(2).Fiber Wet Weight Method
This is a rapid method suitable for production for measuring the length of fibers. It is based on the principle that the longer the fiber, the more fibers it can hang on the frame, and the greater the weight. The length of the fiber is indirectly indicated by the weight, with the unit being grams (g). The frame is hung on the pulping degree meter, and the pulping degree is measured simultaneously with the measurement of the fiber wet weight. During this process, the fiber's wetting effect also has a certain correlation with the subsequent usage performance of Polyester Forming Fabric. High-quality Polyester Forming Fabric can better adapt to different wet weights of fiber slurries.
Due to the numerous factors that affect the fiber coating amount, this method is not very accurate and can only be used under the same stable production conditions. By using the comparison method, it can reflect the pulp coating situation and the changes in the properties of the pulp. Because the wet weight method for fibers is simple in instrument, easy to operate and fast in operation, it is widely used. Especially in the paper production scenario corresponding to Polyester Forming Fabric, it can quickly assist in judging whether the pulp meets the forming requirements.
3. Water Retention Value (WRV)
The water retention value of the slurry can reflect the degree of swelling and fine fiberization of the fibers. The swelling and fine fiberization effects of the fibers directly affect the water filtration efficiency and forming quality of Polyester Forming Fabric. The measurement method is as follows: Put a certain amount of paper material into a small glass tube (now it is mostly replaced by nickel mesh). Place the small glass tube in a high-speed centrifuge for high-speed centrifugal treatment, then remove the free water and keep the fibers only with the swollen water. Then take it out, weigh it until it reaches a constant weight, which is the ability of the fibers to retain water.
The water retention value is calculated as follows: Water retention value = (Wet pulp mass - Dry pulp mass) × 100 / Dry pulp mass
4.Screening Analysis
Fiber length is an important indicator for measuring the quality of the pulp. Besides measuring the average length of the fibers, sieve analysis is also conducted to classify the fibers according to their lengths, and to measure the lengths of each grade of fibers and their respective percentages. For example, the content of long fibers can be separated by a low mesh plate, and the contents of fine fibers and impurities can be separated by a high mesh plate. The sieve analysis results can provide a reference for the selection of Polyester Forming Fabric, ensuring that its pore size matches the fiber classification requirements.
Screen analysis is a relatively good analytical method for identifying the performance of the slurry, and it plays an important role in studying the properties of the slurry and the properties of the paper produced. However, the screen analysis method is time-consuming and is not suitable for use in the production site. It is mostly used in research work, especially in the study of the compatibility of the new Polyester Forming Fabric.
5.Specific Surface Area
The beating process causes the fibers to swell and become finer, thereby increasing the specific surface area of the fibers. The size of the specific surface area has a significant impact on the water filtration speed of the fibers, the flocculation situation, the fiber bonding, as well as the strength, transparency, and porosity of the formed paper. These properties directly determine the service life and forming effect of Polyester Forming Fabric. The specific surface area of fibers usually referred to is the area exposed by each gram of dry fiber itself, expressed in cm²/g.
