Jan Kudláček

Hot-dip galvanizing and the environment

Modern hot-dip galvanizing devices are designed with the consequent use of BAT and are operated so that their impact on the environment, whether it is a production of hazardous waste, emissions into the air, or to soil, is minimized. Emissions are consistently monitored. Waste production is minimized by proper management of chemical pre-treatment solutions and is subject to strict controls.

Properties of Functional Epoxy Coatings Modified by Carbon Nanoparticles

Properties of commercially available epoxy coating were modified using multi-walled carbon nanoparticles (MWCNT) to obtain functional coating with improved abrasion resistance. Simultaneously, corrosion resistance of the epoxy resin could not be negatively affected by the particles addition. Composite coatings with various MWCNT content were prepared and evaluated with regard to their function by abrasion and corrosion tests. We found out that the abrasion resistance of the coatings increased with increasing amount of CNT particles in the matrix. Corrosion protection properties of pure epoxy coating as well as its adhesion were slightly improved by adding 0.5 and 1 wt% MWCNT.

Chemical pre-treatment

The requirement for successful galvanizing is a perfectly clean surface of the steel parts to be galvanized. In the industrial process this is achieved by degreasing and pickling. Prior to immersion in molten zinc, the surface of the part is activated by a flux, which dissolves oxides on the surface and reduces the surface tension of the liquid zinc. Optimal efficiency of the chemical pre-treatment is achieved by proper care of these solutions.

Hot-dip galvanizing

A coating consisting of iron-zinc alloy phases, which are formed during a metallurgical reaction between the two metals, is being applied on the hot-dip galvanized steel components. The piece galvanizing, industrially carried out, is a wet or dry process. The continuous galvanization equipment is intended for bands or wires. Small parts are galvanized in devices with centrifugation.

Luminescence method − instrument used for detection of surface cleanliness

Preliminary notes The process of surface treatment has a significant role in several industrial applications. Among the processes that most affect the quality of surface treatment are mainly the pre-treatment processes aimed at cleaning the processed surfaces. Degreasing of the treated surfaces has in this technological phase an important role. The article is devoted to quality control after surface pre-treatment. It deals with modern method for detecting grease-based surface contamination by the luminescence method. Impurities such as grease, oil and others have characteristic luminescence after illumination by UV light source. This principle can be used to determine the cleanliness of the part’s surface thereby ensuring the quality of the observed surface. Surface cleanliness is a very important factor for the correct application of subsequent technological processes.

Synthesis of zinc–polytetrafluorethylene composite coatings based on electroplating

This article covers the development of the synthesis of the zinc coatings with dispersed polytetrafluorethylene particles (zinc–polytetrafluorethylene composite coatings). The technology was based on zinc electrolytic plating in weakly acid bath. After optimising the parameters of the technology according to the results of coating analyses by infrared spectroscopy and tribological measurements, it was possible to prepare zinc coatings with homogenously incorporated polytetrafluorethylene. This ensured significantly lower friction coefficient of these coatings in comparison with pure zinc coating. The corrosion resistance and self-lubrication character of zinc–polytetrafluorethylene coatings is promising in potential replacement of existing multi-layered zinc coating systems.

Complex Control Method of Degreasing Process

This chapter deals with possibilities of complex control of the degreasing process in industrial applications, i.e., especially the possibilities of checking the state of the surface of the product before and after the degreasing process and checking the condition of degreasing liquids using UV-Vis spectroscopy.

Internal Stresses Analysis in the Shrink-Fitted Joints of the Assembled Crankshafts

The paper describes investigation results aimed to the assessment of the shrink-fitting of the marine diesel crankshaft elements. Since the crankshafts are of the large size (above 20 m) and weight (above 300 tons), the models were made in scale 1:5, keeping the same technical conditions. The measurement of internal stresses was made by a non-destructive ultrasonic method. The obtained results confirmed the existence of the zones where stresses had crossed the yield points, which meant the plastic deformation and weakening of the interference fit.

Alternative Methods of Chemical Pre-Treatment on Hot-Dip Galvanization Surface for Adhesion Organic Coatings

The first part of this paper deals about chemical surface pre-treatments of zinc and the impact of alternative pre-treatments for adhesion of organic coating. The second part is devoted to the experimental part, and there was created several surface pre-treatments of hot-dip galvanization and subsequently applied two kinds of organic coatings. The objective was a comparison of chemical pre-treatments, mechanical pre-treatment and the effect each of them on the adhesion of the organic coating. It was created seven variants pre-treatment of hot-dip galvanization surfaces. Adhesion of these systems was investigated by pull-off test according to CSN EN ISO 4624, adhesion test with X-cut tape test according to ASTM D 3359, adhesion crosscut test according to CSN EN ISO 2409. In this work was investigated two coating systems at six chemical and one mechanical pre-treatment of the surface of the hot-dip galvanization.

The architecture of manufacturing process

Nowadays, simulation as a progressive virtual application as well as a didactic method is playing a more and more important role in not only in the automation industry, where it saves time and costs development. Simulating the production processes can bring massive cost savings. Technically demanding applications such as metal forming, machining, heat treatment, casting and plastics injection molding require powerful material and geometric non-linear capabilities, adaptive meshing and a user environment that speaks the language of manufacturing and process development engineers.