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RKS CARBON S HQ - the original

RKS CARBON S HQ

The patented RKS CARBON S HQ squeegee is used  today  by customers all over the world who are looking for a high degree of reproducibility, standardization and quality.

 

Extremely high market demands in the solar and microelectronics industry require precision and efficiency to throughput, defined parameters, especially when choosing the right blade type.

 

 

The RKS CARBON S concept meets these market requirements and also offers a variety of carrier support strengths and polyurethane speciation’s so that each individual solar cell can be produced in the highest quality and efficiency.

Whether its  fine lines or layer thicknesses below 50μ, from the printing of cavities to "all-over" layer thicknesses this enables Carbon S to be optimized and tailored to the particular print profile requirements.

Product example:

30mm high / 3mm Polyurethane thickness
30mm high / 6mm Polyurethane thickness
30mm high / 8mm Polyurethane thickness
50mm high / 3mm Polyurethane thickness
50mm high / 6mm Polyurethane thickness
50mm high / 8mm Polyurethane thickness
(incl. machining)

RKS CARBON S HQ

Squeegee height :

Available - from 20mm   to 115mm

Squeegee length:

Available - from 100mm to 2.600mm

Carrier thicknesses :

1,2mm , 1,7mm 2,5mm

PU - thickness:

3mm , 6mm , 8mm

Shore hardness (DIN A)

55°, 65°, 75°, 85°

The RKS Carbon S HQ squeegee are purposefully produced with backing support thicknesses of 1.2 mm, 1.7 mm and 2.5 mm.

RKS has managed to bring the present state of the art, the mechanical strength, the required flexibility, and solvent resistance together with abrasion resistance to the best possible mixture.

Before now it was difficult to keep to production times as down time was difficult to predict this is made easier with the use of the RKS squeegee.

The Carbon S squeegee requires less contact pressure than conventional squeegee. The stencils are put under less stress and the overall mechanical stress on the printing machines can be reduced. 

The different carrier thicknesses of 1.2 mm, 1.7 mm and 2.5 mm, offer  the individual user the possibility of adjusting to the desired flexibility and maintaining squeegee pressure and  maintaining print specifications.

A 1.2 mm Carbon S blade offers more flexibility than, for example, a 2.5 mm "thick" Carbon S blade which then far more inflexible, and so has an excellent recovery strength.

To put it simply the more rigid the carrier the finer the line print or lower print/paste thickness.

The Carbon S HQ blades are produced with polyurethane thickness of 3 mm, 6 mm and 8 mm.

As with the selection of the various carrier support thicknesses, the thickness of the polyurethane and its flexibility the requirement is often completely different, although the printing applications are very similar.

While an 8 mm thick print edge still represents is very flexible and so provides a higher lay down of paste / ink ware as a 3 mm thick much more un-flexible thereby allows a lower pastes / ink lay down.

We generally see the different carrier support thicknesses and variable polyurethane widths a form of "fine tuning" in precision screen printing, this is regardless of the selection of the appropriate Shore - hardness.

Reproducible and standardized screen printing

The RKS CARBON S HQ blade is made of a molded carbon fiber reinforced plastic profile, in short CRP, which is irremovably  linked to a high-performance elastomer (HQ).

The CFRP profile remains in comparison with a conventional squeegee dimensionally stable, so it retains a constant and plane-parallel print edge.

 

Conventional polyurethane squeegee (whether diamond, or two/three layered blade) changes through contact pressure and is uncontrollable in turn affecting the printed end result.  

Due to the effects of solvent and other ingredients, the properties of the blade material can be change permanently.

The more print medium that is absorbed in the un clamped/exposed part of the blade and less in the clamped part of the blade so the more distorted the printing edge becomes!

In the area of fittings screws the solvent absorption is particularly critical. Here penetration between the fixing screws the more penetration of the ink at these points. (This inevitably leads to an undefined swelling behavior of the squeegee blade in the downward direction towards the print edge)

IMAGE: Conventional polyurethane squeegee (65 Shore A DIN) in size 50/10.

 

This image illustrates the changes in the dimensions and weight due to the absorption of solvent over a time period of 48 hours.

Change in Shore - Hardness: 65 Shore (DIN A) to 45 Shore (DIN A)

Already after the first 30 minutes the PU starts to change and the squeegee starts to influence the printed results.

 

The squeegee loses its hardness (Shore), this leads to higher application pastes and permanent damage to the printing edge.

 

This has the following direct effects:

 

- Print angle

- Squeegee pressure

- Recovery time

- Pastes / ink application

- Line definition

 

This makes it virtually impossible to maintain the initial paste/ink deposits and printed sharpness constantly throughout the whole print run.

   

Because of this screen printing remains a difficult to be reproduced experiment!