An electric powder coating oven is a type of oven that uses electricity to generate heat and cure powder coating. It is a versatile and efficient option for powder coating applications.
Benefits of Electric Powder Coating Ovens:
- Clean-burning: Electric ovens do not produce any emissions, making them a very environmentally friendly option.
- Versatility: Electric ovens can be used to cure a wide range of powder coatings, including both thermoplastic and thermoset powders.
- Controllability: Electric ovens can be very precisely controlled, which allows for consistent results.
- Low maintenance: Electric ovens are generally very low-maintenance, as they do not require any combustion or fuel handling.
- Cost-effective: Electric ovens are typically more affordable than gas-fired ovens.
Features of Electric Powder Coating Ovens:
- Electric heating elements: Electric ovens use electric heating elements to generate heat. These elements can be either radiant or convection. Radiant heating elements produce heat directly, while convection heating elements circulate hot air to transfer heat.
- Temperature control: Electric ovens have precise temperature control, which allows for consistent curing of the powder coating.
- Airflow control: Electric ovens have airflow control systems that allow for the circulation of hot air around the parts being cured. This helps to ensure that the powder coating cures evenly.
- Overspray collection system: Electric ovens have overspray collection systems that capture the overspray powder, which can be reused or recycled.
Applications of Electric Powder Coating Ovens:
Electric powder coating ovens are used in a wide variety of applications, including:
- Coating automotive parts: Electric ovens are well-suited for coating automotive parts, as they can cure a wide range of powder coatings and provide precise temperature control.
- Coating appliances: Electric ovens are also used to coat appliances, such as refrigerators, stoves, and dishwashers. They can provide a smooth, durable finish that is resistant to scratches, stains, and corrosion.
- Coating other metal products: Electric ovens can be used to coat a wide variety of other metal products, such as tools, hardware, and industrial machinery. They can provide a durable, long-lasting finish that is resistant to the elements.
Overall, electric powder coating ovens are a versatile and efficient option for a wide variety of powder coating applications. They are clean-burning, environmentally friendly, and can be used to cure a wide range of powder coatings.
Features of an Electric Powder Coating Oven
Electric heating elements: Electric ovens use electric heating elements to generate heat. These elements can be either radiant or convection. Radiant heating elements produce heat directly, while convection heating elements circulate hot air to transfer heat.
Radiant heating elements
Radiant heating elements work by converting electrical energy into infrared radiation. This radiation is then absorbed by the parts being cured, which causes them to heat up. Radiant heating elements are very efficient, as they can transfer heat directly to the parts without heating the surrounding air. This makes them a good option for applications where precise temperature control is important, such as curing thermoset powder coatings.
Convection heating elements
Convection heating elements work by circulating hot air around the parts being cured. The hot air transfers heat to the parts, causing them to heat up. Convection heating elements are less efficient than radiant heating elements, as they require more energy to heat the surrounding air. However, they are more versatile, as they can be used to cure a wider range of powder coatings, including both thermoplastic and thermoset powders.
Temperature control: Electric ovens have precise temperature control, which allows for consistent results in curing powder coatings. There are two main types of temperature control systems used in electric powder coating ovens:
PID (Proportional, Integral, Derivative) controllers: PID controllers are the most common type of temperature control system used in electric powder coating ovens. They work by constantly monitoring the temperature of the oven and adjusting the power output of the heating elements to maintain the desired temperature.
PLC (Programmable Logic Controller) controllers: PLC controllers are more sophisticated than PID controllers and can be used to control a wider range of functions in addition to temperature control. For example, they can be used to control the conveyor speed, the air flow rate, and the overspray collection system.
Airflow control: Electric ovens have airflow control systems that allow for the circulation of hot air around the parts being cured. This helps to ensure that the powder coating cures evenly. There are two main types of airflow control systems used in electric powder coating ovens:
Forced convection: Forced convection systems use fans to circulate hot air around the parts. This type of system is effective at curing powder coatings on parts with complex geometries.
Natural convection: Natural convection systems do not use fans to circulate hot air. Instead, they rely on the natural tendency of hot air to rise. This type of system is less effective than forced convection, but it is still suitable for curing powder coatings on parts with simple geometries.
Overspray collection system: Electric ovens have overspray collection systems that capture the overspray powder, which can be reused or recycled. Overspray is the powder that does not adhere to the parts being coated. It can be a nuisance and a waste of powder, so it is important to capture and collect it.
