How to Determine the Ejection Draft Angle of Injection Molding Products?
An appropriate ejection draft angle ensures that plastic parts can be smoothly ejected after molding, reduces mold damage, and improves production efficiency and product quality.
1. Understand the Basic Concept of Ejection Draft Angle
The ejection draft angle refers to the angle formed between the inner surface of the plastic part and the direction of mold opening. This angle is crucial for the smooth ejection of the plastic part from the mold.
2. Refer to the Characteristics of Plastic Materials
Different plastic materials have varying flow properties, shrinkage rates, and adhesion tendencies during molding, and therefore, their required ejection draft angles also vary.
3. Consider the Shape and Structure of the Product
The shape and structure of the product are also important factors in determining the ejection draft angle. More complex geometries or products with deep cavities require a higher draft angle. Especially for plastic parts with vertical walls or significant wall thickness variations, the design of the ejection draft angle needs to be more careful.
4. Follow Industry Standards and Experience
In the injection mold design process, there are some common industry standards that can serve as references. For example, generally, the ejection draft angle for plastic parts ranges from 0.5° to 2°, with the standard draft angle usually around 1°. For products with complex shapes or high precision requirements, a larger draft angle may need to be designed.
5. Mold Trial and Adjustment
Although the ejection draft angle has been considered during the design stage based on material, shape, and structure, the final ejection performance still needs to be verified through mold trials. During the trial, observe whether the product can be smoothly ejected and check for any issues such as mold sticking or warping during the ejection process.
