Application Of Ammonia / Sodium Chloride In Rabbit Fur Dyeing

< p > < strong > preface < /strong > < /p >.

< p > there is a dense scale on the surface of wool fiber. Its hydrophobicity and chemical inertness make it difficult for the dye to diffuse and adsorb.

Therefore, the traditional dyeing temperature is generally high, because only at higher temperatures can the scale of the dried wool scale open and the dye can interact with the fur to achieve the purpose of dyeing.

However, the higher the temperature is, the more serious the damage of wool fiber is. The skin plate tends to shrink at high temperature and lose its elasticity, and its physical and chemical properties are greatly reduced. At the same time, it consumes a lot of energy [1 ~ 3].

In this paper, the pretreatment method of ammonia water is used to peel off some scales of rabbit hair, so that rabbit hair has good dyeing performance at lower temperature.

By comparing the dyeing properties of < a href= "http://cailiao.sjfzxm.com/" > fur > /a > dyeing rate, the optimum conditions for pretreatment of a href= "http://cailiao.sjfzxm.com/" > rabbit hair < /a > were optimized, and the dyeing process was determined.

< /p >

< p > < strong > 1. Experimental part < /strong > < /p >

< p > 1.1 main experimental materials and instruments < /p >

< p > 1. 1.1 the main experimental material < /p >

< p > rabbit skin, laboratory self-made, Jie Li fur blue MB-TNB, fur levelling agent H-GL, weller RR fatliquoring FHL, Beijing pan Bo Technology Co., Ltd., 25% ammonia water (AR), formic acid (AR), Chengdu Kelon chemical reagent, industrial salt.

< /p >

< p > 1. 1.2 main instruments and equipment < /p >

< p > HZS-H water bath oscillator, Harbin East Union Electronic Technology Development Co., Ltd.; FA1004 electronic balance, Shanghai Precision Science Instrument Co., Ltd.; pHS-2C digital pH meter, Shanghai Japan island Scientific Instrument Co., Ltd.; 722 type grating visible spectrophotometer, Shanghai Precision Science Instrument Co., Ltd.

< /p >

< p > 1.2 experimental method < /p >

< p > 1.. 2.1 ammonia water / NaCl pretreatment < /p >

< p > lab made rabbit skin.

The fur was weighed as the basis for the following experimental materials, and the fur was cut into a small skin block (4cm x 5cm) in a conical bottle for pre treatment and contrast test. The pretreatment experiments were carried out at different pH, temperature, concentration and time, respectively.

Then the orthogonal experiment is carried out, and the optimum process conditions are optimized according to the experimental results.

The pretreatment rabbit skin was dyed at 53 C.

< /p >

< p > 1. 2.2 determination of dye uptake [4] < /p >

< p > calculation formula of dye uptake: E% = (1 A/A).

* 100 < /p >

< p > (E: dyeing percentage; A: staining residual liquid absorbance; A).

Dyeing original solution absorbance).

< /p >

< p > 1. 2.3 determination of dye uptake rate [5] < /p >

< p > the dyeing of alkali treated fur and non treated fur was carried out under the same process by using the Jie Li series dye. The dye uptake percentage was measured at intervals of 10 min in dyeing process, and then the dye uptake curve was obtained according to the corresponding time plotting.

< /p >

< p > 1. 2.4 orthogonal test < /p >

< p > according to the previous experimental results, we designed the orthogonal experiment with 4 factors and 3 levels, < /p >

< p > {page_break} < /p >

< p > < strong > 2. Results and discussion < /strong > < /p >

< p > 2.1 the effect of pretreatment temperature on the dye uptake of fur > /p >

< p > with 0.1 mol /L of ammonia, 5 g /L of sodium chloride, and liquid ratio of 20, 30min was pretreated at 20, 30, 40, 50 and 60 degrees Celsius, respectively.

< /p >

< p > with the increase of temperature, the dye uptake is also increased. When the temperature is 50 degrees, the dye uptake reaches over 97%.

This is mainly due to the exfoliation of scales and the swelling of < a href= "http://cailiao.sjfzxm.com/" > Mao < /a > with the increase of temperature.

However, too high temperature will lead to excessive exfoliation of the scales, thus affecting the strength of rabbit hair.

In order to prevent excessive scaling of the scales, the treatment temperature should be controlled at 30~50 C.

< /p >

< p > 2.2 the effect of pretreatment time on fur dye uptake < /p >

< p > with 0.1 mol /L of ammonia, 5 g /L of sodium chloride, 40 temperature, and liquid ratio of 20, 20, 30, 40, 50, 60 min were treated respectively, and then stained with Czech blue, and the dye uptake rate was measured.

< /p >

< p > it can be seen that the dye uptake rate gradually increased with the increase of treatment time before 40 min, and the dye uptake rate began to decrease after 40 min.

This may be because the hydrophilic groups of rabbit hair fibers have been changed over time, thus affecting the adsorption of dyes.

So time should be controlled within 20~40 min.

