Used Galvanizing Lines for Sale — 5

Galvanizing lines process for copper, nickel, brass, tin, and zinc was adapted for commercial purposes. Many of these coated materials were utilized for particular manufacturing and engineering applications. Electroplating is an electro deposition process for producing a dense, uniform, and adherent coating usually of metal or alloys, upon a surface by the process of electrolysis. It is the method of using an electric current to deposit a thin layer of metal over another from a solution containing a dissolved salt of the selected metal. The history of galvanizing precious metal onto common metals can be traced back to around 1800. In the beginning, gold and silver were the most sought metals to be electroplated on other surfaces for obvious reasons such as its value and appearance. There were two main methods commonly employed for depositing gold on other metals. Later on other types of non-decorative metal plating were developed.

Why Galvanizing?

The purpose of galvanizing process is to produce a qualified coating with the desirable attributes. The major reason behind galvanizing materials than manufacturing the desired material as a whole is the high amount of costs involved in the latter. When just a coating of the desired material on another surface is sufficient enough to serve the purpose like corrosion or wear resistance, it is wiser to go for galvanizing rather than directly manufacturing the material. Some of the purposes for which articles are electroplated are:

• To modify their appearance
• To protect the base metal against corrosion, wear etc.
• To induce special surface properties into the base metal
• To improve the engineering or mechanical properties such as hardness, strength, toughness etc.

Electroplated materials are generally used for a specific property or function, although there may be a few overlapping for e. g., a material may be electroplated for making it more decorative as well as for corrosion resistance. Almost all of the galvanizing coatings would come under any of the following six categories: Sacrificial coating, Decorative protective coating, Engineering coating, Minor metal coating, Unusual metal coating, Alloy coating and Multi layered coating.

Galvanizing Line

The parts of a galvanizing machine are described below:

• The external circuit which consists of a source of direct current (DC), for completing the electron flow externally.
• Negatively charged electrode or cathode is the metal to be coated (work piece).
• Positively charged electrodes or anodes are of two types: sacrificial or inert electrodes. Sacrificial anodes are made of the metal to be deposited. Permanent anodes simply complete the electrical circuit, but cannot provide a source of fresh metal to replace what has been removed from the solution by deposition at the cathode. Carbon and Platinum are the commonly used inert anodes.
• Electrolytic solution also called as the bath is the electrical conductor in which current is carried by ions rather than by free electrons as in a metal. Electrolyte completes an electric circuit between two electrodes internally.
• Tank which houses the electrodes and the solution.

Upon the application of electric current, electrolytic decomposition takes place and the metallic ions of the salt in the electrolyte carry a positive charge and are thus attracted to the cathode. When they reach the negatively charged work piece, it provides electrons to reduce those positively charged ions to metallic form and then the metal atoms will be deposited onto the surface of the cathodic work piece.

Types of Electroplating Processes

There are four different types of galvanizing processes commonly adopted in the industries which are:

• Mass Plating – For coating small work pieces in large quantities but it is not used for delicate work pieces.
• Rack Plating – It is done when the work pieces cannot be mass plated because of size, shape restrictions. It involves mounting of jobs on racks for pre-treatment and subsequent coating.
• Continuous Plating – The work pieces to be plated move continuously passing either one row or between two rows of anodes. It is usually performed when the jobs are simple and uniform in geometry.
• In-line Plating – It involves integration of plating and finishing process. Less energy consumption and reduction in waste discharge are some of its advantages.

Applications of Galvanizing Lines

The major advantage of galvanising process is cost effectiveness and any electrically conductive surface can be electroplated. Also special techniques such as coating with metallic loaded paints or silver reduced spray, were also increasingly developed to make nonconductive surfaces such as plastic electrically conductive for galvanizing. Electroplating is carried out on certain materials to make them electrically conductive, highly resistant to larger temperatures and sometimes to make them friction resistant. Galvanising services are widely used in many industries such as automobile, ship building, aerospace, machinery, electronics, jewelry, defense and toy making industries. Copper plating is used to prevent case hardening of steels. Silver plating is used in tableware and electrical contacts while gold plating is carried out extensively in jewelries and watches.

Galvanizing Line Manufacturers

LINHOFF, Technic Inc. - Cranston, RI, SCHMIDT Galvanotechnik GmBH, RIMMLER GmBH, DECKER, AIRCO, DEWE are few of the manufacturers of galvanizing machines in the world.