With the continuous development of 3D printing technology, its application scope has been extended to industrial manufacturing, medical care, education, art and other fields. However, despite the high flexibility and customization advantages of 3D printing technology, the surface of printed products often has problems such as layering, burr and roughness, which affects the appearance quality and usability of products. Therefore, post-processing of 3D printed parts, especially surface polishing, has become an important link to improve product quality. Among them, chemical polishing, as an efficient and simple post-processing method, has been widely used in ABS, PLA and other common printing materials.

First, the basic principle of chemical polishing

Chemical polishing is a technology that uses a specific chemical solvent to slightly corrode the surface of materials, so as to remove the uneven part of the surface and achieve a smooth and flat surface effect. Its core lies in that the solvent can selectively dissolve the tiny structures protruding from the surface of the material without obviously damaging the whole structure.

Taking ABS as an example, the commonly used chemical polishing agent is acetone vapor. ABS will soften its surface in acetone vapor, so that the concave-convex structure originally produced by printing lamination tends to be smooth gradually. PLA materials can be treated with organic solvents such as chloroform or ethyl acetate, although the effect is slightly worse than ABS, but it can still significantly improve the appearance.

Second, the operation steps of chemical polishing

1. Preparation: Make sure that the printed parts have been basically cleaned, and the supporting structures and obvious burrs have been removed. Wear protective gloves, goggles and other safety equipment, and the operation should be carried out in a well-ventilated environment.

2. Preparation of polishing solution or preparation of steam: select the appropriate solvent according to the material. For ABS parts, acetone vapor polishing method can be used, that is, the printed parts are hung in a closed container, and the heated acetone liquid is placed at the bottom to generate steam.

3. Control the polishing time: expose the printed piece to steam, which is usually controlled between 5 and 15 minutes. The effect is not obvious if the time is too short; Excessive time may lead to excessive softening or even deformation of the material.

4. Cooling and treatment: take out the printed piece and put it in a ventilated place for natural cooling, and check the surface effect after it is completely hardened. If necessary, it can be slightly polished or polished again.

III. Advantages and Precautions of Chemical Polishing

Advantages:

-Simple operation without complicated equipment;
-High surface gloss and remarkable visual effect;
-Multiple parts can be processed at the same time to improve efficiency.

Precautions:

-Solvents are volatile and flammable, so attention should be paid to fire prevention and ventilation;
-Different solvents should be used for different materials, and they should not be mixed;
-The polishing time should not be too long to avoid structural deformation;
-Polishing may affect the dimensional accuracy and mechanical properties of parts, and the advantages and disadvantages need to be weighed.

IV. Scope of application and practical application

Chemical polishing is suitable for 3D printed products that require high surface quality and relatively loose dimensional accuracy, such as display models, works of art, prototype design, etc. In the industrial field, it can also be used as a pretreatment step for subsequent processes such as painting and electroplating to improve adhesion and aesthetics.

In a word, chemical polishing, as an important means of post-processing of 3D printed parts, not only improves the appearance quality of printed parts, but also enhances their functionality and practicality. With the continuous progress of materials and technology, it is believed that chemical polishing technology will be more widely used and developed in the future.