There are two main types of overspray collection systems used in electric powder coating ovens:
Wet scrubbers: Wet scrubbers capture overspray powder by passing it through a water mist. The water mist causes the powder particles to agglomerate and fall out of the air.
Dry filters: Dry filters capture overspray powder by passing it through a filter. The filter traps the powder particles, while the clean air is allowed to pass through.
Applications of Electric Powder Coating Ovens:
Electric powder coating ovens are used in a wide variety of applications, including:
- Coating automotive parts: Electric ovens are well-suited for coating automotive parts, as they can cure a wide range of powder coatings and provide precise temperature control.
- Coating appliances: Electric ovens are also used to coat appliances, such as refrigerators, stoves, and dishwashers. They can provide a smooth, durable finish that is resistant to scratches, stains, and corrosion.
- Coating other metal products: Electric ovens can be used to coat a wide variety of other metal products, such as tools, hardware, and industrial machinery. They can provide a durable, long-lasting finish that is resistant to the elements.
Overall, electric powder coating ovens are a versatile and efficient option for a wide variety of powder coating applications. They are clean-burning, environmentally friendly, and can be used to cure a wide range of powder coatings.
Forced Convection
Forced convection is a common type of airflow control system used in electric powder coating ovens. It uses fans to circulate hot air around the parts being cured. This type of system is effective at curing powder coatings on parts with complex geometries.
There are a few benefits to using forced convection systems in electric powder coating ovens:
- Even heat distribution: Forced convection systems can help to ensure that the heat is distributed evenly throughout the oven. This is important for curing powder coatings on parts with complex geometries.
- Faster curing: Forced convection systems can help to cure powder coatings faster than natural convection systems. This is because the fans help to move the powder particles around, which allows them to get closer to the hot air.
- Reduced risk of defects: Forced convection systems can help to reduce the risk of defects such as runs, sags, and blisters. This is because they can help to circulate the powder particles more evenly.
However, there are also a few drawbacks to using forced convection systems:
- Higher energy consumption: Forced convection systems require more energy to operate than natural convection systems. This is because the fans are constantly moving the air around.
- More noise: Forced convection systems are noisier than natural convection systems. This is because the fans are constantly running.
Overall, forced convection systems are a good choice for electric powder coating ovens in applications where even heat distribution, faster curing, and reduced risk of defects are important. However, if energy efficiency and noise are concerns, then natural convection systems may be a better option.
Here are some specific examples of how forced convection systems are used in electric powder coating ovens:
- Fans are used to circulate hot air around the parts being cured.
- Fans are used to create a vortex of air that helps to remove overspray powder.
- Fans can be used to create a laminar flow of air, which helps to prevent the powder from sticking to the parts.
By carefully designing the airflow in the oven, forced convection systems can help to ensure that the powder coating is cured evenly and defect-free.
Even Heat Distribution
Even heat distribution is crucial in powder coating applications to achieve a consistent, high-quality finish. It ensures that all parts being coated receive the same amount of heat, resulting in uniform curing and preventing defects such as runs, sags, and blisters. Several factors contribute to even heat distribution in electric powder coating ovens:
- Oven Design: The oven’s design plays a significant role in heat distribution. Properly designed ovens have adequate airflow channels, strategically placed heating elements, and insulation to minimize heat loss.
- Fan Placement: Fans are essential for circulating hot air throughout the oven chamber. The number, size, and placement of fans directly impact the effectiveness of heat distribution. Proper fan placement ensures that hot air reaches all areas of the oven, including corners and crevices.
- Heating Element Placement: Heating elements are the primary source of heat in electric powder coating ovens. Their placement and spacing determine how evenly heat is distributed. Proper heating element placement ensures that heat is generated uniformly throughout the oven chamber.
- Airflow Control: The speed and direction of airflow within the oven can also affect heat distribution. Adjustable airflow controls allow for fine-tuning the airflow pattern to optimize heat transfer and prevent hot spots or cold spots.
- Part Placement: The arrangement of parts within the oven can also influence heat distribution. Proper part placement ensures that parts with different shapes and sizes do not interfere with airflow or create heat shadows.
- Oven Maintenance: Regular maintenance of the oven, including cleaning and filter replacement, helps maintain optimal heat distribution. Dirty filters and clogged airflow channels can impede airflow and cause uneven heating.
- Conveyor Speed: In conveyorized powder coating systems, the conveyor speed affects heat distribution. Too fast a speed may not allow sufficient time for the powder to cure evenly, while too slow a speed may result in excessive heat exposure.
