The production lines for flocking automobile tailgate springs usually adopt the electrostatic flocking method for flocking. The specific flocking process is as follows:

1. Surface pretreatment of springs

• Cleaning: Use specialized cleaning agents to remove impurities such as oil stains, release agents, and dust remaining on the spring surface during the production process through wiping, spraying, or soaking, so as to ensure a clean surface and lay a good foundation for subsequent flocking. For example, for springs with more oily stains, organic solvents can be used for wiping and cleaning.

• Surface activation (optional): In order to improve the adhesion between the fluff and the spring surface, surface activation treatment can be carried out. Chemical treatment involves using specific activators to have a chemical reaction with the spring surface to increase the active groups on the surface; physical treatment such as plasma treatment uses high-energy particles in the plasma to bombard the spring surface, making the surface produce microscopic roughness and active sites.

2. Preparation of flocking materials

• Selection of fluff: Select fluff according to the usage requirements and design needs of automobile tailgate springs. Materials such as nylon and polyester fiber are often used. For example, if a soft touch and good wear resistance are required, nylon fluff can be chosen; if high strength is needed, polyester fiber fluff can be selected. The length of the fluff is generally between 0.5 and 5 millimeters.

• Dyeing of fluff (optional): If there is a specific color requirement, the fluff needs to be dyed before flocking. Use environmentally friendly dyes to dye under certain temperature, pH value and time conditions to ensure that the color of the fluff is uniform and durable.

3. Coating of adhesives

• Selection of adhesives: Select adhesives that have good compatibility with the spring material and fluff and have appropriate flexibility and strength after curing according to the spring material and flocking requirements.

• Coating methods: The adhesives can be evenly coated on the spring surface through spraying, roller coating and other methods. In some flocking processes, the adhesives will be coated simultaneously with flocking to better fix the fluff.

4. Electrostatic flocking operation

• Equipment operation: In the electrostatic flocking equipment, place the pretreated springs coated with adhesives on the grounded workbench, and the fluff is transported to the flocking gun or flocking head through pipelines.

• Electrostatic adsorption: The equipment applies a high-voltage electrostatic field of 30 - 100 kV between the fluff and the springs, making the fluff charged. Due to the physical characteristics that like charges repel and opposite charges attract, the fluff will accelerate and rise vertically to the spring surface under the action of the electric field and be fixed by the adhesives.

5. Post-treatment

• Curing of adhesives: If heat-curing adhesives are used, put the flocked springs into the drying oven and bake them at a temperature of 80 - 150 °C for 10 - 30 minutes to cure the adhesives; if room temperature curing adhesives are used, just place the springs in a suitable environment and wait for the adhesives to cure naturally.

• Removal of excess fluff: Use blowing, vacuuming and other methods to remove the excess fluff that is not firmly adsorbed on the spring surface. For example, use compressed air to gently blow away the excess fluff on the surface or use industrial vacuum cleaners to suck away the fluff.

• Quality inspection: Conduct quality inspections on the flocked springs, including aspects such as the density of the fluff (measured by the number of fluff in a unit area), adhesion (using the tape sticking method to observe the fluff shedding situation after the tape is torn off), and color consistency (compared with the standard color card).

China Hengjiu Jinyee specializes in manufacturing the production lines for flocking automobile tailgate springs and designs for automobile OEMs (Original Equipment Manufacturers) to meet their requirements.