The surface treatment of hardware accessories is to form a layer with some or more special properties on the surface of the material by physical or chemical methods. Surface treatment can improve the appearance, texture, function and other aspects of product performance. Today, the small edition of Jiatai hardware brings you some introduction to the surface treatment process of Guangdong brand clothing hardware accessories.
Bai Di hardware accessories
- Anodizing
It is mainly the anodizing of aluminum, which uses the principle of electrochemistry 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.
Process flow:
Monochrome, gradient:
Polishing/sandblasting/drawing → Oil removal → anodizing → neutralization → dyeing → sealing → drying
Dual Color:
① Polishing/sandblasting/drawing → oil removal → shielding → anodizing 1→ anodizing 2 → sealing → drying
② Polishing/sandblasting/drawing → oil removal → anodizing 1 → radium engraving 2 → anodizing 2 → sealing → drying
Technical features:
- Improve strength
- Realize any color except white
3, to achieve nickel-free sealing, to meet the requirements of Europe, the United States and other countries for nickel-free
Technical difficulties and key points for improvement:
The yield level of anodic oxidation is related to the cost of the final product, and the key to improving the oxidation yield is the appropriate amount of oxidant, the appropriate temperature and the current density, which requires structural manufacturers to continue to explore and seek breakthroughs in the production process.
Ii. Electrophoresis
Used in stainless steel, aluminum alloy, etc., can make the product show a variety of colors, and maintain the metal luster, while enhancing the surface properties, with good anti-corrosion properties.
Process flow:
Pretreatment → electrophoresis → drying
Advantages:
1, rich color;
2, no metal texture, can be combined with sandblasting, polishing, drawing, etc.
3, processing in the liquid environment, can achieve the surface treatment of complex structures;
4, mature process, mass production.
Cons:
The ability of concealing defects is general, and the requirement of pre-treatment for electrophoresis of die casting is high.
Third, micro arc oxidation
The process of applying a high voltage to an electrolyte solution (generally a weakly alkaline solution) to produce a ceramic surface film, which is the result of a synergistic effect of physical discharge and electrochemical oxidation.
Process flow:
Pretreatment → hot water washing → MAO → drying
Advantages:
1, ceramic texture, dark appearance, no highlight products, feel delicate, anti-fingerprint;
2, a wide range of substrates: Al, Ti, Zn, Zr, Mg, Nb, and its alloys;
3, the pre-treatment is simple, the product corrosion resistance, excellent weather resistance, good heat dissipation performance.
Cons:
At present, the color is limited, only black, gray and other mature, bright colors are difficult to achieve; The cost is mainly affected by high power consumption, which is one of the highest costs in surface treatment.
Four, PVD vacuum plating
The full name of physical vapor deposition, is an industrial manufacturing process, is the main use of physical processes to deposit thin film technology.
Process flow:
PVD pre-cleaning → Vacuum pumping → target washing and ion cleaning → Coating → End of coating, cooling out → post-treatment (polishing, AFP)
Technical features:
Physical Vapor Deposition (PVD) can be deposited on metal surfaces with high hard plating and high wear resistance of cermet decorative coating
- Electroplating
It is a technology that uses electrolysis to attach a metal film to the surface of the metal so as to prevent corrosion, improve wear resistance, electrical conductivity, reflective property and improve beauty.
Process flow:
Pretreatment → Cyanide-free alkali copper → cyanide-free white copper tin → Chrome plating
Advantages:
1, high gloss coating, high quality metal appearance;
2, the substrate is SUS, Al, Zn, Mg, etc.; The cost is lower than PVD.
Cons:
Environmental protection is poor, and the risk of environmental pollution is greater.
Six, powder spraying
Powder spraying equipment (electrostatic spraying machine) is used to spray powder coating to the surface of the workpiece, under the action of static electricity, the powder will be uniformly adsorbed on the surface of the workpiece, forming a powdery coating; The powder coating is cured by high temperature baking and leveling, and becomes the final coating with different effects (different kinds of effects of powder coatings).
Process flow:
Upper part → electrostatic dust removal → spraying → low temperature leveling → baking
Advantages:
1, rich color, highlight, matte optional;
2, the cost is low, suitable for building furniture products and heat sink shell;
3, high utilization rate, 100% utilization, environmental protection;
4, strong ability to shield defects; 5, can imitate wood grain effect.
Cons:
At present, it is less used in electronic products.
Seven, metal drawing
It is a surface treatment method that forms lines on the surface of the workpiece through grinding products and plays a decorative effect. According to the different lines after drawing can be divided into: straight wire drawing, random wire drawing, ripple, spiral.
Technical features:
The wire drawing treatment can make the metal surface obtain a non-mirror-like metallic luster, and the wire drawing treatment can also eliminate subtle defects on the metal surface.
Eight, sand blasting
It is a process that uses compressed air as the power to form a high-speed jet beam to spray the spray material at high speed to the surface of the workpiece to be treated, so that the appearance or shape of the outer surface of the workpiece surface changes, and a certain degree of cleanliness and different roughness are obtained.
Technical features:
1, to achieve different reflective or matte.
2, can clean the small burr on the surface of the workpiece, and make the surface of the workpiece more flat, eliminate the harm of the burr, improve the grade of the workpiece.
3, clear the residual dirt left over during pre-treatment, improve the finish of the workpiece, can make the workpiece show uniform metal color, make the workpiece appearance more beautiful and good-looking.
Nine, polishing
Modification of the surface of the workpiece using flexible polishing tools and abrasive particles or other polishing media. For different polishing processes: rough polishing (basic polishing process), medium polishing (finishing process) and fine polishing (polishing process), the selection of the right polishing wheel can achieve the best polishing effect, while improving polishing efficiency.
Technical features:
Improve the dimensional accuracy or geometric shape accuracy of the workpiece, obtain a smooth surface or mirror gloss, but also eliminate the gloss.
Etching
Usually referred to as etching, also known as photochemical etching, refers to the removal of the protective film of the etched area through exposure platemaking and development, and contact with chemical solution during etching to achieve the effect of dissolution corrosion, forming a concave and convex or hollow forming effect.
Exposure method:
According to the figure, the engineering will draw out the size of the material preparation – material preparation – material cleaning – drying → film or coating → drying → exposure → development → drying – etching → film removal →OK
Screen printing method:
Opening → Cleaning sheet (stainless steel and other metal materials)→ screen printing → etching → film removal →OK
Advantages:
1, can be fine metal surface processing;
2, give the metal surface special effect;
Cons:
Most of the corrosive liquids (acids, alkalis, etc.) used in etching are harmful to the environment.
