Bakelite bushes are vital precision wear-resistant components for gas springs and mechanical equipment. Wear resistance determines service life, while dimensional accuracy affects assembly clearance and running smoothness. During production, factors like raw materials, processes and molds may cause excessive wear, dimensional errors and size fluctuation.

Based on rich experience in thermoset injection molding, this article introduces comprehensive optimization methods to greatly improve wear performance and dimensional stability of bakelite bushes.

1. Select High-quality Raw Materials & Optimize Formula

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2. Adopt high-purity phenolic resin

   Choose industrial phenolic resin with stable molecular structure and low impurity content. Inferior resin has loose internal structure, which leads to poor wear resistance and uneven shrinkage.

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4. Add functional wear-resistant fillers

5. Add glass fiber, graphite or molybdenum disulfide according to working conditions. Glass fiber enhances hardness and compression resistance; graphite and molybdenum disulfide improve self-lubricating property and reduce friction. Keep the proportion stable to avoid rough surface and poor precision.

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7. Control moisture content strictly

   Damp raw materials will generate bubbles and pores inside finished parts, weakening wear resistance and causing expansion after production. Store materials in sealed environment and dry them before use.

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9. Standardize curing agent dosage

   Improper amount of curing agent will result in incomplete curing or over-curing. Under-cured products are soft and easy to wear; over-cured products become brittle and crack easily, accompanied by abnormal shrinkage.

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2. Optimize Injection Molding Parameters

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2. Precise temperature control

   Set barrel temperature at 80-120℃ for preheating only to prevent premature curing. Keep mold temperature stable at 160-200℃ for full cross-linking curing. Fluctuating mold temperature will cause inconsistent shrinkage and dimensional deviation among batches.

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4. Adjust injection pressure and holding time

   Appropriate injection pressure ensures full material filling and higher compactness. Dense structure brings better hardness and wear resistance. Reasonable holding time compensates molding shrinkage and avoids undersized dimensions.

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6. Control curing cycle

   Insufficient curing time leads to loose structure, poor hardness and continuous post-shrinkage. Excessively long curing time makes parts brittle and easy to chip. Set unified curing time according to wall thickness for each production batch.

3. Improve Mold Design & Maintenance

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2. Ensure high mold precision

   As thin-wall precision parts, bushes require molds with high-precision cavity and core. Polished mold surface produces smooth inner wall, lower friction and better wear resistance, as well as consistent overall dimensions.

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4. Optimize venting system

   Gas will be released during bakelite curing. Poor venting creates pores and pinholes, which accelerate wear and cause dimensional anomaly. Design proper vents to exhaust gas completely.

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6. Regular mold maintenance

   Long-term high-temperature operation causes mold wear, dirt and deformation. Clean residual materials and inspect mold dimensions regularly. Repair slight wear timely to prevent mass defective products.

4. Standardize Post-processing Procedures

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2. Constant temperature aging treatment

   Place demolded products under constant temperature for aging to release internal stress, avoid dimensional change caused by stress rebound and improve long-term stability.

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4. Precise deburring and polishing

   Adopt fine deburring process. Excessive grinding will damage product body and change tolerance. Proper trimming keeps accurate assembly size and complete wear-resistant surface.

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6. Surface protection treatment (Optional)

   For bushes working under high-frequency friction, apply special surface treatment to reduce friction loss and extend service life.

5. Strict Inspection & Batch Management

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2. Full dimensional inspection

   Combine sampling and full inspection. Use precision measuring tools to check inner diameter, outer diameter, height and concentricity, and reject out-of-tolerance products.

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4. Wear resistance sampling test

   Conduct reciprocating friction test simulating actual working conditions. Adjust formula and process in time if wear performance fails to meet standards.

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6. Batch traceability

   Record raw material type, process parameters and inspection data of each batch. Trace problems quickly and keep optimizing production standards.

Conclusion

Hitech(HK) International Limited specializes in precision bakelite injection molding. We follow complete quality control systems and provide customized bakelite bushes and guide sleeves with different wear resistance levels and tight tolerances.