Plastic Angle

Out of the many parts and plastic profiles requested of Redwood Plastics and Rubber, plastic angle keeps coming up. This is typically plastic bent at a 90 degree angle halfway. This is primarily used for protection of a surface or object if machined out of UHMW or nylon plastic. However, much stronger (more rigid) fiberglass reinforced plastic (FRP) angle is available and stocked by our supplier. A common example of a FRP angle application would be to bolt it in on the edge of a platform at a train station. FRP angle is available in a variety of widths and thicknesses with 1/4″ and 3/8″ thick being the most common. It is available in all three primary EXTREN resin types (general purpose polyester, fire-retardant polyester, and vinyl ester). These angle profiles are more expensive than steel or aluminum angle; however, for certain applications such as those that demand electric or radio non-conductivity, plastic angle may be your only choice.

To get a quote on an angle profile is easy. Firstly, we need to know the width of each side of the angle, they are not always the same! We then need to know both the thickness and the material required. If you need assistance selecting a material, just ask, but me sure to be ready to answer questions about your application such as what the angle is doing, if there is any chemical or high heat exposure, etc. Angle profiles of all plastic types are typically sold by the 10 foot length; however, there are cases where we can supply shorter or longer profiles.

For a quote on your plastic angle needs, please contact us today.

 

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Space Shuttle Challenger and Rubber: A Cautionary Case Study

The space shuttle “Challenger” explosion in 1986 was a seminal moment for many Americans. The launch was shown on live TV and there was a high amount of interest in teacher Christa McAullife being on the flight. The shuttle exploded 73 seconds into the flight resulting in the deaths of the entire crew. An immediate investigation was launched and it was determined that a failed rubber o-ring system used as seals on the solid rocket boosters led to the explosion. The launch was on an unusually cold day – the o-ring seals were qualified for use at no less than 40 degrees Fahrenheit but the temperature got as low as 18 degrees Fahrenheit the night before.

Prior to launch several engineers attempted to warn against launching due to this reason. The engineers believed that the cold temperatures would weaken the rubber and also lead to a poor seal, which would allow hot exhaust gases to potentially escape the boosters and cause catastrophic damage. It had already been determined that the o-rings were being damaged even on successful flights. The engineers were forced by NASA management to try to prove that the application would fail at low temperature, something the engineers could not do because of a lack of testing data.

Your application with rubber will likely not be as critical as the space shuttle o-ring seals; however, even with our applications there is much to learn.

Firstly, is you need to pick a rubber that will work within the parameters of your application. You need to know what chemical exposure and temperature range the part will need to operate in.

Secondly, once you get the parts you need to use them within the parameters that you have specified because if you introduce, for example, new chemicals or operate the part outside of the prescribed temperature range, it may fail!

The third and final thing we can learn is to listen to the product experts who helped recommend a rubber solution to you. If they strongly believe a certain material is required and can give you concrete reasons, you should consider this thoroughly before going in another direction. This is particularly a concern where a desired price may be a determining factor for a purchasing decision, rather than if the rubber is actually suitable or not.

Redwood Plastics and Rubber has rubber experts standing by to help recommend the best product for your application so contact us today.

Why Choose Silicone Rubber?

Silicone is a remarkable variety of rubber that offers some outstanding properties that can make it the clear choice among competing solutions. Firstly, silicone can handle very high temperatures in operation, up to 230°C (446°F). This allows it to maintain its properties at elevated temperatures that many other rubbers will not be able to handle! In addition, it has excellent resistance to UV and weathering, making it outstanding in outdoor applications. This includes heat, cold, freezing, direct sunlight, etc.

Silicone also has a low compression set – this means it can be compressed for a long period of time and will bounce back to close to its original profile when the weight has been removed. Think of this in a sealing application such as a door which is open and closed many times. The silicone will maintain the seal when compressed and will then return to its original form once the door is reopened. Also, the product is food safe and Redwood Plastics and Rubber can supply it in a new FDA blue variety.

There is a silicone rubber shortage currently in North America but not here! Redwood Plastics and Rubber carries significant levels of silicone stock in our central warehouse including FDA blue. For a discussion on how silicone rubber can benefit your application or for a quotation please contact us today.

Rubber: It’s Not Just Tires!

