Where is EVA hot melt adhesive used, which is better, EVA hot melt adhesive or PUR hot melt adhesive

EVA hot melt adhesive is generally used in book binding, for binding EVA hot melt adhesive, according to the curing time can be divided into high-speed adhesive and low-speed adhesive. The curing speed of high-speed adhesive is slightly faster, and the curing speed of low-speed adhesive is slightly slower. According to the book, it is divided into offset paper and coated paper glue according to different materials.

According to the different positions of use, it is divided into back glue and side glue. Choose different EVA hot melt adhesives to meet the strength and needs of the adherent to achieve a good bonding result. When using EVA hot melt adhesives, it is necessary to master the preparation procedures before use, such as preheating, temperature, etc.

1. Preheating of EVA hot melt adhesive

useEVA hot melt adhesives

Before the solid glue must be preheated to melt. There are two methods of preheating: one is oil bath preheating.

The other is to preheat with an electric hot plate, that is, to preheat directly in the preheating furnace with an electric hot plate device. The warm-up time is generally 2 hours. When the gel reaches the desired heating temperature and has good fluidity, the glue is released through a thermostatic pipe into a working glue pot with a temperature of 160 180 for glue binding books, etc.

2. Adhesion and adaptability of EVA hot melt adhesive

In the actual production process, the adhesion of hot melt adhesive will be different with the heating temperature, the different materials to be adhered to, the width and depth of the milling back, the thickness of the glue, the running speed of the binding machine, etc., will get different bonding effects.

(1) The heating temperature of the hot melt adhesive

The softening point of hot melt adhesive is generally above 80. That is, when heated to 80°C, the colloids begin to soften and melt. This temperature is only the melting temperature of the hot melt adhesive.

In order for it to melt to the point where it can bond the book, the heating temperature must be raised to 140-180°C. At this temperature, the viscosity and strength of the colloid can be suitable for the binding of books.

(2) The relationship between book paper and gluing temperature

Depending on the quality of the paper of the book, the temperature at which the glue is applied should also be different. This is not only because the fibers of the paper are different, but more importantly, due to the different types and textures of the paper, the thermal conductivity of the colloids is different, which changes the cooling rate. Take the thermal conductivity of coated and non-coated paper as an example, the former glue cools faster than the latter.

Because the inorganic matter contained in coated paper is about 10 times higher than that of non-coated paper and offset paper, and the inorganic matter has good thermal conductivity, which can make the hot melt adhesive cool faster.

For example, when the gluing temperature is 170, the tensile test value of the hot melt adhesive on non-coated paper can meet the expected requirements, while the tensile test value of coated paper cannot meet the expected requirements. Therefore, when gluing coated paper, it is necessary to increase the temperature of the glue solution and increase its strength.

(3) The relationship between the opening time of EVA hot melt adhesive and the running speed of production equipment.

In cordless binding production, there are three time phases that must be strictly controlled when using hot melt adhesives, namely the opening time, the curing time and the drying time for cooling and hardening. Opening hours refer to the time when glue is applied to the back of the book. The curing time is the time it takes for the cover and back of the book to be glued together.

Cooling, hardening, and drying time refers to the time it takes for a book with a cover to cool down and set after curing. It is only after these three time stages that the book can be finalized and take the desired shape.

It is generally used as a glue for binding books

You can just think about it.

Dear, I'm glad to answer for you: EVA hot melt adhesive or PUR hot melt adhesive which is better A: PUR hot melt adhesive will be better than EVA hot melt adhesive.

PUR hot melt adhesive is a general-purpose reactive polyurethane hot melt adhesive, which has excellent adhesion, softness and water resistance because of its moisture curing, and is widely used in the bonding of glass, metal, plastic and other materials in home appliance assembly and sealing. The viscosity is stable when heated at a certain temperature, and it has high initial bond strength and strength. It has good weather and chemical resistance when fully cured.

