What knowledge are there about the mirror rollers produced by chrome-plated roller manufacturers?

The mirror-finish rollers produced by chrome-plated roller manufacturers refer to smooth, seamless steel tubes. The key factor determining the appearance of a mirror-finish roller is the chromium coating on its surface. In most cases, the mirror-finish rollers produced by chrome-plated roller manufacturers refer to the electroplated layer applied to the steel, which is usually a bright white. If you look closely, you will notice a slight bluish tint. The thickness of the electroplated coating must be at least 2 mils, or 20 micrometres; otherwise, the roll will not be considered chrome-plated. Below is an introduction to the basic knowledge of mirror-finish rolls produced by chrome-plated roll manufacturers:
I. Industries utilising mirror-finish rolls produced by chrome-plated roll manufacturers
Textile printing and dyeing industry: Calendering of pure cotton, polyester-cotton blends, silk, synthetic fibres, wool and their blended fabrics.
Leather industry: Calendering of artificial leather.
Plastics industry: PVC, ABA, PP, Pt, PC and other plastics.
Paper industry: Surface calendering of various types of paper.
Metallurgical industry: Rolling and pressing of various non-ferrous metals.

II. Manufacturing Process for Mirror-Finished Rolls Produced by Chrome-Plated Roll Manufacturers
1. Component Welding:
Assembly and welding of the inner plate, shaft end, bushing, feed plate, inner tube, etc. The inner tube must have a static balance of within 50g. A rotational line is marked on the inner tube, and flat steel and channel steel are welded in place.
2. Assembly, configuration and welding:
The inner tube dimensions must have a 0.4 mm interference fit with the outer tube dimensions. The two plates are welded at a 15° x 30° angle. The inner tube is ground to remove slag inclusions. The dimensions of the inner tube are checked against the inner diameter of the outer tube. The assembly is heat-fitted into position, and after cooling and contraction, the entire assembly is welded. (Note: 45# steel must be preheated before welding and held at temperature after welding.)
3. Annealing, rough turning, and quenching:
Annealing heat treatment, process adjustment, multiple stress reliefs, rough turning allowance, static balancing; for weights over 50g, it is necessary to calculate deviations and mount the workpiece on a bed.
Quenching: Surface hardness HRC 58°–60°, with no cracking on the roller surface.
4. Finishing turning and rough grinding:
The two shaft ends shall have their centre pin holes reamed; the runout of the two shaft ends relative to the roller surface shall be less than 0.05. The machining length shall comply with the dimensions specified in the drawings, with an outer diameter allowance of 0.5–0.6. Grind the support rings to ensure bracket positioning, and grind the roller surface dimensions to Ra 0.5 in accordance with the drawings. The offset between the two shaft ends and the roller surface shall be less than 0.02.
5. Dynamic Balancing, Electroplating, and Fine Grinding:
Dynamic balance to G40. Seal the ventilation ports; perform a pressure test to ensure no leakage, followed by a hydraulic unblocking test. Apply a hard chrome plating of 0.15 mm thickness uniformly on one side, free from defects such as pinholes or flaking. Fine-grind both shaft ends; the runout of the two bearing roller surfaces must be less than 0.01, with a surface roughness of 0.8. Grind the gears on the other shaft ends to within the tolerance range.
6. Sanding and fine-grinding:
Grind the roller surface using a disc grinding machine, inspecting for defects such as water ripples, spiral marks, pinholes or burrs. Mount on a polishing machine and polish the roller surface to a roughness of Ra 0.01–0.005 (surface finish grade 14) to achieve a mirror finish. The hardness after chrome plating and polishing is HRC 62°.
III. Use of Mirror-Finished Rolls Produced by Chrome-Plated Roll Manufacturers
Firstly, a light-duty lifting frame should be installed between the uncoiler and the re-coiler. The light-duty lifting frame is fitted with a rear-view roller. Guide rollers and distribution rollers are mounted on the frame in the feed direction of the mirror-finished roll. A cooling roller is mounted on the light-duty lifting frame in the direction of the mirror-finish roller’s extension. The light-duty lifting frame is fitted with one or two pressure rollers that work in conjunction with the mirror-finish calendering roller. Support rollers and a web-guiding device are mounted around the periphery of the pressure rollers. Embossing rollers and felt rings are wrapped around the support rollers and web-guiding device, and pressure adjustment mechanisms are provided at both ends of the pressure rollers.
This calendering unit is primarily used to iron the surface of artificial leather, thereby improving the surface grade of the finished leather, enhancing its gloss and brightness, and creating an effect where the raised areas of the leather’s pattern appear bright whilst the recessed areas remain less so. A large-diameter mirror-finished heating roller is employed to sandwich the artificial leather between the mirror-finished roller and the pressure roller within heat-resistant felt. The surface finish of the artificial leather is adjusted by regulating the pressure, temperature and ironing time applied to the material.