Hot-melt adhesives (or thermal adhesives) are non-volatile, solvent-free thermoplastic materials that are solid at room temperature. They are activated by heating above their softening point and applied in a molten state. The adhesives wet the substrate, penetrate the surface, and then solidify, ensuring cohesion. These adhesives do not require a curing period as they set quickly while cooling to their freezing point.

The three operational characteristics of hot melts are hot tack, open time, and setting speed. The open time is the maximum time after adhesive application that one can wait to bond the second substrate while still achieving an acceptable bond. The setting speed is the minimum time required after the second substrate is placed to form a desirable bond. Hot tack is crucial for holding the two bonded substrates together until the adhesive solidifies. The adhesive must also be able to fully wet both substrates and preferably show high specific adhesion.

Hot-melt adhesives require a delicate balance of formulation components, the main elements of which include a base polymer, tackifying resin, wax, antioxidant, and plasticizer. Hot-melt adhesives based on ethylene vinyl acetate (EVA) copolymers contain various percentages of vinyl acetate. Vinyl acetate contributes to adhesion, solubility, improved bonding to polar surfaces, and low-temperature flexibility. Copolymers are produced in a wide range of molecular weights and corresponding melt indexes. Typically, low and high molecular weight polymers are blended together to achieve the best balance between melt viscosity, wetting, and bonding strength. In the formulation of these adhesives, the base polymer provides strength and flexibility. Resins create wetting and adhesive properties. Waxes control viscosity and the open time/setting speed. Antioxidants minimize oxidation due to oxygen and heat, and plasticizers provide more flexibility to the adhesive, helping it to be softer. In general, these adhesives are made from a high molecular weight polymer, to which a synthetic elastomer and a resin are added to enhance properties like adhesion and a resin to improve properties like wetting. Hot-melt adhesives are produced on various bases including POE, APAO, RUBBER (SIS, SBS, ...), EVA, and Polyamide. The precise formulation of hot-melt adhesives is determined by their bonding properties and application conditions such as time, pressure, and temperature.

Thermal adhesives are solvent-free, and their advantages include the elimination of solvents and the absence of volatile organic compounds (VOCs) and recyclability, making them known as environmentally friendly due to their lack of pollutants. The use of these adhesives, compared to solvent-based adhesives, has distinct features such as fast setting, short bonding time, the ability to be remelted after cooling, water resistance, and long-term durability. Depending on your needs, thermal adhesives can be flexible and resistant to temperatures that would typically melt adhesives.

Hot-melt adhesives are a suitable choice for hard and non-porous substrates, and are used by a wide range of industries including packaging, printing and bookbinding, labeling, filter manufacturing, cellulose-hygiene, and footwear. Unlike other adhesives, hot melts are not only efficient in bonding but are also reliable and consistent products. These adhesives do not damage the substrate and are used with a wide range of automatic and semi-automatic machinery. The use of hot-melt adhesives can be considered a serious step towards creating a safe and environmentally friendly space.

Based on the needs of various industries, the Iran Industrial Resins Co. is recognized as the first producer of hot-melt (or thermal) adhesives based on ethylene vinyl acetate (EVA) in the country. This company also produces hot-melt adhesives based on polyolefins (APAO, POE) and rubbers (SIS, SBS, ...).

Our hot-melt adhesives are formulated to provide optimal adhesion, fast setting speed, a range of open times, high bond strength, heat and cold resistance properties, durability, and high quality according to customer needs. Due to their long shelf life, and ease of handling and storage, thermal adhesives are considered a cost-effective choice for meeting the needs of a wide range of industries. The fast drying time of hot-melt adhesives increases their speed of use. Additionally, solvents are not used in the production of hot-melt adhesives. These adhesives have vapor-free, low-toxicity, and environmentally friendly properties, minimizing waste disposal during their production and use.

A wide range of products from the Iran Industrial Resins Co. are provided in granular and molded forms and meet the ever-changing needs of various industries in the country, as follows: