Kuumaliima

Kuumaliima, in English commonly referred to as hot-melt adhesive, is a thermoplastic adhesive that is solid at room temperature and melts when heated. After application, it cools and solidifies, forming a bond. The material is typically supplied as sticks that are melted in a hot glue gun.

Most kuumaliima sticks are EVA-based polymers (ethylene‑vinyl acetate), often with tackifiers and colorants. Other formulations use polyamide, polyurethane, or blends. The adhesive is designed to flow when heated and to harden quickly upon cooling, enabling fast assembly. It bonds well to a wide range of materials, including wood, paper, fabric, many plastics, metals, and ceramics, and it can fill gaps to some extent.

Application and performance: Typical operating temperatures for hot glue guns range from about 120 to 180°C, with high-temperature sticks requiring hotter guns than low-temperature variants. After application, the glue fastens as it cools, offering rapid handling strength. It provides good initial tack and some degree of flexibility, and it can be moisture resistant depending on the formulation. However, kuumaliima generally has limited heat resistance and weathering performance, may degrade under prolonged UV exposure, and is less suitable for high-load, long-term structural bonding or environments with high temperatures.

Advantages and limitations: The method is inexpensive, fast, easy to use, and suitable for crafts, woodworking, packaging, textiles, electronics prototyping, and general assembly. Disadvantages include reduced strength for heavy loads, poor long-term durability in extreme conditions, and residue that can be difficult to remove once cured. Safety concerns include burns from hot glue and fumes during heating, so ventilation and protective measures are advised.