Why Use a Hot Melt Adhesive Supply System?

In plastic extrusion processes, the purpose of using a hot melt adhesive supply system is not simply “to dispense adhesive.”

The real objective is to achieve a continuous, stable, and controllable inline bonding process.

Especially in extrusion applications, which are continuous manufacturing processes, manual adhesive application or simple pressure-fed dispensing systems are usually unable to meet process requirements.

1. Why Is Hot Melt Adhesive Especially Suitable for Extrusion Processes?
Extrusion itself is a continuous production process.
Typical products include:

● Plastic profiles
● Sealing strips
● Films
● Tubes and pipes

These products are continuously extruded while moving forward on the production line without interruption.
Therefore, the adhesive system must also provide:
● Continuous dispensing
● Continuous metering
● Continuous synchronization

Hot melt adhesive is naturally well suited for this type of manufacturing process.

2. Key Advantages of Hot Melt Adhesive Compared with Liquid Adhesives
2.1 Extremely Fast Solidification
Hot melt adhesive flows when heated and solidifies immediately after cooling.
Unlike:
● RTV silicone
● Epoxy adhesives
● PU adhesives
which may require minutes or even hours to fully cure.

2.2 Ideal for High-Speed Continuous Production
Extrusion line speeds may reach:
● 10 m/min
● 30 m/min
● 80 m/min
If the adhesive curing process is too slow, continuous production becomes impossible.

2.3 No Complex Drying or Baking Process Required
Hot melt adhesive bonds simply through cooling.
This helps:
● Save production space
● Reduce energy consumption
● Improve production efficiency

2.4 Easier to Achieve Automated Metering
After heating, hot melt adhesive maintains relatively stable viscosity characteristics.
Therefore, it is highly suitable for:
● Gear pump systems
● Screw pump systems
● Servo-controlled metering systems
to achieve precise adhesive dispensing.

3. Why Is a Dedicated Hot Melt Supply System Necessary?
Hot melt adhesive is not a normal liquid material. It has several special characteristics.
3.1 Heating Is Required
Typical operating temperatures:

Therefore, the system must include:
● Melting function
● Thermal insulation
● Heated hoses
● Heated valves

3.2 High Viscosity
Even after heating, hot melt adhesive remains a high-viscosity material.
A standard pressure tank cannot provide stable dispensing performance.
Therefore, the system requires:
● Precision metering pumps
● Pressure stabilization systems

3.3 Highly Sensitive to Temperature
Even small temperature fluctuations can significantly change viscosity.
This may lead to:
● Dispensing inconsistency
● Stringing
● Clogging
● Material carbonization

Therefore, precise temperature control is critical.

4. Why Are Some Customers Especially Concerned About Low Flow Rates?
Because many applications involve precision inline adhesive coating, such as:
● Thin-layer coating
● Edge bonding
● Micro-lamination
● Sealing layers

In these applications, the adhesive volume may be very small, but stability requirements are extremely high.
5. Why Is Synchronization with Extrusion Speed So Important?
This is the most critical part of the process.
Extrusion line speed is not always constant.
During production, the line speed may vary due to:
● Startup
● Acceleration
● Deceleration
● Process fluctuations
If the adhesive output remains fixed while the line speed changes:

This may result in:
● Product defects
● Bonding failure
● Material waste

6. Therefore, a Synchronized Hot Melt Dispensing System Is Required
Core operating logic:
Extrusion line speed changes
↓
Encoder detects line speed
↓
PLC calculates target flow rate
↓
Servo motor adjusts pump speed
↓
Adhesive output changes dynamically
7. What Problems Does This Type of System Solve?
7.1 Maintains Consistent Adhesive Amount per Unit Length
For example:
Always maintaining 2g of adhesive per meter
7.2 Maintains Stable Adhesive Layer Thickness
This is one of the customer’s most important concerns.
7.3 Improves Product Consistency
Helps prevent:
Missing adhesive
Uneven coating thickness
Bonding failure
7.4 Enables High-Speed Production
Without synchronized control, high-speed continuous manufacturing is extremely difficult.
7.5 Reduces Adhesive Consumption
Hot melt adhesives are usually expensive, and precise metering can significantly reduce material waste.
8. What the Customer Is Really Purchasing Is Not Simply a “Dispensing Machine”
The customer is actually investing in:
Continuous Manufacturing Capability
Therefore, the real concerns behind customer requirements are:

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.