1.What does "meeting the standard" mean?
National Standards (GB/T): Standards such as GB/T 15391-2010 "Cold-rolled steel strip with a width less than 600mm" specify clear tolerances for width, camber, and burrs.
Industry-wide Standards: Many downstream industries (such as automotive and home appliance) have their own, more stringent internal control standards.
Customer Contract Requirements: This is the most crucial standard, usually stricter than national standards. For example, a customer might require a width tolerance of ±0.1mm, while national standards might allow ±0.5mm.
A professional slitting plant aims to meet or even exceed the precision standards required by its customers.
2.How does equipment precision affect the accuracy of slitting dimensions?
Rigidity of the slitting machine (slitting machine): The frame must be sturdy and not deform under high-speed shearing and high tension.
Knife shaft accuracy: The blade shaft of the disc cutter must have extremely high radial and axial runout accuracy (typically required to be within 0.01mm). Excessive runout directly leads to width fluctuations and increased burrs.
Guiding device: The parallelism and centering of the inlet and outlet pinch rollers and guide rollers are crucial for controlling camber.
Tension control system: Stable and adjustable winding and unwinding tension effectively prevents strip deviation and vibration, ensuring smooth shearing.
3.How does the condition of the cutting tool affect the accuracy of the slitting dimensions?
The quality and sharpness of the disc cutter: The material of the cutter (e.g., high-speed steel, cemented carbide), the cutting edge angle, and the sharpness directly affect the cutting quality and burr reduction. A dull cutter will produce a large number of burrs and may even tear the edges.
Cutter clearance and overlap: These are the most important process parameters.
Clearance: Precisely adjusted according to the thickness and hardness of the galvanized sheet. Too small a clearance leads to rapid cutter wear and easy chipping; too large a clearance results in large burrs and edge collapse.
Overlap: Ensures a clean and efficient cut without excessive compression.
Cutter installation accuracy: The cutters must be securely installed with accurate spacing.
4.How does process technology affect precision?
Cutting Technique: Experienced cutting technicians are the guarantee of quality. They can quickly and accurately adjust the gap and overlap based on material characteristics, width, and thickness.
Production Line Speed: The speed needs to be matched to the material thickness and tension. Excessive speed may lead to instability and affect accuracy.
Material Characteristics: The properties of the galvanized coil itself (such as substrate hardness, zinc layer thickness, and yield strength) also affect the shearing effect. Softer materials require smaller gaps.
5.How can we ensure that the dimensional accuracy meets the standards after slitting?
Selecting a qualified supplier: Examine the manufacturer's equipment brand, precision level, technical team experience, and quality control system.
Clarifying technical requirements: Clearly state your required precision specifications in the contract or processing order, for example:
Width tolerance: e.g., ±0.1 mm
Burst height: e.g., ≤0.03 mm (can be measured by fingertip touch or microscope)
Sickle bend: e.g., ≤1 mm / 2m length
Edge quality: No burrs, no collapsed edges, no zinc layer peeling
First piece inspection: Before batch slitting, cut a sample and measure it using calipers, micrometers, tape measures, and sickle rulers. Only proceed with mass production after confirming it meets the requirements.
In-process sampling inspection: Conduct regular sampling inspections during production to monitor the stability of precision.