JPS6122000B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for processing fur raw materials.

More specifically, in the manufacturing process of fur raw materials, the oil and fat contained in the hair and hide of the fur raw materials are removed before tanning to provide fur raw materials with good rehydration properties without sacrificing quality. This is what I am trying to do.

As is well known, crude fur raw materials have substances attached to or contained in them that must be removed before the tanning process, such as fat, dirt, sweat, blood, meat chunks, and rock salt. It varies depending on the type of animal, the place of origin, etc., and is not constant. In particular, the amount of fat deposited differs markedly from animal to animal, and its distribution is also uneven, so uniformly cleaning these raw skins is the most important factor in producing a good product.

Figure 1 shows the conventional pre-treatment steps for tanning fur raw materials. To explain the conventional method based on FIG. 1, the fur raw material 11 is cleaned in a step 12 to remove contaminants that easily fall off, and at the same time it is rehydrated 13, that is, a water rehydration accelerator is added to make it absorb water. The moisture content is 10 to 40
% of fur raw materials are returned to their original rawhide state, softened, and water-soluble contaminants such as salt are removed.
Next, meat lumps, subcutaneous fat, etc. are mechanically removed in a fretting step 14, and fat contained in the skin and hair is removed using an aqueous solution such as soap or a neutral detergent in a degreasing step 15. Tanning 16 is performed to stabilize the skin by blocking carboxyl groups or amino groups, making collagen heat resistant, etc.

However, in this conventional method, the degreasing step 1
There are the following problems in order to perform water rehydration 13 before step 5. That is, since water rehydration is performed while the fat remains in the fur raw material, it is extremely difficult to perform water rehydration uniformly. In other words, parts with a large amount of fat remaining will not be rehydrated sufficiently. Furthermore, if rehydration is performed until that area is sufficiently rehydrated, areas with no or little fat content will be rehydrated excessively, making it impossible to rehydrate uniformly within a single piece of raw hide.

In general, fur that is not rehydrated sufficiently will not be tanned properly, resulting in stiff fur that does not stretch. On the other hand, if the water is rehydrated too much, hair loss or fur rot may occur during the rehydration process. As described above, proceeding to the next step with insufficient or excessive water rehydration is one of the causes of deterioration in the quality of fur products.

Furthermore, in the degreasing step 15, an aqueous solution of a surfactant or the like is used and cleaning is carried out for a long time, which causes the following problems.

(1) Due to insufficient degreasing power and uneven degreasing, a large amount of oil remains in the fur.
In the next tanning process, the penetration of the tanning agent into the fur is insufficient.

(2) Degreasing takes a long time and productivity is poor.

(3) Since a large amount of water is used in the water rehydration and degreasing processes, there is a large amount of wastewater, which places a heavy burden on wastewater treatment.

(4) The process of using soap, neutral detergent, etc. takes a long time, which often causes hair damage, felting, and shedding, and also causes uneven dyeing.

The inventors of the present invention have conducted intensive research to overcome the problems of the conventional techniques that occur due to water rehydration and degreasing with an aqueous solution of soap, neutral detergent, etc. as described above. The present invention was completed based on the finding that the above-mentioned problems can be solved by processing under specific conditions using a solvent. As described above, one feature of the present invention is that a chlorinated organic solvent is used for the degreasing treatment of fur raw materials before tanning. The reasons why such chlorinated organic solvents have not traditionally been used to clean fur raw materials are: 1. The history of degreasing with chlorinated solvents is short, and the history of solvents that are particularly well suited for cleaning fur is short. I had never thought of using a chlorinated organic solvent.

2. The optimal treatment conditions and appropriate process when using chlorinated organic solvents were not discovered.

3 Appropriate machinery for using chlorinated organic solvents,
Equipment, etc. had not been developed.

4 In the past, even if large amounts of water were used and discharged, there were no wastewater regulations and it was not considered a problem.

However, the idea of daring to overcome such problems and use it for degreasing treatment is completely unprecedented before the present invention.

That is, the present invention is characterized in that the fur raw material before tanning is degreased with a chlorinated organic solvent at a treatment temperature of 0°C to 40°C, and then the chlorinated organic solvent is removed from the fur raw material and then rehydrated. This is a method for processing fur raw materials.

The present invention will be explained in detail below.

FIG. 2 is a process explanatory diagram of the fur raw material processing method of the present invention. In the chlorinated organic solvent cleaning step 22, the raw material fur 21 is washed with a chlorinated organic solvent having excellent degreasing ability at a liquid temperature of 0°C to 40°C. After immersing or spraying in a solvent solution, the fur raw material and chlorinated organic solvent are evenly contacted using various physical methods to elute and remove the oils and fats contained in the hair and skin of the fur raw material. At the same time, impurities such as dirt and salt are also removed. Next, the chlorinated organic solvent is removed from the degreased and washed fur by drying at a temperature ranging from 0°C to 40°C. The fur raw material from which the fat content has been removed in this manner can be easily and uniformly rehydrated in the rehydration step 23. Next, after performing fletching 24 and mechanically removing the flesh lumps remaining on the fur,
Perform the tanning process. Furthermore, in the tanning process 25, by tanning using tanning agents such as chromium and alum, the collagen of the fur protein is denatured, resulting in stable fur with high flexibility, heat resistance, and rot resistance. After the tanning process is completed, finishing processes such as dyeing and polishing are carried out.

