Glue dispensing valve

Types of Glue dispensing valves

Glue dispensing valves are the critical components of an adhesive dispensing system. They control the flow of glue or adhesive when applied to surfaces. There are different types of glue dispensing valves, each working uniquely to perform particular functions.

• Pneumatic Glue Valves: As the name implies, a Pneumatic glue valve performs its operations by using compressed air to control the adhesive flow. The perpendicular or parallel movements of the valve are affected by air pressure that comes from the glue dispensing machine. The air compresses or expands to make the valve move either closer to or away from the surface that requires gluing. One advantage of this valve is that it easily integrates into existing air-powered setups. However, the valve's performance is largely dependent on the glue machine's air pressure control.
• Button Actuated Glue Dispensing Valves: This glue valve works like a button switch. When certain surfaces need gluing, the operator pushes a button that then triggers the adhesive dispensation. The glue dispenses when the button is pushed and stops when the button is released. The button-actuated glue dispensing valve provides improved operator control over manual valves but may require frequent valve maintenance and button repositioning between tasks.
• Solenoid Glue Dispensing Valves: The Solenoid glue dispensing valve works electrically. The electrical work is done by a small coil that functions as an electromagnet. The electromagnet pulls a plunger, which then opens or closes the glue channel. When the glue channel is opened, the adhesive flows, and when it is closed, the flow stops. The major selling point of this valve is its fast response time. This feature is great for rapid cycles and high-speed production. However, due to the constant usage of electricity, the solenoid plunger may wear out over time. This is something to consider if the glue machine is to be used in a high-volume production area.
• Timer Control Glue Valves: Timer Control Glue Valves dispense glue according to pre-set time intervals. This may offer consistent application amounts, but it requires additional equipment to set up.

Specifications and maintenance of the glue dispensing valve

The glue dispensing system has various specifications to suit different application needs. Some key ones are listed below.

• Glue Viscosity

  Glue dispensing valves work well with adhesives of different viscosities, from thin (water-like) to very high (paste-like). Some valves are designed to handle specific viscosity ranges for better control and accuracy. For instance, high-viscosity glue may require a valve with more pressure or a particular design feature, such as a heated element, to work effectively.

• Glue Temperature

  Valves can work with cold, room temperature, heat, or hot (up to 200°C) glue. Each adhesive has a functional temperature range. Below or above that range, the adhesive won't work. Hot melt glue must be heated beyond its melting point before dispensing through the valve. For that type of glue, the valve should have a heating option to ensure that the adhesive maintains the proper temperature while being dispensed.

• Glue Pressure

  This is the force the adhesive pump applies to push the glue through the valve. It is usually between 2 psi and 20 psi, but some systems can go as high as 100 psi. Higher pressures may be needed to dispense thicker (high-viscosity) adhesives or to shoot the glue faster through the system. However, better accuracy and control are possible with lower dispensing pressure.

• Operative Parts

  Some adhesive dispensing valves feature a solenoid. Others have a servo motor instead. Pneumatic valves function without electric power and use compressed gas. The choice will depend on the application need.

• Flow Rate

  This is the number of adhesive parts (ml) delivered per second. The valve's motor drive directly influences the flow rate. Motor speed may set it between 0.01 ml/sec and 0.1 ml/sec. Higher motor speeds will increase the flow rate, but the valve may not be able to control small dab sizes.

Proper maintenance of the glue dispensing valve is crucial to its reliability, longevity, and consistent performance. Doing so will help minimize downtime, reduce the cost of spares, and make more efficient use of staff time.

Cleansing should be the first step of valve maintenance. Ensure that the work area is free of contaminants. Capping the hose and the in-feed of the valve will prevent contaminants from getting inside. While the system is still running, use a cleaning agent and cloth to wipe the outside of the valve.

Use the proper cleaning solution for the adhesive. For water-based glue, use water or IPA. For solvent-based adhesive, use the same solvent that was used for cleaning prior to pump change. Use glue strippers or acetone for hot melt adhesives or while cleaning other types of solvents.

If any adhesive residue builds up over time, promptly remove it with the tool that best fits the equipment. If a new adhesive is to be used, ensure it is compatible with all the system components.

If the valve is not to be used for some time, it's better to store it with adhesive in it rather than empty. That's because empty O-rings may dry out and crack, and this storage method minimizes that from occurring.

Occasional lubrication of moving parts, including O-rings and seals, will maintain the valve's operational integrity. Regular cleaning and replacement of damaged parts will keep the valve working well and prevent it from developing faults.

