It is a type of hot melt adhesive application that is made into a film-like product that is sandwiched between the bonded objects when a bond or composite material is required. This product is formed by heating and melting, cooling and hardening, and the process can be reversed. Hot melt adhesive film is an example of this type of application. Because of their speed and lack of impact on the surrounding environment,polyester hot-melt adhesive film have been instrumental in the development of mass production in a variety of business sectors. This not only boosts the efficiency of businesses but also reduces their operating expenses. Additionally, it has made clean production possible, enhanced the atmosphere of the workshop, and contributed to the overall health and happiness of the workforce.

Coating, calendering, blow molding, and calendering are the most common methods that are used to turn hot melt adhesives into films. However, there are many other ways that this can be done. When making hot melt films, it is necessary to take into account the rheological and film-forming properties of the raw material particles and to choose a method of production that is reasonable. Following is a breakdown of each of these approaches:

The coating method is used in the production of hot melt adhesive films.

We frequently come across many hot melt adhesive films that have a piece of paper, known as the release paper, attached to the back of the film. The coating method is the one that is most frequently utilized when producing these hot melt films with release paper as the base material. Paper is not necessarily required to serve as the base material; PE film is another option that is frequently utilized.

The coating method is accomplished with the assistance of a coating machine, which frequently employs a variety of coating methods in accordance with the properties of the adhesive material being applied. Light roll coating, anilox coating, scraper coating, spray coating, and curtain coating are some of the most common types of coating methods. Light roll coating is another option. In most cases, the coating method is only used to produce hot melt films that have a substrate. However, it is possible to peel the paper in order to obtain a hot melt film that does not have a substrate; however, this can result in unnecessary cost losses. When producing hot melt films using the coating method, one must pay careful attention to maintaining a uniform thickness throughout the adhesive surface, ensuring that it is flat, and ensuring that it is clean.

The casting method is used for the production of hot melt adhesive films.

The cast method was initially developed as a means of cutting costs associated with the production of hot melt film products. This was accomplished by doing away with the requirement of a base material for hot melt film, which resulted in the production of base material free hot melt film.

The cast method is carried out with the assistance of a cast machine, which first melts the adhesive pellets before forcing them through an extruder. After passing through the extruder, the molten adhesive pellets flow out of the slit die head and are then directed through the cooling rollers to finish the winding process. After this step, slitting on a wide width is performed in accordance with the requirements of the product. As long as the outflow is reattached to the substrate and put through the cooling rollers, the cast method can also be used to produce hot melt films with a substrate. This is one of the conditions that must be met. The calendering method has significant advantages over the coating method in terms of both the amount of work that can be produced and the quality of the end product that is maintained. During the production process, it is also much simpler to recycle scrap and trimmings, which helps to reduce the amount of material that is wasted. The capital expenditure for the purchase of machinery and equipment is only marginally higher.

The blow molding process is used for the production of films containing hot melt adhesive.

When manufacturing common plastic films, such as LDPE plastic films, the blow molding method is frequently utilized as one of the production processes. The blow molding process is frequently used to produce hot melt film in the absence of a base material. In this process, the rubber is extruded after it has been melted, and then the rubber is led vertically upwards from the ring head, blown, and then directed by the herringbone plate to the haul-off rollers, after which the finished product is obtained by passing it through the guide rollers and winding device.

The production of polyester hot-melt adhesive film through the blowing method has a significant limitation that needs to be addressed. This is due to the fact that the process of blowing results in a product that has thermal shrinkage and a molecular structure that is not equally stretched in both the longitudinal and transverse directions. This results in an extremely easy shrinkage of the blown film during the heating process for hot melt bonding, which ultimately results in a poor bond. In addition, cast film is superior to blown film in terms of its flatness and uniformity. Blown film. Cast film has molecules that are arranged in an orderly fashion, and the product cools quickly, both of which help to improve the product's transparency, gloss, and uniformity of thickness. Additionally, the texture of the film is softer and tougher, and its resistance to impact, heat, and low temperature is superior to that of blown film.

The use of calendering in the production of films containing hot melt adhesive

The calendering method is typically utilized in the production of hot melt films whenever the required thickness ranges from 1-2 millimeters. In the process of calendering, the film is first melted and then extruded through the slit die opening at the head of the machine. Next, the film is calendered and cooled by a three-roller calender, and finally, the finished product is cooled by a conveyor roller and winding device.

When compared to the blown film method, the calendering process results in a hot melt film that has superior thickness uniformity and superior heat shrinkage. However, the most significant benefit of calendering is the ability to produce a product with a variety of thicknesses by utilizing raw materials with a high degree of adaptability. However, the investment required for the calendering process is significantly higher than that required for the blow molding process. The difference is more than ten times as great. The calendering process is superior to the calendering process in that it can produce products with a thickness of 1.5 millimeters or more, whereas the calendering process is unable to accomplish this. The calendering method, on the other hand, is significantly easier to work with for lines of the same size.