How To Fill Adhesive Sealant Or Grease on Tube Filling Machine

Recently, I have frequently encountered clients consulting me about filling solutions for high-viscosity special materials, such as sealing compound aluminum tube filling machines and grease plastic tube filling solutions.

The viscosity of sealing compounds ranges from 6,000 to 20,000 cP, while the consistency of grease falls between NLGI 000 and 6#. Before providing a solution, I believe it’s necessary to briefly explain viscosity and consistency to ensure better understanding.

What is Viscosity?

Viscosity is typically defined as a liquid's internal resistance to flow.

Units of Viscosity

The main units of viscosity include:

• Dynamic viscosity: Pascal-second (Pa·s)

• Kinematic viscosity: Square meters per second (m²/s)

• Commonly used derived units: centistokes (cSt) and centipoise (cP).

Dynamic Viscosity Units

The SI unit for dynamic viscosity (also called absolute viscosity) is the Pascal-second (Pa·s), with dimensions of M/(L·T).
1 Pa·s = 1 Newton-second per square meter (N·s/m²), representing the internal friction resistance of a fluid under shear stress.

Common derived units:

• Poise (P) and centipoise (cP):
  1 P = 0.1 Pa·s
  1 cP = 1 mPa·s

In the selection of filling equipment for materials, we often use dynamic viscosity units for evaluation.
For reference:

• Water at 20°C has a viscosity of 1 cP.

• Honey has a viscosity of around 10,000 cP.
  Viscosity can vary with temperature and dilution levels. Similarly, each material has its corresponding viscosity value.

In the application of tube filling and sealing machines, most materials we encounter have good fluidity and can be filled using peristaltic pumps, ceramic pumps, or piston pumps. However, highly viscous materials like sealing compounds or grease are not suitable for these conventional filling methods. Below is a detailed analysis:

Pump Selection Based on Viscosity

Different pumps can be selected to match materials of varying viscosities:

• Medium viscosity (1,000–50,000 cP): A lobe pump or rotary valve pump is a good choice.

• High viscosity (50,000 cP and above): A specially designed high-viscosity rotary valve pump with a pressure device is more suitable.

How to Determine Viscosity

If the exact viscosity is unknown, you can observe the material’s flowability by transferring it from one container to another. Recording a video and sharing it with me will help me determine and provide a specific filling solution.

Special Cases: Grease

Some materials, such as grease, cannot be described using viscosity. Instead, grease uses a special consistency measurement (NLGI grade), which cannot be converted to viscosity.

For grease filling, we have dedicated solutions:

• For NLGI grade 1 and above, the consistency is high, nearing a semi-solid state. Conventional pumps alone are insufficient for filling, so we typically equip them with pressure-assisted devices to actively feed the material into the pump for filling.

How to Determine the Right Solution

Similarly, you can:

1. Provide the NLGI grade, or

2. Share a video demonstrating the grease’s penetration level.

I will then help determine and provide the most suitable filling solution.

Please let me know if you need any further adjustments or additional details!

More details about the high-viscosity materials tube filling and sealing machine, Pls contact me!!

Ava Duan

Mobile/Wechat/Whatsapp: 0086-13706885851

Email: sales@grand-packing.com