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Key points of this article
- • The plasticizer in PVC resin hoses tends to dissolve easily in oil, causing the hose to gradually harden when used oil flows through it.
- • When used to carry oil, it is best to select a hose made of a material with excellent oil resistance to maintain flexibility over time.
- • Because there are various types of oil, it is important to carefully review data and other information when selecting an oil-resistant hose.
Why are PVC hoses flexible?
Polyvinyl chloride (PVC) resin is often used to make general-purpose hoses. PVC resin is hard at room temperature and cannot be bent. However, the PVC resin used in hoses is called “soft PVC resin” and offers flexibility. Soft PVC resin contains a plasticizer that softens the resin, making the PVC hose soft and easy to use even at room temperature.
Features of soft PVC resin include being easy to work with, durable, transparent, and having good electrical insulation.
Figure: Proportion of PVC to
Why does oil cause PVC hoses to harden?
Now, here’s a question for everyone from Hose Adviser PRO.
What is the main reason hoses harden when used to carry oil?
If you’ve paid attention so far, it should be easy to understand.
Select from among A, B, and C below.
A. Because oil penetrates the hose from its surface
B. Because oil dissolves plasticizers in the hose
C. Because oil allows air to get inside the hose
The correct answer is B. Because oil dissolves plasticizers in the hose.
Although the plasticizer additive makes PVC resin flexible and bendable, it actually tends to dissolve in oil. This means that, in hoses used to carry oil, the plasticizer will gradually seep out of the hose and be lost. This is how oil can harden hoses.
The plasticizer dissolves, preventing hardened hoses from returning to their original condition. They must also be replaced immediately to prevent any problems. However, frequently replacing hoses at short intervals increases material and maintenance costs. This means measures must be taken to prevent hoses from hardening due to oil.
How can hardening due to oil be prevented?
Different types of hoses are available for a variety of purposes. When used for oil, it is recommended to select an appropriate PVC hose with excellent oil resistance. For hoses that offer higher oil resistance to reduce replacement frequency, choose fluorine or polyolefin as an alternative material to PVC.
Using oil-resistant hoses helps reduce how fast oil causes hoses to harden, helping to maintain flexibility for longer. This can reduce the frequency at which hoses are replaced, thereby reducing maintenance costs.
Because there are various types of oil, when selecting an oil-resistant hose, it is important to check for any data on oil resistance or other information to determine whether the hose can be used with the applicable oil type. It is also important to check usage conditions such as temperature and pressure to make sure the hose meets the requirements.
■Mineral oil
■Animal/vegetable oil
TOYOFUSSO Hose Series
High oil resistance, heat resistance, and non-adhesiveness
In addition to the above fluorine material, you can also use the link below to view an experimental video of our highly oil-resistant PVC resin HYPER TOYORON Hose. Click the link below to watch.
Oil resistant hose : Oil resistance comparison (difference in bending force)
HYPER TOYORON Hose
Resistant to hardening, highly oil-resistant and durable
That wraps up our explanation on the causes and countermeasures for hose kinking and collapsing due to oil.
For any other inquiries or consultations, please contact the TOYOX Customer Service Office.
When a hose is used to carry oil, certain types of oil may cause the hose to harden rapidly. Because hardened hoses cannot be returned to their original condition and may cause various types of problems, they should be replaced as soon as possible.
In this article, Hose Adviser Pro will explain how oil can cause a hose to harden, and how to prevent this from happening.