1. Vacuum plating
Vacuum coating is a physical deposition process in which argon gas is injected into a vacuum and directed at a target. The target molecules are then adsorbed on conductive products, resulting in a uniform and smooth imitation metal surface layer.
Typical Products: Surface treatment of reflective coatings, consumer electronics and heat shields
Suitable output: Single piece for large batch
Quality: High quality (highlights and protection of product surface)
Speed: Average production speed, 6 hours/cycle (including painting)
Applicable materials
Various materials can be vacuum coated, such as metals, soft and hard plastics, composite materials, ceramics and glass. Among these, aluminum is the most used material for galvanized surface treatment, followed by silver and copper.
However, natural materials are not suitable for vacuum coating as their moisture content can affect the vacuum environment.
Cost process
Vacuum coating requires manual operations. The process involves spraying, loading, unloading and repainting the part, which results in relatively high labor costs. However, labor costs may vary depending on the complexity and quantity of the part.
Impact on the environment
Vacuum coating has little environmental pollution, similar to the environmental impact of spraying.
Examples:
Vacuum plating for Ducati motorcycles
Vacuum coating of perfume bottles
Vacuum plating of other products
2. Electropolishing
Electropolishing involves using the workpiece as the anode and the insoluble metal as the cathode. Both electrodes are immersed in the electrolytic bath simultaneously, and selective anodic dissolution occurs through the direct current ionization reaction. This process effectively removes small burrs from the surface of the part and increases its shine.
Typical products: Building structures, food handling and storage, as well as medical pharmaceuticals
Suitable output: Single piece for large batch
Quality: The surface is shiny, smooth and hygienic
Speed: Average production speed, 5-30 minutes/cycle
Applicable Materials
Most metals can be electropolished, with stainless steel being the most commonly polished surface (especially for superaustenitic stainless steel).
However, different materials cannot be electrolytically polished at the same time, or even in the same electrolytic solvent.
Process Cost
The entire electropolishing process is basically completed by automation, so the labor cost is very low.
Impact on the Environment
Electropolishing is an environmentally friendly process that uses fewer harmful chemicals compared to other metal finishing techniques. It also only requires a small amount of water and is easy to operate. Furthermore, electropolishing can improve the properties of stainless steel and prolong its corrosion resistance.
Examples
Electropolishing to clean welds
Electropolishing of other products
3. Photo recording
Photographic etching is a surface treatment method that involves creating a tough film image using photographic techniques to protect a surface. The process then generates surface texture by etching metal, plastic or other materials with a chemical acid.
Typical products: Surface treatment for jewelry, nameplates and trophies
Suitable output: Single piece for large batch
Quality: Extend exposure and chemicals can perform photographic recording
Speed: Medium production speed (50-100 microns/5 minutes)
Applicable Materials
Many metals are suitable for photoetching, including stainless steel, mild steel, aluminum, brass, nickel, pewter, copper and silver. Aluminum has the fastest photo engraving speed, while stainless steel has the slowest.
In addition to metals, glass and ceramics can also undergo photoetching surface treatment, but photoresists and specific chemicals are required for this process.
Process Cost
- Low mold cost
- Average labor cost
Impact on the Environment
Scrap metal produced during photographic recording must be managed for recycling purposes. The chemical used for photoetching is one-third ferric chloride, and discarded photosensitive films are treated with caustic soda (a strong alkaline). Both chemicals are dangerous and operators must wear protective clothing when handling them.
Examples
Photo engraving of eyeglass frames
Photographic engraving of metal plates
4. Pad printing
Pad printing: It can print text, graphics and images on the surface of irregularly shaped objects and is now becoming an important specialty printing.
Typical products: Surface printing for vehicle interiors, consumer electronics and sports equipment
Suitable output: Single piece for large batch
Quality: Sharp print details, even on uneven surfaces
Speed: Single print time (1-5 seconds)
Applicable Materials
Almost all materials can use the pad printing process, except materials that are softer than silicone pads, such as PTFE.
