Side action plays a vital role in the molding process by allowing creation of complex shapes in plastic pieces and conveniently producing features such as sloths, internal threads and undercuts which is not possible with straight pull molds.
Without compromising the quality and efficiency, side actions allow a more convenient method to produce complex products by using movable mold parts that work perpendicularly to the main direction of mold opening.
Furthermore, side actions can combine features like efficient cooling channels along with thermal management systems to improve the molding process and can also work with different types of plastics to offer a versatile range of products.
In this article, we’ll further explore how side actions work, what makes them popular in the industry and how they make the molding process efficient without affecting product quality.
What Is Side Action In Design
While typical molds rely on a unidirectional opening and closing motion, side actions refer to mechanisms in injection molding process involving side-to-side movement of mold components to create complex features such as undercuts and internal threads.
This technique allows efficient production while also offering high precision in creation of plastic products and hence can be considered as a game changer in the modern mold design industry.
How Does Side Action Work In Injection Molding Process
Key Terms:
Angle Pins: Angle pins guide the side-to-side movement of side cores as the mold opens and closes.
Hydraulic Cylinders: Provide the force required for operating larger and complex side cores.
Cam Pins: Cam Pins control the precision and motion of the side cores, ensuring accurate engagement and disengagement for maintaining tight tolerances.
Locking Mechanisms: Lock the side cores in position during the injection process to maintain accuracy.
Parting Line: The visible line on a part formed through injection molding where both halves of the mold meet is called parting line.
Ejection Pins: During the ejection phase, ejection pin is used to push the hardened part out of the mold cavity.
#1. Setup Phase
The mold cavity is made with mobile components, which are termed as side cores or side action elements. These parts are set at right angles to the primary direction for opening and closing of the mold. The side action cores get activated by systems that can be mechanical or hydraulic like angle pins, hydraulic cylinders, or pneumatic systems.
#2. Mold Closing Phase
When the injection molding process begins, the mold closes in two main stages:
Mold Closure: The main mold halves come together, sealing the parting line. This ensures a closed cavity for the molten plastic.
Side Action Engagement: As the mold closes, an angle pin or some other similar mechanism is used to push the side cores into position. These side cores slide laterally and move into their desired position to form complex features like undercuts.
#3. Injection Phase
Once the side cores are set, melted plastic is pushed under strong pressure inside the mold cavity. The liquid plastic spreads around these side cores and fills up all small details in them, including those shaped by side action elements. Moreover, efficient cooling pathways together with heat management systems help to control temperature during this step so that material hardens properly without any mistakes or flaws.
#4. Mold Opening Phase
After the plastic solidifies, the mold begins to open. During this phase, the following processes take place:
i. Primary Mold Opening: The main halves of the mold split, allowing for most part of the mold to be released.
ii. Retraction of Side Action: When the mold opens, mechanism for side action is disconnected. Angle pins or hydraulic systems retract side cores and move them away from molded part ensuring that the finished product is released without harm to the part nor to the mold.
#5. Ejection Phase
Once the side cores retract completely, the molded part is finally released from the mold cavity. Mechanisms such as ejection pins may be used to ensure clean removal of the formed part.
Types of Side Action
Some types of side actions used in the injection molding process are given below, each with its pros, cons and brief description.
1. Cam-Driven Side Actions
Cams are smart devices that help open molds by pulling back undercut surfaces from the part. A typical cam design features an angled pin that controls the movement, matching the speed of the mold’s opening and closing. This design allows for more complex shapes in parts without needing extra adjustments or help from operators.
However, the cam pin needs regular checking during production. Because steel can compress, too much pressure can deform the pin, which can impact part quality. Keeping up with cam pin maintenance and inspections is essential for steady performance and part accuracy.
Advantages: Simple design, cost-effective, and reliable for moderate complexity.
Disadvantages: Limited to linear motions and may require additional support for heavy-duty tasks.
