Road arch wool soaking acid, deacidification (1)
After road arch wool is pickled and deacidified, it needs to go through two stages of drying and curing. Drying is to evaporate water. The wool felt turns the dilute sulfuric acid on the wool fibers into concentrated sulfuric acid. The temperature during drying should be lower than 65°C, so that the liquid content can be reduced to about 15%. In this way, the wool fiber can be heated evenly, otherwise the drying temperature is too high, which will cause the acid in the wool to migrate to the surface and accumulate on the surface of the wool. When the temperature is high, the wool dissolves, which shows that the weight loss of the wool is large and the strength is reduced even disappear.
Roasting is the use of concentrated sulfuric acid at higher temperatures to transform plant-derived impurities in wool fibers into brownish-yellow or black-yellow brittle materials due to dehydration charring. The higher the temperature during baking and the longer the time, the more wool weight loss and the heavier the damage. The baking temperature should be gradually increased, rough wool can be increased to 105-110 °C, while the baking temperature of fine hair can be controlled at 100-105 °C. Baking time should not be too long, depending on the thickness of the wool and the miscellaneous conditions, in principle, the shorter the better. After baking, the moisture content of the wool is required to be below 3%, so that plant impurities are easily charred and crushed.
After the charcoal baking, the cellulose impurities in the wool become crunchy. At this time, the charcoal eliminator should be immediately sent to carry out the charcoal, otherwise the crispy impurities will become tough due to the absorption of moisture in the air. It is not easy to crush and remove "wool is pressed through the groove roller of the crusher, the plant impurities are crushed, and then the mechanical dust and the wind force make the crushed dust separate from the wool fiber.
Neutralized water washed with crushed charcoal contains a certain amount of sulfuric acid. If the acid content is greater than 1.5%, it must be treated, otherwise it will promote decomposition of wool fibers during the placement, showing a strong reduction in strength, color yellowing, and acid-containing wool in the textile processing, corrosion of the equipment. After removing the wool residual acid, it can partially recover the strength of the wool.