Casein glue refers to natural pastes of animal origin. It is derived 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 an industrial 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 rubbed through a sieve and washed with warm water, after which ammonia is added dropwise to the resulting slurry until a gelatinous translucent homogenate is obtained. The resulting connection is used for carpentry.
Casein glue can be synthesized in another way. Low-fat milk in order to curdle, put in a warm place,after which it is filtered. To do this, it is better to use filter paper. The filtrate is washed over water, then placed in a stocking and boiled to remove residual lipids.
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 the waste of the dairy industry. The enzyme chymosin (rennet) or acids are added to the processed products of skimmed milk, resulting in acid or rennet casein. It is interesting that both carboxylic (organic) and mineral acids can be used for the synthesis of glue, 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 gluing items made of porcelain, cardboard, ceramics, leather, fabric, plastic, faience, 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-adhesive improve the structure of wood, often used in the production process.furniture. Additional components such as kerosene, copper sulfate, lime, rosin, sodium bicarbonate, and others allow the use of casein glue when working with various types of wood. Furniture using casein paste comes out with the sign "ecological 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. The reliability and strength of the casein compounds make it suitable for use anywhere where excellent quality is required at a low cost.