2. Lifters
Lifters are essential for creating parts with internal undercuts or features that must be released straight up. This includes things like internal threads or bosses that need a certain position. They work in a way that removes the need for an angled pin and lowers the chance of pin damage.
However, features like drafts, bosses, and ribs might need changes to allow for lifter movement. Additionally, designing an injection mold lifter can be complicated, needing thorough planning and testing. Also, the design and timing of the ejector plate are important for making sure the lifters activate and retract correctly.
Advantages: Enables complex designs and minimizes the need for secondary operations.
Disadvantages: Requires precision machining and can increase mold design complexity.
3. Sliders
This type of side action differs from lifters as it creates and releases external undercut features. It provides various actuation options, such as cam-driven, or hydraulic systems, which help in making parts with intricate external shapes.
Injection molding slides are crucial for designing parts with external undercuts or features that must be released without disturbing the main core and cavity. This includes external threads or features that need a certain orientation.
However, designing sliders can be complicated. It requires thorough planning and testing. Proper timing and synchronization with other mold actions are essential to ensure that the slider engages and disengages correctly.
Advantages: Highly versatile and can handle intricate side features.
Disadvantages: Adds cost and maintenance requirements to the mold.
4. Unscrewing Mechanisms
Unscrewing actions, whether done automatically or by hand, help create screws or threaded features by carefully managing the screwing process. This control ensures good quality and avoids damage during production cycles.
Parts made by injection molding that have threaded features, such as screws and fasteners, can be tricky to take out. While it’s easy to add external threads that are straight to the mold design, internal threads and external threads that are not straight require a special unscrewing mechanism. This mechanism is placed in the mold before the injection and is carefully unscrewed from the part once the material has set.
Advantages: Provides precise, consistent thread production.
Disadvantages: Complex to design and maintain, and increases production time.
5. Collapsible Core
Collapsible cores help release circular undercut features, working like lifters. They collapse inward to create space for part ejection. While molding, parts are shaped around the action, which collapses after the material hardens.
This makes it easy to take out both the action and the part from the mold. They are perfect for features with circular undercuts or big internal threads. Additionally, collapsible core actions can create threaded features, increasing their usefulness.
Advantages: Ideal for creating intricate internal geometries.
Disadvantages: High cost and requires advanced mold design expertise.
Comparison Table
| Types | Description | Advantages | Disadvantages |
| Cam-Driven Side Actions | Lateral movement powered by cams or angle pins | Cost-effective, reliable | Limited to linear motions |
| Lifters | Angular motion to release undercuts | Enables complex designs | Complex design and machining |
| Sliders | Lateral movement for external features | Highly versatile, intricate designs | Adds cost and maintenance requirements |
| Unscrewing Mechanisms | Rotates cores to create threads | Consistent and precise thread production | Increases design and production time |
| Collapsible Core | Compresses inward to release internal features | Handles complex geometries effectively | High cost and design complexity |
Types of Cam Pin Methods
Cam pins are very crucial mechanical parts in injection molding process that guide movement of side actions within the mold thus making them essential for ensuring precision and smoothness in operation of side actions.
On closing the mold cavity, the cam pin engages with the side core to slide it into position and during the mold opening procedure, the cam pin retracts the side core, so that the molded part can be released without damage.
There are different types of cam pin methods which are discussed below:
1. Mechanical Cam Pins
Mechanical Cam Pin Systems use mechanical movement to push the pin inside the mold cavity. When this mold is opened, there’s a system that works in sync with it to retract the pin that holds back and releases the molded part.
They are famous for being reliable and accurate especially when producing in large volumes. The main advantage is they last quite long and are able to function at extremely quick speeds. However, it may be necessary to perform substantial upkeep as they often deteriorate over time.
2. Hydraulic Cam Pins
Fluid pressure is utilized by hydraulic systems to manage cam pins, providing them with smooth and controlled motions. This design proves useful when greater forces or additional precision is required, such as in the handling of very large objects or those featuring complex details.