Application Scenarios of Glue Dispensing Valves

Glue dispensing valves play a crucial role in various industries, ensuring precise control, consistent application, and reliable performance in multiple glue-dispensing processes.

• Packaging Industry: Packaging companies frequently employ glue dispensing valves to utilize hot melt adhesive packaging machines. These machines are utilized to apply glue for sealing boxes, ensuring the boxes are sealed securely, and enhancing package strength.
• Furniture Manufacturing: In the furniture manufacturing industry, glue dispensing valves are employed in furniture production lines to achieve automatic adhesive application for bonding. This results in improved productivity and consistent adhesive application.
• Electronics Assembly: Glue dispensing valves are used in the electronics assembly industry to apply adhesive precisely to electronic components. For example, they can be utilized for bonding, encapsulation, and sealing electronic parts, achieving accurate control of adhesive volume and placement.
• Automotive Industry: The automotive industry often uses glue dispensing valves for car body construction and interior assembly. They are employed to apply structural adhesive for bonding car body parts or adhesives for sealing and encapsulating, ensuring quality and durability.
• Medical Device Manufacturing: In the manufacturing of medical devices, glue dispensing valves are used to adhere various components precisely. They are suitable for use in small-volume adhesive applications, achieving accurate control of adhesive dosage, which is crucial for the functionality and reliability of medical devices.
• Textile and Leather Production: Glue dispensing valves can also be utilized in the textile and leather production industry, where they are used for precise adhesive application in bonding fabrics, leathers, and other materials. The valves ensure accurate control of adhesive volume and placement, which is essential for quality and consistency in textile and leather products.

How to choose glue dispensing valves

• Consider application needs:

  Businesses primary application will determine what type of glue dispensing valve they need. For high-precision applications, like electronics manufacturing, a needle valvemight be more suitable because it can offer high accuracy. On the other hand, for high-viscosity adhesive applications, like sealing or potting, aрым valve might be a better choice because it can handle thicker liquids.

• Check the size and capacity:

  Glue dispensing valves come in different sizes and capacities. A small capacity valve might be more suitable for small, intricate jobs, while a larger capacity one would be better for larger, faster jobs to reduce downtime.

• Compatibility with adhesive types:

  Not all glue dispensing valves are compatible with all adhesive types. Make sure that the valve chosen is compatible with the adhesive that will be used in the application. For instance, certain valves are specifically designed for water-based adhesives, while others are meant for solvent-based or epoxy adhesives.

• Ease of clean and changeover:

  It's vital to consider how easy it will be to clean the valve and change it over to different adhesives. Valves with complicated designs can waste a lot of time, whereas simple-to-clean models can save a lot. Automatic cleaning functions may also be available in some models, which can help reduce downtime.

• Integration with existing equipment:

  Integration is important, too. Buyers will want to ensure that the valve they buy can integrate seamlessly with their existing adhesive supplies. This includes the adhesive containers, the means of supplying the adhesive, and any automated systems they already have in place.

• Considering manual versus automated dispensing:

  A manual glue dispensing valve might be preferable for small-scale production or workshops. On the other hand, automated valves are more efficient for large-scale production. These can offer improvements in accuracy, speed, and consistency.

Glue dispensing valve Q&A

Q1. How do glue dispensing valves work?

A1. Glue dispensing valves control the flow of adhesive out of the applicator tip. They work by utilizing a trigger mechanism to apply pressure to the container holding the adhesive, which activates the flow of glue through the nozzle. The amount of pressure exerted by the trigger can determine the size of the glue bead or amount dispensed.

Q2. What are glue dispensing nozzles made of?

A2. Glue dispensing nozzles are commonly made from stainless steel and plastic. Stainless steel is typically used for the tip of the nozzle because it is strong and can withstand the corrosion of certain chemicals. Plastic is often used for the body of the nozzle because it is lightweight and can be easily manufactured in different shapes and sizes.

Q3. What are the trends in the adhesive dispensing market?

A3. The adhesive dispensing market is growing rapidly due to the increasing demand for automation in various industries. The trend towards hand-held adhesive dispensers for home and DIY use is also significant. Additionally, the development of smart dispensers that offer precise dispensing and can be connected to AI systems for predictive maintenance is changing the market landscape.

Q4. Can users get bulk hot glue cartridges?

A4. Yes, people can purchase bulk hot glue cartridges from various suppliers, both online and in-store. It is advisable to ensure that the specifications of the glue cartridges match the requirements of the glue gun for optimal performance.