The chlorinated organic solvent used in the present invention has no effect (damage) on hair or skin, has high degreasing power, high permeability, low toxicity, has no flash point, and can be recovered at low temperatures. It is preferable to use one that has the property of low solvent loss, and specific examples thereof include 1.1.
1-trichloroethane, perchlorethylene, trichlorethylene, methylene chloride, 1, 1, 2-
At least one type selected from the group consisting of trichlor-1,2,2-trifluorethane is mentioned, and among these, particularly high penetrating power, high dissolving power,
1.1.1-trichloroethane and methylene chloride are preferred because of their low toxicity and low boiling point.

The fur raw material applied to the degreasing treatment of the present invention is the fur of slaughtered animals that has been stripped, dried, or salted.The animal type may be any animal that has fur, and there are usually more than a dozen types. but,
Specific examples include mink, sheep, lamb, fox,
taneki, weasel, rabbit, sable, raccoon,
One of the features of the present invention is that it can be applied to mink, sable, fox, and marten, which are particularly expensive raw materials for fur.

The degreasing treatment in the chlorinated organic solvent cleaning process of the present invention is carried out by repeatedly compressing the fur material in the chlorinated organic solvent solution, applying ultrasonic waves, foam irradiation, or liquid flow to remove hair and skin from the chlorinated organic solvent. The fat content is eluted and removed by physically or mechanically stirring the solvent and bringing them into sufficient contact.

The repeated compression action is a processing method in which the fur is passed between multistage rolls or in contact with a chlorinated organic solvent in a rotating drum, and the fur is lifted up and dropped midway through, giving a so-called slapping effect. This is a treatment method that involves spraying a chlorinated organic solvent onto the fur or moving the fur itself in the solution.

In addition, the temperature of the degreasing treatment is an important condition for the present invention, and the treatment temperature of the degreasing treatment, solvent removal, and water rehydration is preferably 0°C to 40°C, and if it is below 0°C, the moisture in the fur raw material will freeze. This is not desirable, and if the temperature exceeds 40℃, the skin will become hard and the rehydration property will deteriorate. More preferably, the lower limit is 10° C. or higher in consideration of the solvent's ability to dissolve fat and oil and the dissolution rate, and the upper limit is 35° C. or lower in view of the flexibility of the skin. In this way, the processing temperature of the solvent has a significant impact on the quality of the fur.
It is preferable to carry out the treatment at the lowest temperature possible, and there is an optimal processing temperature range depending on the type of fur.Specific examples of these are shearling 20-35℃, mink 20-35℃.
27℃, fox 20-30℃. Furthermore, considering the cleaning effect, the degreasing rate of chlorinated organic solvents increases in proportion to the cleaning temperature, so it is more efficient to perform the cleaning treatment at a relatively high temperature as long as the fur is not damaged. As an example, mink fur is 1.1.1-
Figure 3 shows the relationship between the degreasing rate and the cleaning temperature when immersed in trichloroethane for 30 minutes.

Next, in the present invention, when fur raw materials are degreased with a chlorinated organic solvent, the degreasing speed of the hair and skin is different, and the hair is degreased in a very short time, but the skin is faster than the hair. It also takes a considerable amount of time. As an example, FIG. 4 shows a graph of the degreasing rate and cleaning time when sheep fur raw material was immersed and washed in 1,1,1-trichloroethane at 20°C. Because the degreasing speeds of the hair and skin are different, if you wash the hair for a long time to fully degrease the skin, the hair will be over-degreased, causing problems such as hair fur. In addition, insufficient degreasing of the skin results in poor water rehydration as mentioned above, and the leather becomes hard and sticky after tanning. In addition, local oil (residual fat) causes "stains" on the glue.

Therefore, it is desirable to select the optimal washing time for each type of fur that satisfies the washing conditions for both the fur and the skin at the same time.The washing time varies depending on the washing temperature, but the usual washing time is 20 minutes to 2 hours. To give you a specific example, sheep fur raw material is heated to 1.1.
When washing with 1-trichloroethane, about 2 hours is optimal. FIG. 5 shows a graph showing the relationship between the degreasing rate and the washing time when sheep fur raw material was washed with 1,1,1-trichloroethane at 20°C.

Next, in the step of drying and removing the solvent from the fur material after degreasing with a chlorinated organic solvent, the drying temperature is one of the important conditions of the present invention, and the drying temperature is from 0°C to 40°C.
is desirable. If the temperature is below 0°C, the moisture in the fur raw material will freeze, which is undesirable, and if the temperature exceeds 40°C, the hydrophilic groups in the skin will be destroyed, resulting in dehydration and loss of water absorption ability. As dehydration progresses further, a phenomenon of fraying may occur depending on the type of fur. In addition, rapid drying above 40°C causes hardening and shrinkage of the skin.

