What is calendering in paper?
What is calendering in paper?
calendering, process of smoothing and compressing a material (notably paper) during production by passing a single continuous sheet through a number of pairs of heated rolls. The rolls in combination are called calenders.
What is calendering used for?
Calendering is a finishing process used on cloth where fabric is passed between rollers at high temperature and under high pressure. Calendering is used on fabrics such as moiré to produce a watered effect and also on cambric and some types of sateens.
What materials are used in calendering?
PVC, ABS and PS constitute the majority of calendered thermoplastics, although some grades of polyethylene and polypropylene are also used. In a typical calendering process, raw materials are pumped into the storage media in the form of powder or liquids.
Is calendering a permanent finish?
Calendering is not usually a permanent process. Moiréing, embossing, glazing and ciréing, and polishing are all variations of the calendering process. Moiré is a wavy or “watered” effect imparted by engraved rollers that press the design into the fabric.
What is calendering in printing?
The final operation on a papermaking machine, performed to impart to paper a desired finish and to increase the surface smoothness of a paper web. The calender usually consists of a stack of highly-polished steel rollers.
What are the advantages of calendering process?
Advantages of Calendering Process Increase in maximum width of film / sheet. Better control of film / sheet thickness. The properties are more uniform across the width of the product. Better optical properties due to cooling chilled rolls.
What are the types of calendering process?
Different types of Calenders
- Swizzing calendar.
- Chasing calender.
- Compaction calender.
- Embossing calender.
- Friction calender.
- Schreiner calender.
What are the characteristics of calendering?
The technological parameters of calendering may involve the following attributes: the speed of the roll, the output/throughput, the temperatures of the rolls, the separating forces applied to the rolls and the input power of each roll.
Which type of finish is calendering?
mechanical finish
Calendering: Calendering is a mechanical finish essentially used for finishing plain fabrics to impart more lustre. Calendering is performed with sets of rollers revolving against each other imparting smooth to textured effects in fabrics.
What is the disadvantage of calendering process?
One disadvantage is that the process is more expensive to perform which is a major deterrent for many companies. The calendering process also is not as good at too high of gauges or too low of gauges. If the thickness is below 0.006 inches then there is a tendency for pinholes and voids to appear in the sheets.