How to make fish glue for sticky instruments

Fish glue and gelatin production methods are similar, just take different materials, you can see the production process of gelatin:

1, with gray pool:

For the preparation of pre-impregnated, dipping gray with lime water. Generally round cement pool with mixing. The size of the lime pool is generally 2-5 times the size of the lime dipping pool.

2, pre-soak pool

Generally square or rectangular cement pool, pool height should be less than 1.5 meters, the bottom of the drainage valve, the valve should be set in front of the fence. Designed to soak about 200 kilograms of fresh skin per cubic meter, generally set 2-4.

3, soaking pool

Generally square or rectangular cement pool, the height of not more than 1.5 meters, the bottom of the drainage valve, the valve should be set in front of the fence. Designed to soak about 250 kilograms of fresh skin per cubic meter calculated according to the skin raw materials, can be set up 30-50.

4, neutralization pool

with stirring conical cement or steel container, the upper part is round, the lower part is conical, the inner wall should be made of glass fiber reinforced plastic anti-corrosion. Conical part of the top should be a I hole filter, can be made of stainless steel, in order to make the water flow out of the hides to stay, the design of each cubic meter according to the treatment of fresh hides about 100 kilograms of calculation. Generally set 2-4.

5, simmering pot

Simmering pot for aluminum or stainless steel jacketed heating container, the upper part of the round, the lower part of the cone, the cone is placed on the top of the mesh plate with a long strip of holes, the pot in the center of a perforated tube, in order to facilitate the convection of glue. In order to make the simmering glue when the raw material is not pressed and facilitates the rapid release of glue, simmering glue pot is usually designed into a large diameter and height of small, straight side of the ratio of height and diameter is about 1:1.8-2. 500 kilograms of fresh hides and skins per cubic meter of processing material about design.

6, filter

with rusty steel made of conical filter, cone above the porous sieve plate, sieve plate on the filter cloth, filter cloth placed on top of the filter cotton, filter cotton thickness is generally about 35 millimeters, the upper layer and then put the filter cloth.

The thickness of the filter cotton is 35 millimeters, it is calculated according to each square meter per hour to deal with about 650 liters of light glue liquid.

7, evaporator

Generally rusty steel vacuum concentration pot, such as double-effect vacuum evaporator effect is better than a single-effect evaporator to reduce energy consumption by about 50%.

8, drying room

Long flint type drying room, drying room has a number of trolleys, the car has a multi-layer bottom part of the nylon screen wooden cabinet. In the drying room is equipped with air filters, blowers and heat sinks at the exit end, the air filtered into the blower, heated to a certain temperature and film into the drying room in the opposite direction. The upper part of the inlet end of the drying room should have an exhaust port. The import and export doors of the drying room should be sealed.

Since gelatin drying is generally divided into two stages, wind speed and temperature are different, so the drying room should be divided into two sections to make two drying room.

9, cut the skin machine

Circular knife can be used, horizontal knife joint cut to machine, small factories can also be used to cut the skin manually.

10, freezer

The pouring plate of frozen gelatin generally need a freezer and a brine tank, small gelatin factory ice lolly machine can also be used.

11, pulverizer

General-purpose hammer mill.

Other equipment such as air compressors, storage tanks, vacuum pumps, slurry pumps.

Production process:

I. Alkali process flow block diagram

Hide Lime Hydrochloric acid

Sorting out the pre-preg ash chopping soaking ash retreating ash neutralization and washing

Simmering gelatin Filtration Concentration Preservation Freezing Cutting drying and washing products

Two, the process

1, hide sorting

Hide sorting purposes Is to make the same batch of raw materials of uniform quality, in order to soak the ash time is consistent with the preparation of the same level of gelatin. Leather finishing should pay attention to the following points.

(1) different kinds of hides and skins (such as dry and fresh hides, cowhide and pigskin, yellow and buffalo hides, thick and thin hides, upper and lower section of the skin, scalp, foot skin, etc.) to be separated from the different parts of the skin (buttocks, back, abdomen) should be divided into processing.

(2) Degreasing: If there is more oil on the fresh pork skin, it should be scraped off with a knife.

(3) Hair pig skin should first be soaked in 5% concentrated lime water or 0.5-1% sodium sulfide solution to remove the hair.

(4) Large pieces of skin should be cut into 10-centimeter-wide strips.

(5) Dried skins should be softened before feeding. Salt skins should have the salt removed and be soaked in water to soften them. To prevent bacterial erosion, the water should be changed daily and soaked for about 3 days to soften.

(6) When dry and fresh skins are mixed, the fresh skins should be treated first to avoid deterioration.

After sorting and classifying the hides, the counting is divided into batches and pools for soaking.

2, with gray

Lime first add water to form a thick slurry, generally 1 kilogram of lime with 1.2-1.5 kilograms of water, and then stored for about 15 days, add water to dilute, filter to remove coarse particles, standby.

Lime mixing is carried out in the lime mixing tank, adding water and thick slurry according to the required concentration, and under constant stirring, using a slurry pump to pump the lime water into the pre-soak ash tank or soak ash tank.

3, pre-impregnated ash

Pre-impregnated ash is to make the initial expansion, remove the skin of blood, dirt and odor; in addition, because of the role of the skin and lime to make the skin become hard, cut the skin easier to cut. Pre-impregnated ash in the pre-impregnated pool. Soak the hides in lime water containing about 1% calcium oxide for about 2 days.