Hot melt PUR glue, adhesion and toughness (elasticity) adjustable, has excellent bonding strength, has good high and low temperature resistance, water resistance, wear resistance, chemical corrosion resistance and aging resistance of No. 0, suitable for plastic, metal bonding, widely used in the field of electronics, automobiles, textiles, electromechanical, aerospace and other national economic fields. --PUR hot melt adhesive and EVA hot melt adhesive difference 1, the composition is different, PUR belongs to the polyurethane category, EVA uses ethylene vinyl acetate;2. The reaction mechanism is different, PUR moisture is solidified, and it is irreversible after the reactionEVA is a physical bond, cooled and cured, remelted after heating, and reversible operation. 3. PUR is irreversible after curing, has higher strength and high and low temperature resistance, and has excellent heat resistance, cold resistance, water vapor resistance, chemical resistance and solvent resistance.

EVA hot melt adhesives have relatively poor rigidity and a low softening point relative to PUR polyester, most of which are around 100, limiting its range of use.

The melting temperature of hot melt adhesive is 160 degrees, so it will stick tighter with an iron, and it is best to clean it with gasoline or acetone.

Summary. 1. The ingredients are different:

The main ingredient of PUR is terminal isocyanate polyurethane prepolymer, and the main component of EVA hot melt adhesive, that is, the basic resin is made of ethylene and vinyl acetate copolymerization under high pressure, and then combined with tackifiers, viscosity modifiers, antioxidants, etc. to make hot melt adhesives.

2. Different characteristics:

PUR has adjustable adhesion and toughness, and has excellent bond strength, temperature resistance, chemical resistance and aging resistance. EVA hot melt adhesives are usually solid at room temperature, melt into a liquid when heated to a certain extent, and quickly become solid once cooled below the melting point.

What is the difference between PUR hot melt adhesive and EVA hot melt adhesive?

1. Different compositions: the main component of PUR is terminal isocyanate polyurethane prepolymer, and the main component of EVA hot melt adhesive, that is, the basic resin is made of ethylene and vinyl acetate copolymerization under high pressure, and then combined with tackifier, viscosity modifier, antioxidant, etc. to make hot melt adhesive. 2. Different characteristics:

PUR has adjustable adhesion and toughness, and has excellent bond strength, temperature resistance, chemical resistance and aging resistance. EVA hot melt adhesives are usually solid at room temperature, melt into a liquid when heated to a certain extent, and quickly become solid once cooled below the melting point.

3. Different scope of application: PUR glue is designed to adapt to a variety of different weights of printing paper, plastic film varnish and ink and other materials, EVA hot melt adhesive for electrical appliances, hardware tools, toys, handicrafts, tourism products, stationery, cosmetics.

The melting range of EVA hot melt adhesive film is generally between 60 -85.

There will be slight differences according to the specific model, such as the melting range of HJV85 EVA hot melt adhesive film is 65 -80, and the melting range (melting temperature) of HJV90 EVA hot melt adhesive film is 70 -85.

The melting point of the hot melt adhesive film is not a single value, and we will add about how many degrees Celsius when we introduce it, so the melting point of the hot melt adhesive film should be called the melting temperature range accurately.

EVA hot melt adhesive film is one of the hot melt adhesive films, which plays an indelible role in the material composite at low temperatures. Especially in the application of sponge and foam products, it is irreplaceable.

The main ingredient of EVA hot melt adhesive film is EVA, that is, vinyl acetate copolymer, because of the composition itself, the melting point temperature is only about 70 degrees Celsius, which is already very low in the hot melt adhesive film, so EVA hot melt adhesive film belongs to the hot melt adhesive film with low melting point, we call it low-temperature EVA hot melt adhesive film.

1::EVA is the abbreviation of ethylene vinyl vinyl acetate. EVA is a plastic material composed of ethylene (E) and vinyl acetate (VA).

The ratio of these two chemicals can be adjusted to meet the needs of different applications, and the higher the content of vinyl acetate (va content), the higher the transparency, softness and toughness. 2.: The EVA melting point is mainly determined by the VA content, and secondly, the melting index will also have a certain effect on the melting point.