- Part Shape and Size: Parts with complex geometries or varying sizes may require adjustments in airflow patterns or heating element placement to ensure even heat distribution.
- Powder Coating Material: Different powder coating materials may have varying curing temperatures and heat transfer properties. Understanding these properties and adjusting oven settings accordingly can help achieve even heat distribution.
- Oven Monitoring: Regularly monitoring oven temperature and airflow patterns can identify potential issues and allow for timely corrective actions to maintain even heat distribution.
By carefully considering these factors and implementing appropriate measures, powder coating operators can ensure that their ovens provide consistent, even heat distribution, resulting in high-quality, defect-free finishes on all parts.
Electric Powder Coating Oven
An electric powder coating oven is a special oven heated by radiant heating tubes and used to cure powder coating at 200 C
Here we describe a dual chamber powder coating electrical curing oven using a radiation method of heat transfer which is generally used in all powder coatings oven machines. A curing oven is a machine used for powder coating (powder stick with metal by heating) operation done on components. In radiation, heat is transferred in the form of electromagnetic wave motion from one body to another body.
No medium for radiation to occur. The rate of heat radiation that can be emitted by a surface at a thermodynamic temperature is based on the Stefan-Boltzmann law. Generally, this machine is used for a single color powder coating process due to this there is too much time to deliver to different customers for different colors.
Nowadays, many small-scale industries emerge for simple production works, they try to achieve high production rates at a minimal amount of time as well as cost, etc. The main advantage of our system is that it increases productivity and gives quick delivery to customers.
Characteristics of an electric powder coating oven
A curing oven is an industrial oven that is intended to create a chemical reaction in a material once a specific temperature is achieved. Definitions of curing offer different viewpoints on the process. In Engineering, curing is the process of increasing the strength and durability of a substance.
Curing allows the material to be toughened by heating individual links of the material until they can be cross-linked together into a chain; like a chain of DNA.
Powder coating oven temperature
The primary function of the curing oven is to create polymers. A polymer can be hundreds, thousands, or millions of molecules that have been linked together. Polymers can be combined to form more simple structures like a chain or more complex structures to DNA strands. Polymer products are used in manufacturing industries for making different types of products in industries.
Polymer categories include epoxy (strong adhesive), phenolics (a key ingredient in pharmaceutical drugs and detergents), polyesters (used to make bottles, films, and filters), and silicones (used in sealants, medical applications, and many more).
The curing process for powder coating is normally done in a special oven. The coating has to be exposed to a temperature range of 350℉ to 400℉ (160℃ to 210 ℃) for 25 minutes it has to maintain for a perfect curing process. Powder coating is a part of industrial coatings that is being developed during this decade because of environmental concern.
This type of coatings is used as a dry powder and does not require a solvent to keep the binder and fillers in a liquid suspension form. The powder coating process involves application of dry finely ground particles of pigment and resin to surfaces prior to a curing process. The coating is typically applied electrostatically, and then cured under heat to allow for flow and coating formation.
Tunnel Type Electric Powder Coating Oven
Powder coating is an excellent coating system, superior to paint in many ways using dry powders. The main determination to heat oven by temperatures as 250℃, and for time periods up to 25 minutes, depending on the type of powder used. For smaller objects, an old curing oven can be used for load single colour at a time, but using this double chamber oven we have to load two different colours at a time.
The oven is assembled from a series of panels which is actually rigid fiberglass board wrapped in Sheet metal. Each panel is different from the others, but all have at least one dimension, which is the largest size that my brake will handle.
All fastenings are steel pop rivets, except a few screws which hold the panels together to form the oven. The base is a lightweight frame built up of light gauge metal drywall studs, with heating surface filling in the open areas of the frames. Heat is provided by 4 heating elements (heating rods each one 0.75 kW), of about 3000 watts.
Powder Coating Oven Temperature Controller
The energy intensive operations in the powder coating operation are curing. Typical curing operations are with the use of convection ovens. The use of convection heating can be very slow and very costly if the parts are large and heavy since the evaporation or curing will be dependent on the bulk temperature of the part. Therefore, large volumes of air need to be heated and exhausted from the convection oven to effectively dry or cure the parts.
This is much less of a problem for thin walled or low mass parts since the hot air can heat the parts relatively quickly with a resultant faster curing process.
