Types of Drying Equipment for Can Lid

Types of Drying Equipment for Can Lid

After the metal caps are formed through stamping and adhesive application, drying is essential to complete the process. Here’s a detailed explanation of the types of drying machines:

(1) Tunnel Dryers: These dryers typically have a horizontal structure where the adhesive-coated metal caps are placed on a conveyor chain that passes through a tunnel. Heating elements are arranged on both sides for drying. This simple structure usually requires manual loading and unloading, making it suitable for various adhesive-coated metal caps. However, since the caps are stacked together during drying, solvent evaporation is not efficient, resulting in slow drying, low production efficiency, poor equipment sealing, and high energy consumption.

(2) Vertical Dryers: This type uses several pairs of screws or chains to transport the adhesive-coated metal caps upwards. Heating elements are arranged on the inner walls, accompanied by a blower to ensure uniform temperature distribution. The screws or chains separate each cap, allowing hot air to directly heat each one, which increases drying speed and production efficiency. Vertical dryers are ideal for producing products with fewer varieties and high output. Compared to tunnel dryers, they also feature better sealing performance, lower energy consumption, and smaller footprint.

(3) Medium-Frequency Dryers: Developed in the 1970s, medium-frequency induction heating has been used in steel smelting, heat treatment, and forging. This advanced induction heating equipment is compact, lightweight, energy-efficient, low-noise, and provides high-quality heating, aligning with modern energy-saving and environmentally friendly concepts. Medium-frequency dryers heat the metal caps internally, achieving high efficiency and rapid heating. Theoretically, they eliminate issues like "wrinkling" or "bubbling" of the adhesive. Additionally, their simple structure results in lower costs and maintenance expenses. They also provide uniform heating, ensuring that each cap receives nearly the same amount of thermal energy, leading to a 100% product compliance rate as long as the set temperature meets process requirements.