Casein glue refers to natural pastes of animal origin. It is obtained from casein (milk protein). History does not say who and when for the first time tried to glue objects with products of milk processing. There is information that casein glue was used by ancient Egyptians. Synthesis of paste on a production scale began in Switzerland and Germany as early as the beginning of the 19th century. The process of making biocides is quite simple. Casein glue in a small volume can be made by yourself. So, for its preparation, low-fat cottage cheese is shredded through a sieve and washed with warm water, after which ammonia is added dropwise to the resulting pulp until a gelatinous translucent homogenate is obtained. The resulting joint is used for carpentry.
Casein glue can be synthesized in another way. Lean milk to make it curled, put in a warm place, after which it is filtered. For this, it is better to use filter paper. The filtrate is washed over the water, then placed in a stocking and boiled to remove the residues of lipids. The resulting mass is dried at room temperature. As a result, we get the so-called dry casein. To give it an adhesive properties, water and sodium borate (borax) are added thereto. In industrial conditions, glue from milk protein is obtained from waste products of the dairy industry. In the products of processing skimmed milk add enzyme chymosin (rennet) or acid, resulting in an acid or rennet casein. It is interesting that the synthesis of the glue can use both carbon (organic) and miniral acids, most commonly used lactate acid.
The main components of the above glue 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 products from porcelain, cardboard, ceramics, leather, fabric, plastic, faience, foam. Most often, the above substance is used to join products from wood. Casein glue is a necessary component of plywood, woodworking and cardboard production. The unique properties of bioglues improve the structure of the tree, it is often used in the process of furniture production. Additional components, such as kerosene, copper sulphate, lime, rosin, sodium bicarbonate, and others allow the use of casein glue when working with a variety of wood grades. Furniture with the application of casein leaves goes with the sign "ecological furniture" or "environmentally friendly".
Casein glue can be bought in any special store. This substance is a part of many putty, putty and alkali-resistant paints. The reliability and strength of casein compounds make it possible to use this composition everywhere, where excellent quality is required without much expense.