The main advantage of using hydraulic cam pins lies in their ability to ensure consistent and repeatable movement. However, it should be noted that these setups can be more complicated and costly due to many factors such as expensive hydraulic components and maintenance requirements.
3. Spring-loaded Cam Pins
The spring-loaded system allows to keep the cam pins in their places while pulling them back when required during the die opening process by using springs. So, we can say that arranging these springs is not as difficult compared to mechanical or hydraulic ones.
The main benefit obtained from using such systems connects to low starting set up cost and easy replacement though some doubt that springs do not have the long life compared to mechanical or hydraulic systems making them exposed to damage over time, thus limiting their usage under severe conditions.
Advantages of Using Side Action
Using Side Action in the injection molding process provides numerous benefits to the designers and producers including improved quality, cost efficiency, time efficiency etc. Some of these advantages are discussed further.
Undercut Features
As formation of undercut features can be a challenge for the designers, the side actions solve this problem with their ability to not only form these features but also create more complex shapes without requiring any other supplementary operations.
Reduction in Operations
By incorporating complex features directly into the mold cavity, side actions streamline the manufacturing process while eliminating need of additional machines or processes after the molding is completed. The overall benefit of this is the improved efficiency in the overall operational process of molding.
Time and Cost Savings
As discussed above, the ability of side actions to form discussed features such as undercuts and inner threads eliminates the need for secondary operations which significantly cuts down the production time and cost. By making the production process more time and cost efficient, side actions are considered as an attractive option for tight deadline or tight budget projects.
Enhanced Design Flexibility
As features like undercuts and internal threads pose a challenge in case of simple molding process, side actions can allow manufacturers to achieve such designs with ease hence enabling innovation and creativity in product development.
Improved Part Quality
By ensuring high precision and minimum distortion in the injection molding process, side actions are able to achieve consistent part quality. This ability to produce high quality molds reduces waste and improves the reliability in manufacturing.
Design Considerations For Side Actions
As choosing a certain side action for your project can be a challenging decision, here are some factors that play a key role in design considerations:
Selecting the type of side action
According to the complexity of the molded part, required features and production requirements, the suitable type of side action can vary as explained with examples given.
For high force applications where precision and power are prioritized, hydraulic systems are most suitable as they are often used for large parts or molds requiring heavy-duty side actions
For lightweight applications where high pressure is not required, simpler and cost effective pneumatic systems can be used.
For straightforward designs requiring minimal movement, mechanical systems such as cam pins or angle pins are mostly preferred.
Careful analysis of the part’s geometry, production volume, and tooling costs is essential to select the most appropriate mechanism.
Selecting the type of side action
According to the complexity of the molded part, required features and production requirements, the suitable type of side action can vary as explained with examples given.
For high force applications where precision and power are prioritized, hydraulic systems are most suitable as they are often used for large parts or molds requiring heavy-duty side actions
For lightweight applications where high pressure is not required, simpler and cost effective pneumatic systems can be used.
For straightforward designs requiring minimal movement, mechanical systems such as cam pins or angle pins are mostly preferred.
Careful analysis of the part’s geometry, production volume, and tooling costs is essential to select the most appropriate mechanism.
Material Selection
The materials needed for side action parts must fulfill strict levels of longevity and efficiency. Important points to take note of are:
Resistance to corrosion: Materials such as stainless steel or treated alloys are often used for standing up against the humid, corrosive climates in molding processes.
Thermal Expansion Control: Side effects must keep their size precise even when they are exposed to different temperatures during the molding cycle.
Resistance to Wear: High quality materials guarantee that the parts can hold up under repeated use without too much deterioration, prolonging the lifespan of a mold.
Choosing the right material has a direct effect on how durable and dependable the side action mechanism is, particularly when it comes to large scale production.
