What is casein glue and what is it needed for

Casein glue is considered one of the oldest among adhesives. To date it is unknown when this glue came into practice. But archaeological excavations demonstrate that prehistoric people used animal glue in their activities. Commercial-scale production of casein glue was launched after the first industrial plant started operating in The Netherlands. Due to good adhesive properties, casein glue can be used to bond many different materials. Natural glue was used everywhere for long until it started to yield to synthetic polymers.

What is casein glue

Casein glue is an adhesive containing animal protein. Casein is produced by milk setting. It is produced at specialized dairy plants. Commercial-grade glue is made of acid casein with high adhesiveness.

What does casein glue bond

Casein glue is used in many industrial areas, such as woodworking, furniture making, the chemical industry, printing, packaging and the building industry.

Casein glue is a general-purpose environmentally green polymer capable of gluing chinaware, earthenware, leather and other materials. Casein glue in building and construction work is used to prepare mixes for finishing jobs. The adhesive is added to the compounds of spackling paste, enamels and emulsions. However, casein glue became most popular in the woodworking and pulp-and-paper industries for making plywood and cardboard.

Casein glue is produced as a powder and in a ready-to-use liquid form. The dry mix is diluted with water and applied onto a surface. The product composition already includes all the requisite components to make the gluing of materials easier.

Due to the glue’s natural origin, producers can use the “Green Product” symbol.

For what other things is casein glue needed?

Casein glue is also used for gluing labels onto containers. In this case, the adhesive’s role is secure retaining of a label, back label, neck label and other additional labeling elements.

It is critical that the glue does not show on the container and alter label properties. The label should not fade and discolor under the effect of the glue to keep the products on the shelf looking neat and attractive.

For labeling, Lux LLC offers a line of "Lux-C" casein glues. The adhesives are capable of working effectively even with an intricate paper metalized label and a neck label with a changed configuration at high equipment operating speeds. “Lux-C” is a water-soluble glue based on natural polymers, and stabilizing and preserving agents. The products of this group are non-toxic, environmentally safe and are therefore allowed for use in all food industry segments.

Cold casein glue “Lux-C” for labels has the following properties:

  • Permits working with equipment at a speed of up to 70 000 bottles per hour;
  • Excellent adhesion characteristics and a high setting rate;
  • The glue can be applied as a thin layer onto a surface, making its consumption economical;
  • A label stuck on with casein glue is very resistant to slipping;
  • Satisfactory wash off of glue residue on returnable containers;
  • High resistance to condensate on a bottle.

Glue resistance to condensation is especially crucial during the summer period when products are labeled. In the hot season the air temperature is higher than the product filling temperature and this difference makes condensate appear on the bottle. Due to this, the glue fails to dry in time and the label can come off.

It is worth mentioning that the Lux-X nomenclature of products has a special product for labeling beer containers and champagne. This is the so-called IWR adhesive, which is resistant to "ice-cold" water. This means that when a bottle is dipped into water at about 5 ºС for several days the glue does not swell and keeps the label in place. Just as important is that this product can be readily washed off returnable containers in a bottle-washing machine. Such an adhesive is economical in consumption and effective when operating at high speeds.

“Lux-C” line glues are intended for working with equipment, but also can be applied by hand onto a surface. With application by hand, it is advisable to choose a low-viscosity glue.

Cases when casein glue is needed:

  • To stick labels onto glass containers at enterprises producing liqueur and spirits, beer, mineral water, and canned products;
  • To stick on excise stamps;
  • To stick labels onto metal containers with overlapping when packaging canned products or paints and varnishes;
  • To stick labels onto PET containers with overlapping when producing beverages, drinking water, oils or household chemical goods.

Advice for casein glue use

  1. Use casein glue with an automatic labeling machine with a line speed of up to 70 000 bottles/hour.
  2. Labels can be stuck onto dry and hot containers at up to 70 °С and onto wet and cold ones at as low as 4 °C
  3. Sticking labels with overlapping onto PET and stiff containers.
  4. Do not mix casein glue with starch or semisynthetic adhesives.
  5. Glue is stored best under +5 to +30 °С conditions. Take care that glue does not freeze because subsequent glue defrosting will damage its structure and the product will undergo phase separation. It is also recommended to store the adhesive in tight containers in dark rooms to keep light away from the product.

Labeling is a critical and intricate process. When failing to account for equipment features and glue specific performance, the label can come off fast to spoil the looks of the product.

Follow our recommendations to achieve quality labeling of containers:

  • Control the temperature and amount of glue applied with account for the product brand and the equipment used;
  • Label sticking quality is affected by the label material and storage conditions. Prior to container labeling in bulk, we recommend doing a labeling test run. This will help identify potential problems in time and eliminate them without impairing the production process;
  • Store labels in a ventilated room at an optimal air humidity of 55% and temperature 21 °С.

Where to buy casein glue?

Glue for labels can be purchased in volume directly from the producer Lux-X LLC in Kharkiv. Delivery of orders in excess of 30 kg is free-of-charge across Ukraine. A manager will always choose glue that will be especially suitable for your enterprise, considering equipment and label features. If required, glue will be specifically developed and produced to customer’s production specifications. Professionals will provide overall technical and information support, with a visit to your enterprise. For close consultation on the product range and cost, or to place orders for a glue, call us by the telephone numbers on the Lux-X LLC website in section Contacts or use the call-back option.