the base paper is negative confusion

Paper has positive and negative of the points, paper affixed to the paper machine wire section called opposite side, the other side is called positive. Positive than smooth. Because paper is not the same as well as equipment manufacturers of coated abrasives manufacturer requirements are  grinding disc not the same, paper front and back are quite different, not the same as oil absorption, smoothness are quite different, and therefore according to the production requirements of enterprise production varieties coarse grained selection Use positive and negative plant sand. There are paper manufacturers factory marked positive and negative, are not marked, you can use the following methods to determine: the naked eye structurally different sides of the paper can be folded up the complex pattern observed and compared. Another method of the paper placed in an oven dried, to observe the crimping method, often referred to in the opposite side of the curl. 4, the paper temperature gauge. Since differences in paper manufacturing process, the decision paper heat resistance, ordinary waterproof sandpaper 70-80 ℃ to meet production requirements, the use of rosin sizing agent A grade paper or paper produced over if  cutting disc handled 100 ℃, or the drying time is too long paper are prone to brittle, particularly prone to break, breakage phenomena. But the use of Class A paper sizing process production can reach 120 ℃ not crisp. Therefore, the base paper production enterprises to understand the performance, according to different process requirements reasonable control of temperature, so that the proper use, in order to avoid damage due to high temperature substrate, resulting in quality problems sandpaper.
5, the greater the paper tension is not necessarily easy to use. Papermaking process, if we do not rely on chemical additives pulp fiber, its strength is not enough, in order to improve adhesion between the fibers, paper strength enhancing water resistance, usually papermaking pulp or by adding a certain amount of chemical additives. However, if you use this additive will prevent excess resin infiltration, also we often say no oil, the better the pursuit of paper on a misunderstanding tension, only this one indicator does not reflect the quality of paper inside, must be integrated detection of other physical indicators, such as quantitative, tightness, folding, absorbency, water and so on.
 Third, the paper requires a sandpaper appearance quality. Generally speaking paper fortune teller, a color to be basically the abrasive flap disc  same, each batch of special qualities of paper to be consistent, otherwise it will affect the surface color trademark. Two dust can not be excessive, does not allow creases, wrinkles, through the curtain, eyelet, especially various colors of paper can not have a piebald. Three smoothness of the paper should be smooth, felt marks can not be too obvious, both quantitative and thickness to be consistent, otherwise the production is likely deviation. Four volumes ends neat trimming, can not have the break. Five paper core tube intact, and the hardness is better, not too much weight per Roll, generally based on the size specifications of each roll with 300-600kg appropriate. 2, within the quality. First of sand paper should be used 100% softwood kraft pulp production, you can not select the "sandwich paper" on paper papermaking when adding a certain amount of paper between layers of waste paper pulp, and then use a good paste noodles, the production of paper, looks no different with puree .