Kalanderoinnin

Kalanderoinnin, often referred to as calendering, is a mechanical finishing process used primarily in the paper and textile industries to improve the surface properties of a material. It involves passing the material between a series of heated rollers, known as calenders. The pressure and heat applied during this process can alter the material's thickness, smoothness, gloss, and density.

In papermaking, calendering is crucial for producing smooth, uniform paper suitable for printing and writing. The process can enhance the paper's brightness and reduce its porosity, allowing ink to sit on the surface rather than soaking in. Different types of calenders, such as machine calenders and supercalenders, offer varying degrees of surface treatment, with supercalenders employing alternating layers of hard and soft rolls to achieve a higher gloss finish.

In the textile industry, calendering is used to impart a smooth, lustrous finish to fabrics. It can also be used to emboss patterns onto the material or to compress fibers, affecting the fabric's drape and texture. The heat and pressure can permanently set certain finishes, making the calendering process a key step in the production of materials like sateen and damask. The specific settings of temperature, pressure, and roller speed are carefully controlled to achieve the desired outcome for each material.