1、Introduction

Hot melt adhesive, suggests that the latter is heated to become molten state by applying various materials bonded together and glue. Compared to other hot melt adhesives and adhesive has the following characteristics: 100% solids composition, solvent-free and water components; thermal plasticity, which can be repeated heating and cooling melt solidification, this process is reversible chemical physics of hot melt adhesive nature does not change; hot melt adhesive must be heated to become molten state to a coating; hot melt adhesive produced by cooling and solidifying the adhesive force.

Since the advent of hot-melt adhesives, due to the large adhesive strength, curing speed, etc., it is widely used in food packaging, bookbinding, disposable hygiene products industry, the furniture industry, the label industry and so on.

2、 the new technology and hot melt adhesive industry trends

① The low temperature hot melt adhesive

Low temperature hot melt adhesive to break the limits of the general use of conventional hot melt adhesive. Its normal operating temperature is only 110 ℃ ~ 130 ℃, low temperature hot melt adhesive than traditional hot melt adhesive temperature above 30 ℃. Low temperature hot melt adhesives and hot melt adhesive compared to traditional significantly lower viscosity values, to ensure that meet the requirements of the coating process at a low temperature operating conditions.

Direct benefits of low temperature hot melt adhesive is brought machines to save electricity and maintenance costs. A large number of practical applications show that the same hot melt machine, low temperature hot melt adhesive can save customers approximately 15% of the electricity. And because of its low temperature hot melt adhesive at 110 ℃ ~ 130 ℃ normal operating temperature of the almost complete absence of crust, coke and other aging, so that maintenance costs of the machine is greatly reduced. More importantly, low temperature hot melt adhesive PE film will not burn

② hydrophilic hot melt adhesive

Conventional hot melt adhesive generally hydrophobic, hydrophilic hot melt adhesive through a special formula to make it hydrophilic, each one hydrophilic hot melt adhesive applications can be assigned to higher value-added products, so that the production manufacturers in the current highly competitive market, effectively differentiate their products, and ultimately win consumers.

③ The hot melt adhesive of other new technologies

In addition to these aspects, the new hot melt adhesive technologies include: anti-oil hot-melt adhesives; hot melt adhesive spray suitable for high-frequency; high wet strength hot melt adhesive; biodegradable hot melt adhesive and so on.

3、melt coating technology classification

①. Scratch system

It was plastic coating process is often uneven, which requires a certain degree of gum scraping mechanism, the squeegee evenly. Squeegee scraper mechanism main stainless steel sheet, comma scraper, scraper, wire scraper, airflow scraper and so on.

②.Textured coating

This coating equipment, mainly for the anilox coating roller rubber coating. Its uniform coating, and the coating amount is more accurate. But once the type of plastic coated anilox and calm, it is difficult to adjust the amount of coating applied and this is the main reason for textured coating roll subject to restrictions.

③.Calender coating

This method uses the calender rubber and other materials coated on the surface of the paper or fabric substrates, thin film coating and calendering calendering powder coating division. After the former is coated with a plastic film, by heating and melting calender roll bonded to the surface of the substrate; the latter system the powdered resin spray on the substrate surface, and then by heating and melting calender roll bonded together.

④.Spray Systems

After this coating equipment primarily solid type of glue melted by heating by means of hydraulic rubber coated die sprayed directly on the substrate.

4、No scratch coating technology

In 2007, in response to market demand, put into hot melt adhesive coating equipment technology research and development for the film-like material. The new no scratches hot melt coating head available, the device has the following characteristics:

"No scratches" effect, particularly suitable for coating composite PET, PVC, OPP and other materials; minimum weight of up to 15g / m, running at speeds up to 180m / min; high degree of automation, PLC control, and a variety of functions HMI operating together in order to ensure the operator to easily control the device.

The successful development of the device, fill the gaps in China's technology in this area, for domestic initiative. Solve the hot melt adhesive coating and UV curing hot melt adhesive coating PET, PVC, OPP and other materials dependent on imported equipment situation for the industry's products save a lot of money into upgrading.

In recent years, foreign countries have developed a new generation of green such as degradable, water-dispersible bio-melt adhesives and other new improvements. The improved due to the traditional types of plastic thermosetting, solvent-based adhesives and so different, does not contain any solvent, not because of solvent evaporation and pollution to the environment, therefore, the new environmentally friendly hot-melt adhesive attracted more and more people in the industry attention and favored by the market.