Vulcanized o-rings are made by cutting extruded cord stock and bonding it together, whereas moulded o-rings are compressed or injection moulded as one piece. Vulcanized o-rings make a great choice for fixed sealing applications where moulded o-rings cannot be used because of:
- Big or non-standard dimensions
- Only a few pieces are required
- The application requires an o-ring immediately and you cannot wait for the usual lead times of moulded production.
COR’s in-house production team can make vulcanized o-rings in any size from a range of elastomers.
How are they made?
Two principal steps are involved to make a vulcanized o-ring. These steps include:
- A continuous length cord is cut as per the required diameter of the o-ring.
- The two ends of the cord are joined together in a mould at a high temperature for a specified period (depending upon the type of elastomer used) by applying a bonding agent. This bonding process results in creating a strong joint at a molecular level.
Are they Suitable for your Application?
The most important question you have to ask yourself is if you need an o-ring for a dynamic application (where moving parts come in contact with the o-ring) or a static application (where there are no moving parts coming in contact with the o-ring). If the o-ring will be subjected to moving parts around it, then one must not consider the use of a vulcanized o-ring for their application. If the equipment or machinery in use is a static one with no moving components, then a vulcanized ring can be the ideal solution for your application. Read about other factors to consider before choosing between vulcanized and moulded o-rings. Contact us for any questions you may have.
Pressure: Up to 1200 psi Max.
Requirements: 24 hours to cure
- As discussed above, vulcanized o-rings are not suitable to handle dynamic applications as a lot of stress is subjected to them due to the moving components.
- If your application needs a large number of o-rings, it would be more cost-effective to use custom moulded o-rings and to create proper tooling for the application. They can get costly for such applications.
Various Application-Specific Options of Vulcanized O-Rings
Vulcanized o-rings are made in various profiles to meet the application-specific requirements. The main features that describe a vulcanized o-ring’s profile include:
- Type of rubber used
- Cross Section (CS) of durometer (aka thickness of the cord)
Cord Length (CL)
It is calculated based on the required diameter of the vulcanized o-ring for the application.
By default, a 90º cut is made where the cord is cut straight from top to bottom. For some applications, a Bevel Cut (45 degrees) angle cut is required. This kind of cut is used to make the joint stronger by having more of elastomer’s surface in contact.
How to find a suitable Cord Length for your Application?
COR has made a simple Cord Length calculation tool, which you can utilize to find the suitable cord Length for your application.
Click here to use our tool.
The common use of Vulcanized o-rings includes:
- To seal flanges or lids (of any shape)
The important aspect is to design the groove properly and then the vulcanized o-ring will work very effectively.
For any application questions, please contact COR’s industry expert team.