clients due to reduced production times.

Urethane is a highly useful material because it is able to transfer power to a driven shaft without causing misalignment issues. The urethane can also absorb vibrations which can reduce the amount of damage that connected equipment receives. Urethane is also resistant to stress, chemicals, and high temperatures, which makes it the ideal material for transporting hot metal across a factory.

Any steel mill that incorporates the use of polyurethane rollers into their steel transportation methods should see an increase in production and profitability.

Originally Posted At: http://blog.iqsdirectory.com/plastic-rubber/urethane-rollers/

Polyurethane rollers have uses in a variety of industries, from roller skate wheels to large conveyor rollers that transport heavy objects from one place to another. Choosing the right kind of roller is important for any job. If the wrong roller is chosen, then the equipment cannot function properly. Try using these selection tips to help find the best replacement rollers for your equipment:

Load weight: Some rollers can take more weight than others. The load weight is especially important for urethane wheels, such as caster wheels and wheels that need to support over 400 pounds. Check the load weight of the equipment and the load bearing capabilities of the roller to ensure they are a good match.

Environmental conditions: Environmental conditions can have a big impact on the kind of roller necessary for the job. If the roller will be used in oily, acidic, or chemical environments, the roller needs resistance to these materials. If the rollers are used as wheels, the wheels have to be strong enough to move over cracks, bumps, and other problems with the floor.

Rolling: Different internal rollers help the rollers perform better under different conditions. Roller bearings are ideal for heavy loads, but do not roll as easily. Ball bearings roll easily but cannot carry as heavy of a load.

Lubrication: Most polyurethane rollers require lubrication for optimal operation. The kind of lubrication that you use will depend on several different factors, including use and the temperature of the room. Make sure your rollers are compatible with the kind of lubrication you must use before purchasing.

Following the above guidelines can help make the somewhat overwhelming process of roller selection easier. When common sense is used, there should be no difficulty in choosing the best roller for the job.

Originally Posted At: http://blog.iqsdirectory.com/plastic-rubber/polyurethane-rollers/

Polydrive Industries processes high quality, industrial grade, castable polyurethanes. These castable urethanes can be separated into two main categories as they are identified as either polyester based polyurethanes or polyether based polyurethanes. Both of these urethane chemistries are excellent for precision rollers and many other non-roller applications. Both are strong, tough and durable elastomers with excellent physical properties. They can be formulated to work equally well in some applications but there are other applications where, after considering all the physical and environmental aspects of the application, one will be a more appropriate choice than the other.

Polyester Polyurethanes – Typically, we use polyesters for our softer urethanes, where we formulate them in a durometer range from 15A to 85A . In general, the polyester polyurethanes are known to have excellent physical properties when it comes to tear and tensile strength as well as resistance to abrasion, oil, grease, fuel and organic solvents.

Polyether Polyurethanes – Typically, we use polyethers for our harder urethanes, where we formulate them in a durometer range from 70A to 60D. In general, the polyether polyurethanes have superior dynamics properties which makes them an excellent choice in heavily loaded roller applications which subject the urethane to a repetitive compression force. The polyethers are also superior in cold or wet applications.

When comparing polyether polyurethanes to polyester polyurethanes, the following is generally true, especially if you compare them at the same durometers.

Polyether Polyurethanes

Better for higher durometer formulations

Better dynamic properties (lower hysteresis)

Better water resistance (resists hydrolyzation)

Better low temperature flexibility

Better resistance to molds and fungi.

Polyester Polyurethanes

Better for lower durometer formulations

Better abrasion resistance

Better tensile strength

Better tear resistance

Better oil, grease and fuel resistance

Better organic solvent resistance

Lower cost

Polydrive manufactures polyurethane products for a wide range of applications. In general, the applications can be categorized by the type of urethane most commonly used.

  Our polyester polyurethanes are used in the following applications.

Mail handling equipment rollers

Labeling equipment rollers

Magnetic tape drive rollers

Ticket dispensing rollers

Credit card handling rollers

Sewing equipment rollers

Packaging equipment rollers

Printer rollers

Banking equipment rollers

Paper handling equipment rollers

Vacuum fixtures

Automation clamps and hold downs

Capping equipment fixtures

Our polyether polyurethanes are used in the following applications.

Wire Feed rollers

Sheet metal forming rollers

Stone grinding equipment rollers

Refrigeration equipment rollers

Cradle rollers

Automation clamps and hold downs

Clean room conveyor rollers

Conveyor rollers

Water blast equipment rollers

Punch strippers

Marine equipment rollers

Do you have additional questions? Give us a call to discuss your specific needs: 800-563-3381

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