Characteristics of the hottest pur hot melt adhesi

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Characteristics of PUR hot melt adhesive ep48v coating head

the main advantages of PUR hot melt adhesive are good heat and cold resistance, strong chemical (ink) corrosion resistance, high bonding strength, good leveling, etc. At present, the mainstream EVA hot-melt adhesive is not as good as P in these properties. It plays an invaluable role in expanding the utilization of this kind of material in NASA. Ur hot-melt adhesive, especially to maintain a high bond strength to paper while also having good flattening, is a very difficult thing. EVA hot-melt adhesive is generally powerless

generally speaking, PUR hot melt adhesive has strong adhesion to paper and metal, and it also has good adhesion after hardening. 5: regularly check the screw elasticity of the jaw. In addition, in the waste paper reproduction project, PUR hot melt adhesive can be completely separated, which is also beneficial to improve the recycling quality of waste paper. Especially after complete curing, it has strong flux resistance, and is especially suitable for the bonding of photo albums and high-end books using coated paper

pur hot melt adhesive is characterized by its heat resistance, which is a property that thermoplastic hot melt adhesive does not have. When using pur hot melt adhesive, although it is the same as general hot melt adhesive, it should be heated, melted and coated to the spine and other parts, and then cooled and solidified; However, PUR will also absorb moisture in the air to produce a secondary reaction and form a cross-linked structure. Such molecules have high structural strength

another feature is that due to the high bonding strength, the amount of hot melt adhesive can be reduced. In order to improve the bonding strength of EVA hot-melt adhesive, the adhesive layer must be coated with a thickness of 1mm, while pur hot-melt adhesive can obtain a high bonding strength when the thickness of the adhesive layer is more than 0.4mm (some manufacturers believe that the bonding strength is high and the flattening property is good when the thickness of the adhesive layer is about 0.3mm). Even considering the unit price and operating cost of hot melt adhesive, there are many cases worthy of serious study

pur hot melt adhesive, which was first adopted in Europe, is not only applied in the binding field, but also widely used in building materials, auto parts and other fields

to obtain accurate data; Although pur hot melt adhesive entered Japan in the 1980s, it has not yet been widely popularized. The reasons can be listed as the type factors, price factors, operation factors and so on. Different from the general hot melt adhesive, it will bring difficulties to use due to the reaction after coating. In addition, in terms of production, it also requires a high degree of technology. In the binding field, the roller coating method of PUR hot melt adhesive has been widely used in Japan, but daily cleaning is necessary

the ep48v nozzle coating device developed by a Japanese company is a special hot melt adhesive nozzle designed based on the experience of PUR hot melt adhesive used in the binding market

the usual roll coating method is equipped with a glue box for melting hot-melt glue. The glue is applied to the back of the book by rotating the upper rubber wheel put into the glue box

different from this, ep48v cloth applicator adopts the method of conveying the hot melt glue melted in the bucket type glue pot to the cloth applicator through a hose. The characteristics of the cloth coating head are as follows:

1) non contact coating method is adopted

2) the part of hot melt adhesive exposed to air is very small

3) excellent high-speed adaptability (can be matched with the binding speed of 12000 books/hour)

4) less maintenance hours

5) it is easy to change the format, and so on

among the above points, points 2 and 4 are the most important advantages

in the case of roller coating, if hot melt adhesive such as EVA is used, the power supply will be cut off at the end of each day's operation; When using pur hot melt adhesive, the cleaning operation should be increased, but the ep48v device only has the tip part of the nozzle in contact with the atmosphere. The cleaning after the end of daily operation is limited to the cleaning of the nozzle part, which can greatly reduce the cleaning workload. In other words, there is almost nothing to clean

the ep48v system produced by this Japanese company has increased the export volume of Germany, which has strict requirements on recycling treatment, year by year, and this trend has been shown in North America, South America and Japan. This coating method has established the status of replacing roll coating

source: PRINT world

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