Different specialty papers have different paper properties and special uses, so there are different performance requirements for the corresponding paper making press felt. Only by understanding the special requirements for felts can qualified felt be produced with targeted measures.
Prevent felt lint: Some special papers that need to be printed, such as wood grain base paper, water pine base paper, etc., have strict requirements for felt lint. Otherwise, the "batt" that falls off the felt will adhere to the surface of the paper sheet, which can easily lead to "missing printing" and "pasting" problems; At the same time, as the "batt" falling off the felt accumulate more and more in the surface adhesive solution, these fine batt are easily adhered to the surface of the paper with the adhesive solution; The paper type that needs to be coated on the surface is prone to linear coating "scratches" on the paper surface due to the fine batt falling off the felt, which are easily trapped between the coating blade and the paper sheet.
No felt marks: The vast majority of special paper requires no felt marks, especially some paper containing anti-counterfeiting watermarks. If there are felt marks, it will greatly affect the clarity of the anti-counterfeiting watermark, and unnecessary felt marks will also seriously affect the appearance of the paper.
Required felt marks: Some papers, such as sketch paper and craft packaging paper, require clear, natural, and beautiful strip-shaped marks on the paper surface, and these marks are mostly produced by striped felts. The mechanically pressed patterns are stiff, too regular, and lack aesthetic appeal, and cannot compare to the patterns produced by striped felts.
The surface of the felt is flat and delicate: This is also the basic requirement of the vast majority of special paper for felts. If the felt surface is too rough, it will inevitably lead to unevenness on the paper surface. Of course, there are some paper types that require a rougher surface, which in turn requires a rougher surface for the felt.
Filter performance and air permeability settings: This performance is crucial for paper making felts. Some special papers, such as tracing paper, have a high degree of tapping, making it difficult for the pulp to filter water. However, some paper types, such as tea bag paper and filter paper, have a low degree of tapping, making the pulp filter water quickly. All of these require paper making felts that are matched with them to have suitable water filtration performance, water retention performance, and anti rewetting performance.
Acid resistance requirements: Some specialty papers are made under acidic conditions, which requires felts to have acid resistant oxidation properties. We need to use some acid resistant raw materials to produce press felts.
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