PRE-TREATMENT APPLICATIONS

-        Phosphate coating

-        Surface cleaning with special solvents

-        Aluminum chromate coating

-        Sandblasting

Phosphate Coating

What is Phosphating?

When ferrous and non-ferrous metals combine with the oxygen of the air, they undergo oxidation and cause corrosion. Thanks to the surface treatments, the metal is protected by preventing corrosion.

Phosphating is the formation of an insoluble phosphate layer on the surfaces by treating metal surfaces free from oil, rust, grease, oxide layers with a metal phosphate (zinc, iron or manganese phosphate) solution. This process can be used especially on iron and steel surfaces, as well as on aluminum, zinc, cadmium and magnesium-type metal surfaces.

Phosphating and black oxidation in iron and steel materials, and anodized and chromium-free coating / chromate coating in aluminum and aluminum alloys are prevented and a suitable environment is created for the next process.

 

Phosphate Coating Types

Iron Phosphate: The most suitable phosphating type for metal parts working or stored in a closed environment is iron phosphate coating due to the low investment cost and the low unit costs of the chemicals used. Iron phosphate coating chemicals can be applied by hand wiping, dipping or spraying before coating metal parts that do not require very high corrosion resistance.

Zinc Phosphate: It is used under corrosive conditions when a long material life is desired. It increases the adhesion of the paint to a zinc phosphate coated surface. Zinc phosphate crystals form a porous layer on the surface and they can absorb the paint film layer and adhere mechanically. Thanks to this feature of zinc phosphate, surfaces that are much more resistant to corrosion are obtained. On the other hand, in zinc phosphate systems, the number of processes is high and the control of baths is more difficult.

Manganese Phosphate: It has a black color, rough structure. They form a crystalline porous layer on iron and steel surfaces. Manganese phosphate acts as a layer on the metal surface. It is widely used in gear, piston and weapon industries due to its oil absorption and long-term retention properties. It facilitates the sliding of moving machine parts working in oily environments. It reduces the friction between metals. It has a structure that is more resistant to pressure and temperature than zinc phosphate. Immersion tank temperature and waiting time is higher than zinc phosphate.

 

Single Cation (Zinc)

Two Cations (Zinc - Nickel)

Three Cations (Zinc - Nickel - Manganese)

The three-cation zinc phosphate coating mentioned above is used today especially in the automotive and white goods industry. This kind of phosphate coating has higher corrosion resistance than others.

• The important factors affecting the selection of the process are:
• The structure of the metal to be coated,
• The shape and condition of the metal,
• The number of parts to be coated and
• The homogeneity of the surface condition,
• The working intensity of the coating bath,
• The number of baths.

Phosphating process can generally be listed as follows;

1. Degreasing and cleaning,
2. Rinse,
3. Removing rust and scaling,
4. Rinse,
5. Activation,
6. Phosphating,
7. Rinse,
8. Finishing (Passivation or neutralization).

 

The bathroom layout given above is an ideal order. The process sequence can be lengthened or shortened depending on the circumstances. For example, if there is no rust on the metal surface, there is no need for acid rust removal. On the other hand, some steps can be combined, phosphatizing and degreasing can be applied in the same bath. These phosphating types are generally applied to iron and steel surfaces, and less frequently to zinc-coated (galvanized) surfaces.

 

 

 

 

The industrial applications of phosphate coating can be given as follows:

• Steel Industry
• Defense Industry
• General Industry (White Goods, Machinery Industry etc.)
• Automotive Main Industry (All bodywork parts are phosphated before coating)
• Automotive Supply Industry

 

What is Sandblasting?

Sandblasting is a method applied to remove oil, dirt, rust and corrosion due to the rust and corrosion of the metal over time and to extend the life of the metal by coating. Sandblasting is done with specially manufactured grit, various abrasive materials. Sandblasting reveals the essence of the metal, as well as eliminating visible or micronized rust and corrosion on the metal surface. If the metal is left in a humid environment after the sandblasting process, it is observed that it is exposed to oxidation, which manifests itself with color change within a few hours. For this reason, the sandblasted metal should be protected as soon as possible, and the contact of the metal with air should be stopped by coating.

As Elax Boyama ve Kaplama, we make these applications professionally by our trained and experienced employees. The aim of the sandblasting process is to completely clean the metal to be applied and to create pores and roughness where the paint to be applied can hold on the metal surface. The sandblasting process provides a roughness just like sandpaper. It is not possible for the applied paint to adhere to the metal surface by any chemical reaction. In order for the adhesion to be complete, the surface should be roughened with suitable abrasives.

 

Sandblasting Application:

Sandblasting is the process of impacting the sand to the metal surface with high pressure. It cleans unwanted substances such as dirt, oil, rust on the surface. Sandblasting pots are used for open area sandblasting. Sandblasting of ships or large structures in shipyards is performed with open systems. Smaller blasting booths are set up for medium-sized pieces. The surface cleaning of the parts is done in this cabin. Small and closed system sandblasting cabins are among the ideal sandblasting techniques for companies with small spaces.

BURAYA KADAR KONTROL ETTİM

Automatic or Manual Sandblasting?

Turbine automatic sandblasting machines are used for sandblasting of unwelded, profile or sheet materials and steel material that has been cut-welded in certain dimensions. The biggest advantage of the automatic sandblasting system is that the materials that can enter the machine can be blasted economically quickly. The downside is that large parts do not fit in automatic machines. For example; Shipbuilding or large construction equipment in shipyards will not fit into automatic sandblasting machines. Manual sandblasting is applied for this type of large machines.

 

What Are the Materials Used in Sandblasting?

Various sandblasting abrasive materials are used in sandblasting machines. These materials; Abrasives such as stainless steel balls, glass beads, aluminum oxide balls, steel grids, basalt silica, quartz can be used. Especially silica sand is used together with the very light sandblasting technique. Using silica sand will ensure that the surface is not damaged. Grid is the type of sand with the highest blasting power. Grid, also known as iron residue, is used especially on large surfaces. Protective products such as nozzle, nozzle holder, mask and gloves should be used while sandblasting. This helps both for safety and for efficient work.

How to Determine the Sandblasting Quality:

There are some standard ratings around the world for determining the quality of blasting. Swedish Standard in Turkey, "Swedish Standards For Ground Vibrations and Airblast" SA 1, SA2 and SA3 SA2,5 degrees are used. These grading measures have been accepted exactly as TS EN ISO 8501-1 on 08.04.1999 by the TSE.

Surface cleaning values according to 3SA standards are as follows according to ISO 8501-1.

 

SA 1: <80% LIGHT CLEANED

SA2: 80% WELL CLEANED

SA2.5: 96% VERY WELL CLEANED

SA3: 99% FULLY CLEANED