< /p >

< p > 2.3 the effect of pretreatment ammonia concentration on the dye uptake of fur > /p >

< p > at 5 g /L of NaCl, 40 C, and liquid ratio of 20, 30min was pretreated with 0.1, 0.2, 0.3, 0.4 and 0.5 mol /L respectively.

< /p >

< p > it can be seen that when the concentration of ammonia is 0.1, 0.3 and 0. 5mol /L, the dye uptake rate is gradually increasing.

This is probably because ammonia promotes the hydrolysis of two sulfur bonds and breaks the dyed barrier. At the same time, alkali can clear the grease and sweat on the surface of rabbit hair, change the surface properties of rabbit hair, and promote the adsorption of dye [6].

At 0.2 and 0.4 mol /L, the dye uptake decreased slightly, which may be that some hydrophilic groups have been changed.

In order to prevent the excessive damage of scales and affect the strength of wool, it is advisable to choose 0.1 ~ 0. 3mol /L of ammonia concentration according to the index of dye uptake.

< /p >

< p > 2.4 the effect of pretreatment sodium chloride concentration on the dye uptake of fur > /p >

< p > at 0.1 mol /L of ammonia, 40 C, and liquid ratio of 20, 30min was pretreated with sodium chloride of 3, 6, 9, 12 and 15 g /L respectively.

< /p >

< p > it can be seen that when the concentration of NaCl is 6 g /L, the dye uptake reaches the maximum 95.37%, and then with the increase of NaCl, the dye uptake decreases.

During the experiment, when the amount of sodium chloride exceeds 10 g /L, the dye will have a small amount of precipitation.

So the amount of sodium chloride should be controlled at about 5 g /L.

< /p >

< p > {page_break} < /p >

The orthogonal experiment of < p > 2.5 rabbit hair pretreatment < /p >

< p > comprehensive single factor experiment results, orthogonal experiment was designed, and the above dyeing rate was used as index.

< /p >

< p > we can see that according to the index of dye uptake, the best process of this paper is A3B2C1D1, which is basically consistent with the result of single factor experiment.

From the value of extreme R, we can see that the order of primary and secondary effects of each factor is A > D > C > B, and temperature has the greatest influence on them.

So this paper chooses 50 min, 3 G /L, 0.1 mol /L and 30 min.

< /p >

< p > 2.6 after pretreatment with ammonia / NaCl, the dyeing rate of fur > /p >

< p > the best treatment conditions for alkali treatment have been determined by orthogonal test before. Therefore, we pretreated the fur under the best pretreatment conditions, then stained the treated fur and untreated fur separately at lower temperature, and measured the dye uptake at different times (0, 10, 20, 30, 40, 50, 60, 70, 80, 120 min).

< /p >

< p > it can be seen that the dyeing rate of ammonia / sodium chloride treated fur is significantly higher than that of untreated fur, and the dye uptake has reached a high level at 30 min, and has reached equilibrium at about 40 min, while the untreated fur has a slow dye uptake rate and reaches the dye balance at about 60 min.

This is probably because ammonia promotes the hydrolysis of two sulfur bonds, breaks the dyed barrier and accelerates the dyeing speed. At the same time, alkali can clear the grease and sweat on the surface of rabbit hair, change the surface properties of rabbit hair, and promote the adsorption of dyes.

With the addition of fatliquoring agent, the dye uptake decreased slightly by [6], which may be due to the presence of fatliquoring agent, but the dye uptake began to pick up as time went on.

< /p >

< p > 2.7 comparative experiment < /p >

< p > the dyeing effect of treated rabbit hair at lower temperature (53 degrees) was compared with the dyeing effect of untreated at lower temperature (53 degrees) and the dyeing effect of conventional (68 degrees).

< /p >

< p > it can be seen that after pretreatment, the dyeing rate of rabbit hair at low temperature (53 degrees) reached over 96%, which was close to that of conventional (68 C) dye uptake.

The dyeing rate of untreated rabbit hair at low temperature (53 degrees) was significantly lower than that of conventional (68 C) dye uptake.

This shows that the pretreatment method is feasible and the dyeing effect is good.

< /p >

< p > < strong > 3. Conclusion < /strong > < /p >

< p > (1) ammonia / sodium chloride pretreatment can effectively destroy the scale of rabbit hair, break the dyed barrier, reduce the potential energy of dyeing, make dye easier to diffuse and adsorb, and achieve a lower temperature dyeing.

< /p >

< p > (2) dyeing at the lower temperature (53 degrees) with brine dye, the dyeing rate of rabbit hair treated by ammonia / sodium chloride was accelerated, and the dye uptake percentage reached 96.58%, which was close to that of conventional dyeing (68 C).

< /p >

< p > (3) the main factors affecting ammonia / sodium chloride pretreatment are temperature, time, concentration of ammonia and NaCl concentration.

Under the conditions of this paper, the best conditions for pretreatment of ammonia / NaCl are: temperature 50 C, liquid ratio 20, NaCl 3 G /L, ammonia 0.1 mol /L 30 min treatment.

< /p >

< p > (4) for better dyeing, the rabbit hair after ammonia / sodium chloride pretreatment needs to be neutralized, and the pH of rabbit hair and bath liquid should be adjusted to about 4.

< /p >