Before injection molding, it is key to carefully design the structure of the electric toothbrush key. Reasonably set the key stroke, key cap shape and size to ensure that the key can move smoothly during pressing and will not interfere with surrounding parts. At the same time, design a suitable guide structure, such as setting a guide column or guide groove around the key, so that the key can maintain an accurate position when moving up and down, reducing the possibility of jamming. In addition, in order to improve the sealing, a sealing groove can be designed at the contact point between the key and the shell, and a sealing ring can be added to the groove or a sealing rubber ring can be used for one-piece injection molding to prevent moisture and dust from entering.
The performance of the material has an important influence on the quality of the key. Materials with good wear resistance, low friction coefficient and appropriate elasticity should be selected. For example, some high-performance thermoplastic elastomers (TPE) or silicone rubber, which not only provide a comfortable key touch, but also maintain good elasticity in long-term use, reducing key jamming caused by material deformation. For sealing requirements, the material should have good water resistance and chemical resistance to prevent expansion, deformation or corrosion in a humid environment or when in contact with toiletries, affecting the sealing effect.
Precise control of injection molding process parameters is the key to ensure the quality of keys. In terms of injection molding temperature, the barrel temperature and mold temperature should be reasonably adjusted according to the characteristics of the selected material. Too high a temperature may cause excessive softening of the material, affecting the dimensional accuracy and rigidity of the keys, and then causing the problem of jamming; too low a temperature may cause poor material fluidity, resulting in defects such as lack of material and weld marks, affecting the sealing. The injection pressure and speed also need to be precisely controlled. Appropriate pressure and speed can ensure that the material fills the mold cavity evenly, avoiding local overfilling or underfilling, thereby ensuring the dimensional accuracy and surface quality of the keys, and reducing the risk of jamming and poor sealing.
High-precision molds are the basis for producing high-quality keys. The processing accuracy of the mold directly affects the dimensional accuracy and surface quality of the keys. In the mold manufacturing process, advanced processing technology and equipment, such as EDM and wire cutting, are used to ensure that the dimensional accuracy and surface roughness of the mold cavity meet the design requirements. In particular, the mating parts of the keys, such as guide holes and sealing grooves, must ensure that their processing accuracy is at the micron level to achieve a close fit between the keys and the housing, improve sealing and prevent jamming.
Good demoulding design helps to avoid damage or deformation of the keys during demoulding, thereby reducing jamming and sealing problems. In mold design, demoulding mechanisms such as ejector pins and push plates are reasonably set to ensure that the keys can be smoothly ejected from the mold. At the same time, an appropriate demoulding slope is adopted, generally between 1° and 3°, so that the keys can be smoothly ejected from the mold along the slope direction during demoulding, avoiding deformation of the keys or damage to the sealing structure due to excessive demoulding force.
In the production process, it is essential to establish a strict quality inspection and control system. Perform a comprehensive appearance inspection, dimensional measurement and performance test on the keys after injection molding. The appearance inspection mainly includes whether there are defects such as bubbles, scratches, deformation, etc. on the surface of the keys; the dimensional measurement is to ensure that the dimensions of the keys meet the design requirements, especially the dimensions related to sealing and matching; the performance test includes the test of the key's pressing feel, travel, sealing, etc. Through the analysis of the test data, problems in the production process can be discovered in time, and corresponding improvement measures can be taken.
After the button is injection molded, some post-processing can be performed as needed, such as surface polishing, deburring, etc., to improve the surface quality and finish of the button, reduce friction, and prevent jamming. During the assembly process, pay attention to the assembly order and method of the button and other components to ensure that the button is installed in place and the sealing structure is not damaged. At the same time, the assembled electric toothbrush is tested for overall sealing, such as using water immersion test or air pressure test to check whether there is water leakage or air leakage in the button part, and timely rectify the problems found.
Through the above comprehensive measures from design, materials, process, mold, detection to post-processing, the problems of button jamming and insufficient sealing in the electric toothbrush button injection molding process can be effectively solved, and the quality and user experience of the electric toothbrush can be improved.