Process Cost
- Low mold cost
- Low labor cost because most processes are completed by machining
Impact on the Environment
As this process is limited to soluble paints (which contain harmful chemicals), it has a huge impact on the environment.
Examples
Personalized pad printing and Swiss army knives service
Clothing pad printing
Silicone cell phone pad printing
Pad printing of another product
5. Galvanization
Galvanizing is a surface treatment technology that involves coating a layer of zinc on the surface of steel alloy materials. This process has two purposes: to improve the appearance of the material and to prevent the formation of rust. The zinc layer on the surface functions as an electrochemical protective layer that helps prevent damage to the metal. The main methods used for galvanizing are hot-dip galvanizing and galvanizing.
Typical products: Surface treatment for buildings, bridges, vehicles, furniture, etc.
Suitable output: Single piece for large batch
Quality: Perfect protective layer, appearance largely depends on the quality of the steel
Speed: Fast and basic 10 minutes/cycle
Applicable Materials
Since the galvanizing process depends on metallurgical bonding technology, it is only suitable for the surface treatment of steel and iron.
Process Cost
- No mold cost, short cycle, so the cost is low
- The labor cost is average, because the surface quality of the part largely depends on the artificial surface treatment before galvanizing.
Impact on the Environment
The galvanizing process can increase the service life of steel parts by 40-100 years, thus preventing rust and corrosion of the part, which has a positive effect on the environment. Furthermore, the galvanized part can be returned to the galvanizing tank after the end of its useful life, and reusing the liquid zinc will not result in any chemical or physical waste.
Examples
Hub galvanization
Galvanizing Plant
Construction Firmware Galvanization
Galvanization of another product
6. Electroplating
Electroplating is a process that involves using electrolysis to attach a metallic film to the surface of a part. This process can prevent metal oxidation, improve wear resistance, improve electrical conductivity, increase light reflectivity and improve corrosion resistance, as well as improve aesthetics. Many coins also feature a galvanized outer layer.
Typical products: Surface treatment for transportation, consumer electronics, furniture, jewelry and tableware, etc.
Suitable output: Single piece for large batch
Quality: Extremely high gloss, resistant to oxidation and corrosion
Speed: Average speed, depending on material type and coating thickness
Applicable Materials
Different metals have different levels of purity and plating efficiency, making them suitable for galvanizing. The most common metals used for plating are tin, chromium, nickel, silver, gold and rhodium. Rhodium is a type of platinum known for its high cost and ability to maintain high shine for a long time. It can resist most chemicals and acids and is typically used for products that require extremely high surface gloss, such as trophies and medals.
The plastic commonly used for electroplating is ABS, as it can withstand high electroplating temperatures (60°C or 140°F) and has strong bonding strength between galvanized and non-galvanized layers.
It is important to note that nickel metal should not be used for electroplating products that come into contact with the skin because nickel is known to cause skin irritation and toxicity.
Process Cost
There are no mold costs involved, but fixtures are needed to secure the parts.
The time cost varies depending on the temperature and type of metal used.
Labor costs are medium to high and depend on the type of coating used. For example, silver plating or jewelry requires highly skilled workers due to their demanding appearance and durability standards.
Impact on the Environment
Due to the use of a significant amount of toxic substances in the electroplating process, it is crucial to have professional maneuvering and extraction methods to minimize environmental impact.
Examples
Domestic factory live coating processing
Spoon electroplating
Electroplating of other products
7. Powder Coating
Powder coating is a type of dry spraying method used to coat metal parts. The powder is sprayed or applied via fluidized bed to the surface of the workpiece. Through electrostatic attraction, the powder is adsorbed on the surface of the piece, forming a protective film when completely dry.
Typical products: Vehicle, building and white goods coating
Suitable output: Single piece for large batch
Quality: The surface of the product is smooth and evenly colored
Speed: Speed depends on the size of the piece and the degree of automation and takes at least 30 minutes to dry.
Applicable Materials
Although powder spraying is suitable for surface spraying of some metal, plastics and glass parts, it is mainly used to protect or add color to aluminum and steel.