Side action mechanism
The selection of side action system decides the efficiency of side cores to generate undercuts or other complicated elements. Important aspects to consider are:
Hydraulic Systems: They provide exact and strong movement for lateral actions, perfect for precise and challenging uses.
Pneumatic Systems: Provide a lightweight and cost-efficient alternative for less demanding molds.
Angle pins or cam pins: These systems are cheap and reliable for more simple designs, but they might not offer the same adaptability as hydraulic or pneumatic machinery.
Selecting the right mechanism ensures smooth operation and consistent molding quality.
Locking Mechanism
A strong lock system makes sure that the side core stays stable during the injecting phase. If not, pieces might have size errors or problems. Usual choices are:
Positive Locking Systems: These secure side cores in place while injection is happening, making sure the molding of undercut features is done precisely.
Mechanical locks: Often they are used together with cam or angle pins, these offer dependable operation at a cheaper expense.
Hydraulic or Pneumatic Locks: These are utilized in more complicated systems, where there is requirement for exact control.
The mechanism for locking needs to be planned with care, so it can manage the forces applied during phases of injection and ejection without breaking.
How Are Side Action Molds Manufactured?
Making side action molds require careful planning, precise building and detailed finishing so they work well overtime. By using modern technology, makers can create molds that meet the needs of today’s injection moldings. These deliver strong parts even with complicated shapes.
Design
Being the foundation of manufacturing side action molds, the design process involves detailed planning to confirm that the mold meets the desired specifications and performance requirements. Some important aspects under the design process are as follows:
Mold Cavity and Core Design: Keeping the complex geometries and specific mold requirements such as undercuts, threads, complex details etc. in mind, the mold cavity and side cores are designed to meet such requirements. The position and mobility of side action components is also determined using the same mentioned requirements.
Mechanism Layout: As discussed earlier, selection and inclusion of integral mechanisms like hydraulic systems, cam pins, locking mechanisms is important for enabling precision and efficiency in operation of side actions.
Heat Management Systems: To ensure uniform and rapid cooling of molded parts, a heat management system or a cooling system should be incorporated into design with efficient cooling channels.
Advanced CAD software and simulation tools are used to validate the design, analyze potential issues to optimize the mold’s operational efficiency before fabrication begins
Fabrication
On finalizing the design, the next step for the mold is the fabrication phase which involves precise machining and assembling of components. Key steps for fabrication include:
Precision Machining: The mold cavity, cores, side action components are created using technologies such as CNC or EDM (Electric Discharge Machining) with tight tolerances to ensure parts can be assembled properly and function well.
Assembly of Side Action Mechanisms: The created components in machining step are now assembled carefully and installed to enable smooth operation for the injection molding process. Careful attention is required in this step so that parts of side action are not only assembled properly but also synchronized with main mold activity.
Testing for Fit and Functionality: Once the components have been created and assembled, the last stage is testing in which rigorous testing is performed to check that the system operated as intended and adjustments are made in case potential issues are detected.
Finishing
After design and fabrication, the next phase is finishing in which the mold is refined and prepared for production. Key tasks under finishing include:
polishing mold surfaces to ensure that ejection phase operates smoothly and molded parts have a clean surface finish.
fully assembling all mold components including side actions and calibrating them to ensure alignment and efficient operation.
using protective coatings on mold components for corrosion resistance and improving the durability of mold.
a final round of testing where mold’s performance is evaluated under actual operating conditions and issues are resolved before approving mold for production.
Conclusion
To create complex features with tight tolerances efficiently and effectively, injection molding side action is a crucial and powerful tool which can be further optimized to achieve efficient and consistent performance by use of mechanisms such as hydraulic systems, angle pins etc.
Therefore, next time you design a side action mold, pay careful attention to material selection, choosing appropriate working mechanisms and robust locking systems to make sure that not only the mold system is optimized with respect to cost but also quality of results is maximized.
With such planning and use of side actions, the most complex and challenging designs can be brought to life conveniently while ensuring efficiency and effectiveness in production is not compromised.