At the same VA content, the lower the melting index, the higher the melting point. The lower the VA content, the higher the melting point. The melting point is about 90 degrees, and the general VA content is about 18.

The approximate range is:

VA content 28 melting point about 70 degrees.

VA content 18 melting point about 80 degrees.

VA content 14 melting point about 90 degrees.

Summary. Pro, the colloids generally used in EVA plates are hot-melt adhesives, which are relatively polluting, and glass glue can also be considered.

Pro, the colloids generally used in EVA plates are hot-melt adhesives, which are relatively polluting, and glass glue can also be considered.

What glue is best for EVA to use.

Dear, first of all, EVA because of its own surface properties, in fact, no matter what non-water-soluble super glue is used, it has good adhesion, so 502, the good use of the brothers is no problem, but because it dries too fast, and it is more troublesome after sticking to the hand, so it is recommended to use woodworking glue here. Some woodworking glues are also called all-purpose glue, like glue, and the mess is usually used to bond the tires of Zheng socks.

What is EVA special composite glue called.

Pro, it is called EVA composite glue is a kind of glue and jujube, the main ingredients are thermoplastic styrene-butadiene rubber, rosin modified resin, petroleum resin, solvent. It is mainly used for the bonding of EVA materials, wood, leather, EPE and other materials.

Performance characteristics provided by [Special Solid Hot Melt Adhesive Company]:

1. It is usually solid at room temperature, melts into liquid when heated to a certain extent, and quickly becomes solid once it cools below the melting point, (i.e., solidifies again);

2. It has fast curing, low pollution, strong adhesion, and the adhesive layer has a certain flexibility, hardness, and toughness;

3. The glue is applied to the adhesive layer after cooling and curing on the adherent, and it can also be heated and melted again, and then turned into an adhesive body and then bonded with the adherent, which has a certain degree of re-adhesiveness;

4. When using, as long as the hot melt adhesive is heated and melted into the required liquid state, and applied to the object to be adhered to, the bonding and solidification can be completed in a few seconds after pressing, and the degree of hardening, cooling and drying can be achieved within a few minutes.

EVA hot melt adhesive is a solid fusible polymer that does not require solvents and does not contain 100% moisture. It is solid at room temperature, and becomes a fluid and viscous liquid when heated to a certain temperature. Molten EVA hot melt adhesives are light brown or white in color.

EVA hot melt adhesivesIt consists of a base resin, tackifier, viscosity modifier and antioxidant.

1 The color of the glue.

If there are no special requirements for the color of the substrate itself, it is recommended to use yellow EVA hot melt adhesive. In general, yellow EVA hot melt adhesives are more viscous than white ones.

2 Substrate surface treatment.

The surface treatment of EVA hot melt adhesives is not as strict as that of other adhesives, but the dust and oil on the surface of the substrate must also be properly treated to make EVA hot melt adhesives work better.

3 Operating time.

Fast handling is a hallmark of EVA hot melt adhesives. The working time of EVA hot melt adhesives is generally about 15 seconds. With the wide application of modern production methods - assembly lines, the working time requirements for EVA hot melt adhesives are getting shorter and shorter, such as book binding, speaker manufacturing, etc.

The operation time needs to reach about 5 seconds.

4 Temperature resistance.

EVA hot melt adhesives are temperature sensitive. When the temperature reaches a certain level, the EVA hot melt adhesive begins to soften. Below a certain temperature, EVA hot melt adhesives become brittle. The selection of EVA hot melt adhesives must take into account the temperature changes in the environment in which the product is exposed.

5 Stickiness.

The viscosity of EVA hot melt adhesives is divided into early viscosity and late viscosity. EVA hot melt adhesives and substrates can only remain stable when the early viscosity is consistent with the later viscosity. In the production process of EVA hot melt adhesive, it is necessary to ensure that it has oxidation resistance, halogen resistance, acid and alkali resistance and plasticity.

Depending on the material to be bonded, the viscosity of EVA hot melt adhesives is also different. Different EVA hot melt adhesives should be selected according to different materials.