What is the working principle of hot melt adhesive dispensing equipment?
The working principle of hot melt glue dispenser mainly includes four core steps: heating and melting, pressure delivery, precise coating and cooling and curing. The following is a detailed description:
1.Heating and melting
● Solid glue conversion: Add solid hot melt glue (glue strips, glue particles or glue blocks) to a heating device (such as a glue tank or a melt tank), and heat it to a molten state through an electric heating element (such as a PID temperature control system) (usually the temperature range is 120℃~180℃, depending on the glue type).
● Temperature control: Equipped with a high-precision temperature control system to ensure stable fluidity of the glue liquid and avoid carbonization or deterioration. Some equipment supports segmented heating or oil bath insulation treatment (such as EVA glue needs to avoid open flame heating).
2.Pressure delivery
● Pressurized extrusion: The molten glue is pressurized by a gear pump, piston pump or air pressure system and extruded from a nozzle or dispensing valve. The pressure can be adjusted according to the viscosity of the glue liquid and the coating requirements.
● Delivery stability: The two-stage filtration design reduces nozzle clogging, and the progressive preheating of the melting cylinder increases the melting speed to ensure uniform glue output.
3.Precision coating
● Motion control: Through the three-axis/four-axis robot, visual positioning system or CAD import program, three-dimensional path glue coating (such as points, lines, arcs, complex trajectories, etc.) can be achieved with an accuracy of up to micron level.
● Flow regulation: The glue output can be precisely controlled (such as an accuracy of 0.001 seconds), supporting diversified coating needs such as drawing points, lines, surfaces, arcs, circles and irregular curves.
4.Cooling and curing
● Rapid curing: The glue quickly cools and solidifies after contacting the air or the surface of the adherend to complete the bonding. The open time (the time from the extrusion of the glue to the curing) needs to match the dispensing speed, usually a few seconds to tens of seconds.
● Bonding strength: The cured hot melt adhesive forms a high-strength bond, which is suitable for a variety of materials such as wood, plastic, metal, and non-woven fabrics.
Core components and functions
● Heating system: electric heating element + temperature control system to ensure that the glue is melted evenly.
● Spraying/dispensing system: gear pump, nozzle, valve, etc., to control the glue output method (dispensing, spraying, rolling, etc.).
● Control system: PLC or industrial computer programming, support automatic path planning, acceleration and deceleration control (such as trapezoidal and S-curve acceleration to avoid glue accumulation).
● Safety design: anti-curing needle blocking function, automatic preheating system, filter cleaning prompt, etc.
6-30L floor-standing hot melt adhesive system
The first choice for large-scale production scenarios, using gear pump glue supply technology, the dissolution speed is as high as 12L/h – 20L/h. The Teflon coating on the inner wall of the cylinder delays the aging of the glue, and the independent temperature control and real-time status monitoring of the partitions ensure 24-hour uninterrupted and stable operation. It is suitable for high-load conditions such as home appliance manufacturing and large panel bonding.
5.30cc Hot Melt Adhesive Module
Designed for small – scale hot melt adhesive applications, it’s compatible with mainstream 30cc adhesive packages like Loctite, Henkel, and 3M. Its full insulation design prevents operational burns. With an independent temperature control module, it works without platform limitations. Paired with Second Intelligent’s 100T/200S controller, it achieves millisecond – level response and precise pressure control, and is widely used in electronic component packaging and precision assembly bonding.
hot melt adhesive dispensing machine
6-30L Floor-Standing Hot Melt Adhesive System
The preferred choice for large-scale production, it employs gear pump technology with a melting rate of 12L/h to 20L/h. The Teflon-coated tank interior delays adhesive aging. Independent zone temperature control and real-time status monitoring ensure 24/7 stable operation, suitable for high-load applications like appliance manufacturing and large panel bonding.
5-55 gallon industrial hot melt adhesive system
With ultra-large capacity, it features dual motors, dual pumps, and independent supply. The maximum melting rate reaches 20L/h. Progressive heating technology reduces energy consumption and minimizes adhesive charring. The new recirculation valve ensures uniform coating of high-viscosity adhesives in automotive glass sealing and industrial filter core assembly.
Application scenario examples
● Automotive industry: headlight sealing, interior bonding, battery packaging.
● Electronic manufacturing: mobile phone shell dispensing, PCB board component fixing.
● Packaging industry: carton sealing, label lamination.
● Medical field: medical protective clothing lamination, medical device sealing
Summary
The hot melt glue dispensing equipment achieves efficient and accurate automated bonding through the process of “heating → pressurization → coating → curing”, combined with high-precision temperature control and motion control. Its advantages are immediate coating and curing (no drying required), environmental protection and no VOC emissions, and adaptability to multi-material scenarios. It is widely used in automotive, electronics, medical, packaging and other fields.
Second Intelligent has played an important role in theresearch, development, manufacturing, pre-sales and after-sales services of fluid dispensing robot, potting and coating solutions which range from various types of automatic fluid dispensing, potting, two-component potting machines and coating machines with desktop, free-standing, inline or cobot combined systems, and widely used in global electrical, electronics, home appliances, automobile, telecom, pharmaceutical, automotive electronics, semiconductor, aerospace, LED and more.
