Frequently Asked Questions

1.    What does Pallas need in order to prepare an offer?

We need specifications of the dimensions and weight of the component. It also helps if you can give us drawings or photos. The properties and delivery condition of the component give us an indication of any preparatory work that may be required. If you cannot name the type of coating (zinc, nickel, PTFE or carbide, etc.), please specify the application details (operating temperature, atmosphere, wear and corrosion conditions, etc.).

 

2.    How does Pallas calculate the time required for a coating?

The average time required for a coating depends on four factors:

-      the size and shape of the component to be coated

-      the quality of the base material

-      the selected procedure 

-      the plant capacity

 

3.    What does PTFE stand for?

Polytetrafluoroethylene is a fully fluorinated polymer. Its non-stick properties and its very low coefficient of friction make it the coating of choice for a wide range of technical applications. PTFE coatings are particularly suitable for use in the food-processing industry and in branches of industry that work with aggressive chemicals or where plastics have to be demoulded. Click here for more details…  

 

4.    What requirements must a component fulfil so that it can be coated with PTFE?

As a rule, a component has to go through three main processing stages, each of which places particular demands on it:

-      The previous coating – or in the case of new components any grease or other organic residues – are removed and the surface of the component is lightly roughened. Ideally, this is done with a jet of white corundum. The component must be stable enough to withstand this sand blasting.

-      Next, several coats of lacquer are sprayed on. This means that the surfaces of the component that are to be coated must be easily accessible.

-      Finally, the PTFE coating is sintered on at temperatures ranging from 260 °C to 420 °C. The component must be able to withstand these temperatures.

 

5.    Can a PTFE coating lead to deformation of the component?

Blasting with white corundum causes tension on the surface of the component. Depending on the geometry of the component, this tension may lead to deformation in the case of thin or long and very flat components. In the case of machined components, the tension introduced during roughening may disperse at process temperatures of up to 410°C and lead to deformation. However, this is unlikely in the case of components that have been coated before, as they will have already been exposed to such temperatures.

 

6.    What's the difference between technical coatings of hard chromium and laser hardening?

Technical coatings of hard chromium provide excellent wear and corrosion protection. A homogenous hardness profile is achieved with working materials like steel, iron or non-ferrous metals. Hard chromium coatings also give the components additional characteristics like good antifriction properties. Laser hardening is only suitable for components made of hardenable types of steel. A laser beam is used to put a precise, localised wear-resistant finish on the critical parts of the component. The hardness profile depends very much on the types of steel used. Depending on the geometry of the component, there may be a risk of distortion.

 

7.    What is electroplating?

In electroplating, components are enhanced with functional metallic coatings. They are moved through electrolytic baths containing an aqueous solution of metal salts in which they are given custom-configured coating thicknesses that provide optimal protection against wear and corrosion. Click here for more details… 

 

8.    What does thermal spraying mean?

Thermal spraying applies to a wide range of processes in which the selected coating material, in the form of wire or powder, is melted by means of a variety of burner systems and sprayed onto the surface of the component. Depending on the material, coating thicknesses of up to several millimetres are possible. In addition to wear and corrosion protection, the electrical, temperature-resistant or mechanical properties of the component can also be enhanced. Multifunctional coating systems are also possible. Click here for more details…  

 

9.    Which branches of industry rely on thermal sprayed coatings?

The industrial sectors in which thermal spraying is used include the automotive industry, food-processing, textiles and paper, printing, mechanical engineering and even medical technology and the aerospace industry.

 

10.   What's the difference between laser coating and laser alloying?

In laser alloying, the base material of the metallic surface of the component is melted using a laser beam, a filler material is applied to the surface and remelted so that alloys with the base material. In contrast to laser coating, where a separate layer is added, in laser alloying the degree of intermixing of base material and filler material is much greater.

 

11.   What are duplex and triplex coatings?

Duplex and triplex coatings are combination coatings of a wear-protective metal or ceramic layer and a sealing surface layer with non-stick or non-friction properties. Click here for more details…

 

12.   What does Eloxal mean?

Eloxal stands for electrolytic oxidation of aluminium. In an electrochemical process called anodic oxidation, a layer of oxide is formed on the surface that is firmly bonded with the aluminium substrate. Typical layer thicknesses range around 15-20 µm, with about two thirds of the layer fusing into the surface and one third building an outer layer. Click here for more details…  

 

13.   What are the advantages of laser coating over conventional welding procedures?

With laser coating, a denser coating with consistent thickness and minimal porosity is achieved. The surface structure is finer and the coating can be placed more precisely. In addition, the processing time is shorter. Another advantage is that the component is exposed to a lot less thermal stress. Click here for more details…  

14.   Are there ecological factors that favour surface finishing technology?

Surface enhancement increases the service life of components and equipment. This saves on the scrap and disposal costs that would be incurred in the production of replacement products. The extreme durability of surface-enhanced products and the economical use of coating materials mean that valuable sources of raw materials are protected. Click here for more details…