HOT MELT COATING MACHINE : ROLL TO ROLL The use of hot melt as a bonding adhesive in the industry has been transformed over the past few years and is gradually replacing conventional solvent or water-based systems and flame lamination. Trasy Enterprises is one of the leading designers and builder of a wide range of Hot Melt Coating machines. Accuracy & precision coating is assured. Our machines are high quality and are designed specifically for use in the packaging, speciality tapes, upholstery fabric lamination, medical packaging, surgical pouches, Insect sticky traps and other related industries. Hot Melt Coating process is very similar process to wax coating process. Hot melt adhesives are similar to wax. Hot melt adhesives are of two types: 1. The Thermoset hot melt adhesive. 2. The Pressure Sensitive Adhesive commonly known as PSA. This coating can be done with various methods. Commonly it was done with reverse roller coating or gravure coating. Gravure coating gives uniform coating but the disadvantage of this coating type is every time you have to change the engraved roller for different grammage of coating. In roller coating the challenge was to achieve thin coating and high speeds. The rotating roll churns the Hot melt and forms bubbles. This results in spotted coating. In both these processes the molten adhesive is exposed to the air and loses its heat so the hot melt adhesive changes its viscosity and this results in variation of coating thickness. Normally the ends of the coating roll lose heat compared to the centre of the roll hence the coats more grammage at the sides and less at the centre of the web. Sometimes the coating roller gives fumes due to high temperatures of the roller and thin layer of the adhesive on the roller hence the hot melt degrades due to high temperatures and loses its sticking property. So this process has limitation to achieve minimum coating thickness. (not less than 25 gsm.) Hence, the best method to coat hot melt is through a slot die coating. Advantages of this process are minimum heat loss compared to the other processes. The molten adhesive is never open to air. (Safety factor) Can coat on almost all materials like BOPP, PET, Cloth, HDPE fabric, Felt, Paper, Nonwoven, Aluminium foil, etc. The coating range in method can be 15 gsm to 600 gsm depending upon requirement. A proper Die and Back up roll setting gives even coating along the width. Also the Proper sync with glue pump and substrate speed and constant melting flow of adhesive, gives even coating along the length. High coating speeds or heavier GSMs can be achieved with the high capacity Melting units. This is to ensure the uninterrupted melt flow while coating. Our Model ‘HMC20’ ensures all these specialities: