Views: 0 Author: Site Editor Publish Time: 2026-06-23 Origin: Site
In the field of custom injection molding, complex plastic parts with deep undercut structures always bring great challenges to mold design. Today we will analyze a typical long-stroke hydraulic cylinder side core pulling injection mold in our workshop, which is specially developed for plastic products with long lateral undercuts that cannot be demolded by conventional slider mechanisms. This three-plate pin-point gate mold realizes automatic high-volume production through hydraulic driving, precise positioning and standard ejection systems.
This mold adopts a standard three-plate mold base, consisting of top clamping plate, runner stripper plate, A plate (cavity plate), B plate (core plate), ejector plate and bottom clamping plate.
Pin-point gate feeding design: During mold opening, the runner material is automatically separated from finished products on the runner stripper plate. No manual gate trimming is required, which keeps the product surface smooth and clean, perfectly matching automated production with manipulators.
Four large-diameter guide pins and guide bushes are installed around the mold base: They guarantee high coaxial precision in repeated mold clamping, effectively avoid mold misalignment, flash and product dimensional deviation during long-term mass production.
The most distinctive design of this mold is the long horizontal hydraulic cylinder mounted on the side, which solves the demolding difficulty of deep lateral undercuts that traditional angle pin sliders cannot handle.
Stable large pulling stroke: Different from limited stroke angle pin sliders, the hydraulic cylinder can realize ultra-long lateral pulling distance. It provides strong locking force under high injection pressure, preventing the slider from being pushed backward by molten plastic and causing flash or burrs on finished parts.
Complete wear-resistant slider assembly: The slider is equipped with wear strips, wedge locks and positioning blocks. The wedge lock tightly clamps the slider during mold closing to offset lateral injection pressure; wear-resistant components reduce friction loss in frequent reciprocating movement and greatly extend the service life of the entire mold.
Safe automatic control: The hydraulic cylinder can be equipped with travel limit sensors to feed back position signals to the injection molding machine. Only when the slider fully returns to the designated position can the mold be closed, which effectively avoids mold collision and equipment damage.
A conventional mechanical ejector system is adopted in this mold, including ejector pins, return pins, reset springs and ejector plates.
After mold opening, the injection molding machine pushes the ejector assembly to eject plastic products from the core cavity smoothly.
The built-in reset springs ensure that all ejector components return to the initial position before mold clamping, which prevents ejector pins from pressing the cavity surface and causing mold damage or product defects.
The modularized ejection structure facilitates daily maintenance and replacement of vulnerable parts such as thimbles, which greatly reduces post-production maintenance costs and downtime.
Wide Application Range: Suitable for deep cavity housings, medical accessories, tubular connectors and other plastic parts with long lateral undercuts; compatible with most common engineering plastics including ABS, PC, PP and PA.
High Automation & Production Efficiency: The combination of three-plate pin-point gate and hydraulic core pulling supports unmanned continuous production, shortens molding cycles and significantly cuts down unit production costs for mass orders.
Excellent Dimensional Stability: Balanced melt filling from pin-point gates effectively lowers internal stress of plastic parts, so finished products have low warpage rate and stable dimensional tolerance, meeting strict appearance and assembly requirements.
Long Service Life & Easy Maintenance: Standardized modular components make wear part replacement convenient, without the need to disassemble the entire mold core, which saves repair time and prolongs the total service life of the injection mold.
Travel induction switches must be configured for hydraulic cylinders to guarantee safe mold opening and closing sequences.
Wedge locks need sufficient locking allowance to resist high injection pressure and prevent slider retreat.
Extra venting gaps should be reserved between sliders and mold inserts to eliminate trapped air, avoiding burning, short shot and weld line defects on plastic products.
Long-stroke hydraulic core pulling three-plate injection molds are an essential customized solution for complex undercut plastic products. By integrating precise mold frame design, stable hydraulic driving structure and standard ejection systems, this type of mold balances production safety, product yield, manufacturing efficiency and long-term service life. For manufacturers that need large-volume production of special-shaped plastic parts, hydraulic side core pulling mold design is a reliable and cost-effective choice.
