Powder coating is a type of coating that is applied as a free-flowing, dry powder. Unlike conventional liquid paint which is delivered via an evaporating solvent, powder coating is typically applied electrostatically and then cured under heat or with ultraviolet light. The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals, such as household appliances, aluminium extrusions, drum hardware, automobiles, and bicycle frames. Advancements in powder coating technology like UV curable powder coatings allow for other materials such as plastics, composites, carbon fiber, and MDF (medium-density fibreboard) to be powder coated due to the minimum heat and oven dwell time required to process these components.
Powder coating（powder spraying） is a type of coating that is applied as a free-flowing, dry powder. Unlike conventional liquid paint which is delivered via an evaporating solvent, powder coating is typically applied electrostatically and then cured under heat or with ultraviolet light. The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals, such as household appliances, aluminium extrusions, drum hardware, automobiles, and bicycle frames. Advancements in powder coating technology like UV curable powder coatings allow for other materials such as plastics, composites, carbon fiber, and MDF (medium-density fibreboard) to be powder coated due to the minimum heat and oven dwell time required to process these components.
What are the technological processes of Powder coating?
The quality of the pretreatment process directly affects the quality of the powder coating film. If the pretreatment is not good, the coating film is easy to fall off, bubbling and other phenomena. Therefore, the pretreatment work must be paid attention to.
Chemical pretreatment can be used for sheet metal stampings. Namely: degreasing → derusting → cleaning → phosphating (or purification), etc. For most rusted or thick surface workpieces, use sandblasting, shot blasting and other mechanical methods to remove rust, but after mechanical rust removal, ensure that the surface of the workpiece is clean and free of scale.
Scrape putty. Scrape the conductive putty according to the defect degree of the workpiece, and smooth it with sandpaper after drying, and then the next process can be carried out.
Protection (also called shielding). If some parts of the workpiece do not require coating, they can be covered with protective glue before preheating to avoid spraying paint.
Preheat. Generally, preheating is not required. If a thicker coating is required, the workpiece can be preheated to 100-160 °C, which can increase the coating thickness.
The workpiece enters the spray gun position of the powder spraying room through the conveyor chain to prepare for the spraying operation. The electrostatic generator discharges high-voltage static electricity (negative electrode) through the electrode needle of the gun mouth to the space in the direction of the workpiece, and the high-voltage static electricity is generated. The mixture of powder and compressed air ejected from the nozzle of the spray gun and the air around the electrodes are ionized (negatively charged). The workpiece is connected to the ground (grounding pole) through the conveying tool through the hanger, so that an electric field is formed between the spray gun and the workpiece. The powder reaches the surface of the workpiece under the double push of the electric field force and the compressed air pressure, and forms a uniform layer on the surface of the workpiece by electrostatic attraction. coating.
3. Baking and curing
The sprayed workpiece is sent to the drying room at 180-200℃ through the conveyor chain for heating, and kept for a corresponding time (15-20 minutes) to melt, level and solidify, so as to obtain the desired surface effect of the workpiece. (Different powders vary in baking temperature and time). This should be noted in the curing process.
4. Clean up
After the coating has cured, remove the protector and trim the burrs.
For the cured workpiece, the daily main inspection is the appearance (whether it is smooth and bright, whether there are defects such as particles and shrinkage holes) and the thickness (controlled at 55 ~ 90μm). Repair or re-spray the detected workpieces with defects such as missing spray, pinholes, bumps, and air bubbles.
After inspection, the finished products are sorted and placed in transport vehicles and turnover boxes, and are separated from each other by flexible packaging buffer materials such as foam paper and bubble film to prevent scratches and wear (packaging can be made according to customer requirements)
The outstanding advantages of powder spraying process:
1. A thicker coating can be obtained with one coating. For example, a coating of 100-300 μm is used. With a common solvent coating, it takes about 4-6 coating times, while with a powder coating, this thickness can be achieved at one time. . The corrosion resistance of the coating is very good.
2. The powder coating contains no solvent and no pollution of the three wastes, which improves the labor hygiene conditions.
3. New technology such as powder electrostatic spraying is adopted, which has high efficiency and is suitable for automatic assembly line painting; the powder utilization rate is high and can be recycled.
4. In addition to thermosetting epoxy, polyester, and acrylic, there are a large number of thermoplastic grease-resistant coatings that can be used as powder coatings, such as polyethylene, polypropylene, polystyrene, fluorinated polyether, nylon, polycarbonate and various Fluorine resin, etc.
Applications of powder spraying process:
Powder coatings began to be used in protection and electrical protection. With the development of science and technology, they have been widely used in the automotive industry, electrical insulation, corrosion-resistant chemical pumps, valves, cylinders, pipes, outdoor steel components, steel furniture, castings, etc. surface coating.
