Automatic cartoning machines are fully compatible with duplex board with grey back (coated duplex grey board). Thanks to its superior bending stiffness, excellent compressive strength, and notable cost advantages, grey board is one of the most mature and widely adopted substrates in automated packaging.
In practical production, due to variations in layered fiber structures, the hardness and springback resistance of grey board impose specific mechanical requirements on carton-erecting suckers, folding push blades, and tuck-in guide tooling. Understanding the mechanical response characteristics of grey board under automated conditions is essential for matching and manufacturing custom precision mechanism parts.
1. Grammage Adaptability & Carton Erecting Mechanism
Automatic cartoning equipment typically handles grey board ranging from 250 g/m² to 600 g/m². Higher-grammage grey board offers higher structural rigidity for the finished carton, but it also creates greater springback force along the score lines. If the erecting mechanism lacks rigidity or the opening angle is improperly configured, carton jamming or rebound distortion can occur at high speeds.
To address the opening resistance of varying board grammages, Hansheng Automation custom-machines high-rigidity carton-opening blades, suction distributor linkages, and magazine separation fingers based on customer engineering drawings. We utilize high-strength aviation aluminum (e.g., 7075-T6) or wear-resistant tool steel for precision CNC milling, ensuring parts resist cyclic rebound shocks without deflecting and guaranteeing smooth, accurate opening for heavy-weight grey board.
2. Surface Coating & Friction Control on Guiding/Conveying Components
To improve aesthetic appeal and print protection, grey board surfaces are commonly treated with film lamination, varnishing, or UV coating. While these finishes enhance moisture resistance, they alter the surface friction coefficient. Suboptimal surface finishes on conveying channels can cause slippage or scratch marks on glossy cartons.
We provide custom precision machining for low-friction conveying guides, profiled support rails, and lateral carton hold-down bars based on customer drawings. We deliver versatile surface treatment options-such as mirror polishing, low-friction PTFE (Teflon) coatings, and hard anodizing-to balance contact friction, ensuring laminated grey board cartons travel smoothly at high speeds without surface abrasions.
3. Die-Cutting/Creasing Accuracy & Precision Fit of Flap Tucking Tooling
The multi-ply structure of duplex grey board is sensitive to die-cutting depth and creasing rule width. At flap tucking and sealing stations, minor misalignments between folding tooling and carton creases can cause corner cracking, ply delamination, or incomplete tongue insertion.
Hansheng Automation utilizes precision wire EDM and CNC profile grinding to manufacture custom tuck-in guides, folding plow plates, and pneumatic sealing pressing heads according to customer prints. We maintain component tolerances within ±0.005 mm using high-grade tool steels (e.g., DC53, SKD11) or tungsten carbide, combined with vacuum heat treatment (HRC 58–62), ensuring tooling edges preserve their sharp geometry and high wear resistance over millions of continuous folding cycles.
4. Economic Benefits & Custom Component Manufacturing Support
Compared with virgin wood pulp solid bleached sulfate (SBS) board of equivalent caliper, grey board delivers unmatched cost efficiency in high-volume, standardized outer packaging. It is extensively utilized across household chemicals, hardware, electronic accessories, dry food, and OTC healthcare packaging.
To assist customers in accommodating thickness tolerance variations across different paper batches, we offer agile low-volume prototyping and precision rework machining services. From micro-adjustable eccentric shafts and width-adjustable infeed rails to custom forming cores for irregular cartons, we respond rapidly to customer CAD drawings, providing dependable manufacturing support for the stable, high-efficiency operation of automated packaging lines.
