Heald Frame Guiding and Beating-Up Mechanism of Air-Jet Looms: 800 Reciprocations per Minute — SAVI Bearings Provide Quiet, Durable Support for High-Speed Looms

Products used: EPJ wear-resistant sliding bearings + LIN series plastic linear bearings

Application positions: Heald frame guide rails, heald frame side guide blocks, beat-up connecting rod hinges, shedding arm rotary supports

Operating requirements: High-frequency reciprocating motion, fiber dust resistance, low noise, maintenance-free operation, low friction, long service life

Customer Background

An air-jet loom manufacturer producing high-speed air-jet looms with reed widths of 190–360 cm, a maximum weft insertion rate of 1,500 m/min, and heald frames reciprocating 500–800 times per minute. Each loom is equipped with 4–10 heald frames, each with 4 guide points. Hundreds of looms run together in the weaving workshop, making noise and dust the two top priorities of workshop environment management.

After successful adoption, loom noise was reduced by 6 dB, the guide rail maintenance interval was extended to 2 years, and weaving efficiency improved by 5%.

Problem Description

The air-jet loom previously used metal linear guide rails and bronze bushings in the heald frame guiding and beating-up mechanisms, with the following problems:

1. Rapid guide rail wear. The heald frames reciprocate at high frequency of 500–800 times per minute. Metal guide rails wear severely in fiber-dust environments, and the bronze bushings develop obvious clearance after just 3 months. Heald frame wobble leads to unclear shed formation and a rising fabric defect rate.

2. Cumulative noise exceeding limits. With hundreds of looms running simultaneously, the impact noise of metal guide components accumulates, pushing workshop noise above 95 dB — far exceeding the occupational health standard of 85 dB. Workers are exposed to high noise levels over long periods.

3. Difficult and frequent lubrication maintenance. Each loom has 28 guide points requiring manual oiling every month. Maintenance hours consume substantial production time, and lubricating oil splashes contaminate the fabric.

Solution

SAVI recommended LIN series plastic linear bearings for the heald frame guide rails. The all-plastic structure of this product is insensitive to fiber dust, which cannot adhere and form oily sludge under oil-free conditions. The LIN linear bearing achieves a friction coefficient as low as 0.06–0.12, delivering stable low-friction operation under high-frequency reciprocating motion when paired with a hardened steel guide shaft.

The heald frame side guide blocks and the beat-up connecting rod hinge points use EPJ wear-resistant engineering plastic sliding bearings. With an elastic modulus (2,800 MPa) far lower than that of metal, this material naturally dampens vibration and reduces noise, absorbing the impact noise generated by hundreds of reciprocations per minute. The shedding arm rotary supports also use EPJ, suited to low-speed oscillating motion.

Each loom uses a total of 32 SAVI bearings. Because plastic bearings require no lubricating grease, the risk of oil-stained fabric is eliminated while workshop noise levels are substantially reduced.

Customer voice: "Workshop noise has always been our biggest headache — with several hundred looms running, workers had to shout to be heard. After switching to SAVI plastic guide components, the noise of a single loom dropped by 6 dB, and workshop noise on the entire line fell to 89 dB. Workers say the working environment is clearly much better. The heald frames no longer wobble, and the fabric defect rate has dropped noticeably."

Customer Benefits

6 dB noise reduction per loom: Engineering plastic dampens vibration and absorbs sound; entire-line workshop noise reduced to 89 dB.

2-year guide rail maintenance interval: Changed from monthly oiling to 2-year maintenance-free operation; maintenance hours reduced to zero.

Lower fabric defect rate: Stable heald frame guiding and clear shed formation reduce the fabric defect rate by approximately 18%.

+5% weaving efficiency: Fewer fault-induced stoppages; operational efficiency improved from 92% to 97%.

No oil-stained fabric: Plastic bearings exude no grease; fabric cleanliness meets standards.

Dust-resistant without seizure: Dry-running design does not pick up fibers; stable operation in dusty environments.