Bone glue is one of the most widely used animal bonding materials.Because of its bead-like appearance, it is also called bead-like bone glue.Its characteristics are: good adhesion, high strength, less moisture, fast drying, good adhesion and setting, low price and easy to use, especially suitable for bonding and pasting hardcover book enclosures, good results can be obtained.

Bone glue properties

The main component of animal glue is gelatin peptide protein.A kind of bone glue with low purity is called bone glue.Bone glue is a brittle hard solidified body.Collagen is a protein that is insoluble in water. After heating and other treatments, it becomes another form of protein called collagen, which is soluble in hot water and has adhesion properties.

After the film of bone glue is formed, it is very strong and elastic: however, the bone glue is not resistant to water. When encountering water, the adhesive layer will expand and lose its adhesion strength: its corrosion resistance is also poor, and the temperature is too high and the humidity is too high to cause changes.

Bone glue use

① As a binder, it is used for bonding pencils, emery cloth, sandpaper, etc., gluing woodware, binding books, etc.

②Used for printing plate making and metal nameplates and badges manufacturing.Bichromate is added to the bone glue solution, applied to the metal surface and dried. After exposure, an insoluble thin layer can be formed. The part that is covered but not exposed can still be dissolved in water and washed away, so that etching can be used to make printed plates and other products.It can also be used for screen printing.

③Used as an electroplating additive.Adding a small amount of bone glue to the plating solution can brighten the surface of the coating.

④It can be used as a gluing agent and is used in the papermaking and textile industries.After the straw hat is applied with bone glue, it is treated with formaldehyde, which is not easy to deform and waterproof.

⑤It can be used as a coagulant.Bone glue is a kind of animal glue. It is a chain-shaped natural polymer substance. The main component is protein. Its molecular weight is between 3000 and 80,000. It is soluble in water. After being added to water, it mainly relies on adsorption and bridging to promote the aggregation of unsteady colloidal particles.

Production process

The aggregate is crushed to pieces with an average size of 1~8cm, and the bone oil is extracted with organic solvents such as benzene and petroleum ether to reduce the fat content in the aggregate to less than 1%, generally about 0.3 to 0.5%, and then the aggregates are rubbed against each other in a drum to separate the remaining meat and tendons on the surface.Then load it into a bleaching tank, add water and pass in sulfur dioxide gas.Sulfur dioxide dissolves in water to form sulfite, which has the effects of sterilization and acid treatment in addition to bleaching.Sulfur dioxide converts part of the calcium phosphate in the aggregate into calcium dihydrogen phosphate and dissolves in water, which can make osteoporosis easy to extract with water.This process is commonly known as smoked bone in some production enterprises.After sulfur dioxide treatment and washing, it is sent for extraction.The extraction is carried out at a pressure of about 0.25MPa, so the temperature is higher.Extractors are generally divided into groups of 6 to 8, and the extract is regularly flowed in reverse tank by tank.The most concentrated extract is extracted from the newly loaded extractor.The extract was filtered and then evaporated and concentrated to about 50%.After adding appropriate preservatives, it is cooled to form a gel and dried to become bone glue.

How to use

When using bone glue, first soak the bone glue in equal or slightly more water (preferably hot water) for about 10 hours to soften the glue block, and then heat it to about 75℃ to make it a glue and it can be used.The ratio of glue to water should be based on the required viscosity. If there is more water, the viscosity is low and thin: if there is less water, the viscosity is high and thick.When hot gluing, the glue temperature should not be too high. If the temperature exceeds 100℃, the viscosity will decrease due to molecular degradation, and the glue will age and deteriorate.There is a trace amount of precipitation of bone glue in use, so it is necessary to add water and stir as necessary to adjust the viscosity and fluidity.When hot glue is used, the bath method must be used, and the container where the glue is stored must never be directly heated.

Bone glue must be kept at a certain temperature before it can be used. Therefore, when water needs to be added in use, the temperature of the added water and the colloid should be basically the same, and cold water should not be added.Because the bone glue must be maintained at a certain temperature (75℃±10℃), the temperature of the glue will drop sharply after adding cold water, which will cause condensation and blockage, which will affect the bonding effect.When using bone glue, the gluing speed should be fast and uniform, and do not dip too much glue at a time to cause uneven glue layer, penetration, adhesion, glue leakage and other problems.