Casein glue belongs to natural pastes of animal origin. It is obtained from casein (milk protein).
History is silent about who and when first tried to glue objects with milk processing products. There is information that casein glue was used by the ancient Egyptians. The synthesis of paste on a production scale began in Switzerland and Germany in the early 19th century. The process of making bioglue is quite simple. Casein glue in a small volume can be made independently. So, for its preparation, low-fat cottage cheese is ground through a sieve and washed with warm water, after which
ammonia is added dropwise to the resulting slurry to obtain a gelatinous translucent homogenate. The resulting compound is used for carpentry.
Casein glue can be synthesized in another way. Non-skim milk to put it curled, put in a warm place, and then filtered. To do this, it is better to use filter paper. The filtrate is washed with water, then placed in a stocking and boiled to remove lipid residues.
The resulting mass is dried at room temperature. As a result, we get the so-called dry casein. To give it adhesive properties, water and sodium borate (borax) are added to it. In industrial conditions, milk protein glue is obtained from waste from the
dairy industry. Chimosin
(rennet) or acid enzyme is added to
skim milk products, resulting in acid or rennet casein. It is interesting that for the synthesis of glue, you can use both carboxylic (organic) and mineral acids, most often lactic acid is used.
The main components of the above adhesive are nitrates, inorganic phosphates and calcium caseinate. Milk protein is insoluble in water, changes its structure when interacting with weak solutions of alkalis or acids.
Casein is a phosphoprotein containing a complete set of essential amino acids. Casein glue is effective for bonding products from porcelain, cardboard, ceramics, leather, fabric, plastic, earthenware, polystyrene. Most often, the above substance is used to connect wood products. Casein glue is a necessary component of plywood, woodworking and cardboard production. The unique properties of bio-glue improve the structure of wood, often used in the furniture manufacturing process. Additional components, such as kerosene,
copper sulfate, lime, rosin,
sodium bicarbonate, as well as others, allow the use of casein glue when working with various types of wood. Furniture using casein paste comes with the sign “environmental furniture” or “environmentally friendly”.
Casein glue can be bought at any special store. This substance is part of many putties, putties and alkali-resistant paints. Reliability and strength of casein compounds make it possible to use this compound everywhere where excellent quality is required without any special expenses.