There are many parameters that characterize the calender, including the number of rolls and their arrangement, the diameter and length of the rolls, the speed regulation range of the rolls, the speed ratio and production capacity, the minimum thickness and thickness tolerance of the calendered products, and the thickness of the rolls. Transverse pressure and drive power, etc.
Aspect ratio
The length and diameter of the roller refers to the length and diameter of the working part of the roller. This is a characteristic parameter that characterizes the size of the calender.
1. Roller length
The roll length characterizes the maximum extent of the calendered product. Since the two ends need to leave the position of the stopper plate, the effective length of the roller is the length of the roller minus the length of the non-working surface (about 15% of the length of the roller).
2. Roller aspect ratio
The ratio of the length to the diameter of the working part of the roller is called the aspect ratio. The aspect ratio of the roller (or the diameter of the roller) mainly affects the thickness and dimensional accuracy of the calendered product (except for the reducing roller). It is not only related to the performance of the calendered material, the material of the roller and the length of the working part, but also mainly depends on the quality requirements of the calendered product.
3. The relationship between roller diameter and transverse pressure and power, length-diameter ratio and stiffness
The relationship between roller diameter and transverse pressure and power is shown in the figure. The larger the diameter of the roller, the greater the transverse pressure, and the greater the required driving power, which is almost a linear relationship.
The aspect ratio of the roller mainly affects the rigidity of the roller. The figure shows the rigidity ratio of the roller with a diameter of 610mm under different aspect ratios. It can be seen from the figure that the larger the aspect ratio, the worse the rigidity.
4. Determination of roller length, diameter and aspect ratio
The length, diameter and aspect ratio of the roller are mainly determined according to the production process requirements of the product, that is, according to the type of raw materials to be processed, the thickness range and width range of the calendered product, and the calendering speed of the roller (ie, output requirements).
In order to ensure the thickness and dimensional accuracy of the calendered products, according to practical experience in production, the aspect ratio of the rollers should be limited to the following ranges (except for reducing rollers):
For processing soft materials (such as rubber), the general aspect ratio is 2.5 to 2.7. no more than 3;
For the processed hard materials, the aspect ratio is about 2.0 to 2.2.
Standard series of roller length and diameter: φ360 × 1120; φ450 × 1200; φ550 × 1600; φ610 × 1730; φ710 × 1800
