In the production of plastic molds, threaded plastic parts have higher requirements for demolding methods due to their complex geometric structure. The demolding of threaded structures not only affects product integrity, but also directly relates to the service life and product quality of plastic molds. Choosing the appropriate demolding method can effectively avoid thread damage, improve production efficiency and product accuracy. This article will introduce several common demolding methods and application scenarios for threaded plastic parts, helping you optimize plastic mold design.
1.Rotary demolding is the most commonly used method, suitable for internal and external threaded plastic parts. In plastic molds, the threaded part is demolded through a rotatable core or cavity, usually driven by a hydraulic motor or mechanical gear. This method is suitable for products with deep threads and high precision requirements, such as bottle caps, nuts, etc.
2.Forced demolding is suitable for plastic parts with shallow threads or good flexibility. The product is ejected directly from the threaded core through the elasticity of the material itself, without the need for a rotating mechanism. This method has a simple structure, low manufacturing cost for plastic molds, and is suitable for materials with good toughness such as PP and PE. It is commonly used for threaded plastic parts with low precision requirements, such as disposable container lids. But forced demolding may cause slight deformation of the threads, which is not suitable for high-precision or hard materials such as PC plastic products.
3.Sliding blocks or inclined top demolding are suitable for plastic parts with lateral threads or complex structures. Plastic molds separate threaded parts from the core through lateral movement of sliders or slanted tops, commonly used in automotive components or home appliance parts. This requires precise calculation of the slider angle and motion trajectory in plastic mold design to ensure smooth demolding. For example, a plastic part of a car knob was successfully removed from the mold through oblique top demolding, avoiding thread damage and achieving a product qualification rate of 99%. However, the slider mechanism increases the complexity of the plastic mold and incurs higher maintenance costs.
4.Split type core demolding is suitable for ultra complex or deep threaded plastic parts. The threaded core of plastic molds is composed of multiple detachable components. When demolding, the core is first decomposed and the plastic part is then removed. It is commonly used for medical devices or precision instrument parts. This method can ensure the integrity of the threads, but the precision requirements for plastic mold processing are extremely high, with tolerances controlled within ± 0.005mm, and the production cycle is long, suitable for small batches and high-value products.
When choosing the demolding method, it is necessary to comprehensively consider the thread depth, material characteristics, production batch size, and plastic mold cost. CAE simulation can analyze demolding risks in advance and optimize design; High precision CNC machining ensures core tolerance; Regular maintenance to reduce plastic mold wear. A reasonable demolding method is the key to the success of plastic molds, and scientific processes and processing can help you create high-quality threaded plastic parts. If you need professional plastic mold solutions, please feel free to contact us!
Send Email
Skype