Process Cost
- There are no mold costs, but equipment costs are very high
- The time spent is short, but the drying time needs at least half an hour
- Labor costs are quite low
Impact on the Environment
Compared with wet spraying, powder spraying has a higher material utilization rate due to the electrostatic adsorption of powder particles. This results in a spray utilization rate of up to 95%.
Examples
Cube powder coating
Live footage of powder coating plant
Powder coating of gratings
Powder coating of other products
8. Hydrotransfer printing
Hydrotransfer printing is a process that involves transferring color patterns from transfer paper to the surface of a three-dimensional product using water pressure. As people increasingly demand better packaging and surface decoration for their products, the use of hydrotransfer printing is becoming more widespread.
Typical products: Transportation printing, consumer electronics, and military products
Suitable output: Small batch to large batch
Quality: The surface texture of the product is precise and clear, but there is a slight stretch
Speed: Fast, about 10 to 20 cycles/hour
Applicable Materials
All hard materials suitable for hydrotransfer printing are also suitable for spraying. The most commonly used materials for hydrotransfer printing and spraying are injection molded parts and metal parts.
Process Cost
There are no mold costs involved, but accessories are required to perform hydrotransfer printing on multiple products simultaneously, which helps reduce the total time required.
The time required for the process is minimal, typically not exceeding 10 minutes per cycle.
Impact on the Environment
Compared with product coating, the application of printing ink through hydrotransfer printing is more thorough, which reduces the likelihood of residue leakage and material waste.
Examples
Hydrotransfer printing from an underwater perspective
Hydrotransfer printing using a water gun
Hydrotransfer printing of other products
9. Screen printing
Screen printing is a printing technique that transfers ink to a substrate through the mesh of the graphic piece by squeezing a scraper. This process replicates the same graph as the original. The equipment used for screen printing offers several advantages, such as simplicity, ease of operation, low cost and great adaptability. Plate making and printing are simple, making it an accessible technique.
Screen printing finds wide applications in various fields such as colorful oil paintings, posters, business cards, decorative covers, merchandise signage and printed textiles.
Typical products: Used for clothing, electronics and packaging
Suitable output: Single piece for large batch
Quality: High precision of pattern details
Speed: Manual screen printing (1-5 cycles/minute), machine screen printing (1-30 cycles/minute)
Applicable Materials
Almost all materials can be screen printed, including paper, plastic, metal, ceramics and glass.
Process Cost
The cost of molds is normally low, but can vary depending on the number of colors needed, as each color must be plated separately.
Time cost: Mechanical screen printing can take up to 30 prints per minute, while manual screen printing can take 1 to 5 prints per minute.
Labor cost: In manual screen printing, labor costs tend to be high, especially when it comes to color printing.
Impact on the Environment
Light-colored screen printing inks have a lower environmental impact. However, paints that contain PVC and formaldehyde contain harmful chemicals and must be recycled and disposed of properly to avoid water pollution.
Examples
Skateboard pattern screen printing
Clothing screen printing
Screen printing of other products
10. Anodic Oxidation
Anodic oxidation, also known as anodizing, is a process used primarily for aluminum. It uses the principle of electrochemistry to create an Al2O3 (alumina) film on the surface of aluminum and aluminum alloys. This oxide film layer has unique properties such as protection, decoration, insulation and abrasion resistance.
Typical products: Mobile phones, computers and other electronic products, mechanical parts, aircraft and automobile parts, precision instruments and radio equipment, daily necessities and architectural decoration.
Suitable output: Single piece for large batch
Quality: Oxide film has special characteristics such as protection, decoration, insulation and abrasion resistance.
Speed: Tens of minutes
Applicable Materials
Aluminum products such as aluminum and aluminum alloys
Process Cost
During the anodizing production process, there is a significant consumption of water and electricity, especially during the oxidation phase. Furthermore, the machines themselves require cooling through water circulation, which also increases overall energy consumption. Energy consumption per ton is typically around 1000 degrees. Reducing the number of auxiliary installations can help reduce energy consumption.
