Industry-wide Bottleneck: A Common Technical Hurdle Awaited Resolution
Each large-size heavy-duty O-ring weighs 1 kilogram, featuring a thick cross-section and large outer diameter. During rubber vulcanization molding, uneven flow of rubber compound and poor clamping force of mold closing easily lead to "edge shrinkage" defects such as material shortage at corners, shrinkage and edge damage.
Previously, similar products across the industry generally suffered from low yield rates, abundant surface blemishes and unstable sealing performance. These issues not only drove up production costs significantly, but also failed to meet the stringent precision and durability requirements for sealing parts applied in high-end equipment including construction machinery, large pipelines and pressure vessels. For a long time, this has restricted the mass delivery of extra-large rubber seals.
Breakthrough via R&D: Multi-dimensional Process Innovation Eliminates Edge Shrinkage Defects
To fully resolve the technical bottleneck of edge shrinkage, the company set up a special R&D task force to conduct parallel research from three core dimensions: mold structure, rubber formula and vulcanization molding process:
Mold Structure Upgrade: The runners and flash gutters of mold cavities were re-optimized, and the positioning & locking structure for mold closing was improved to balance pressure distribution of rubber compound during vulcanization, preventing retraction and voids of compound at product edges.
Raw Material Formula Tuning: The ratio of raw rubber, reinforcing fillers and softeners was optimized to enhance melt flowability and shape retention of rubber compound, lower vulcanization shrinkage rate, and reduce shrinkage defects at the source of raw materials.
Precise Control of Molding Parameters: Vulcanization temperature, pressure and pressure holding duration are accurately controlled in stages. Custom demolding tooling is adopted, and a constant-temperature slow cooling procedure is added after molding to eliminate edge collapse and shrinkage after product cooling.
After hundreds of sample verifications and repeated parameter adjustments, the team finally realized stable full-process production. Finished products are free of edge shrinkage and material shortage with intact and smooth edges. All performance indicators including dimensional tolerance, compression set and medium aging resistance meet standards, and the yield rate of 1kg large O-rings has been greatly improved.
Upgraded Production Capacity to Boost Market Competitiveness in Heavy-Duty Seals
This technical breakthrough means our company has developed exclusive mature manufacturing technology for extra-large rubber seals, enabling stable mass supply of 1kg heavy-duty O-rings. The products are suitable for heavy-load and high-pressure sealing scenarios such as large hydraulic equipment, water conservancy pipelines, mining machinery and large storage tanks. Supported by defect-free molding technology, we can provide customers with sealing solutions featuring longer service life and more reliable sealing performance.
In the future, the company will continue to deepen core technologies for rubber seals, continuously optimize production processes for various large-size and special-shaped sealing parts, and overcome persistent manufacturing difficulties in the industry. Driven by technological innovation and product upgrading, we will supply higher-quality and cost-effective sealing products for domestic and overseas clients, and consolidate our core competitive edge in the heavy-duty seal manufacturing sector.
