10 classic materials surface treatment processes!

The purpose of surface treatment is to meet the corrosion resistance, wear resistance, decoration or other special functional requirements of the product. Our more commonly used surface treatment method is mechanical grinding, chemical treatment, surface heat treatment, spraying surface, surface treatment is to clean the workpiece surface, cleaning, deburring, oil, oxidation skin, etc. Today we will learn about the lower surface treatment process.

Common surface treatment processes are:

Vacuum electroplating, electroplating process, anodic oxidation, electrolytic polishing, pad printing process, galvanized process, powder spraying, water transfer printing, screen printing, electrophoresis, etc.

01. Vacuum electroplating

Vacuum electroplating is a physical deposition phenomenon. That is, argon is injected in a vacuum, and the argon hits the target, which is separated into molecules that are adsorbed by the conductive goods to form a uniform and smooth metal-like surface layer.

Applicable materials:

1, many materials can be vacuum plating, including metal, hard and soft plastics, composite materials, ceramics and glass. The most common surface treatment for electroplating is aluminum, followed by silver and copper.

2, natural materials are not suitable for vacuum plating treatment, because the moisture of natural materials will affect the vacuum environment.

Process cost: In the vacuum plating process, the workpiece needs to be sprayed, loaded, unloaded and resprayed, so the labor cost is quite high, but it also depends on the complexity and quantity of the workpiece.

Environmental impact: Vacuum electroplating has very little environmental pollution, similar to the impact of spraying.

02. Electrolytic polishing

Electropolishing is an electrochemical process in which atoms of a workpiece immersed in an electrolyte are converted into ions and removed from the surface by an electric current, resulting in the removal of fine burrs and increased brightness.

Applicable materials:

1. Most metals can be electrolytically polished, most often for the surface polishing of stainless steel (especially for austenitic core grade stainless steel).

2. Different materials can not be electrolyzed at the same time, or even put in the same electrolytic solvent.

Process cost: The whole process of electrolytic polishing is basically completed by automation, so the labor cost is very low. Environmental impact: Electrolytic polishing uses less harmful chemicals. The whole process requires a small amount of water and is simple to operate. In addition, it can extend the properties of stainless steel and play the role of delaying corrosion of stainless steel.

03. Pad printing process

The ability to print words, graphics and images on irregularly shaped surfaces is now becoming an important specialty of printing.

Applicable materials:

Pad printing can be used for almost any material, except for materials softer than silicone pads, such as PTFE.

Process cost: Low mold cost, low labor cost.

Environmental impact: Because this process is limited to soluble ink (which contains harmful chemicals), so it has a great impact on the environment.

04. Galvanizing process

The surface treatment technology of plating a layer of zinc on the surface of iron and steel alloy material is beautiful and rust proof. The zinc layer on the surface is an electrochemical protection layer, which can prevent metal deterioration. The main method is hot dip galvanizing and electric galvanizing.

Applicable materials:

Because the galvanizing process relies on metallurgical bonding technology, it is only suitable for the surface treatment of steel and iron.

Process cost: No die cost, short cycle time/medium labor cost, as the surface quality of the workpiece is largely determined by manual surface treatment before galvanizing.

Environmental impact: Because the galvanizing process has increased the service life of iron and steel parts for 40-100 years, it can well prevent the rust and deterioration of the workpiece, so it has a positive effect on protecting the environment. In addition, the zinc-plated workpiece can be returned to the galvanized tank after its service life expires, and the repeated use of liquid zinc will not produce chemical or physical waste.

05. Electroplating process

The use of electrolytic effect to attach a layer of metal film on the surface of the parts of the process, so as to prevent metal oxidation, improve wear resistance, electrical conductivity, reflective, corrosion resistance and improve the appearance of the role, many coins are also electroplated outer layer.

Applicable materials:

1. Most metals can be electroplated, but different metals have different levels of purity and plating efficiency. Among the most common are: tin, chromium, nickel, silver, gold and rhodium.

2. ABS is the most commonly used plastic for electroplating.

3. Nickel metal should not be used for plating products that touch the skin, because nickel is irritating and toxic to the skin.

Process cost: No mold cost, but fixture is required to fix the parts/time cost depends on the temperature and type of metal/labor cost (medium - high), depends on the specific type of electroplating parts, such as the plating of silver and jewelry requires extremely skilled workers to operate, because of its high requirements for appearance and durability.

Environmental impact: A large amount of toxic substances will be used in the plating process, so professional shunt and extraction is required to ensure minimal environmental impact.

06. Water transfer printing

It is a way of using water pressure to print color patterns on the surface of 3D products. With the improvement of product packaging and surface decoration requirements, water transfer printing is used more and more widely.

Applicable materials:

All hard materials are suitable for water transfer, and materials suitable for spraying must also be suitable for water transfer. The most common are injection molding parts and metal parts.

Process cost: there is no mold cost, but it needs to use jig to carry out water transfer printing of multiple products at the same time, and the time cost is generally less than 10 minutes per cycle.

Environmental impact: Compared with product spraying, water transfer printing makes fuller use of printing coatings, reducing the possibility of waste leakage and material waste.

07. Screen printing

Through the extrusion of the scraper, the ink is transferred to the substrate through the mesh of the text part, forming the same text as the original. Screen printing equipment is simple, easy to operate, printing, plate making and low cost, strong adaptability.

Common prints are: color oil paintings, posters, business cards, bound covers, commodity labels and printing and dyeing textiles.

Applicable materials:

Screen printing can be done in almost any material, including paper, plastic, metal, pottery and glass.

Process cost: Mold cost is low, but it still depends on the number of colors, because each color has to be made separately. Labor costs are high, especially when it comes to multi-color printing.

Environmental impact: light color screen printing ink has less impact on the environment, but the ink containing PVC and formaldehyde has harmful chemicals, need to be recovered and treated in time to prevent pollution of water resources.

08. Anodizing

It is mainly the anodizing of aluminum, which uses the electrochemical principle to generate a layer of Al2O3 (alumina) film on the surface of aluminum and aluminum alloys. This layer of oxide film has protective, decorative, insulating, wear resistance and other special characteristics.

Applicable materials:

Aluminum, aluminum alloy and other aluminum products

Process cost: In the production process, the consumption of water and electricity is considerable, especially in the oxidation process. The heat consumption of the machine itself requires constant cooling with circulating water, and the electricity consumption per ton is often about 1000 degrees.

Environmental impact: Anodizing is not great for energy efficiency, and in aluminum electrolysis production, the anode effect also produces gases that have a damaging side effect on the ozone layer in the atmosphere.

09. Wire drawing

It is a surface treatment method that forms lines on the workpiece surface through grinding products and plays a decorative effect. According to the different lines after drawing can be divided into: straight drawing, random drawing, ripple, spiral.

Applicable materials: Almost all metal materials can use metal drawing process.

Process cost: simple process method, simple equipment, very little material consumption, relatively low cost, high economic benefit.

Environmental impact: pure metal products, surface without paint and any chemical substances, 600 degrees high temperature does not burn, does not produce toxic gas, composite fire protection environmental requirements.

10. In-mold decoration

It is a molding method that puts the printed pattern film into the metal mold, infuses the resin used for molding into the metal mold and joins the film, so that the printed pattern film and resin form a whole and solidifies into the finished product.

Applicable material: plastic surface

Process cost: Only need to open a set of molds, can reduce the cost and time of high automation production, simplified process, there is an injection molding method, molding and decoration at the same time.

Environmental impact: The technology is environmentally friendly and avoids the pollution caused by traditional spray paint electroplating.