The choice of felt products also has different requirements for raw material composition according to different uses, types and properties. For example, filter felt requires high filtration efficiency and no hair loss when filtering gasoline. Therefore, it is required that there is no dead wool in the mixture, with low impurity content, fine wool fibers, high crimp and good shrinkage. For example, the felt in shoes is used to pad the soles of cotton shoes or to make cotton shoes. Felts are required to have good warmth retention and low price, but the color requirement is not high. Therefore, when choosing the ingredients of mixtures, the color and luster are not taken into account. Black hair and white hair can be produced, usually with various kinds of miscellaneous hair.
Making every effort to reduce the cost of wool fibers generally accounts for 80-85% of the total production cost. Therefore, the determination of the ingredients of the mixture has a great impact on the production cost. On the premise of ensuring the quality of the product, we should select the raw materials with lower grade and reuse wool and regenerated wool as far as possible, which can not only reduce the cost, but also expand the raw material resources and solve the problem of insufficient raw materials for felt.