Why Rubber Tubing Tolerances May Be Different Than Plastic/Rigid Tubing Tolerances

01-18-2013

Why Dimensional Tolerances of Hygenic®, HYTONE™ and HYSYNAL® Rubber Tubing are Wider than Plastic/Rigid Tubing

Even though manufacturing tolerances of rubber tubing are wider than plastic/rigid tubing, rubber can provide product solutions not available in plastic or metal.

“Manufacturing Tolerance” is defined as the difference between the upper and lower limit dimensions of the part. It is usually expressed as a “plus” or “minus” which means the nominal dimension can vary within the “plus or minus” range. For instance, if the manufacturing tolerance on an Inside Diameter of rubber tubing is: 0.250 ID +/- .010, the actual Inside Diameter of the tubing can range from 0.240 to 0.260 and still be considered “in size”.

Why are the manufacturing tolerances of rubber wider than plastic? That is a good question! There are actually a lot of reasons why and here are a few:

• The softer the material, the harder it is to hold very tight tolerances.
• Natural rubber is just that – natural. It will vary from lot to lot and this can affect the ability to hold a specific tolerance from lot to lot.
• Variations in the manufacturing process. Rubber can swell or shrink during the manufacturing process and the amount of swelling and shrinkage cannot always be predicted.
• Rubber and synthetic rubber are compounded with other ingredients to help set off the cure. These other ingredients, or the compound, can affect the ability to hold tight tolerances.

Beyond these factors, the flexibility of the material will limit how well you can measure it. Because rubber is soft and flexible, there is some “give and take” when measuring the ID, Wall or OD of a tube. So deformation due to the measurement method can significantly alter the measured value.

Even though dimensional tolerances for rubber and synthetic tubing are wider than those of more rigid materials such as metal or plastic, we can often develop a rubber product solution that meets a customer’s unique application and the very things that limits the ability to hold tight tolerances (material softness/ deformation) may eliminate the need for tight ranges as the material can conform to the surrounding materials and in-use forces.

Product overview

Natural Rubber

Hygenic Extruded Natural Rubber Tubing - Hygenic’s natural rubber tubing is produced from dry natural rubber. Our proprietary manufacturing process allows us to make tubing with no detectable levels of surface proteins. Because we compound and mix our own rubber, we can offer many different formulations to meet your requirements. We offer a wide variety of standard sizes of natural rubber tubing in amber and black.

HYTONE™ Natural Rubber Latex Tubing – This tubing is produced using a continuous dipped manufacturing process. Using this process allows us to produce a latex rubber tubing product with undetectable levels of latex protein. HYTONE™ latex rubber tubing has superior elongation properties, offers excellent gripping characteristics, can be custom printed, cut to size and packaged to your specifications.

Natural rubber is inherently an environmentally friendly material and is biodegradable. It is harvested from live trees that do not have to be cut down which makes it a renewable resource.

Synthetic Rubber

HYSYNAL® Synthetic Rubber Tubing is a non-latex synthetic rubber tubing product that has been successfully tested to the ISO10993 standard for various medical applications. It is manufactured with less curvature than is usually associated with latex or natural rubber tubing. HYSYNAL® Synthetic Rubber Tubing is latex protein free and bonds easily to plastic fittings.

With our custom formulations, research and development, and engineering capabilities, Hygenic can help find a custom rubber product solution for your company’s unique application. Let us support you from product ideation through realization. Throughout the years, we’ve backed our superior elastic products with a commitment to exceptional customer service, responsiveness and innovation, making Hygenic a rubber industry leader.

Our products are used in so many different and creative ways, the only limitation to how you can use them is your imagination!