In 2025, we officially introduced a new four-corner pressurized polishing solution designed specifically for MMC fiber polishing: the Bulls-3900 fiber optic polisher equipped with the MMC/APC-36KZ, MMC/APC-24KZ, and related dedicated fixture series. The core of this solution lies in the adoption of an innovative, isobaric adjustable four-corner pressurized polishing mechanism, establishing a new performance benchmark for polishing quality in multi-fiber optical connectors.
 

Challenges
MMC connectors achieve a smaller form factor and higher-density routing while maintaining the same connection efficiency as MT connectors. However, this miniaturized structure introduces unique polishing challenges. In center-pressurized polishing systems, the inevitable installation clearance between the fixture and the equipment limits further improvement in positioning accuracy and structural stability. Meanwhile, existing four-corner pressurization solutions either lack automatic pressure balancing or adopt a center-lifting pressure adjustment mechanism, both of which present limitations in process flexibility and long-term structural reliability.
To address these issues, the Bulls-3900 Fiber Optic Polisher employs a four-corner pressurization mechanism with precisely coordinated pressure control across all pressure points, ensuring uniform load distribution on the MMC connector end-face. The accompanying quick-locking polishing fixtures further resolve common challenges found in traditional fixtures, such as unstable positioning and uneven clamping pressure.
This solution overcomes the limitations of conventional center-pressurized approaches when applied to miniaturized connectors. Through zoned pressure control to ensure balanced force distribution and a precision alignment interface to mitigate clamping deviation caused by reduced positioning reference surfaces, the system significantly enhances polishing accuracy and process stability, providing a reliable foundation for high-precision MMC connector manufacturing.

Solution Architecture and Key Advantages
1) Core Advantage: Four-Corner Pressurization for Precise and Efficient Control — Latest Patented High-Precision Isobaric Pressure Regulation
The core of the Bulls-3900 Fiber Optic Polisher lies in its innovative four-corner pressurization mechanism. This technology integrates high-precision isobaric pressure adjustment with a proven closed-loop control system, enabling synchronized, uniform, and stable pressure distribution across all four pressurization points. By doing so, it fundamentally minimizes the adverse impact of cable pulling, variation in buffer coating thickness, and other instability factors that can affect the polishing process.
This approach directly improves critical polishing metrics such as 3D interference values and end-face angular parameters, which are essential for high-density data transmission. When equipped with our dedicated quick-locking polishing fixtures—protected under structural patent No. 2025209846349—the solution significantly enhances polishing quality and efficiency while reducing operator-dependent variation.
The system supports up to 50 customizable polishing programs with fine-grained pressure sequencing control, enabling it to meet the latest manufacturing requirements for MMC and SN/MT connectors. As a result, every connector achieves consistently excellent end-face performance and optical transmission reliability.
  

2) Dedicated Fixtures: Stable, Efficient, and Production-Proven
The MMC/APC-36KZ and MMC/APC-24KZ dedicated polishing fixtures serve as core components of the Bulls-3900 system. Utilizing a high-precision alignment structure, these fixtures effectively control ferrule deformation during clamping, ensuring consistent end-face geometry and stable polish-out dimensions. In actual high-volume production environments, they demonstrate excellent repeatability, tight 3D parameter concentration, and reliable interference performance. The fixtures have successfully passed rigorous process validation by multiple customers and fully meet the technical and performance requirements for high-consistency polishing.
Featuring a multi-position fixture layout, the series supports rapid, continuous production with straightforward loading and unloading procedures, significantly improving polishing efficiency and operational convenience. Users may flexibly choose between the 24-position configuration (optimized for single-ferrule pressure control) and the 36-position configuration (optimized for high-throughput batch processing), enabling better alignment with different production capacities and process needs.

3) Market Feedback
Based on the four-corner pressurization polishing solution for MMC connectors, the Bulls-3900 polishing system, when used with the dedicated fixtures, has achieved significant results at multiple customer production sites. User feedback indicates that the system enables a breakthrough improvement in polishing accuracy through isobaric four-corner pressure regulation, resulting in a substantial increase in end-face interference pass rates and industry-leading consistency in 3D parameters.
The intelligent control system supports multiple stored process profiles and permission-based management, making product changeovers more efficient while enhancing process traceability and control discipline. In addition, the soft-start and soft-pressurization functions effectively prevent fiber end-face impact, greatly reducing defect rates.

We are deeply engaged in the development of optical fiber polishing technologies and are committed to supporting complex and advanced manufacturing processes. If you encounter challenges in polishing special-type connectors or new material structures, BULLS is prepared to collaborate with you, leveraging our mature process expertise to deliver highly efficient, customized polishing solutions.