Surface Protection

PLASTIFICATION

Surface protection of aluminum by electrostatic dyeing – plasticizing in Alu Holding is carried out in a brand new, state-of-the-art facility that guarantees the fulfillment of strict world standards.Aluminum Products (Profiles and Supporting Elements) Electrostatically Powder Coated with Polyester Powder CoatingsQUALICOAT. It is possible to plasticize aluminum profiles of all configurations with a maximum length of up to 7 m and sheets with a maximum dimension of 7 m x 1.7 m.
The exceptionally high capacity of the plant (150 tonnes of aluminum profiles per month) is designed not only to meet the needs of our own production, but also to provide plastics services to external customers.
The facility has three different powder coating booths, which provides extremely high flexibility and the ability to plasticize even the smallest amount of aluminum profiles.
Of particular importance is the fact that the provision of services to external customers can be organized in one day, with prior appointment.

The chemical preparation process consists of the following stages: degreasing, deoxidation, rinsing, passivation, rinsing in demineralized water, drying with warm air.
Chemical preparation is done by the technology of a reputable German company“SurTec”, with full technological support, which is a longtime partner of our company.

  • Passivation in a 0.5 – 1.5 micron layer provides complete corrosion protection and excellent plasticization support, in accordance with the recommendations of the standard QUALICOAT.

  • Electrostatic powder application (in one of three cabins) is done with the latest equipment from a Swiss company “ITW GEMA”. Powder application is completely even and programmed for each profile, depending on the profile configuration.

  • Powder polymerization is performed in a sensor furnace in which there is a constant of temperature during all three phases of polymerization (profile heating, powder polymerization and profile cooling).

    The thickness of the polyester powder layer is 60 – 80 microns, which allows complete surface protection of aluminum from further external influences. The thickness of the layer and the quality are measured on each piece of the final product in the company’s own laboratory, and in accordance with the standards and requirements of QUALICOAT.

The process is optimized to:

  • the best price

  • the shortest period of service

  • najviši kvalitet  po QUALICOAT standardu

Stručni tim tehnologa pruža potpunu tehničku podršku za sve zahteve i pitanja kupaca.

Anodisation

Anodic oxidation of aluminum profiles is carried out in a brand new plant with a capacity of 60000 A. The process takes place in 25 different bathrooms and guarantees the fulfillment of strict European standards “QUALANOD”. Anodizing and electrochemical staining is done on its own map and with the tone map of the European Association of Anodic OxidationEURAS  (which are compatible)  starting from the natural color of aluminum, over light bronze, medium bronze and dark bronze to black.Anodizing of aluminum profiles of all structures and lengths up to 7.5 m and sheets of maximum dimensions 7.5 m x 2.0 m is possible. The thickness of the oxide oxide layer is 10, 15, 20 or 25 microns, depending on the customer’s requirements and the purpose of the profile. The capacity of the plant is 450 tons of aluminum profiles per month and is designed not only to meet the needs of its own production but also to provide services to external customers.

The technological process consists of the following stages:

  • Mechanical preparation performed by brushing profiles with a modern high – performance machine SPAL 104. The machine is equipped with fine stainless steel brushes that give a uniform appearance to a significant profile surface;
  • Mechanical preparation performed by blasting aluminum profiles. Sandblasting is performed by a very powerful machine for sandblasting stainless steel balls, so that a very uniform surface is obtained.
  • Chemical preparation that degreases and corrodes the aluminum surface to produce a high quality alumina layer at a later stage. By adding a satin agent, a fine silky aluminum surface is obtained at the end of this phase.
  • Anodic oxidation — an electrochemical process that artificially creates an aluminum oxide coating on the metal surface, which at the same time plays a protective, decorative and functional role. Anodic protection of aluminum and its alloys achieves corrosion protection, electrical insulation, increases abrasion resistance, adhesive bonding, which is important for eventual coating, etc.

The quality of the anode layer depends on the quality of aluminum, mechanical and chemical preparation, electrolyte concentration, temperature and current density. Significantly, the control of these parameters is not left to the human factor alone, as there is computer programming and monitoring. The software constantly monitors and controls the process of anodization, uniformity of current density, concentration of solution, temperature, and thickness of the anode layer. When the preset thickness of the layer is reached, the rectifier shuts off and the achieved results remain written to the computer, which enables the written reports on the achieved quality of anodizing of individual batches.

The total capacity of the pulse rectifiers is 60000 A, which allows for anodization about  450 t aluminium profilesper month.

  •  Electro-chemical dyeing – a phase in which all anodizing colors are obtained except the natural color of aluminum in such a way that metal ions are deposited in the pores of the anode layer. 

A uniform anode layer achieved in the previous phase of anodic oxidation, good electrolyte concentration and constant current density are required for color uniformity.At this stage, the control and control is carried out with the help of a computer, which can set up to 70 different programs for color shade, voltage and color time. This means that all the solutions in the technological process of anodizing are automatically and constantly dosed according to pre-programmed and set parameters.The key equipment at this stage is the TECNO 4 transformer, which allows the large batches to be evenly colored in electro-colored bathrooms. Its greatest advantage is the ability to increase and penetrate current on sheltered surfaces;

  • Final seling – quality permanent closing of aluminum oxide pores. 
  • Final packing of profiles – by wrapping paper or PVC tape of a group of several profiles, depending on their configuration.

The final products of anodic oxidation are tested daily in our own laboratory according to QUALANOD standards, under the guidance of a team of technologists with years of experience, which guarantees the quality of the delivered product.