Drying And Finishing Operations In Fur Processing

Drying and finishing operations in fur processing

After wet processing such as tanning, dyeing and fatliquoring, it needs to be pferred to the drying and finishing stage of fur.

The main processes include drying, moisture regain, rolling soft, soft hook, grinding, leather degreasing, rinsing, combing, dedusting, refurbishing, measuring and checking.

1. after drying and tanning, the water content of the fur is generally over 60%, and the moisture content of the fur product is 12%~18%.

The wet skin has large plasticity, and the skin fiber is not fixed. It can not be operated mechanically. After drying, the skin fiber structure is stereotyped, so that it can be easily arranged and beautified.

There are 4 commonly used drying methods.

(L) natural drying, laying fur on the ground or hanging the leather on a pole or string, and drying the skin with the natural flow of air.

(2) drying and drying in the drying room or drying channel is equipped with the facilities of adding heat, blower and exhaust. It is not affected by environmental climate, and has the characteristics of fast drying speed and high efficiency.

(3) fixed drying to fix fur on board or frame and then dry.

The moisture content of the skin before drying is controlled at 30%~40%.

(4) rotary drum drying passes through hot air in the drum and rotates side by side to dry. It has the function of rolling soft and drying.

No matter which method is used to dry, the moisture content in the skin should be evenly distributed. After drying, the skin should be laid for more than 12 hours to balance the moisture in the skin.

2., the skin that has been dried up has been regenerated. Because of the need of processing, it needs to reabsorb water. It is called moisture regain or softening.

After drying, the fiber is in a bonding state, the area is contracted, and the skin is stiff.

The purpose of moisture regain is to make the dried fur get the appropriate moisture and become soft, so as to facilitate the process of shovel and soft.

The correct moisture regain requires that the skin should not be dried or floating. The moisture content of the whole skin is uniform. After the moisture regain, the skin board can be pulled out and white.

Water content is most 18%~20%.

Rotary drum reversion method and direct water spray method can be used.

3. soft hooks and soft shedding soft skins are used to make certain mechanical operations on the skin plates with blades, hooks, soft shovels and grinding machines, so that the skin fibers are loose and stretched, and the meat dregs on the skin plates are removed. The skin boards are softened, thinner and lighter as possible by soft shovel and grinding operations.

Four

Degreasing and rinsing are not enough for degreasing large fur, such as sheep, marten, and so on. It is not enough to prepare degreasing before tanning, as the preparation section can only remove grease from the surface, and there is a lot of grease in the leather. If it is not removed, it will affect the use of fur.

In the finishing stage, degreasing is often used in dry cleaning machines.

The skin plate is washed away from the skin after being washed in the detergent solution, so as to further remove the dirt, impurities and greasy matter on the fur, so as to make the finished product soft and plump, improve the elongation and permeability, and increase the gloss of the fur.

The main equipment used for rinsing is grooving.

Technical conditions: liquid ratio is 30 liters / sheets, detergent 4 g / liter, soda 0.5 g / liter, temperature 50 centigrade, time 1 hours, pH value 9.5~10.

5. roll and stretch in order to make the skin plate soft, the hair is loose, flexible, bright and clean, remove the floating color on the dyeing fur, increase the gloss of the fur, and need to roll the fur.

Rolling and stretching operations can be repeated many times.

In order to enhance the rolling effect, the clean sawdust can be added into the sawdust, and some organic solvents such as light gasoline or turpentine can be added to the sawdust.

6. beat the wool on the wool machine, remove the dust, sawdust and so on.

7. carding is usually done on the carding machine, and the combed hair is combed to make the wool go in a certain direction, and at the same time remove sawdust, dust and floating fur remaining in the wool, so that the appearance of the finished product is beautiful.

Careful operation is required to minimize hair loss and not to damage the skin.

8. shearing

It is carried out and used in some low-grade leather imitation leather.

After shearing, the wool is smoothed and reached the required wool length.

9. dust removal is to remove dust from fur.

Ask for fur to shake in the sun without dust.

The cage can be used for dust removal.

The best fur should be dusting by vacuum cleaner.

After the 10. gauge is qualified, the area of the skin is measured to provide basis for the cutting section.

When measuring the skin, the area error should not exceed 2%.