The evolution of plastic manufacturing has witnessed a paradigm shift from the initial dominance of horizontal injection molding machines to the increasing prevalence of vertical types. Specifically, in the realm of insert molding, vertical machines offer an array of benefits that are compelling manufacturers to reconsider their equipment choices. As we explore the nuances of injection molding advancements, it’s crucial to differentiate between these two categories and understand why vertical options are gaining favor.
This discussion aims to highlight the distinct features and advantages of vertical injection molding machines in comparison to their horizontal counterparts.
A visit to the Chinese Injection Molding Institute would reveal an assortment of diverse molding equipment. The best choice often becomes apparent only with hands-on experience.
Vertical injection molding machines excel with their versatility in production cycles, cost-effectiveness, and the diversity of products they accommodate. Consider insert molding, where a pre-existing part is placed into a mold to be surrounded by newly molded plastic (refer to accompanying imagery).
The process necessitates the removal of a completed part and the placement of a new one with each cycle.
On a horizontal machine, this task can prove cumbersome and inefficient, as it struggles against gravity, potentially decelerating the process and increasing the likelihood of defective outputs. Particularly in medical injection molding, where precision is paramount, horizontal machines may pose heightened risks.
Conversely, vertical machines facilitate the easy and precise insertion of parts, enhancing alignment and efficiency.
For those new to injection molding, we provide foundational knowledge on the process and its mechanics.
An additional perk of vertical machines is their compatibility with book molds and rotary tables.
Book molds clamp tightly onto the inserts, securing them throughout the molding phase. Rotary tables, capable of holding and rotating multiple molds, streamline the insert replacement without interrupting the molding operations.
This combination boasts the quickest cycle times and maximizes efficiency, even allowing simultaneous production of related items.
An instructional video further up showcases a vertical injection molding machine equipped with a rotary table.
Vertical machines also have a spatial advantage, requiring considerably less room than horizontal models, as illustrated by side-by-side images of both machine types.
The clamping units in vertical machines are designed for adaptability, enabling a wide range of mold tooling applications.
When injecting resin in vertical machines, the shorter distance to the mold cavity allows for heightened control, reducing the risk of premature cooling and potential defects associated with longer resin travel paths in horizontal machines.
Two critical aspects influencing the quality of insert molded products are clamping force and shot size.
The clamping force ensures the mold remains sealed during injection. With vertical systems, particularly when utilizing book molds, gravity aids in maintaining mold closure, minimizing the demand for excessive clamping pressure.
Moreover, the robust clamping units of vertical machines support a broad spectrum of mold tooling.
The shot size, or the required volume of molten plastic for each injection, benefits from vertical injection’s top-down approach, which can minimize runner size, decrease costs, and limit waste, all while maintaining process efficacy.