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JUSTIFYING YOUR TRUST

lab equipment

Figures 1 and 2

lab equipment

Figure 3

lab equipment

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Lab additions further enhance our quality assurance capabilities.

by Rick Hudson

The old saying about “build a better mousetrap and the world will beat a path to your door” certainly is true. Since establishing our own in-house quality assurance department back in 1997, we here at RL Hudson have seen the volume of parts that go through our lab multiply several-fold every year.
Not because of an increase in problems, mind you, but simply because more and more of our customers have decided to take advantage of the inspection and verification services we offer. As a matter of fact, one of the reasons we needed to build a larger home was to be able to further expand our quality assurance capabilities so as to keep pace with this ever-increasing demand.

To that end, we recently invested in three new pieces of equipment for our lab: an enhanced video imaging system, a radial lip force tester for use with shaft seals, and an FTIR material analysis station. I’d like to take this opportunity to give you a brief overview of the usefulness of each.

VIDEO IMAGING Since our QA lab’s inception, we’ve utilized a Voyager 1000 video imaging system to assist with inspection of complex or miniature parts via a camera-computer interface. Earlier this year, we upgraded both the Voyager’s hardware and the View Metrology Software (VMS) so as to give us even more detailed images and greater measurement capabilities.

As shown in Figure 1, we have now also added an Opti-Flex™ 4000 Series video imaging system. Manufactured by Flexbar®, the Opti-Flex gives us another precision measurement and inspection station. The Opti-Flex magnifies up to 276 times, and it’s accurate to within .00015 of an inch.

In many ways, the Opti-Flex is very much like the Voyager, with the main difference being that the Opti-Flex allows images to be directly annotated with dimensional data or other helpful labels. An example of an annotated image is shown in Figure 2. These annotated images can then be stored for future retrieval or even sent as e-mail attachments. The e-mailing comes in particularly handy as an instantaneous way to communicate with our factories and our customers.

RADIAL LIP FORCE TESTING As a major supplier of radial lip shaft seals, we have a vested interest in verifying that the seals we provide will perform as expected in service. That is, that they will exert the right amount of radial force on the shaft onto which they are installed. Too little force means the sealing lip won’t maintain proper contact with the shaft, allowing a leak path to develop. Too much force on the shaft will increase both friction and wear, shortening seal life.

As detailed in the Rubber Manufacturers Association (RMA) Handbook OS-6 (“Radial Force Measurement”), lip force can be gauged through use of a split-shaft testing device. One half of the shaft is held motionless, while the other half is free to move and therefore capable of reflecting how much force is being exerted on it by a shaft seal’s lip. Depending on the device in use, measurement may be mechanical (as calibrated by a spring), pneumatic (using an air pressure gauge), or electronic (via a transducer). Studies conducted by the RMA have shown the electronic devices to be preferable. The electronic device we’ve purchased for use here in the RL Hudson lab is shown in Figure 3.

MATERIAL ANALYSIS & VERIFICATION We have also purchased a Spectrum One™ FTIR (Fourier Transform InfraRed) spectroscope manufactured by Perkin Elmer. As shown in Figure 4, this is a very sophisticated piece of equipment that allows us to analyze samples of rubber and plastic. Through analysis, we can verify that the materials we receive from our sources are the exact same materials that we approved for a given application.

So how does it work? Spectroscopy is a way to gauge the amount of radiation a particular material absorbs at various wavelengths. Subjecting a material sample to a beam of infrared radiation produces a recordable spectrum, a spectrum unique to that material. Study of this spectrum can yield useful information about the molecular makeup and chemical bonds of the material.

But how does that help us (and our customers)? A sample taken from all first articles is analyzed using the FTIR, and an IR spectrum is generated. It’s in the form of a graph such as the one shown in Figure 5. This graph can be permanently stored in our computer base. A stored graph can serve as reference when analyzing samples from subsequent batches to make sure the material from those batches matches the originally approved material. In other words, it’s a high-tech way to absolutely verify material consistency. The FTIR also affords us the ability to analyze any rubber or plastic material submitted to us so that we can determine (and, if need be, improve) the base material.

MOVING AHEAD I’m proud of all three of these recent additions to our laboratory repertoire. I’m sure they won’t be the last upgrades we make. Thanks to our new building, we now have more space than ever to fill, right? All kidding aside, though, I’m reminded of another well-worn saying: “If you’re not moving ahead, you’re falling behind.” We don’t intend to fall behind, and the addition of these instruments to our lab is further proof that, here at RL Hudson and Company, we never stop investing in quality. Be sure to call us at 1-800-722-6766 if we can help you with any quality-related issue.