What's the production process of colored aluminum coils?

Raw Material Preparation

Aluminum Coil Selection:

High - purity aluminum ingots with few impurities, good ductility, and stability are chosen as raw materials. These aluminum ingots are then made into aluminum coil blanks with a certain thickness and width through processes such as melting - casting and casting - rolling.

Quality Inspection:

Each roll of aluminum coil blanks undergoes strict weighing and quality inspection to ensure that it meets the production standards. For example, the thickness, width, and flatness of the aluminum coil are checked to see if they meet the standards.

Uncoiling and Pretreatment

Uncoiling:

The aluminum coil is placed on an uncoiler, and the uncoiler rotates to unwind the aluminum coil, preparing it for subsequent processing.

Degreasing:

Chemical agents such as degreasers are used to remove grease and dirt from the surface of the aluminum coil to ensure good adhesion between the coating and the aluminum substrate. Common degreasing methods include immersion and spraying, and the appropriate degreasing process can be selected according to the actual situation.

Water Washing:

After degreasing, the aluminum coil needs to be washed with water to remove the residual degreaser and impurities on the surface to prevent them from having an adverse effect on the subsequent coating.

Brightening:

Chemical or electrochemical methods are used to treat the surface of the aluminum coil to make it more shiny and flat, further improving the quality and decorative effect of the coating.

Re -water Washing:

The aluminum coil is washed again to ensure that the surface is thoroughly clean and free of any residual substances.

Drying:

The aluminum coil after water washing is sent to a drying device for drying to remove the surface moisture and provide a dry surface condition for the subsequent passivation treatment.

Passivation:

A chemical conversion treatment is carried out to form a passivation film on the surface of the aluminum coil, which enhances the corrosion resistance and antioxidant property of the aluminum coil and prolongs the service life of the product.

Re - drying:

The passivated aluminum coil is dried again to make the passivation film more stable and firm.

Coating Stage

Primer Coating:

The pretreated aluminum coil enters the primer coating process, and the roll - coating process is usually adopted. The prepared primer paint is poured into the paint tank of the roll - coating machine. When the aluminum coil passes through the roll - coating machine, the primer paint is evenly coated on the surface of the aluminum coil. The role of the primer is to enhance the adhesion between the coating and the aluminum substrate and provide a good foundation for the topcoat.

Primer Drying:

The aluminum coil coated with the primer enters a drying oven for drying to evaporate the solvent in the primer paint and solidify the coating. The drying temperature and time are adjusted according to the type and thickness of the primer. Generally, it is between 180°C - 250°C, and the drying time is 1 - 5 minutes.

Topcoat Coating:

After the primer is dried, the aluminum coil then undergoes topcoat coating. The color and performance of the topcoat are selected according to the customer's requirements. For example, fluorocarbon topcoat with high weather resistance and polyester topcoat with strong decoration are available. The roll - coating process is also used to evenly coat the topcoat paint on the surface of the primer to form the required color and decorative effect.

Topcoat Drying:

After the topcoat is applied, it is dried again to fully solidify the topcoat paint and improve the hardness, wear resistance, and weather resistance of the coating. The control of the drying temperature and time is crucial for the performance and appearance quality of the topcoat. Generally, the drying temperature is between 200°C - 300°C, and the drying time is 2 - 10 minutes.

Curing and Cooling

Curing:

The painted aluminum coil is cured at a high temperature to make the resin in the paint fully cross - linked and form a hard, wear - resistant, and corrosion - resistant coating. The curing temperature and time are set according to the type and performance requirements of the paint. Generally, it is between 200°C - 350°C, and the curing time is 5 - 15 minutes.

Cooling:

The cured aluminum coil needs to be cooled to around room temperature for subsequent processing and handling. Cooling methods such as air - cooling, water - cooling, or natural cooling can be used, and the appropriate cooling method can be selected according to the production efficiency and product quality requirements.

Quality Inspection and Coiling

Quality Inspection:

During the production process, the colored aluminum coil undergoes multiple - quality inspections, including coating thickness inspection, adhesion inspection, appearance inspection, and color difference inspection. Professional testing equipment and tools such as coating thickness gauges and cross - cut testers are used to ensure that the product meets relevant standards and customer requirements.

Coiling:

The qualified colored aluminum coil is coiled into a coil with a certain specification for storage, transportation, and use. During the coiling process, attention should be paid to the control of tension to avoid deformation and scratches on the aluminum coil.

Specific data sheet for paint weight and paint film on color coated aluminum coils

Changzhou Dingang Metal Materials Co., Ltd. stands as a highly professional factory with two decades of dedicated expertise in the production of top-notch color-coated aluminum coils. Our state-of-the-art manufacturing processes and strict quality control measures ensure the delivery of premium products. For all your requirements and inquiries regarding color-coated aluminum coils, do not hesitate to reach out to us. We are eager to establish a fruitful cooperation and provide you with the most professional service and solutions.