With the rapid development of China's economic construction, the improvement of people's living standards, the rapid development of China's construction industry, aluminum demand continues to increase, therefore, aluminum extrusion die design, manufacturing and production demand is also increasing.
    Aluminum products in all walks of life have been widely used, and products continue to toward the diversification and complexity of the development of the product processing accuracy requirements are getting higher and higher. Extrusion dies are the basis of the extrusion process, not only to determine the shape of the extruded product, dimensional accuracy and surface conditions. Quality requirements are getting higher and higher, the processing requirements of the mold also will increase. Processing accuracy is the processing of the maximum requirements, so how to effectively improve the precision machining of precision plastic mold has become a difficult problem to solve today.

1, mold processing quality, including processing accuracy and surface quality
    The machining accuracy is the degree of conformity between the three geometrical parameters of the actual size, shape and position of the part after machining, and the ideal geometric parameters required for the drawing. The ideal geometric parameters, for dimensions, are the average size; for the surface geometry, the absolute circle, the cylinder, the plane, the cone and the line, etc .; for the mutual position between the surfaces, the absolute parallel , Vertical, coaxial, symmetrical, etc. The deviation between the actual geometry of the part and the ideal geometric parameter is called the machining error.

    Machining accuracy and machining errors are terms that evaluate the geometrical parameters of the surface. The machining accuracy is measured by the tolerance level, the smaller the level value, the higher the accuracy; the machining error is indicated by numerical values, the larger the value, the greater the error. High precision machining, processing error is small, and vice versa. The actual parameters obtained by any machining method are not absolutely accurate. From the function of the part, the machining accuracy is guaranteed as long as the machining error is within the tolerance required by the part drawing.

    The quality of the machine depends on the quality of the parts and the quality of the assembly of the machine. The machining quality of the part includes the machining precision and the surface quality. The machining precision refers to the actual geometric parameters (size, shape and position) and the ideal geometry Parameters in line with the degree. The difference between them is called machining error. The size of the machining error reflects the level of machining accuracy. The greater the error the lower the machining accuracy, the smaller the error the higher the machining accuracy.

2, the main aspects of the impact of processing accuracy
2.1 dimensional accuracy
    Refers to the actual size of the parts after processing and the size of the parts of the tolerance with the center of the degree of compliance.
Dimensional accuracy is controlled by dimensional tolerances. Dimensional tolerances are the allowable amount of change in part size during machining. In the case of the same basic size, the smaller the dimensional tolerance and the smaller the dimensional accuracy.

    Refers to the degree to which the actual geometry of the surface of the part after machining is consistent with the ideal geometry. Accuracy of the shape of the project has a straightness, flatness, roundness, cylindrical degree, line contours and other 6 items. Shape accuracy is controlled by the shape of the tolerance, the shape of the tolerance, in addition to roundness, cylindrical degree of 13 precision levels, the rest are divided into 12 precision levels. Level 1 highest, lowest 12 level.

2.3 Position accuracy
    Refers to the difference in the actual position accuracy between the parts related to the surface after processing. The items with the accuracy of the position are parallelism, verticality, inclination, coaxiality, symmetry, position degree, round beating and full beating. Position accuracy is controlled by position tolerance, and the position tolerance of each item is also divided into 12 precision levels.

3, dimensional accuracy, shape accuracy and position accuracy
   Usually in the design of machine parts and the provisions of precision machining parts, it should be noted that the shape error control in the position tolerance, the position error should be less than the dimensional tolerance. That is, precision parts or parts of the important surface, the shape accuracy requirements should be higher than the position accuracy requirements, position accuracy requirements should be higher than the dimensional accuracy requirements.