The quality of printing paper and paper disease (below)

2) Streaks: refers to strip marks that are different from paper gloss or color under light irradiation.
3) Gross cloth mark: refers to the imprint of the latitude and longitude lines of the papermaking felt on the paper.
4) Other impressions: Net marks, watermark roller marks, and vacuum roller marks.
Creases and creases 1) Creases: Folds or overlaps in paper sheets to form moiré or creases. Can be divided into dead and sub-folding two.
2) Warping and arching: Warpage refers to the state where the paper is curled on both sides or corners, and the middle is concave; the arching refers to a state in which a large area in the middle or in the middle of the paper is arched, and two sides or four corners are concave.
3) Bubbling and bubble sands: Partial shrinkage of the blistering finger sheet, resulting in protruding foam on the paper surface, and fine wrinkling on the paper surface around the bubble; bubble sand is an arrangement of the paper surface A dense, fine bubble point.
4) Various wrinkles: According to the size and shape of the wrinkles, fine oblique wrinkles, curly wrinkles and so on.
Other paper diseases 1) Rift: It refers to a crack or break in the middle or edge of the paper sheet.
2) The edges of the paper are not neat and unclean: The edge of the paper is not neat. On the one hand, it means that the paper edges cannot be parallel or rectangular after the paper sheet is cut or the edges of the paper are burrs, bends, and twists. On the other hand, it means cutting out the entire selection. After the paper size is uneven or the back-end surface of the rewinder has a phenomenon of "in and out". Unclean paper edges refer to burrs, zigzag edges, incomplete edges, and dirty edges on cut sheets.
3) Hue inconsistency: refers to the inconsistency of the whiteness and color of the same batch of products even with the ream.
4) "Load lace": It means that the edge of the paper, especially the longitudinal edge, loses its flat state, and it is in a curved state that is not in the same plane as the paper surface.
5) Obvious two-sidedness: The gross difference between the two sides of the paper can be seen with the naked eye (except for single-sided offset paper and single-sided coated paper).
6) Incomplete, broken and shredded paper: Incomplete and broken sheets refer to papers with incomplete pages, which have missing corners, lack of edges, broken or only half, etc.; shredded paper refers to the size of paper that is not included in the paper. A small piece of paper.
The appearance quality of paper refers to the quality of paper that can be discriminated only by human senses without using equipment. It can be divided into the appearance quality of the paper itself and the appearance quality of the piece of paper formed by a sheet of paper or a long strip of paper.
No matter what kind of appearance quality affects the use of paper to varying degrees. The poor appearance quality will not only reduce the paper's use value and the printed product yield, but also cause the paper to be scrap when serious. In addition, some serious paper defects in paper, such as hard paper blocks, will also squash the plates and rollers during printing, causing damage to printing equipment. The appearance quality and physical properties of paper are also closely related. For example, papers with apparent seersuckers may also suffer from smoothness and opacity.
The appearance quality inspection of paper should achieve the following three purposes:
Check the quality of the paper. Mainly include: whether the shape of the paper is good, the size is qualified, the packaging quality and the degree of damage.
Master the basic paper quality of paper. Including color, uniform level, flexible tensile, smoothness and cleanliness.
The approximate miss rate of lithographic paper (the percentage of the total number of papers with significant paper disease) was checked.