CNC machining and 3D printing are commonly methods of making prototypes. CNC machining includes metal parts CNC machining and plastic parts CNC machining; 3D printing includes metal 3D printing, plastic 3D printing, nylon 3D printing, etc.; The craft of duplication of modeling can also realize prototypes making, but it needs to cowork with CNC fine machining and manual grinding or polishing. Most of the prototype products need to be manually sanded and then surface treated before delivery so as to achieve the appearance effect and the strength of materials and other physical properties of the parts and components surface.
One-stop delivery service is our domination strength, we can provide product design, design optimization, appearance design, structural design, industrial design, hardware design, software design, electrical development, prototyping, mold design, mold manufacturing, duplication of modeling, Injection molding, die casting, stamping, sheet metal fabrication, 3D printing, surface treatment, assembly and testing, mass production, low-volume production,product packaging, domestic and offshore logistics and transportation, etc.
Product assembly and testing are essential to ensure the normal delivery of products. All prototyped products are required to pass strict quality inspections before they shipping; for mass-produced products, we provide IQC inspection, online inspection, finished product inspection, and OQC inspection
And all test records are required to be archived.
All design drawings will be evaluated and diagnosed by our professional engineers before the molding. We will notify you as soon as there are design defects and hidden processing problems such as shrinkage. With your permission, we will optimize the design drawings until it meet production requirement.
We provide mold design and manufacture, product injection molding and assembly, whether it is plastic injection mold or aluminum alloy die-casting mold, we will provide storage services for all molds or dies.
Usually, we recommend you order an entire of transportation insurance for all logistics and transportation, so as to reduce the risk of loss of goods during transportation.
We provide door-to-door logistics services. According to different trades, you can choose transportation by air or by sea, or a combinated transportation. The most common incoterms are DAP, DDP, CFR, CIF, FOB, EX-WORKS…,
In addition, you can arrange the logistics as your way, and we will assist you in completing the logistics and transportation from the factory to your designated location.
We currently support wire transfer(T/T), letter of credit(L/C), PayPal, Alipay, etc., Usually we will charge a certain percentage of the deposit, and the full payment needs to be paid before delivery.
The surface treatment of products includes surface treatment of metal products, surface treatment of plastic products, and surface treatment of synthetic materials. Our common surface treatments consist of :
Sand blasting, Dry Sand Blasting, Wet Sand Blasting, Atomized Sand Blasting, Shot Blasting,etc.
Spraying,Electrostatic Spraying, Fame Spraying, Powder Spraying, Plastic Spraying, Plasma Spraying, Painting, Oil Painting etc.
Electroless Plating of Various Metals and Alloys,Copper Plating, Chromium Plating, Zinc Plating, Nickel Plating,Anodic Oxidation, Electrochemical Polishing, Electroplating etc.
Bluing and Blackening, Phosphating, Pickling, Grinding, Rolling, Polishing, Brushing, CVD, PVD, Ion implantation, Ion Plating, Laser Surface Treatment ect.
The security of customer information and products is our priority consideration. We will sign the confidentiality agreements(such as NDA) with all customers and establish independent confidential archives. JHmockup has strict confidentiality systems and practice procedures to prevent leakage of customer information and product information from the source.
The cycle of product development depends on what state the products are in when you deliver them.
For instance, you already have a complete design plan including drawings, and now you need to verify the design plan through prototypes making; Or in case of your design has been made with a prototype in other places, but the effect is not satisfactory, then we will optimize your design drawings and then make a prototype to reverify it;Or,
your product already has completed the appearance design, but there is no structural design, or even a complete set of electrical and software solutions, we will provide the corresponding design solutions to offset; Or, your product has been moulded, but the injection-molded or die cast parts cannot meet the function of the overall assembly or finished product, we will re-evaluate your design, mould, dies,materials and other aspects to create an optimized solution. Therefore, the cycle of product development cannot be simply answered, it is a systematic project, some can be completed in one day, some may take a week, and some may even be completed in several months.
Please contact our professional engineers to discuss your project, so as to reduce your cost and shorten development timeline.
Customized service of products design and manufacturing is our key core capability. Different product customizations have different customization standards, such as partial product customization, overall product customization, partial customization of product hardware, partial customization of product software, and customization of product electrical control. The custom manufacturing and fabrication service is based on a comprehensive understanding of the customer’s product function, material strength, material processing technology, surface treatment, finished product assembly, performance testing, mass production, cost control and other factors before comprehensive evaluation and program design. We provide a complete supply chain solution. Probably your product does not use all the services at the current stage, but we will help you consider the scenario that may be needed in the future in advance, which is what differentiates us from other prototype suppliers.