Finding the right polyurethane tubing part 1 – resistance to envirinmental influences
In general, polyurethane tubing is pretty durable in various environments. Nevertheless, the experienced eye sees it over and over again in practice: Tubing gets used in a completely unsuitable specification for the purpose. That not only creates frustration, it is expensive and last but not least unsustainable as well. Hence, our goal at PAPUREX is to find the perfect polyurethane tubing for all customer applications.
This post series provides an overview of the most relevant topics for this. The series consists of the following parts:
- Polyurethane resistance against environmental influences
- Working pressure and bursting pressure
- Flexibility – the minimum bending radius
- The Pricing of polyurethane tubing
Starting with the resistance of polyurethane against environmental influences:
Temperature resistance of polyurethane:
The temperature at which polyurethane tubing is used, influences almost all of its characteristics. That is because polyurethane is a so-called thermoplastic. Thermoplastics deform within a certain temperature range. Nothing else contributes to its manufacturing when the tubing comes into its form for the first time.
Does the intended application include high temperatures? Then it could make sense to use a harder polyurethane variant. Otherwise, the tubing could become too unstable in the heat. In contrast, in a cooler environment, a softer variant could be more favorable, so that the lines do not become too brittle. The various polyurethanes offer resistance against a wide range of temperatures – finding the right one for each application is the real deal.
Resistance of polyurethane to UV-radiation
If polyurethane tubing gets exposed to UV radiation during its application, negative effects can occur when the wrong tubing type got used. One of the rather harmless consequences is bleaching out. Certain material types contain their color better than others under UV stress. Much more important is the potential loss of mechanical properties. Certain polyurethanes become brittle under UV stress faster than others. Of course, that has an impact on their pressure resistance and flexibility. Thus, it is crucial to choose a resistant variant if the tubing’s applied outdoors or under artificial UV lighting.
Resistance of polyurethane to abrasion
If the tubing gets inserted with moving parts, friction against other materials can become a critical factor for its longevity. Some polyurethanes are very robust and abrasion-resistant. These can even be used with drag chains without significantly shortening their life cycle.
Water and microbe resistance of polyurethane
Basically, most polyurethane tubes are resistant to hydrolysis to a certain degree. Hydrolysis is a technical term for the dissolving of chemical compounds in water. There are differences in quality. Thus, only resistant polyurethane tubes should get used for applications with water. Besides hydrolysis, the usage of water leads to another problem: microbes. Microbes attack the surface of many plastics, and so they do with polyurethane. Fortunately, there are variants of polyurethane that are resistant to microbes. Polyether-based polyurethanes are predestined for usage with water.
Resistance of polyurethane to chemicals
Admittedly, resistance against chemicals does not belong to the strengths of polyurethane. Many chemicals such as chlorine, acetone, isopropanol, or different oils can attack its surface. Nevertheless, there are some special forms of the material that are suitable to get used together with many chemicals.
Resistance of polyurethane against environmental influences- conclusion
Generally speaking, there is a polyurethane variant with good resistance against almost any environmental influence. Hence, it is necessary to think about the purpose of the tubing and what it has to endure beforehand. Five of the most common circumstances, that can attack the material are:
- Extreme temperatures
- Water and microbes
Ideally, you contact your favorite manufacturer right now and find the perfect solution for your case before the application.