Bonnell spring cores remain the foundational mattress inner-spring architecture across global hospitality and commercial residential markets. Achieving maximum plant profitability requires continuous high-speed wire coiling without pitch deformation, automated heat-treating to eliminate internal wire stress, and precision helical wire lacing that locks individual double-cone springs into a rigid, non-skewed matrix.
This technical guide breaks down how Infinity Machinery's automated Bonnell spring production ecosystem resolves these manufacturing challenges. By pairing the IF-B90 High-Speed Computerized Bonnell Spring Coiling Machine, the IF-L Spring Lacing Machine, and the IF-OZL-MM Double Edge Guard Supporting Spring Machine, inner-spring manufacturers establish an end-to-end automated core line capable of producing 90 springs per minute with zero manual wire handling.
Precision double-cone Bonnell spring forming requires exact wire tension control, end-ring knotting, and instantaneous heat tempering. Un-tempered spring wire exhibits elastic hysteresis and permanent set under compression loading. The IF-B90 High Speed Computerized Bonnell Spring Machine automates wire feeding, coiling, knotting, heat treatment, and alignment output at 90 springs per minute.
Equipped with a high-capacity 15 KVA electric tempering station that applies precise thermal energy to every coiled spring immediately after knotting, restoring crystal lattice grain alignment for zero compression sag.
Features a computerized control system with 2.2 KVA swift frame wire payoff that adjusts coiling pitch and end-ring diameters (62-75mm / 75-95mm) dynamically without manual mechanical re-tooling.
Once individual Bonnell double-cone springs are coiled, they must be laced together using continuous helical spring wire. Hand-lacing spring units is slow, inconsistent, and causes core skewing. The IF-L Wire Drawing Spring Machine winds helical wire, feeds springs, and laces top and bottom end-rings into a perfectly square mattress matrix at speeds up to 32 pcs/min.
The perimeter border of a Bonnell mattress receives the highest compression stress when users sit on the edge. Without heavy edge guard springs, perimeter collapse occurs rapidly. The IF-OZL-MM Double Edge Guard Supporting Spring Machine forms heavy-duty M-shaped or M-butterfly edge support springs from 2.8 - 4.0mm thick wire at speeds up to 25 pcs/min.
Formed with heavy-gauge steel wire to produce rigid perimeter arch clips that clip directly onto the border frame and outer Bonnell coils.
Heavy 12 kW motor drive delivers massive bending force required to shape thick 4.0mm spring steel wire cleanly without die wear.
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When steel wire is cold-coiled into double-cone shapes, severe internal torsional stress accumulates in the metal lattice. Inline 15 KVA electric tempering on the IF-B90 momentarily heats the wire to relieve stress, restoring molecular equilibrium so springs retain 100% height memory without sag under body compression.
For standard Bonnell coil wire (1.8mm to 2.2mm), 1.6mm to 1.7mm high-tensile helical wire yields optimal matrix binding strength without adding excess core weight.
Since two IF-B90 coiling machines produce 180 springs/min, a single IF-L lacing machine (operating at 32 pcs/min per lacing row) can lace a complete King spring unit in approximately 3 to 4 minutes, perfectly balancing production flow.
Consult with Infinity Machinery's spring coiling engineers to receive a custom core production layout, capacity simulation, and ROI breakdown.
