Angel hairs and tube abrasions are the nemeses of cap and closure conveyance. On Apr 1, 2009 Shrikant Dhodapkar (and others) published "Understanding Bends in Pneumatic Conveying Systems" in Solids Processing. The document is widely available online. The article has...
Problems and Solutions
How to identify the radius of a bend for a bend less than 180 Degrees. Imagine if you got a picture like this in your email and your customer said, "make us one just like this." On top of that, they insist that this is a bend on a 24" radius. They can't ship you the...
We were asked to provide a Coefficient of Static Friction for our butyrate tubing. The problem is that the surface roughness is only one part of the equation, the base material is another. We defined our materials as aluminum and steel with CAB.The simple test for...
Whenever I hear of a "circle within a circle" I think of the bizarre description of deity in Ezekiel Chapter 1 (well, in his case it's a wheel within a wheel). In our case, it's a prototype. And it was a challenge. We were to produce an air-tight, water-tight...
Cleaning Butyrate tubing: Cellulose Acetate Butyrate, as any transparent tubing can accumulate grime, oils, and get scratched by abrasives. Also, it will weather and age due to UV light and oxidizers. When the latter occurs, the tubing cannot be cleaned by traditional...
We often fit bends to pneumatic (or other) systems from a distance. We ask the customers to send us as much information as they can provide. From that, we do our best to calculate OD, radius, and angle of the bend. Here is another example from last week. As you can...
Tight –radius bends are a problem to all tube benders. On a tight radius, we can run into excessive flattening, cracking of the outside wall, or buckling in the inside wall (most commonly). The problem is intensified in transparent, thermoplastics benders, for we do...
We recently had quite a challenge from Metraflex regarding a transparent tight-radius 4” pipe 90° bend. They required a transparent 4” Sch 40 long-radius elbow to observe a metal fin in a fluid system. The pipe bend needed to maintain a tight tolerance for ovality as...
Sometimes we just have to be creative when we get calls from damsels in distress. We received a call from such a damsel who needed to replace a worn-out PVC tube and a more worn-out HDPE carrier. Busada pneumatic tubing consists of three major parts; the tube, the...
Ovality, or out-of-roundedness can be a problem in pneumatic conveying. Our tolerance of out of roundness varies with our tube outer diameter. Ovality can be checked with calipers (as usually the case checking the OD) but in certain circumstances, we need a machined...
Busada makes long-radius sweeps (bends) in CAB (butyrate), Provista, Polycarbonate, and PVC, but recently completed its first PETG bend. The bend was on a 24" Radius with extended tangents. All bends are made to order, with a 10 point check to see that degree, radius,...
Problem: Extrude a heavy-walled small diameter pneumatic tube; in this case the wall area composes 75% of the tubing area. The difficulty comes in maintaining wall uniformity while eliminating “lensing,” uneven cooling, uneven shrinkage (curling) and chatter lines....