In response to a growing market demand for large sealing applications, Apple Rubber developed the MacrOring®: a large o-ring ranging in size from 2″ to 500″ inside diameter, and cross section ranging from .070″ to 1″. Today’s applications require strong, dependable o-rings that will last in tough environments—outdated slash and glue seals just won’t cut it.
To find out why MacrOrings® are the economical, superior sealing options, here’s four important facts you need to know:
1. Thermobonding Produces Tighter Tolerances
Thermobonding is a manufacturing process developed by Apple Rubber to create large o-rings with greater flexibility. During the Thermobonding process, the joint and proprietary adhesives and cures are molded together to produce a well-blended joint with little to no mismatch and excellent flexibility.
In typical cold bonding methods, glue is used to bond the joint, however in this case, the bond cannot be vulcanized—it needs to be left to dry on it’s own. This method provides little flexibility, so the seal may not fit as well in it’s application. Thermobonding avoids this issue by heating up the mold to approximately 325 to 350 degrees, cutting the material to size, applying non-cured type adhesive to the ends and then vulcanizing with heat and pressure to cure and seal the ring.
2. Quality Inspection Is Critical
Apple Rubber takes quality inspection very seriously. While the Thermobonding process conforms to all ISO 9001 and AS9100 guidelines, there are extra measures set in place to ensure every MacrOring® seal is up to standards. These inspections include:
- Cord Inspection: Full acceptance testing on all cord is performed before it is used. All cord is sampled for durometer, density, tensile, elongation and cross sectional measurement
- Complete Part Inspection: Quality assurance testing is completed after the MacrOring® is produced. Inner diameters are measured with fully calibrated measuring equipment
- Complete Quality Documentation: For high-quality requirements, Apple Rubber can provide all the quality documentation you need, including Statistical Analysis, FMEA, PAPP, Control Plans and compliance to ASTM D2527
3. MacrOrings® Come In a Variety of Materials
Material selection is an important step in designing any large o-ring to ensure the material is compatible with the sealing environment. Apple Rubber offers the most popular materials available on-hand for fast production, however special materials are also available upon request. The most popular sealing materials for MacrOrings® are:
While the Thermobonding process typically uses neoprene sponge cord, we can also apply Thermobonding to medium density, closed-cell sponge cord.
4. MacrOrings® Cut Down Costs
When you need a large o-ring, MacrOring® seals are a cost effective solution for large and small production runs. Apple Rubber reduces costs by applying automatic cutting and measuring equipment, which also results in higher production efficiency. Additionally, Thermobonding eliminates the need for costly tooling and material waste associated with traditional molding techniques.
To learn more about Apple Rubber capabilities, check out our online literature.
Want to talk more about MacrOring® seals?
Contact an engineer today for more information or request a quote.