0 Preface

With the continuous development of social economy, people’s living standards have been gradually improved. As a very convenient means of transportation, automobiles have become more and more indispensable in the daily life of the public, which has also greatly promoted automobile manufacturing. development of technology. In order to reduce the weight of automobiles and improve the performance of automobiles, plastic parts have been widely promoted in automobiles and replaced a large number of original automobile metal parts. However, plastic parts have more fragile characteristics than metal parts, which also makes the repair work of plastic parts for automobile sheet metal get widespread attention. Therefore, it is of great practical significance to carry out research on the maintenance of plastic parts of automobile sheet metal.

1 Overview of Auto Sheet Metal Repair

As a technical method of automobile maintenance, automobile sheet metal maintenance refers to a series of repair work other than body anticorrosion and decorative spraying after the car is damaged, including automobile body damage assessment, sheet metal shaping, body measurement, Stress relief welding, etc.When an accident occurs in a car, because the appearance of the car body is damaged and deformed, if only the traditional “smashing, pulling and welding repair” is adopted on the car, it will inevitably have an adverse effect on the strength and service life of the car body.[1]. Therefore, at this stage, the repair of the sheet metal of the car can be regarded as the secondary manufacturing and assembly of the car body to a certain extent, and the repair of the gaps and hidden dangers that are difficult to detect with the naked eye is carried out. Therefore, automobile sheet metal maintenance requires not only the car maintenance personnel to effectively understand the overall dimensions and technical parameters of the car, but also to clarify the characteristics of the body material, and then use reliable measuring tools to carry out a comprehensive and systematic inspection of the body and analyze the damage of the car. Evaluate the hidden dangers of body deformation, establish a scientific and effective maintenance plan, and then use a series of maintenance techniques to carry out maintenance on the car.

2 Maintenance methods of automotive sheet metal plastic parts

At this stage, there are two main maintenance methods for automotive sheet metal plastic parts, namely bonding method and welding method. Among them, the bonding method is the most widely used. The specific steps to carry out the repair of automobile sheet metal plastic parts are: first, carry out the cleaning work of the repaired plastic parts and carry out pretreatment on the surface. For example, cleaning the sundries on the plastic parts to ensure the dryness of the surface of the plastic parts, etc. Then, after the cleaning work is completed, the maintenance parts are polished, and the maintenance treatment is carried out with special bonding materials. Finally, the repair surfaces of plastic parts are dried, polished, and painted. When using the bonding method to carry out the repair of automobile sheet metal plastic parts, it is necessary to pay special attention to the fact that various types of adhesives cannot be mixed.

3 Repair of plastic parts of automobile sheet metal

3.1 Bumper maintenance

For the car, the bumper is a very important part. It can buffer and absorb the impact force when the car collides, and then play a corresponding protective role for the driver and the body, which also determines The bumper is one of the most easily damaged parts in a car.In the process of repairing the damaged bumper, the maintenance personnel should first use relevant tools to remove the plastic burrs caused by the collision on the bumper to ensure the flatness of the bumper surface, thereby creating effective convenience for the subsequent maintenance. [2]. If there is a depression on the bumper, the maintenance personnel should fill it with materials such as putty to ensure the overall smoothness. Generally speaking, a certain amount of dust and dirt will often stick to the damaged part of the bumper in the collision. The maintenance personnel should use a brush or high-pressure water gun to clean it to ensure the firmness of the adhesive putty itself. The cleaning work is completed,Combine treatment, and then brush the mixed putty to the damaged area. After painting and placing for a certain period of time, polish and paint the surface of the repaired bumper, and the bumper repair is completed.Then you should choose a putty with a similar color to the bumper, and then mix the putty with the hardener, It is worth mentioning that after the repair of the bumper is completed, the maintenance personnel should also carry out a comprehensive and systematic inspection of the bumper as a whole to ensure the quality of the repair.

3.2 Scratches and cracks treatment

Scratches and cracks are very common problems in automotive plastic parts, and maintenance work is relatively simple.First of all, the maintenance personnel should confirm the damaged part, and then clean the damaged part. During the cleaning process, the damaged part can be cleaned with a clean rag coated with solvents such as paraffin, grease, etc. After wiping, the damaged part should be left to dry. To ensure the dryness of scratches and cracks[3]. Secondly, carry out cutting treatment on scratches and cracks to ensure that the damaged surface generates corresponding inclined surfaces, and use tools such as sandpaper to polish the damaged parts to promote the orderly development of subsequent bonding work. Finally, adjust the pre-alignment of scratches and cracks, grasp the strength of the alignment, use professional tools to heat the damaged parts, apply adhesive and adhesion promoter on both sides of the scratches and cracks, and at the same time. , apply corresponding pressure, improve the bonding level, complete the processing work, and then carry out effective grinding and painting for the scratches and cracks of the processed plastic parts.

3.3 Treatment of large area damage

In the process of dealing with large-scale damage to the car, because the damaged part is large, it is easy to affect the strength of the plastic part. Therefore, in view of this situation, the maintenance personnel should use the same material as the plastic part to treat the damaged part. First of all, the damaged part should be cleaned and pretreated to ensure that the surface of the damaged part is clean and dry. Secondly, use reliable fixing equipment to ensure the effective fixing of plastic parts, and then remove the damaged parts. Third, integrate the material of plastic parts, select plastic parts of color and material to repair materials, and carry out pretreatment according to the current situation of damaged parts. Then use sandpaper, grinder, etc. to polish the damaged parts, and make up the edges of the material, and ensure the firmness of the bond. Finally, apply adhesive and adhesion promoter to the damaged part of the plastic part to ensure the effectiveness of the bond. The damaged parts and supplementary materials are then bonded a second time to improve the firmness level, and further grinding, painting and other treatments are carried out.

4 Conclusion

All in all, automobile sheet metal repair is an important part of automobile repair processing. As an important part of automobiles, it is very important to carry out the repair of plastic parts of automobile sheet metal. Therefore, automobile maintenance personnel should increase their research efforts, improve their effective understanding of the connotation and characteristics of automobile sheet metal maintenance, strengthen in-depth analysis of the maintenance methods of automobile sheet metal plastic parts, carry out the maintenance of automobile sheet metal plastic parts, and effectively ensure the maintenance of automobile sheet metal plastic parts. safe operation.

Link：Talking About The Maintenance Of Plastic Parts Of Automobile Sheet Metal

REF: Metal Stamping Service, China 3D Printing Service, Plastic Injection