O-rings are one of the most cost-effective ways to provide a seal between two harder components. They also prevent contamination from chemicals, air or water, and reduce friction. O-rings are also used in almost every industry, from food service to aerospace — which is saying a lot for a cheap rubber circle.
O-rings work because of their shape. If you tried to make a seal with a rectangular cross-section, you wouldn’t get the same seal. In fact, many o-rings will withstand additional psi beyond its stated capacity and still seal thanks to characteristics of their basic design.
However, just because the o-ring is so simple, doesn’t mean it is not evolving.
The Need for Improvement
Several factors are driving this need for continuous improvement. One issue is user expectation. Once upon a time, there was a larger acceptable difference from mean values. A certain level of imprecision was tolerated, even expected. In today’s six-sigma world, that just isn’t the case.
Some of this insistence is simply because people have gotten used to a smaller number of errors, but some of it is thanks to the more precise needs that certain technology demands. For instance, today’s elastomers and polymers need to be able to withstand more extreme temperatures and more chemicals than ever before. In addition, food safety standards have increased, drawing a need for better seals and gaskets.
The materials used in manufacturing seals, o-rings and gaskets have increased over the years. There are more than 20 being used today, and they can be compounded to provide specific strengths. This has led to significant developments in the rubber seal industry. Hydraulics & Pneumatics explains that existing technologies have been modified by polymer manufacturers to enhance their products’ performance. For example, they were able to make fluorocarbon-based polymers more chemical resistant and enhance their thermal stability by varying the percentage of fluorine in the polymer.
The basic design of the o-ring has not changed since its development in 1937, but that doesn’t mean that it hasn’t been refined somewhat. For example, many o-rings have redundant features to help ensure that there will be no leaks. There is also a variety of tools available to help engineers determine the best o-ring design or seal configuration for their needs, like software packages.
Material technology has improved vastly over the years. The fluid dynamics of composites and plastics are better understood in this modern era, and that understanding has been applied to sealing products. Engineers are also better able to test o-rings and gaskets for extreme conditions that mirror real-life situations so they can better predict failures and field test solutions.
The Apple Rubber Difference
Apple Rubber is one of the manufacturers that has been at the forefront of these developments in o-ring design. They offer a wide variety of sizes and materials so you can get precisely what you need for your application.
O-rings may appear unchanged over the years but look closer. They have evolved with regard to the materials, seal configurations and characterizations used to be better suited to modern applications.