All kinds of writing and printing papers that are produced from chemical pulps include various coated and non-coated delicate papers that usually have a little mechanical pulps, or completely lack the mechanical pulps, and consist of 5-25% of fillers. According to US Customs Tariff Act, the maximum amount of mechanical pulp is 10%. The chemical pulps of Broad-leaved tree and needle-leaved tree woods are used in these papers.
Suitable strength, high brightness, and proper archival capability (long-term maintenance) are the most important characteristics of this paper. Recently, various high quality and delicate papers have been produced that consist of a rather high amount of mechanical which are made of poplar.
Various papers that are made from chemical pulps are usually produced in a neutral or alkaline papermaking process and provide suitable strength properties for the paper sheets. The neutral paper-making conditions enabled us to use sodium carbonate as the main filler and provided good archival properties for the paper. A high amount of fillers and broad-leaved pulps leads to proper paper formation. Modern used technologies include shoe press that increases the machine speed and the dry percentage of the paper sheet before using the drier. Additionally, recently, slotted sheet-making technology was used to achieve better sheet formation and faster paper drying.
Additive layer manufacturing technology can also provide suitable quality properties for this paper. Today, the surface of uncoated delicate papers is painted or sized using different sizing agents. Coated delicate papers are either directly painted (low-weight coat papers) or first a basic coating is applied with a sizing agent and then the main coat is applied on them. These papers can have even triple coating (art papers). Historically, the uncoated delicate paper was ironed in an ironing machine embedded into the paper machine (built-in ironing machine) using one or two pairs of roller presses. The new technology is moving towards soft ironing. Regarding the various coated delicate papers, today, Preliminary ironing is more considered than soft ironing.
The complementary ironing is performed after preliminary ironing. Various finished opaque papers are soft-ironed commonly continuously in the paper machine and through an ironing machine connected to it and using one or two pairs of soft roller presses.
Delicate papers are available in roll or sheet forms which depends on the final use. Usually, various papers are available for duplication in form of A4-sized sheets and bigger sizes are available for providing posters. The papers used in commercial printing and for preparing forms and catalogs are mainly available in rolls. The delicate paper customers have somehow major differences from mechanical pulp-produced paper customers.
First, in the business space of delicate papers, businessmen play an important role in terms of paper storage and providing services to the end customer. Second, office equipment manufacturers include an important part of these paper customers indirectly and develop new products and enhance their quality.
Usually, office equipment producers test all kinds of papers and issue use permission for a specific kind of paper in their machines. Experts of these companies constantly evaluate the produced paper qualities in the market.