When you think of “rubber” what is the first thing that comes to mind? It’s probably car tires, perhaps tires on your bike, but the point is “just tires” for many people. However, rubber is so much more than just tires. Rubber is used across a wide variety of industries performing in countless applications. Some are interesting, such as in prosthetics or medical devices. Others such as belt skirting on an ore conveyor are perhaps less interesting to the casual eye. Used in everything from mining, to sawmills, to even space – rubber should not be discounted as a simple material for tires! Gaskets, rollers, flanges, molded parts, wear parts, anti-vibration applications, electrical insulators – rubber has a place in all of those applications.

The short video below will display more applications that this versatile material can be used in. Maybe it will jump start your mind for a rubber application you might have?

Industry Spotlight: Aggregate

The aggregate industry is defined by the processing and movement of extremely abrasive wet or dry materials, usually by a network of conveyors. This process may also include equipment to pulverize, shape, clean, or otherwise sort the aggregates. Due to the abrasive nature of these materials, wear is a major concern on expensive equipment. Redco products have supplied viable, downtime-reducing, solutions for this industry over many decades. The primary workhorse is Redco polyurethane. This elastomer has extremely high wearing properties and can thrive in abrasive environments involving virtually any wet or dry aggregates.

The applications are too many to name but conveyor and hopper lining are two of the largest. When used as a liner, urethane protects the metal equipment and handles the wear of being in direct contact with the aggregate. However, polyurethane can essentially be used anywhere this wear occurs, including the area the aggregate first contacts the conveyor to any discharge chutes. Contact us with details of your application in order to get a recommendation of the optimal grade of urethane. Some polyurethane products actually exist specifically for aggregate including the innovative Redco Switchblade belt scraper with its replaceable and Redco Green Screens.

A few more notes. Rubber has significant applications in this industry as well, primarily as belt skirting and in areas where constant vibration is a concern. For slurry applications specifically, the Redco VYPUR series of pipe sections and elbows provide exceptional service life above and beyond metal in abrasive or corrosive applications. It’s best if customers reach out directly to us for a consultation, so if you’re involved in the aggregate industry and are looking for some solutions to maintenance costs and downtime, please contact us today.

You can see pictures and read more about our aggregate solutions here: https://www.redwoodplastics.com/industry-solutions/aggregate/

Not Sure What Rubber You Need? Start Here

Ordering rubber products is easy enough when you know exactly what you need and a defined spec is available. However, what if that information has been lost? The answer is to start at “square one” and work your way up to an optimal solution. To that end you need to know five pieces of information:

  • Application – What are you doing with it?
  • Contact with – What aggregates or other materials will contact the rubber?
  • Exposed to – which chemicals?
  • Operating Temp – Lowest and highest?
  • Durometer – What is the hardness (example, 60A)?

The first four pieces of information on the list must be supplied by the customer and should be easy to put together. “Durometer” is a little trickier if not known as that requires a specialized piece of equipment. In that case, a sample of material can be mailed to us and we can test it here. Having this information will help us, help you maximize success in your application.

For assistance with your rubber needs please contact us today.

Weathering and Exposure Concerns

There is unfortunately some misinformation in the plastics world regarding weathering, exposure, and UV-resistance. In some cases where applications go wrong, customers simply did not consider how a certain plastic might handle being exposed to certain environmental factors. One of the largest pieces of misinformation is that reprocessed-black UHMW often called “UHMW black” is UV-stable. It is not; however, and has only some limited UV-resistance due to the addition of carbon black in the resin. The following are examples of weathering and exposure concerns for some popular plastics and options to mitigate these issues.

Nylon:

-Brittle in cold temperatures (below -15 degrees C)

-Absorbs water

Solution:

-Switch to acetal or Tuffkast

UHMW/Polyethylene:

-Poor UV-resistance makes it prone to cracking with UV-exposure

Solution:

-Procure a fully UV-stable grade

Polyurethane:

-Certain varieties weaken and break down in wet environments (hydrolysis)

Solution:

-Work with a plastics expert to select a polyurethane variety not weakened by hydrolysis

Polycarbonate:

-Poor weathering resistance, will yellow and crack with exposure

-Poor scratch resistance and tends to become cloudy with small marks when used in outdoor applications

Solution:

-Request sheets with UV stable and/or scratch-resistant masking. These will be typically unstocked.