Further, a more desirable drying temperature is 20 to 40°C. If the temperature is lower than 20°C, the drying speed will be slow and the drying time will be long, which is uneconomical. There is an optimal drying temperature range depending on the type of fur; specific examples include 20-35°C for sheep, 20-27°C for mink, and 20-30°C for foxes.

The effects of the present invention are listed below.

(1) Because a chlorinated organic solvent with high degreasing power is used, degreasing can be done uniformly in a short time.As a result, water penetrates into the fur quickly and thoroughly during the water rehydration process, resulting in uniform degreasing. You can get fur with excellent rehydration properties.

(2) As the oil has been thoroughly degreased, local oil will not seep out.

(3) Good quality fur can be obtained with little effect on hair and skin.

(4) There is no hair slip due to excessive water rehydration, so water can be rehydrated thoroughly and quality can be improved.

(5) Degreasing and water rehydration can be done uniformly and thoroughly in a short time, resulting in high productivity and improved quality.

(6) The hair has excellent dyeing properties and is evenly dyed.

(7) The water drying time after tanning can be greatly shortened.

(8) No wastewater is generated as water is not used in the degreasing process.

Next, the present invention will be explained in more detail based on Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 After putting raw material skins of 90 mink (male of type Sahuaiya) with brown skin on the silver side into a rotating drum (diameter 1050 mm x length 500 mm) having many holes,
Rotate at a rotation speed of 35 rpm, and heat the drum at 20°C.
Shower 1,1-trichloroethane, and after 25 minutes, stop the shower, increase the rotation of the drum to 350 rpm, squeeze out the 1,1,1-trichloroethane from the raw material wool, then reduce the rotation speed and heat the drum at 25℃. After drying with air circulation, the mink was removed. After degreasing and drying, the mink's shin surface turned white and its hair was in a straight-lined state. This mink fur is placed in water at 27℃.
After soaking for 12 hours, they were taken out and checked for hardness, and all were found to be very soft and contained sufficient water.
Furthermore, as a result of finishing through the alum tanning process,
The result is mink fur that is highly flexible, has little shedding, and has a glossy coat. A coat made from this mink was worn or stored for one year, and was dry-cleaned several times during that time, but no deterioration, rot, or loss of flexibility of the leather was observed.

Comparative Example 1 Mink raw material skin of the same kind as in Example 1 was placed in a Haspel-type cleaning tank measuring 2 m long x 1.5 m wide x 1.5 m high containing 18°C water and a surfactant, and was rehydrated for 16 hours. As a result of fretting and rehydration for 4 hours, the material came out as a raw material skin that was harder overall than in Example 1 and moreover had difficulty absorbing water. The raw material skin was passed through the same tanning process as in Example 1, and as a result, the overall flexibility was poor, and 11 of the 90 animals shed some hair, and the hair can be seen in microscopic photographs. I was thinking. On the other hand, a large amount of wastewater was generated after treatment, and it was introduced into a wastewater treatment facility.

Comparative Example 2 When 1,1,1-trichloroethane was treated in the same manner as in Example 1 except that the temperature during washing was changed to 43°C and the temperature during drying was changed to 45°C, and the water was rehydrated,
A mink raw material skin with poor water retention was obtained. When this was tanned and finished in the same manner as in Example 1, mink was obtained that was hard and had little elongation, and the ends of the hair were curled.

Comparative Example 3 In Example 1, when cleaning was carried out using 1,1,1-trichloroethane at a temperature of -2°C and drying at a temperature of -5°C, the mink fur was hard after degreasing and washing. Also, water froze in the condenser that collects the solvent during drying, making it impossible to operate for a long time. The degreased mink was rehydrated in the same manner as in Example 1 and passed through the tanning process, resulting in a lot of hair loss and an overall hard finish.

[Brief explanation of the drawing]

Fig. 1 is a process diagram of the conventional method, Fig. 2 is a process diagram of the method of the present invention, Fig. 3 is a graph showing the washing temperature and degreasing rate of mink fur, and Fig. 4 is a graph showing the washing temperature and degreasing rate of mink fur. Graph showing skin cleaning time and degreasing rate,
FIG. 5 is a graph showing the cleaning time and degreasing rate of shearling fur.

Claims (1)

[Claims] 1 Fur raw material is treated at a temperature of 0°C before tanning.
A method for processing fur raw material, which comprises degreasing the fur raw material with a chlorinated organic solvent at a temperature of 40°C to 40°C, and then removing the chlorinated organic solvent from the fur raw material, followed by reconstitution with water. 2. The method for processing fur raw material according to claim 1, wherein the fur raw material is degreased by repeatedly applying compression action, ultrasonic action, bubble irradiation, or liquid flow to the fur raw material in a chlorinated organic solvent. 3. The method for processing fur raw material according to claim 1, wherein the fur raw material is mink, sheep, lamb, fox, raccoon, weasel, rabbit, sable, or raccoon fur. 4 The chlorinated organic solvent is 1,1,1-trichloroethane, perchloroethylene, trichlorethylene, methylene chloride, 1,1,2-trichloro-
The method for treating fur raw material according to claim 1, which comprises at least one kind selected from the group consisting of 1,2,2-trifluorethane.