Elongate Machine Life with Urethane Rings

Elongate Machine Life with Urethane Rings

Rings are an integral part of all types of machinery, from the simplest to the most complex.

In some cases, rubber rings are selected for their flexibility and compression; other times metal rings are used for their strength and longevity.

In either case, there is a material that can do the job better: polyurethane rings.

The right urethane rings for the job can elongate machine life, minimize downtime due to maintenance or part failures, and save material costs overall.

Physical Properties of Urethane Rings

Urethane rings can be custom engineered to display a wide range of physical properties that can make them a suitable upgrade for both rubber and metal rings alike.

Physical Properties of Urethane vs. Rubber Rings

When it comes to replacing rubber rings, urethane rings have two distinct advantages: elasticity and deflection.

The superior elasticity of urethane rings allows them to maintain their original shape after being stretched, heated, or cooled. Rubber, on the other hand, is subject to deform more easily and disintegrate with exposure to high and low temperatures.

Beyond elasticity, what really sets urethane rings apart from rubber rings is their deflection capabilities. When a force acts on a rubber ring, it will compress, meaning that its overall volume will change so long as the force continues to act on it. Instead of compression, urethane rings display a property called deflection. Deflection allows these rings to maintain their volume through displacement. By deflecting instead of compressing, urethane rings can last longer in load-bearing applications and therefore elongate machine life.

Like other physical properties, the degree of deflection that a urethane ring exhibits can be adjusted with custom urethane formulations.

PSI Urethanes has a “dead” formulation for high shock absorption urethane rings. Urethane rings made with this formulation will dissipate any energy that is transferred during an impact, which reduces deflection of the part. In use cases where a urethane ring needs to remain as stationary as possible, a dead formulation is the way to go.

Oppositely, a “rebound” formulation for high flexibility urethane rings is available as well. Urethane rings cast from this formulation will store any energy transferred during an impact. This makes it the preferred formula for applications where it’s important for the ring to flex but still maintain its original shape.

Physical Properties of Urethane vs. Rubber Rings

Metal rings are commonly used in applications like bushings and washers, but urethane rings can outperform their metal counterparts in terms of strength and longevity.

Thanks to their excellent deflection, urethane rings handle impacts and high forces much better than metal rings do. Where a metal ring might bend or dent and ultimately experience a part failure, a urethane ring will instead deflect as a response to any strong or sudden forces.

As an added benefit, urethane rings will not scratch any mating parts the way that metal rings might. By preserving the integrity of these mating parts, urethane rings can further help elongate machine life.

Need stronger rings? Contact PSI Urethanes to start developing a custom urethane ring for your application today!

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Chemical Properties of Polyurethane Rings

As with physical properties, the chemical properties of polyurethane rings can be adjusted with the power of custom formulations. The effectiveness of each urethane formulation depends greatly on the chemical’s concentration, temperature, and duration of contact, so be sure to have that information ready to provide to your manufacturer when developing polyurethane rings for a specific application.

There are many factors that go into developing a formula for polyurethane rings. Polyester vs. polyether, MDI vs. TDI, and thermoset vs. thermoplastic are all selections that will influence the properties of the final polyurethane rings.

Chemical Properties of Polyurethane vs. Rubber Rings

Compared to rubber rings, polyurethane rings are better suited for nearly any application in which the ring will regularly come into contact with a chemical. The formula used for cast polyurethane rings can be modified to increase resistance to certain chemicals, so knowing the parts’ intended use is vital to developing the proper formulation for the job.

Here are just a few chemicals that PSI Urethanes has dedicated urethane formulations for:

  • Hydraulic Fluid
  • Ozone
  • Mineral Oils
  • Hydrocarbons
  • Fats & Greases for FDA Approved Use
  • Petroleum Products
  • Chemical Solvents

For a full list of chemicals that polyurethane rings are compatible with, refer to PSI Urethanes’ urethane compatibility chart.

Chemical Properties of Polyurethane vs. Metal Rings

shock absorber

The most significant advantage that polyurethane rings have over metal rings

is their corrosion resistance. Corroded metal rings are highly ineffective at performing their intended function. Metal rings like washers often fail after they have corroded through and become brittle. Corrosion also creates a contamination risk, as rust flakes may fall off of corroded metal rings and inhibit

 the performance of surrounding mechanisms.

With polyurethane rings, the issue of corrosion is eliminated. For uses where

  a polyurethane washer will come into contact with water, hydrolysis resistance is a factor that can be enhanced with a custom formula.

These factors combined with the physical advantages of polyurethane rings make them the superior choice for a multitude of use cases.

If your current washers, bushings, or couplers just aren’t cutting it, give PSI Urethanes a ring

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Advantages of Urethane Capper Rings

Capper rings are an excellent example of an application where polyurethane rings are commonly selected for their advantages over more traditionally used rubber rings.

Most rubber rings are designed to exhibit the same level of hardness, or durometer. 60 Shore A hardness is the most common durometer used for capper rings; however, in such a versatile packaging method there isn’t a single one-size-fits-all solution.

PSI Urethanes specializes in the development of specialty polyurethane capper rings to suit each specific capping mechanism on a case by case basis. Aside from durometer, the composition of urethane capping rings is also determined by selecting from other variables such as ethers and esters; MDI and TDI resins; and whether or not an FDA wet or FDA dry formula will be necessary.

With so many avenues to highly customize a formulation to perfectly suit the intended use, urethane capper rings are guaranteed to outlast and outperform their rubber counterparts.

Whether you need capper rings, washers, gaskets, or bushings, PSI Urethanes has the experience to formulate the right urethane rings to maximize machine life.

About PSI Urethanes

Since 1966, through our own independent research and activity in the Polyurethane Manufacturers Association, PSI Urethanes has stayed on the leading edge of urethane technology – including developing advances in new materials, comprehensive designs, and processing technologies. Today we are among the most respected and trusted suppliers of custom polyurethane products.

We operate from our 45,000-square-foot manufacturing facility in Austin, Texas, which houses an extensive stock of polyurethane products. Our fully equipped manufacturing facility includes a versatile range of processing machinery, which allows us to work on unique, one-of-a-kind projects, as well as high volume components. Our in-house engineering, tooling, and custom mold shop, produces custom and stock production orders with exceptionally fast turn-around times. From conception to prototyping, to final production runs, our technical representatives and design engineers will work closely with your staff to meet your critical tolerances and specifications. You are guaranteed to receive experienced, professional, and personalized service from the first contact through your on-time delivery, with complete confidentiality and dedication to protecting your good name.