Question 1

What solutions does axiss offer for dispensing 2K materials?

Accepted Answer

axiss offers electric e-dispensers for directly dispensing 2K materials from dual cartridges. The A and B components are precisely pushed out of the cartridge by pistons and only come together in the static mixer.Typical materials include epoxy resins and polyurethanes. Our electric e-dispensers ensure a consistent flow of both components, enabling precise mixing and an even material

Question 2

What should be considered when choosing the container size for 2K materials?

Accepted Answer

For 2K materials, common cartridge sizes are 50 ml, 200 ml, and 400 ml. When selecting the material, it is important to check whether the required adhesive is available in a suitable cartridge size.For small dispensing volumes with our e-dispensers, smaller dual cartridges are particularly suitable. For dispensing volumes of around 0.1 to 0.2 ml, for example, we recommend 50 ml dual cartridges.Manual filling should be avoided whenever possible, as it can introduce air bubbles or trapped air into the material. If refilling is necessary, it should be carried out professionally by a specialized contract filling service.

Question 3

What role does viscosity play when dispensing 2K materials?

Accepted Answer

The viscosity of the A and B components has a significant impact on the dispensing process. Depending on the material, viscosities can vary considerably and place different demands on the dispensing equipment.With very low-viscosity 2K materials, for example around 1,000 mPa·s, the components can flow very easily through the static mixer. This may cause the material to continue flowing or drip after dispensing has stopped. For these applications, our 4385 shut-off valve with a replaceable shut-off element can be used. It opens and closes automatically, stopping the material flow after dispensing.With high-viscosity 2K materials, sufficient force is required to reliably push both components through the dispensing system and the static mixer. As viscosity increases, the flow resistance and pressure drop within the mixing system generally increase as well.For this reason, our electric e-dispensers provide a maximum force of 5,000 N.

Question 4

What should be considered when dispensing thermal interface materials?

Accepted Answer

Thermal pastes often have a high viscosity and pronounced thixotropic behavior. During dispensing, shear can make the material significantly more fluid, causing it to flow more quickly from the static mixer. After dispensing stops, the material gradually returns to its original viscosity.This behavior can lead to variations in the dispensed volume, especially when dispensing individual dots at short intervals. In such applications, a shut-off valve can help stop the material flow immediately and maintain more consistent conditions in the mixer. Piston retraction can also be disabled to avoid additional pressure changes in the system.

Question 5

What role does dispensing speed play with high-viscosity 2K materials?

Accepted Answer

The dispensing speed can have a significant impact on the dispensing process. Especially with high-viscosity materials, higher dispensing speeds can lead to increased forces and greater back pressure in the static mixer.For this reason, we recommend adjusting the dispensing speed to the specific material during dispensing trials. With our electric e-dispensers, the dispensing speed can be set accordingly.

Question 6

Why should the dispensing speed be kept as constant as possible?

Accepted Answer

Frequent changes in dispensing speed can affect the pressure in the static mixer and, as a result, the material flow. To ensure a stable dispensing process, the dispensing speed should therefore be kept as constant as possible.If different bead diameters are required, the speed of the axis system or robot can be adjusted instead.