Vulkollan®

Vulkollan FAQ

What is Vulkollan and what applications is it used for?  

Vulkollan® is the most widely distributed polyurethane elastomer and is more than ever the quality standard. Vulkollan® is also a hot-cast polyurethane and is therefore always superior to cold-cast polyurethanes. 

In which hardnesses is Vulkollan® produced?

For specific applications, there are also productions of 80 shore A. Rubbers : 25 - 80 shore A. Plastics : 55 - 95 shore D. Vulkollan : 80 - 90 - 95 shore A. The optimum properties of Vulkollan® are realised at a hardness of 90 shore A. Vulkollan® 95 shore A offers the advantage of a higher load-bearing capacity (approx. 15% higher than with VK 90 shore A), while Vulkollan® 80 shore A can offer a solution where better grip on the running surface is required.

What is the tensile strength of Vulkollan® compared to other materials?

Vulkollan® has high elongation + high tensile strength + high rigidity. Vulkollan® 90° shore A can be stretched to almost 7 times its original length. Plastics and metals: high tensile strength + high stiffness, but small elongation, and very small elasticity. Rubbers: large elongation, but small tensile strength + small stiffness.

How resistant is Vulkollan® to cracking?

Vulkollan® has very good tear resistance. Moreover, its tear resistance when notched is also very good. Although lower than when not notched, the tear resistance is not matched by any non-reinforced elastomer, according to Graves. Vulkollan® is insensitive to cut damage and even if the covering was damaged, the material does not break further and thus remains functional.

At what temperatures can Vulkollan® be used?

Vulkollan® remains elastic and shock absorbent down to - 40°C. At temperatures up to approximately 125°C, with the exception of modulus of elasticity, a reversible reduction of most properties occurs. Resistance to cracking, and therefore resistance to wear, are greatly reduced at temperatures above 80°C. At temperatures above 125°C, permanent damage to the chemical structure occurs.

Does Vulkollan® have a longer lifespan than rubber?

Vulkollan® has exceptionally good abrasion resistance and has up to 2 times less volume loss through wear than natural rubber. Softer Vulkollan® often has lower wear than the harder ones because the Vulkollan® can give way. To maintain optimum wear resistance, the temperature should not be too high.

How strong is Vulkollan® adhesion?

DM Wheel Systems has a special surface treatment that realises optimal chemical adhesion to all metal surfaces (cast iron, steel, aluminium, stainless steel, ...) We guarantee at room temperature and neutral chemical environment, the Vulkollan® adhesion to the metal is as strong as its own tensile strength.

Can Vulkollan® still be machined after it has been cast and polymerised?

Vulkollan® can still be machined, but the elastic characteristics of the material must be taken into account. For this, DM Wheel Systems has experienced technical people who can turn, mill and drill the Vulkollan® without any problems.

How do environmental influences affect quality?

The natural colour of Vulkollan® is yellow-brown. Under the influence of UV light, Desmodur 15 causes Vulkollan® to darken to black. Colour changes, even uneven ones, do not affect quality.

What can be done about hydrolysis?

Hydrolysis is the decomposition of polyurethanes by contact with (hot) water. In hot and humid environments, hydrolysis degradation can be slowed down by adding STABAXOL to Vulkollan®..

Problem of flatness during prolonged downtime under load. What about Vulkollan®?

Vulkollan® has a very small permanent deformation compared to other polyurethanes. As a result, wheels with Vulkollan® suffer the least from "flat sides", also called the Monday morning sole.

Is Vulkollan an insulator or a conductor?

Vulkollan is an insulator.  However, after extensive research, Vulkoprin has managed to develop an electrically conductive Vulkollan as well.  This Vulkollan C otherwise has almost the same properties as the standard Vulkollan, but has an electrical resistance noticeably lower than 10^4 Ohm (standard to be able to use the term 'electrically conductive').  Vulkollan C is produced in black (non-marking !), as is common in the wheel industry for antistatic (electrical resistance between 10^5 and 10^7 Ohm) or electrically conductive (resistance < 10^4 Ohm) wheels.