Plastic Tubing

Tubing as jewelry

tubeguy — Thu, 10 Feb 2011 18:06:14 +0000

Here’s something interesting. I don’t think the photo is showing the product off very well but the idea is interesting.

http://epoxymoron.tumblr.com/post/3203319974/day-25-feb-5-2011-gemstones-in-plastic-tubing

Make a trumpet with a length of tubing

tubeguy — Fri, 28 Jan 2011 21:37:28 +0000

I came across this online today. It’s pretty cool… looks like a fun little project.

Video

Marble Machine

tubeguy — Mon, 13 Dec 2010 18:03:21 +0000

I guess I’m a sucker for a good marble machine video. It’s a nice use of 200′ of plastic tubing.

Radiant Heat Floor – Video

tubeguy — Thu, 02 Dec 2010 16:35:54 +0000

I don’t have any experience with PEX tubing but this looks like a great project.
Radiant Heat Floor Video

Pressure

tubeguy — Tue, 30 Nov 2010 20:18:53 +0000

Most of the time, when we’re talking about pressure, we’re talking about positive pressure inside the tube. Most commonly, it is measured in “Pounds per Square Inch” or PSI.

Generally speaking, the softer the tube, the lower that tube’s pressure rating. Another way to look at it is that the higher your pressure requirement, the less flexible your tubing can be. In my world, we deal a lot with a very soft and flexible 70A durometer polyurethane. It has really low pressure ratings. One of our standard 70A tubes has a working pressure at 75 degrees Fahrenheit of just 50 PSI. On the other end of the spectrum, we work with a high pressure formulation of Nylon 11. That tubing can go up to 800 PSI.

As mentioned in a previous post, pressure and temperature are related. All thermoplastic tubing will lose ability to handle pressure, as the temperature increases above 75 degrees.

Most of the points made in this post so far have referred to positive pressure. Tubing is also used in vacuum installations with negative pressure. Because vacuum situations vary so much, you will definitely want to get a sample and test it. Again in general terms, you can’t expect a tube’s positive pressure rating to equate to a negative pressure rating. In other words, a tube that is rated to handle 150 PSI of positive pressure would probably not be able to handle 150 PSI of negative pressure. Thicker walls are needed to improve a tube’s ability to work with negative pressure. Tubing with ribs or some other form of reinforcement may also be required.

This article is part of a series related to the S.T.A.M.P.E.D. article posted on 11/11/2010.

Media in Tube

tubeguy — Wed, 24 Nov 2010 21:16:47 +0000

Arguably, the most important factor when selecting your tubing is what’s going to be in it. It will likely be in the closest, most continuous contact with the tubing material, for the longest period of time. How the tubing and the media react to each other is critical to the success of your plastic tubing.

Every thermoplastic has a range of chemicals and gasses that it excels in handling or does not handle well (or at all). The example that I like to use is, how can super glue – that will bond anything – not bond up the tube that is holding it? Or the old question, what makes Teflon(R) stick to the pan? The answer is that the plastic and the media are working in sync.

The starting point for determining what plastic to use is a chart showing chemical resistance of various plastics. There are entire research volumes devoted to the subject but using one of the readily available charts is the easy first step. There are many available online but the one I use is here: Chemical Resistance Chart.

I can’t over-emphasize the point that this is just where to start. Even those thick research volumes are only just so helpful. The best research is done by you. Even if you’re just going to run water through the tubing, get a sample and test it. Most manufacturers are happy to send you several feet of tubing to run a test. Make sure that your unique circumstance will work with the particular plastic that you’re considering for your project.

This article is part of a series related to the S.T.A.M.P.E.D. article posted on 11/11/2010.

Application

tubeguy — Thu, 18 Nov 2010 17:14:36 +0000

One of the most interesting things about my job is seeing all of the uses people have found for plastic tubing. I’m sure all of the manufacturers have similar stories, but we’ve had our tubing used in movies, rockets, robots, and mops. It’s been used as handles for shopping bags, frames for crab pots and in art sculptures.

