Chemical composition verification
Spectral analysis on every batch shows the alloy composition fulfils the material specification and design requirements.
Quality Control and Inspection
Quality Built into Every Screw Element, Barrel, and Shaft—from Material Verification to Final Inspection.
Under high-torque, high-load, high-fill, and heavy-wear conditions, the service life of a twin-screw extruder's screw elements is determined not only by material performance but also by the manufacturing process's stability and uniformity.
For both extruder manufacturers and end users, the actual risk is not a single quality aberration, but rather batch-to-batch fluctuation, dimensional drift, and an untraceable manufacturing process. Lesun, a long-term supplier to equipment manufacturers and industrial customers around the world, operates a whole-process quality-control system that includes raw material, heat treatment, machining, final verification, and delivery, ensuring that every product meets a verifiable, traceable, repeatable quality standard.
01
MATERIAL CONTROL
Raw Material Control
The quality of raw material is the foundation for ensuring the durability of twin-screw extruder parts. All raw materials are sourced from certified, reputable suppliers and undergo thorough arrival examination.
Ultrasonic testing (UT)
Confirms internal quality by finding and rejecting inclusions, shrinkage cavities, and cracks, hence lowering the chance of fatigue failure.
Batch traceability
Each material batch has a unique traceability code, linking material source, inspection records, and subsequent manufacturing.
02
HEAT TREATMENT
Heat Treatment Process Control
Heat treatment directly determines hardness, toughness, and wear resistance; the fundamental step at which element performance is formed. Lesun implements standardized process control and batch verification.
Process monitoring
Strict control of the heating temperature, holding time, and cooling rate maintains the process steady and repeatable.
Metallographic verification
Metallographic verification entails inspecting and grading the post-treatment microstructure to ensure that carbide distribution is uniform and structural integrity meets the design criteria.
Mechanical property verification
Furnace-companion samples from each batch undergo hardness, tensile, yield, and impact toughness testing.
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Metallographic verification
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Pendulum impact test
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Tensile test
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Bending test
03
PRECISION MACHINING
Precision Machining Control
Dimensional precision affects assembly quality, torque-transmission capacity, and running stability. Lesun provides in-process quality control throughout the whole machining sequence.
Standardized operation: each operation follows a standard operating procedure (SOP), with in-process control of important parameters.
In-process assessment of critical dimensions includes spline dimensions, tooth-form parameters, outer-diameter size, concentricity, and symmetry, with validated handover between processes.
Dynamic tool-accuracy adjustment: tool settings are monitored and corrected to maintain machining precision over production runs.
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Height measurement
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Measurement of end-face perpendicularity
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Verticality inspection
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Dynamic tool accuracy compensation
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Hardness testing
04
FINAL INSPECTION
Final Verification and Delivery Assurance
Cleaning
Cleaning is a standardized process that eliminates remaining cutting fluid, metal powder, and machining impurities.
Full-dimension final inspection
Finished parts undergo final dimensional inspection (including ring-gauge, go/no-go gauge, Rockwell and Vickers hardness, CMM, and dye-penetrant flaw detection) to ensure they satisfy drawing and customer assembly standards.
Permanent identification
Laser marking provides each part with a unique identification code for full-process traceability.
Protective packaging
Rust, moisture, and impact-protection methods keep products undamaged during storage and overseas delivery.
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Cleaning
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Dimensional inspection
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Ring gauge inspection
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Rockwell hardness testing
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Vickers hardness testing
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Go-gauge inspection
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No-go gauge inspection
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CMM Inspection
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Dye penetrant inspection
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Visual inspection
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Laser Marking of Screw Elements
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Protective Packaging Control
Quality Traceability
Each part has a comprehensive manufacturing record:
- 01Raw material batch traceability
- 02Heat treatment batch traceability
- 03Key process record traceability
- 04Inspection data traceability
- 05Shipment record traceability