Operation of Circular Knitting Machines: Comprehensive Guide

Circular knitting machines are indispensable in the textile industry, offering high efficiency and precision in producing knitted fabrics. Proper operation and maintenance ensure the machine performs optimally, reducing downtime and ensuring fabric quality. This guide provides detailed insights into the operational steps and adjustments for circular knitting machines, focusing on precision measurements, initial checks, and system adjustments.

Precision Measurements and Standards

To achieve high-quality fabric production, maintaining the machine's precision is crucial. The following measurements and standards should be strictly adhered to using a dial indicator or feeler inspection:

1. Dial Flatness (Pingdu):

Standard: Less than 0.05mm.

2. Dial Roundness:

Standard: Less than 0.05mm.

3. Needle Cylinder Roundness:

Standard: Less than 0.05mm.

4. Needle Cylinder Flatness (Pingdu):

Standard: Less than 0.05mm.

5. Co-Circularity Between Needle Plate and Needle Cylinder:

Standard: Less than 0.05mm.

6. Clearance Measurements:

Upper Wall Triangle to Needle Cylinder: 0.15mm–0.20mm.

Lower Wall Triangle to Needle Cylinder: 0.15mm–0.20mm.

Maintaining these precision standards ensures uniform fabric texture and minimizes operational inconsistencies.

Pre-Use Inspection and Primary Adjustments

Before operating the machine, it is essential to conduct thorough inspections and adjustments for safe and efficient use.

1. Motor Drive Check

Procedure:

Once the power is connected, immediately check the drive motor's direction.

Verify alignment with the motor shell tags.

If the motor's rotation direction is incorrect, adjust the wiring in the motor terminal box. In a three-phase system, interchange two phases to correct the direction.

2. Drive Belt Inspection and Adjustment

Procedure:

Check the tension of the drive belt.

Apply a pressure of 1–1.8kg to the belt's midpoint; the deformation should not exceed 3.5mm.

If the belt is too loose or tight, adjust it by:

Loosening the motor seat's fixed screws.

Moving the motor outward or inward to achieve the required tension.

Tightening the screws after adjustment.

Note:

Recheck the belt tension three days after initial operation.

Perform subsequent inspections every three months.

3. Dust Blowing System Adjustment

Objective:

Ensure the fan in the dust blowing system is optimally positioned.

Proper fan rotation ensures that dust is effectively blown away from all corners, maintaining a clean yarn and needle environment.

4. Yarn Feeding Transmission System Adjustment

Procedure:

Fine-tune the yarn feeding system to regulate the yarn supply, ensuring consistency and preventing fabric defects.

Use an aluminum plate for adjustment:

1. Loosen the top nut on the yarn feeding aluminum plate.

2. Rotate the upper cover toward the "+" direction to expand the aluminum plate, increasing the yarn feed.

3. Rotate the cover toward the "-" direction to retract the aluminum plate, reducing the yarn feed.

4. Tighten the nut after adjustment.

Impact:

Proper adjustment of the yarn feeding system ensures accurate yarn transmission and avoids material wastage.

Operational Guidelines for Smooth Functioning

Starting the Machine

Ensure all adjustments have been made and checked before initiating the machine.

Gradually increase the speed to prevent sudden strain on the machine's components.

Monitoring During Operation

Regularly observe the machine's performance, including the rotation of the needle cylinder, yarn feeding consistency, and dust extraction efficiency.

Routine Maintenance

Schedule routine inspections to identify potential wear and tear.

Lubricate moving parts to reduce friction and extend their lifespan.

Error Detection and Rectification

Address unusual noises, inconsistent knitting patterns, or abnormal vibrations immediately.

Stop the machine for troubleshooting to prevent further damage.

Key Benefits of Proper Machine Operation

Enhanced Efficiency

Proper adjustments and maintenance optimize the machine's performance, increasing productivity.

Superior Fabric Quality

Precision in yarn feeding and needle cylinder alignment ensures uniform texture and reduces defects.

Reduced Downtime

Regular checks and adjustments minimize unexpected breakdowns, ensuring continuous operation.

Cost Savings

Efficient use of materials and reduced wear on components lower operational costs.

Operator Safety

Adhering to operational standards and precautions reduces the risk of accidents.

Conclusion

Operating a circular knitting machine requires meticulous attention to detail and adherence to precision standards. Regular inspections, proper adjustments, and maintenance are critical to ensuring the machine functions effectively, delivering high-quality knitted fabrics while reducing operational costs. By following the guidelines outlined above, operators can maximize the machine's lifespan and contribute to efficient textile production.