1.How is flatness error measured?
Many well-known processing companies (such as Daming International) use flatness (usually referring to the height of waviness or warping at any position on the sheet surface) as an internal quality control standard when unwinding conventional cold-rolled coils, and can control it to within 1 mm.
2.How is the flatness per square meter measured?
Some high-precision leveling line equipment manufacturers specify that the flatness error should not exceed 1.5 mm within a one-square-meter area.
3.How is diagonal error measured?
For small pieces of board material cut to specific dimensions, high-precision machining can control the diagonal length difference to within 0.5 mm or 1 mm, which is also an important indicator for measuring the squareness of the board material.
4.What are the key factors affecting flatness?
The core function of the equipment: The core of the leveling line is the leveling machine. It typically consists of multiple sets of staggered rollers that repeatedly bend and roll the sheet metal to release and eliminate the internal stress (i.e., "curling memory") formed in the coiled state. The number, precision, and adjustment capability of the rollers directly determine the final flatness.
The original state of the material: If the cold-rolled coil itself has severe edge waviness, center waviness, or rib waviness, although the leveling process can improve it, it is difficult to completely eliminate it, which directly affects the flatness of the final product.
Differences in operating techniques: Experienced operators will precisely adjust the leveling machine's reduction, tension, and other parameters according to the thickness, material, and shape of the incoming sheet to achieve the best flatness.
5.How to control the flatness after cold-rolled coils are unrolled and leveled in a modern machining center?
In modern processing centers, controlling the flatness fluctuation of the entire sheet to within 1 mm after cold-rolled coils are leveled is an achievable high-quality standard. This already meets the stringent requirements of most industries such as home appliances, building materials, and light industry.
If you have very high requirements for flatness, it is recommended that you clarify your specific standards with the supplier when placing the order (e.g., "flatness requirement ≤ 1mm"), and choose manufacturers with high-precision imported or domestically renowned brand leveling machines for processing.