Impact on the Environment
Anodizing is not known for its energy efficiency. Furthermore, during the production of aluminum electrolysis, the anode effect can generate gases that have harmful impacts on the ozone layer in the atmosphere.
Examples
Lenses made with anodic oxidation
Color metal back box reader
11. Electrophoretic deposition – ED
Electrophoretic Deposition (ED): Refers to the movement of a charged particle towards its opposite electrode under the influence of an electric field.
Typical products: Automobiles, building materials, hardware, household appliances, etc.
Suitable output: Mass production
Quality: The product comes in a variety of colors and maintains a metallic shine. At the same time, the surface performance is improved and has good anti-corrosion performance.
Speed: Fastest production speed
Applicable Materials
Stainless steel, aluminum alloy, etc.
Process Cost
It can realize mechanization and automatic continuous operation, it also has low labor costs and low total costs.
Impact on the Environment
ED (electrophoretic deposition) coatings use water as a solvent, making them non-flammable and non-toxic. This not only saves a significant amount of organic solvents, but also greatly reduces air pollution and environmental risks. Additionally, it eliminates the risk of fire, making it a safer option.
Examples
12. Microarc oxidation – MAO
Microarc oxidation, also known as microplasma oxidation, is achieved by combining an electrolyte with corresponding electrical parameters. This process creates a ceramic film predominantly composed of base metal oxide on the surface of aluminum, magnesium, titanium and their alloys. The film grows through the instantaneous high temperature and high pressure generated by the arc discharge.
Typical products: Aerospace, IT products
Suitable output: Single piece for large batch
Quality: The material has high surface hardness and good wear resistance
Speed: Fast
Applicable Materials
Al, Ti, Zn, Zr, Mg, Nb and their alloys
Process Cost
The application of microarc oxidation is limited due to its high initial arc voltage, high current density, low current efficiency, large power consumption and high processing cost.
Impact on the Environment
The electrolyte used in microarc oxidation does not contain toxic substances or heavy metals. Furthermore, it has strong anti-pollution capabilities and can be reused multiple times, resulting in minimal environmental pollution.
Examples
13. Metallic design
Metal drawing is a surface treatment method used to create decorative lines on the surface of a workpiece through grinding. Depending on the resulting texture, metal design can be divided into four categories: straight design, random design, ripple and swirl.
Typical products: Construction industry such as elevator door panels, taps, handles, etc., cabinets such as hoods, sinks, etc.
Suitable output: Single piece for large batch
Quality: Brushing can cause the metal surface to have a non-mirror metallic shine. At the same time, brushing can also eliminate small flaws on the metal surface.
Speed: Fast
Applicable Materials
Metal drawing can be used on almost all materials
Process Cost
The process and equipment are simple, the material consumption is very low, so the cost is relatively low and the economic benefit is high.
Impact on the Environment
Pure metal products, the surface is free from paint and any chemicals. The high temperature of 600 degrees does not burn, does not generate toxic gases, meets environmental and fire protection requirements.
Examples
14. Mold decoration – IMD
In-Mold Decoration (IMD) technology is a molding method that involves placing a printed film into a metal mold, injecting molding resin into the mold, and bonding the film together to create an integrated product. The resin is then cured to produce the finished product.
Typical products: Decorative and functional control panels for household appliances, automobile dashboards, air conditioning panels, cell phone covers/lenses, washing machines, refrigerators, etc.
Suitable output: Single piece for large batch
Quality: It can be used for complex images, the product is abrasion resistant, can prevent surface scratches, and can maintain color vibrancy for a long time and is not easy to fade.
Speed: Fast
Applicable Materials
Plastic surface
Process Cost
Simply opening a set of molds can help reduce system and inventory costs, as well as costs associated with labor hours. Through highly automated production, a simplified manufacturing process and a single injection molding method that achieves molding and decoration simultaneously, ongoing costs and labor hours can be reduced, resulting in more stable production.
Impact on the Environment
This technology is environmentally friendly and avoids pollution caused by traditional spray painting.
Examples
Injection Molding Mobile Phone Protective Case