The major components of curing oven are,
1. Radiant heater tubes
2. Insulation
3. Thermocouple
4. Frame
5. Metal sheet
6. Digital temperature controller
7. Controller box
8. Door lock
9. Exhaust pipe
Radiant heater tubes of an electric powder coating oven
The heating elements are screened electrical resistances of smaller diameter designed to be shaped and incorporated into heating systems from the simplest to the most sophisticated. They consist of one or two straight current carrying cores in a flexible metal sheath, electrically insulated from one another and from the sheath by the means of a highly compacted refractory powder.
The outer sheath is continuous only the inner core construction changes, these ends can be fitted with connectors. By combining small diameter and hard packed insulation, a heater is made of such a cable can be given virtually any shape without deterioration of either its insulation or its sheath. To improve the heat contact, and thus heat transfer, the cable can be deformed, brazed or welded together into its optimum position
| Parameters | Specifications |
| Material | Nichrome |
| Voltage | 240 V |
| AMPS | 12.5 amp |
| Power | 3 kW |
| Number of heaters used | 4 no’s |
Insulation of an Electric Powder Coating Oven
Thermal insulation is the reduction of heat transfer (i.e., the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials. Heat flow is an inevitable consequence of contact between objects of different temperature.
The insulating capability of a material is measured as the inverse of thermal conductivity (k). Low thermal conductivity is equivalent to high insulating capability (Resistance value). In thermal engineering, other important properties of insulating materials are product density (ρ) and specific heat capacity (c).
| Parameters | Specifications |
| Material | Rockwool |
| Thickness | 25-100 mm |
| Density | 70-150 Kg/ |
| Dimensions | Width: 1.22m Length: 1.52-4 m |
| Facing and covering | Galvanized steel or stainless-steel hexagonal wire netting (mesh) |
Thermocouple
A thermocouple is an electrical device consisting of two dissimilar electrical conductors forming electrical junctions at differing temperatures. A thermocouple produces a temperature-dependent voltage as a result of the thermoelectric effect, and this voltage can be interpreted to measure temperature.
Thermocouples are a widely used type of temperature sensor. Commercial thermocouples are inexpensive, interchangeable, are supplied with standard connectors, and can measure a wide range of temperatures.
In contrast to most other methods of temperature measurement, thermocouples are self-powered and require no external form of excitation. Thermocouples are widely used in science and industry. Applications include temperature measurement for kilns, gas turbine exhaust, diesel engines, and other industrial processes. Thermocouples are also used in homes, offices and businesses as the temperature sensors.
| Parameters | Specifications |
| Material | Nickel copper |
| Type | Type -T thermocouple |
| Temperature range | 0-950℃ (30-1223℉) |
Frame of the Oven
The metal frame is generally made of mild steel bars for machining, suitable for lightly stressed components including studs, bolts, gears and shafts. It can be case-hardened to improve wear resistance. They are available in bright rounds, squares and flats, and hot rolled rounds. Suitable machining allowances should therefore be added when ordering.
It does not contain any additions for enhancing mechanical or machining properties. Bright drawn mild steels is an improved quality material, free of scale, and has been cold worked (drawn or rolled) to size. It is produced to close dimensional tolerances. Straightness and flatness are better than black steel. It is more suitable for repetition precision machining. Bright drawn steel has more consistent hardness, and increased tensile strength. Bright steel can also be obtained in precision turned or ground from if desired
Sheet Metal
Sheet metal is metal formed by an industrial process into thin, flat pieces. Sheet metal is one of the fundamental forms used in metalworking and it can be cut and bent into a variety of shapes. Countless everyday objects are fabricated from sheet metal. Thicknesses can vary significantly; extremely thin sheets are considered foil or leaf, and pieces thicker than 6 mm are considered plate steel or “structural steel. “Sheet metal is available in flat pieces or coiled strips.
The coils are formed by running a continuous sheet of metal through a roll slitter. In most of the world, sheet metal thickness is consistently specified in millimetres. Parts manufactured from sheet metal must maintain a uniform thickness for ideal results. There are many different metals that can be made into sheet metal, such as aluminium, brass, copper, steel, tin, nickel and titanium. Sheet metal of iron and other materials with high magnetic permeability, also known as laminated steel cores, has applications in transformers and electric machines.
Digital Temperature Controller
As the name implies, a temperature controller – often called a PID controller is an instrument used to control temperature. The temperature controller takes an input from a temperature sensor and has an output that is connected to a control element such as a heater or fan.
To accurately control process temperature without extensive operator involvement, a temperature control system relies upon a controller, which accepts a temperature sensor such as a thermocouple or RTD as input. It compares the actual temperature to the desired control temperature, or set point, and provides an output to a control element.