4, chopped

The purpose of chopping is to speed up the speed of soaking ash and boiling glue. Generally use the skin cutting machine or manually cut the hides into pieces less than 10 × 10cm2. Cutting the skin should pay attention to cut as small as possible, but should be soaked in ash washing does not lead to the loss of the limit; the same batch of material should be cut to a similar size, so that the effect of ash immersion is consistent.

5, soak ash

The process of soaking the skin raw materials with lime water is called soaking ash, soaking ash is the key process of gelatin production, to improve product quality has a great impact.

When soaking lime, lime water in the annual calcium content is generally controlled at 2-4% (specific gravity 1.015-1.035). When the temperature is high with low concentration, low temperature with high concentration, limewater amount should be about 4 times the amount of wet skin, PH value control in 12-12.5, the most suitable temperature of lime for about 10 degrees, the highest can not exceed 20 degrees. Too high a temperature affects the yield and quality of gelatin.

The length of time for soaking ash is determined by the type of raw materials and product varieties, and the skin's dry and fresh \ thick and thin and soaking temperature. Generally speaking, the soaking time of fresh pig skin is about 30 days, and the soaking time of fresh cowhide, dry cowhide and dry pig split skin is about 2 months. When producing photographic gelatin, the soaking time is longer.

Because in the soaking lime, lime constantly act and reduce the leaching of proteins, organic matter in the water more and more, in order to accelerate the speed of soaking lime must be replaced. In general, the lime water can be replaced regularly according to the number of days in the table below. If the lime water is found to be turbid or yellow, it should be replaced in advance. When replacing the lime, you should first drain the old lime water, wash the leather with water once, and then add the new lime water.

The number of times of lime dipping 1, 2, 3, 4 and above

Time of lime changing (days) 1-2, 4-7, 10-20, 20-25

In the whole lime dipping operation, in order to improve the efficiency of lime dipping and shorten the time, the interval of about 8 hours should be turned over once by compressed air, and it is required to turn over thoroughly.

The end point of digital ash can be determined according to the following four methods.

(1) empirical judgment: according to the expansion of the skin, fluffy, color and so on, through the hand visual with practical experience to determine the end point of soaking ash.

(2) contraction temperature: take a small piece of skin has been immersed in ash, washed with water, will be hung with the thermometer in the same beaker of cold water, slowly heated. When the skin along its longitudinal direction began to shrink the temperature of curling that is the shrinkage temperature of the hides. Untreated fresh cowhide shrinkage temperature of about 65 degrees, soaking gray finished shrinkage temperature down to about 40 degrees.

(3) collagen PH value: the collagen PH value of the hides from 6 to 4.75, indicating the completion of soaking gray.

(4) the speed of glue: take a small sample of simmering glue, according to the simmering time to determine the concentration of glue, such as has reached the specified requirements when the end of the soaking ash has arrived.

Soak ash to a certain time that is to check the shrinkage of the skin temperature, etc., in a timely manner back to the ash, otherwise soak the ash for too long will affect the yield.

After the end of soaking ash, the lime will be discharged, and the skin will be transferred to the neutralization pool.

6, the ash

The purpose of the ash is to remove the lime adsorbed by the hides and other debris (such as dissolved proteins, etc.). Retreating ash in the neutralization pool, under constant agitation, every 30 minutes to change the water, **** about 10 times. Thereafter, change the water every 1 hour. The ratio of raw materials and water should be about 1:6 each time, generally 24 hours to complete the ash.

Whether the retreat is complete, with phenolphthalein test solution to check, take a piece of skin, drop a few drops of phenolphthalein indicator in the top of the skin, when the light red (PH is 9.5 or so), that is to say that the retreat can be the end of the ash, or else you need to continue to return to the ash.

7, neutralization

Neutralization that is the use of acid to remove the skin in the collagen and calcium oxide calcium salts.

First add water to make the leather submerged in water, start stirring, will have been diluted more than double the water hydrochloric acid solution slowly added to the water to maintain the PH of 3 or so, neutralization began, every 30 minutes to add acid, 4 hours later, every hour to add acid, about 8 hours to add the full range of acid, and continue to stir for 4-8 hours.

Neutralization with the amount of fresh pig skin for about 4% of the weight of the wet skin, wet cowhide, dry pig skin with the amount of acid for about 8% of the weight of the skin

8, water washing

Water washing is the use of water to remove excess acid and salts generated during neutralization. Water washing should be stirred constantly, every 1 hour to change the water a number of times, *** change about 10 times. The PH value of the skin after washing should be in line with the requirements of boiling glue, generally about 5.5.

9, boiled gelatin

The raw material skin and water heated together, collagen dissolved in water to gelatin process is called boiling gelatin. Gelatin boiling is one of the keys to gelatin production, the general approach of boiling gelatin by channel. First put a certain amount of water to the simmering pot, heated to the lowest temperature of the simmering gelatin, and then wash the skin into the simmering pot, pay attention to the casting of wells under the stone pine, do not make a ball. Then add water to make the skin just submerged, slowly heating to the surface of the boiling glue temperature. Note that you can not add too much water, otherwise the glue is too thin. Simmering glue PH should be controlled at 5.5. or so.

Boiling glue to a certain time, when the glue up to a certain specific gravity, that is, from the bottom of the glue, re-injected into the water for the next boiling glue, and accordingly increase the temperature, generally higher than the previous 5-10 degrees, the last time you can boil.

Put the glue liquid should pay attention to not put all, and the speed should be slow, so as to avoid grease mixed into the glue.