What is Hide Glue?

Glue is an intermediate that connects two materials. It mostly appears as a water agent. It belongs to the fine chemical industry.

surroundings

Conditions of use Glue and sealant should be used in a certain environment, and the working conditions have an important effect on the bonding performance. In use conditions, there are stress conditions, ambient temperature and humidity, chemical media conditions, outdoor conditions and so on.

(1) Force situation. When the adherend is subjected to peeling force and uneven peeling force, good toughness rubber, such as rubber glue, polyurethane glue, etc. can be selected; when subjected to uniform peeling force and shear force, hardness and strength can be selected. High glue, such as epoxy glue, acrylate glue.

(2) Temperature conditions. Different glues have different heat resistance. According to different temperatures, different glues are used.

(3) Humidity. Moisture and moisture are detrimental to the stability of the bonding interface and can be said to be harmful and unhelpful. Because the water molecules are small in size and large in polarity, they penetrate and diffuse, and play a role in hydrolysis, which can cause the adhesive surface to break or self-detach, resulting in lower adhesive strength and durability. Adhesive parts require good water resistance, such as epoxy glue, polyurethane glue, etc.

(4) Chemical medium. Chemical media mainly refers to acids, alkalis, salts, solvents, etc., different types of glue, different curing conditions, and different media resistance. Therefore, the glue and sealant should be selected according to the medium to be contacted.

(5) Outdoor conditions. The conditions for outdoor use of adhesive joints are relatively complex. Changes in temperature, wind and rain, and freezing in the sun will accelerate the aging of the adhesive layer and shorten its life. Therefore, under outdoor conditions, the glue should be selected for high temperature curing and good weather resistance, such as phenol-acetal glue, epoxy-butyronitrile glue; seal using silicone sealant.

Two-component polyurethane adhesive

Two-component

Glue viscosity

The viscosity of the glue is measured with a Brookfield viscometer and the unit is "cps centipoise". Glue viscosity readings are generally between 300 and 30,000 cps. In water-soluble adhesives, the solid content does not determine the viscosity of the glue, but the plasticizer, tackifier, etc. in the formula of the glue affect the viscosity value of the glue. In general, the higher the ambient temperature is, "viscosity ", "temperature viscosity ". Water has a viscosity of 1 at 27 ° C.

Glue bonding process

Because there are many types of glue and adherends, the bonding processes used are not exactly the same. In summary, they can be divided into:

Preparation of glue;

Surface treatment of adherends;

gluing;

Allow the gel to evaporate from low-molecular substances such as solvents (only limited to some special glues, and general glues do not need to be allowed to dry);

superimposed pressure;

Remove the glue remaining on the surface of the product (this step can be avoided when you pay attention to the glue application).

Glue adhesive

All media materials that can connect the same or different types of solid material surfaces are collectively referred to as adhesives, and the method of connecting solid surfaces by the adhesive force of adhesives is called bonding or gluing.

Thousands of years ago, humans noticed the phenomenon of bonding in nature, such as crustaceans sticking firmly to rocks. The phenomenon of bonding existing in nature has inspired humans to use bonding as a method of connecting objects. Early adhesives were derived from natural materials, such as rosin used to bind arrows, spearheads, natural asphalt, bone cement, and lime. In the period of long-term use of natural adhesives, bonding technology has not been significantly developed. Until the beginning of the 20th century, the invention of phenolic resin in the United States began. Adhesives and bonding technology entered a new period of development, occupying an important position in human society.

Adhesives play a major role in all sectors of the national economy. For example, it has a wide range of applications in the aerospace industry, the automobile and vehicle manufacturing industry, the electronic and electrical industry, and medicine. Most modern aviation industries use high-performance phenol-acetal structural adhesives. About 400 to 2200 kg of adhesive is required to manufacture each aircraft, and the amount of adhesive used by a single aircraft often represents the technological level of a country's aircraft manufacturing industry. In the electronics and electrical industries, adhesives are mainly used as insulation materials, impregnating materials and potting materials. Most of the adhesives used are products for modified epoxy, phenol-acetal and silicone polymers. In medicine, adhesives based on various acrylate polymers or monomers are widely used, such as bone bonding during bone fracture and osteosynthesis, thoracic surgery, and adhesion of skin damage. Hemostasis is an important application example. ^[5]