Material surface treatment Process.
01. Vacuum electroplating
Vacuum plating is a physical deposition phenomenon. That is, the forming gas is injected under a vacuum state, the absorbed gas contacts the target, and the separated components of the target are adsorbed by the conductive goods to form a uniform and smooth imitation metal surface layer.
Applicable materials:
Many materials can be vacuum electroplated, including metals, soft and hard plastics, composite materials, ceramics and glass. Among them, aluminum is most commonly used for electroplating surfaces, followed by silver and copper.
- Natural materials are not suitable for vacuum plating because the moisture in the natural materials themselves will affect the vacuum environment.
Process cost: During the vacuum plating process, the workpiece needs to be sprayed, loaded, unloaded and re-sprayed, so the labor cost is quite high, but it also depends on the complexity and quantity of the workpiece.
Environmental impact: The reduction of environmental pollution caused by vacuum electroplating is similar to the impact of spraying on the environment.
02.Electrolytic polishing
Electropolishing is an electrochemical process in which the atoms of a workpiece immersed in an electrolyte are converted into ions and removed from the surface due to the passage of current, thereby achieving the effect of removing fine burrs and increasing brightness on the surface of the workpiece. Applicable materials: 1. Most metals can be electrolytically polished, which is most commonly used for surface polishing of stainless steel (especially suitable for austenitic nuclear grade stainless steel). 2. Different materials cannot be electrolytic polished at the same time, or even placed in the same electrolytic solvent. Process cost: The entire process of electrolytic polishing is basically completed automatically, so labor costs are very low. Environmental impact: Electrolytic polishing uses less harmful chemicals. The entire process requires a small amount of water and is simple to operate. In addition, it can extend the properties of stainless steel and delay corrosion of stainless steel.
3. Pad printing process
Being able to print text, graphics and images on the surface of irregular shaped objects is now becoming an important special printing. Applicable materials: Pad printing can be used on almost all materials, except for materials softer than silicone pads, such as PTFE. Process cost: low mold cost and low labor cost. Environmental impact: Since this process is limited to soluble inks (which contain harmful chemicals), it has a significant impact on the environment.
04. Galvanizing process
Surface treatment technology that coats the surface of steel alloy materials with a layer of zinc for aesthetics and rust prevention. The zinc layer on the surface is an electrochemical protective layer that can prevent metal corrosion. The main methods used are hot-dip galvanizing and electro-galvanizing.
Applicable materials:
Since the galvanizing process relies on metallurgical bonding technology, it is only suitable for surface treatment of steel and iron.
Process cost: no mold fees, short cycle time/medium labor cost, because the surface quality of the workpiece largely depends on manual surface treatment before galvanizing.
Environmental impact: Since the galvanizing process increases the service life of steel parts by 40-100 years and prevents rust and corrosion of the workpieces, it plays a positive role in protecting the environment. In addition, galvanized workpieces can be returned to the galvanizing tank after their service life expires, and the repeated use of liquid zinc will not produce chemical or physical waste.
05.Electroplating process
The process of using electrolysis to attach a metal film to the surface of parts, thereby preventing metal oxidation, improving wear resistance, conductivity, reflectivity, corrosion resistance and improving appearance. Many outer layers are also electroplated.
Applicable materials:
- Most metals can be electroplated, but different metals have different levels of purity and plating efficiency. The most common of these are: tin, chromium, nickel, silver, gold and rhodium.
- The plastic most commonly used for electroplating is ABS.
- Nickel metal cannot be used for plating products that come into contact with the skin because nickel is irritating and toxic to the skin.
Process cost: No mold costs, but fixtures are required to fix the parts/time cost depends on temperature and metal type/labor cost (medium-high), depending on the type of specific electroplated parts. For example, electroplating of silverware and jewelry requires extremely skilled workers to operate because of its high requirements for appearance and durability.
Environmental impact: A large number of toxic substances are used in the electroplating process, so professional diversion and extraction are required to ensure minimal environmental impact.
06.Water transfer printing
It is a method of printing color patterns on transfer paper onto the surface of three-dimensional products using water pressure. As people's requirements for product packaging and surface decoration increase, water transfer printing is used more and more widely.
Applicable materials:
All hard materials are suitable for water transfer printing, and materials suitable for spraying must also be suitable for water transfer printing. The most common ones are injection molded parts and metal parts.
Process cost: There is no mold cost, but you need to use a fixture to water transfer multiple products at the same time. The time cost generally does not exceed 10 minutes per cycle.
Environmental impact: Compared with product spraying, water transfer printing more fully applies printing coatings, reducing the possibility of waste leakage and material waste.
07. Surface treatment of Screen printing
Through the squeezing of the scraper, the ink is transferred to the substrate through the mesh of the graphic part, forming the same graphic and text as the original. Screen printing equipment is simple, easy to operate, easy to print and plate making, low in cost, and has strong adaptability.
Common printed materials include: color oil paintings, posters, business cards, binding covers, product signs, and printed and dyed textiles, etc.
Applicable materials:
Almost any material can be screen printed, including paper, plastic, metal, ceramics and glass.
Process cost: The mold cost is low, but it still depends on the number of colors, because each color needs to be plated separately. Labor costs are on the high side, especially when it comes to multi-color printing.
Environmental impact: Light-colored screen printing inks have less impact on the environment. However, inks containing PVC and formaldehyde contain harmful chemicals and need to be recycled and processed in time to prevent contamination of water resources.
08.Anodizing
Mainly anodizing aluminum, which uses electrochemical principles to generate an Al2O3 (aluminum oxide) film on the surface of aluminum and aluminum alloys. This oxide film has special properties such as protection, decoration, insulation, and wear resistance.
Applicable materials:
Aluminum, aluminum alloy and other aluminum products Surface treatment
Process cost: During 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 use of circulating water for cooling, and the power consumption per ton is often around 1,000 degrees.
Environmental impact: Anodization is not excellent in terms of energy efficiency. At the same time, in the production of aluminum electrolysis, the anode effect also produces gases that have damaging side effects on the atmospheric ozone layer.