Probe Into Water Content And Ph Value Of Paper
Basic raw material of paper plant fiber, usually subdivided into two types of wood and non wood. Most Paper Are caused by wood fiber, which is due to the various parts of wood, have a lot of fiber, and its costs are cheaper. However, other than in the selection of wood, some paper is caused by non-wood fibers, such as bagasse, reed, rags and so on. Different materials will affect the paper have different chemical properties. The following paper will be on the water content and acid tendons of both, to discuss with you.
Water content of paper
Usually water content of paper is based on the weight of moisture content in the paper, and paper weight as a percentage. The water content of normal printing paper, about 4 to 8%, according to this proportion, one ton of paper, about 40 ~ 80 kg of weight of water.
Paper how many Baxian water is a very important issue. The water content of the paper, whether too much or too little effect on the printing and how many will be affected. Too little water, paper is easy to become brittle, and very easy to produce in excess of electrostatic printing press on; but the paper too much water, nor is it a good thing, because it will not easy drying printing ink. However, relatively speaking, the amount of water, the impact of the printing is fairly small, and its greater impact paper itself, the paper tensile strength, flexibility, folding endurance, will be the changes in the sky due to changes in water content .
Mentioned earlier, Papermaking The basic raw material is vegetable fiber. Plant fiber with a hydrophilic, is a hydrophilic material. All original material hydrophilic, has a characteristic is to use water as the medium to combine. That is to say, the pressure to squeeze the paper fibers alone, the loss of water for reconciliation, will not end with the fiber, resulting in the paper. But this does not mean that more water, fiber will end more closely, the so-called extremes meet, fiber bonding strength, water relations and cooperation as a bell curve (bellcurve), assuming a certain amount of water increased, the paper structure will become loose, fiber bonding strength began to decline, affecting tensile paper.
Conversely, too little water on the paper are also affected. Because too little moisture, the paper becomes too rigid, brittle and are easily made, is also easy to slip between fiber and greatly reduce the flexibility of paper and folding. So the paper to play its best performance, we must properly control the moisture content of the paper.
However, we also need to take to the air humidity. When the paper of the fiber is exposed to air, it will naturally absorb the moisture in the air, how quickly absorbed, depending on the humidity and temperature may be; and if the air was very dry, then paper in the water, it will in turn drain in the air. The paper will absorb the water, or will the loss of water, is based on the paper and air relative humidity. If the water content of paper with the same water content of the air, then to balance the water, the structure of the paper not because of the humidity and then Jiu change. Different paper, under different relative humidity, there is a corresponding balance of water, but even in the same humidity, the paper will be different in different water balance. The more a hydrophilic paper, paper moisture, the higher the balance, and vice versa.
Method to measure the moisture is not complicated, a simple explanation, is to test the samples into the 100 ~ 105 ° C oven for to [constant weight] (Huan weight mean it is twice the amount of weight The sample weight difference in the two ten thousandths of age), then the following formula:
X = (m1-m2) / m1 × 100%
X: sample moisture content (%)
M1: the quality of the sample before drying
I am China Computer Parts writer, reports some information about compound bow manufacturers , orange county chopper merchandise.
Processing your request, Please wait....