How you are going to use your tubing is a pretty important factor in deciding which tubing will work for you. One common issue we see is that people need it to flex and then spring back to its original shape. Another thing we see frequently are applications where the tubing is moving and rubbing against other tubing. If it’s too tacky, the tubes will get hung up on each other.

Color might be important to the application. You may want the tubing to color coordinate with your machine. On the other hand, you may have lots of tubing bundled for a long run. In that case you may want to color code your lines so it’s easier to connect your tubing.

Another consideration is if a single tube is what you want. Maybe you’d like several tubes bonded together. Maybe you are using short lengths of tubing and would like the manufacturer to cut it for you.

The point is that there are lots of ways that you might be using plastic tubing. It’s important to look at the whole project and think about what features you need the tubing to have. With all of the resins available, the right feature mix probably exists.

This article is part of a series related to the S.T.A.M.P.E.D. article posted on 11/11/2010.

Temperature

tubeguy — Tue, 16 Nov 2010 16:40:22 +0000

There are two temperatures to be concerned with in regards to plastic tubing: external and internal.

External: You need to think about not just the general temperature of the environment, but also the tubing’s proximity to a heat source. The space for instance may be a comfortable 70 degrees F, but the tubing might be running past a radiant heat source that gets much hotter.

Internal: The other temperature to take into account is the temperature of the media in the tube. And not just the temperature as media enters the tube, but I can also imagine scenarios where the effect of friction within the tube could possibly be a factor as well.

So why does temperature matter? All of Freelin-Wade’s tubing is made of thermoplastic. This means that heat is used to form it. Just as heat was used to make it, heat can destroy it. Where you see the effect is in how the tubing handles pressure. A certain polyurethane tube for example, that at 75 degrees F can handle 210 PSI, might manage only 85 PSI at 150 degrees F. Flexible PVC struggles the most in warm environments. In our catalog, I see one tube that is rated at 110 PSI at 75 degrees but only at 15 PSI at 150 degrees.

As you can see, knowing the temperature is an important consideration when choosing your tubing solution.

This article is part of a series related to the S.T.A.M.P.E.D. article posted on 11/11/2010.

Robotic Arm Video

tubeguy — Fri, 12 Nov 2010 17:42:35 +0000

I came across another video that I thought I’d share. This one is from Festo and it shows a pneumatic powered robotic arm. It’s pretty cool.

Click to watch video

Size

tubeguy — Fri, 12 Nov 2010 16:34:54 +0000

In the industry, generally speaking, tubing is sold by its outside diameter (O.D.). Hose* is typically sold by its inside diameter (I.D.). In practice, this means if a person says that they want a “half-inch tube”, they’re talking about a tube with an OD of 1/2“. On the other hand, when I’m looking for a “three-quarter inch garden hose,” I’m looking for one with a 3/4″ ID.

Tubing can be lumped into three general diameter categories: micro, small and large.

Micro tubing would be any tubing smaller than 1/8”. Tubing in this category is often used for medical and high-tech purposes. It’s a specialty tubing that is sometimes made in a clean-room environment. As you can imagine, due to the small size, precision is critical and quality standards are very strict.

Small diameter tubing ranges from 1/8” in diameter up to about 1” in diameter. Small diameter is what my employer (Freelin-Wade) makes, and the tubing that I am most familiar with. As a rule of thumb, smaller tubing has higher pressure ratings (there are other important factors too).

Large diameter tubing is a different sort of product altogether. You can’t make large diameter tubing the same way that you make small diameter tubing. As the diameter increases, the wall has to get thicker to support the shape and weight. A thicker wall means the tubing gets more expensive, heavier and less flexible. To deal with this problem, what tube makers do is they make large diameter tubing out of more rigid materials; such as high-density polyethylene (HDPE) or rigid PVC. To give it flexibility, they corrugate it.

This article is part of a series related to the S.T.A.M.P.E.D. article posted on 11/11/2010.

* So what’s the difference between a tube and a hose? Hoses are reinforced with an inner-braid of thread or other fiber.