Hot Melt Adhesives – Application Techniques

Hot melt adhesives have emerged as versatile and efficient bonding solutions for a myriad of applications. From packaging to automotive assembly, the success of hot melt adhesives lies not only in their formulation but also in their quick, efficient application. In this blog post, we will explore various hot melt adhesive application techniques, the equipment best suited for each method, and essential tips to achieve optimal bond quality.

Dots and Beads

One of the most common methods for applying hot melt adhesives is through dots and beads. This technique involves dispensing controlled amounts of adhesive in small dots or continuous beads onto the substrate. Hot glue guns equipped with nozzles designed for precise dispensing are commonly used in this method.

Hot glue guns can be cartridge based or hose fed. Cartridge-based handguns are portable and handy. They prove cost-effective for on-the-go tasks, touch-ups, and assembly with low volume requirements. However, they need relatively expensive cartridges and frequent refilling. On the other hand, hose-fed handguns sacrifice portability for a more consistent application of adhesive.

Spray

Spray application involves atomizing the hot melt adhesive into fine particles, creating a mist that evenly covers the substrate. This method is suitable for large surface areas and uneven substrates. Specialized spray systems, such as airless spray guns or LVLP (Low Volume Low Pressure) air sprayers, are commonly employed for efficient coverage. Spray systems are often automated, enabling controlled deposition and reduced over-spray. However, application must be carefully monitored to avoid problems such as poor coverage and adhesive bleed-through.

Coating

Coating is a method where the hot melt adhesive is applied as a continuous film or web onto the substrate. This technique is particularly effective for applications requiring a the depositing of a uniform and thin adhesive layer onto a flat, even surface. Automated dispensing systems are often used for coating, ensuring consistent coverage over the entire substrate. Coating equipment includes automated wheel and roll systems, ideal for laminating applications, and slot applicators, commonly used on pressure sensitive tape and label applications.

Film Application

Film application involves applying a pre-made hot melt adhesive film or sheet onto the substrate. This method is advantageous for its simplicity and suitability for automated processes. Hot melt film applicators are used to bond large surface areas quickly and efficiently, making it a preferred choice in industries like packaging and automotive assembly.

Tips for Optimal Bond Quality

To achieve optimal bond quality, consider the following tips:

• Ensure proper substrate preparation, including cleaning and priming if necessary.
• Maintain the hot melt adhesive at the recommended temperature for consistent viscosity.
• Calibrate equipment regularly to ensure accurate adhesive application.
• Monitor adhesive consumption to avoid over-application or shortages.
• Conduct regular quality checks to identify and address any issues promptly.

By understanding the various hot melt adhesive application techniques and selecting the right equipment, manufacturers can enhance efficiency and produce high-quality products across diverse industries. Whether it’s dots and beads, spray, coating, or film application, each method offers unique advantages tailored to specific applications.

At Conro Electronics, we’ll show you how to improve product reliability while increasing performance and lowering costs. Our team of technical support specialists will provide your company with dependable global supply, unrivalled efficiency, and superior technical support.

Feel free to contact us on 0208 953 1211 or send us an email to info@conro.com