Experts in Custom Tube Bending

Axenics’ qualified technicians can bend plastics to fit almost any shape and/or space requirements, without the need for adding multiple joints and fixtures. It’s important to ensure that the appropriate amount of heat and consistent heat is applied to the tube being bent to avoid developing kinks, which can restrict liquid or chemical flow.

Plastic tube bending is a great solution for building systems where space is limited or a specific shape is required. Plastic tube bending is a great alternative to welding since it eliminates the need for multiple fittings within a system or complex assembly. Axenics performs custom tube bending and develops specialty piping kits to meet a variety of business challenges for our customers.

Axenics is capable of bending the following polymer-based materials:

  • Polytetrafluoroethylene (PTFE/FPA)
  • Polyvinyl Chloride (PVC)
  • Chlorinated Polyvinyl Chloride (CPVC)
  • Polypropylene (PP)
  • High density polyethylene (HDPE)
  • Polyvinylidene fluoride (PVDF)
Plastic Tube Bending

Benefits of Plastic Fabrication

Though metal manufacturing services are highly valuable and critical to every manufacturing sector, there are many benefits that plastic manufacturing offers. Plastic offers a low-cost, flexible and durable solution to a variety of manufacturing challenges where other materials, such as metal or glass, might not be appropriate. With the right skills and expertise, plastics also might be fabricated or assembled in much the same way that other materials are.

Another important advantage to obtaining pipe bending services from contract manufacturing companies such as Axenics is that we have a Class 100 cleanroom to ensure that every tube is bent using a clean process if that is necessary for your industry or operation. This service is desired by original equipment manufacturers (OEMs) in a range of industries where tube contaminants have the potential to ruin assembly systems or end products.

By having your pipe or tube bending services performed by Axenics, you get a reliable and durable bent tube that meets your specifications every time.

Creating the highest-quality bends in tubing is something that every manufacturer strives for. Over the years, there have been many technological advances and improvements in technique with regards to tube bending. However, regardless of the technology or technique used, there are a few factors that have remained the same.

Each process uses different seam configurations depending on the materials used and the look and/or shape desired. Welded, open and lock-seams are the main seam types. However, seamless tubing also may be produced for a cleaner look.

Ram-type bending utilizes a ram to push a tube against rollers or pivot blocks using hydraulic force. Ram-type bending is one the oldest, simplest and least-expensive methods used for tube bending. However, the process is difficult to control compared with other processes. It is most often used for square bending applications, where a concave surface is desired. Ram-type bending isn’t the ideal method for applications where there are tight bending requirements and/or the cosmetics of the final product are important.

Roll bending can be performed using a variety of machines to create bends for large tubing components and are most commonly used for producing spiral shapes. One machine type consists of three rolls set in a pyramid formation, which can be aligned either vertically or horizontally depending on the size of the section to be bent. This machine is best suited for producing bends with larger radii. Another machine commonly used is a two-roll, pinch-style roll bending machine, consisting of an upper and lower roll, which can be adjusted to produce specific bend angle

Compression bending involves bending a piece of tubing using a roller/compression die, which bends the tubing around a bend die which is stationary. The tubing is clamped to the system, and the roller then works to compress the tubing against the central bend die. Using this method, the bend’s outside surface is often flattened somewhat, since the inside diameter (ID) is not being supported. This particular bend method is often used for creating components with identical bends on each side and is commonly used for producing household and commercial products.

Rotary draw bending is a technique used often for creating precision bends where producing tight radii is required, as this particular method allows the bender to have optimal control over the amount of wall thinning and that occurs. The straight section of the tubing is held by a pressure die, and a clamp die is used to rotate the tubing around a bend die. From here, a mandrel and a wiper die are typically used to prevent wrinkles that often form on the inside radius of the bend. This process allows for effective support of the outside radius (with a pressure die) and inside radii during the bending, which results in more precise bending than any of the other methods.

Things to Consider with Plastic Tube Bending

There are a few things to be aware of during the process of tube bending, some of which can negatively affect the quality of the bend:

  • Springback: When bending tubing or piping, it is common for the tubes to experience something called springback. This occurs when the material tries to return to its original shape after it has been bent and results in radial growth. Harder tube and pipe materials typically result in more radial growth. When bending copper, for example, there is typically less radial growth than with steel because it is a lighter metal and, therefore, results in less springback.
  • Weld Seams: Although some tubing and piping are seamless, both are usually produced with a longitudinal weld. When bending tubing or piping, the quality, size and consistency of the weld seam (if applicable) are very important. If the edges of the weld joint aren’t perfectly aligned, the tube or pipe roundness can be negatively affected, which will create issues, such as elongation and inevitably wrinkling, during bending.
  • Elongation: When elongation occurs, the outside radius of the tube or pipe stretches which results in wall thinning. The material will respond by resisting the wall thinning, which will cause the outside surface of the bend to cave in and distort the shape of the tube or pipe. When the outside radius stretches, the inside radius compresses, forcing wrinkles in the bend.

Tooling Options & Requirements

In addition to choosing the right bending machine for the job, another factor to consider is what type of tooling is required, based on the materials you’re working with and the bend you’re trying to achieve. This is particularly important for rotary draw bending. Some basic tooling specifications to consider are as follows:

  • Mandrel: The hardness or softness of a mandrel is crucial, depending upon the hardness or softness of the tubing to be bent. When working with a hard piece of tubing, we use a soft mandrel, and vice versa for a soft piece of tubing. This will prevent the mandrel from sticking to the inside of the tube, which can negatively impact the bending process.
  • Bend Die: The radius of a bend die should take into account the hardness or softness of the material being bent, in order to adjust for radial growth. For example, when bending a harder material, a bend die with a smaller radius might be required.
  • Clamping Die: The length of a clamping die should be three times as long as the diameter of the tube. If a clamp is too short, it will put excess pressure on a short section of the tube, which could result in a deformed product.

Do you need to fit a complex system into a small space?

Our expert technicians and engineers excel at providing custom tube bending solutions. Contact us today to find the right tube bending solution to your business needs.

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