Today, LED street light fixture manufacturer Tianxiang will introduce the forming method and surface treatment method of lamp shell to you, let’s take a look.
Forming method
1. Forging, machine pressing, casting
Forging: commonly known as “ironmaking”.
Machine pressing: stamping, spinning, extrusion
Stamping: Use pressure machinery and corresponding molds to manufacture the required product process. It is divided into several processes such as cutting, blanking, forming, stretching, and flashing.
Main production equipment: shearing machine, bending machine, punching machine, hydraulic press, etc.
Spinning: Using the extensibility of the material, the spinning machine is equipped with the corresponding mold and the workers’ technical support to achieve the process of LED street light fixture. Mainly used for spinning reflectors and lamp cups.
Main production equipment: round edge machine, spinning machine, trimming machine, etc.
Extrusion: Using the extensibility of the material, through the extruder and equipped with a shaped mold, it is pressed into the process of LED street light fixture we need. This process is widely used in the manufacture of aluminum profiles, steel pipes, and plastic pipe fittings.
Main equipment: extruder.
Casting: sand casting, precision casting (lost wax mold), die casting Sand casting: a process of using sand to make a cavity for pouring to obtain a casting.
Precision casting: use wax to make a mold that is the same as the product; repeatedly apply paint and sprinkle sand on the mold; then melt the internal mold to obtain a cavity; bake the shell and pour the required metal material; remove the sand after shelling to obtain a high-precision finished product.
Die casting: a casting method in which molten alloy liquid is injected into the pressure chamber to fill the cavity of the steel mold at high speed, and the alloy liquid is solidified under pressure to form a casting. Die casting is divided into hot chamber die casting and cold chamber die casting.
Hot chamber die casting: high degree of automation, high efficiency, poor high temperature resistance of the product, short cooling time, used for zinc alloy die casting.
Cold chamber die casting: There are many manual operation procedures, low efficiency, good high temperature resistance of the product, long cooling time, and it is used for aluminum alloy die casting. Production equipment: die casting machine.
2. Mechanical processing
Production process in which product parts are directly processed from materials.
The main production equipment includes lathes, milling machines, drilling machines, numerical control lathes (NC), machining centers (CNC), etc.
3. Injection molding
This production process is the same as die casting, only the mold process and processing temperature are different. Commonly used materials are: ABS, PBT, PC and other plastics. Production equipment: injection molding machine.
4. Extrusion
It is also called extrusion molding or extrusion in plastic processing, and extrusion in rubber processing. It refers to a processing method in which the material passes through the action between the extruder barrel and the screw, while being heated and plasticized, and is pushed forward by the screw, and continuously extruded through the die head to make various cross-section products or semi-finished products.
Production equipment: extruder.
Surface treatment methods
The surface treatment of LED street light fixture products mainly includes polishing, spraying and electroplating.
1. Polishing:
A process method of shaping the surface of the workpiece using a motor-driven grinding wheel, hemp wheel, or cloth wheel. It is mainly used to polish the surface of die-castings, stampings, and spinning parts, and is generally used as the front process of electroplating. It can also be used as a surface effect treatment of materials (such as sunflowers).
2. Spraying:
A. Principle/Advantages:
When working, the spray gun or spray plate and spray cup of electrostatic spraying are connected to the negative electrode, and the workpiece is connected to the positive electrode and grounded. Under the high voltage of the high-voltage electrostatic generator, an electrostatic field is formed between the end of the spray gun (or spray plate, spray cup) and the workpiece. When the voltage is high enough, an air ionization zone is formed in the area near the end of the spray gun. Most of the resins and pigments in the paint are composed of high-molecular organic compounds, which are mostly conductive dielectrics. The paint is sprayed out after being atomized by the nozzle, and the atomized paint particles are charged due to contact when they pass through the pole needle of the gun muzzle or the edge of the spray plate or spray cup. Under the action of the electrostatic field, these negatively charged paint particles move toward the positive polarity of the workpiece surface and are deposited on the workpiece surface to form a uniform coating.
B. Process
(1) Surface pretreatment: mainly degreasing and rust removal to clean the workpiece surface.
(2) Surface film treatment: Phosphate film treatment is a corrosion reaction that retains the corrosive components on the metal surface and uses a clever method to use the corrosion products to form a film.
(3) Drying: Remove moisture from the treated workpiece.
(4) Spraying. Under a high-voltage electrostatic field, the powder spray gun is connected to the negative pole and the workpiece is grounded (positive pole) to form a circuit. The powder is sprayed out of the spray gun with the help of compressed air and is negatively charged. It is sprayed onto the workpiece according to the principle of opposites attracting each other.
(5) Curing. After spraying, the workpiece is sent to a drying room at 180-200℃ for heating to solidify the powder.
(6) Inspection. Check the coating of the workpiece. If there are any defects such as missing spraying, bruises, pin bubbles, etc., they should be reworked and re-sprayed.
C. Application:
The uniformity, glossiness and adhesion of the paint layer on the surface of the workpiece sprayed by electrostatic spraying are better than those of ordinary manual spraying. At the same time, electrostatic spraying can spray ordinary spray paint, oily and magnetic blended paint, perchlorethylene paint, amino resin paint, epoxy resin paint, etc. It is simple to operate and can save about 50% of paint compared with general air spraying.
3. Electroplating:
It is the process of plating a thin layer of other metals or alloys on certain metal surfaces using the principle of electrolysis. The cations of the electroplated metal are reduced on the metal surface to form a coating. In order to exclude other cations during plating, the plating metal acts as the anode and is oxidized into cations and enters the electroplating solution; the metal product to be plated acts as the cathode to prevent the interference of the plating gold, and to make the plating uniform and firm, a solution containing the plating metal cations is required as the electroplating solution to keep the concentration of the plating metal cations unchanged. The purpose of electroplating is to plate a metal coating on the substrate to change the surface properties or size of the substrate. Electroplating can enhance the corrosion resistance of the metal, increase hardness, prevent wear, improve conductivity, lubricity, heat resistance, and surface beauty. Aluminum surface anodizing: The process of placing aluminum as the anode in an electrolyte solution and using electrolysis to form aluminum oxide on its surface is called aluminum anodizing.
The above is some relevant knowledge about LED street light fixture. If you are interested, please contact Tianxiang to read more.
Post time: Mar-20-2025
