Gas Assist Injection Molding
Get Higher Quality Components and Lower Costs
We inject nitrogen gas into the hot melt stream during the molding process, displacing the resin in thick-walled sections, to create a hollow core. This innovative process is ideal for several important reasons:
- Increase Design Options: Since this process is not constrained by typical tool design requirements, parts with complex designs can be produced with less complicated tooling.
- Improve Part Quality: The Gas Assist process creates uniform pressure throughout the part which minimizes any potential warp issues. The technology can also be used to eliminate sink marks at rib and boss locations. Parts with varying wall thicknesses can be molded without the need for complicated cores.
- Reduces Costs: Since Gas Assist parts require less material and run at faster cycle times the corresponding piece prices are reduced accordingly.
- Part Consolidation: With gas assist molding, several components that would normally be produced separately with conventional injection molding can be combined into a single part.
Request a Free Consultation
Learn With EnTech
You've perfected your design. The 3D printed prototype fits flawlessly, functions exactly as intended, and even impresses the stakeholders. But now comes the reality check: transitioning from that successful 3D printed prototype to injection molded production parts isn't always a straight path forward. At EnTech Plastics, we regularly work with engineers who face this exact challenge. While 3D printing and injection molding both create plastic parts, they operate under fundamentally different rules—and what works brilliantly in additive manufacturing may not be possible to produce using injection molding. The Engineering Reality: Different Processes, Different Design Rules The freedom that makes 3D printing so appealing for prototyping—layer-by-layer construction with infinite geometric possibilities—becomes a constraint when you need to fill a mold cavity with molten plastic under high pressure and temperature. Draft Angles: The Hidden Design Requirement Your 3D printed part likely features perfectly vertical walls, sharp internal corners, and complex geometries built up layer by layer. But injection molding demands draft angles to allow the part to release cleanly from the mold. Those vertical walls that printed perfectly? They'll cause ejection problems, potential part damage, and premature tool wear in injection molding. Every vertical surface needs to be slightly tapered, and every internal corner needs a generous radius to facilitate material flow and part ejection. Wall Thickness: Consistency is Critical 3D printing builds support where needed, allowing for dramatic wall thickness variations within a single part. Injection molding, however, demands consistent wall thickness throughout the part to ensure uniform cooling, minimize warpage, and prevent sink marks or voids. Areas with thick sections will cool more slowly than thin sections, creating internal stresses that can lead to warpage, cracking, or dimensional instability. What appears as elegant design optimization in 3D printing creates significant quality issues in injection molding. Undercuts and Complex Geometries: The Mold Constraint Challenge Perhaps the most significant difference lies in geometric freedom. 3D printing can create virtually any shape—overhangs, internal cavities, interlocking parts, and complex undercuts—all in a single print job. Injection molding requires that every part feature can be formed by the opening and closing of mold halves. Complex undercuts require side actions, lifters, or collapsible cores—sophisticated tooling solutions that add significant cost and complexity to your custom injection molding project. These types of features can be accomplished if there are no design alternatives; in many cases, however, EnTech can provide Design for Manufacturability (DFM) analysis to provide design suggestions that will accomplish the intended function but with lower cost tooling. Gas-Assisted Injection Molding: Bridging the Design Gap Although conventional injection molding requires uniform wall thicknesses, EnTech also offers Gas Assist Injection Molding which accommodates designs that don’t have uniform wall thickness. Gas Assist Injection Molding allows for hollow sections, varying wall thicknesses, and complex internal geometries—bringing some of the design freedom of 3D printing into the injection molding realm. Gas assist injection molding can eliminate sink marks in thick sections, reduce material usage, and enable part consolidation that would otherwise require multiple components or assembly operations (see: https://entechplastics.com/gas-assist . Material Performance: Beyond Geometric Constraints The materials themselves behave differently between processes. Most 3D printing materials are designed for layer adhesion and printability, while engineered resins used in injection molding are optimized for flow characteristics, dimensional stability, and long-term performance. Your 3D printed prototype might use a material with completely different thermal, chemical, or mechanical properties than what you'll achieve with production-grade injection molding resins. This can affect everything from dimensional tolerances to environmental resistance. From Challenge to Solution Every transition from 3D printed prototype to injection molded production presents unique challenges. Whether you're dealing with complex geometries, demanding material requirements, or tight tolerance specifications, EnTech Plastics brings the engineering expertise and manufacturing capabilities to turn your design challenges into manufacturing successes. We specialize in the complex, the challenging, and the "difficult to run" parts that other molders struggle with. From custom injection molding and tool building to engineered resin selection and advanced manufacturing techniques, we have the resources and expertise to bridge the gap between your prototype vision and production reality. Contact our engineering team today to discuss your specific application. We'll work with you to understand your design intent, identify potential manufacturability challenges, and develop solutions that deliver both the performance you need and the production efficiency your business demands.
Tool transfer in injection molding—transferring production to a different facility—can go smoothly if done properly. Systematic planning and execution will ensure a smooth transition that maintains production continuity and part quality. Pre-Transfer Assessment: Building the Foundation Successful tool transfers begin with a comprehensive sharing of knowledge before the actual move takes place. Mold and Machine Compatibility Analysis : Start by documenting the mold specifications including dimensions, weight, tonnage requirements, and tie-bar spacing. This information will allow the new facility to determine what machines the transfer tools will be assigned to. Process Documentation Review : Whenever possible, gather whatever process parameters are available.This includes molding conditions, mold temperatures, injection pressures, and any special processing notes from operators. Though this data would be helpful, it is not essential if the existing supplier is not willing to share it. Auxiliary Systems Inventory : Catalog all supporting equipment including hot runners, temperature control units, material dryers, conveyors, and automation systems. Determine which components will transfer with the mold and which must be sourced at the destination. Quality Standards Assessment : Provide all quality specifications, inspection requirements, and acceptance criteria. The Quality Department at the new facility can then review, and clarify, this information with the customer. This will ensure that, as soon as production begins, the customer will receive parts that meet the required quality specifications. The more documentation available the easier the transfer process becomes. It should be stated however, that there have been many successful tool transfers with a minimal amount of knowledge being shared. Risk Mitigation and Contingency Planning To minimize the risk in any tool transfer program, the following strategies should be considered: Production Continuity Planning : Develop detailed schedules that minimize production disruption. Consider strategies such as building inventory buffers and scheduling transfers during planned maintenance windows. Quality Risk Assessment : Identify potential quality risks associated with the transfer and develop specific mitigation strategies. This includes understanding critical-to-quality characteristics and implementing enhanced monitoring during the initial production period. Emergency Response Procedures : Allow enough time in the transfer schedule for unexpected scenarios such as extended setup/startup times, or quality issues that prevent production startup. Industry-Specific Considerations Different market segments may present unique challenges that require specialized attention during tool migration. Some industry specific considerations are as follows: Automotive Applications : Focus on rigorous dimensional validation, material traceability, and compliance with IATF 16949 requirements. Plan for capability studies and potential PPAP (Production Part Approval Process) submissions. Medical Device Manufacturing : Emphasize contamination control, process validation requirements, and FDA compliance considerations. Consumer Products : Balance quality requirements with cost considerations, focusing on consistent appearance, functionality, and cycle time optimization to maintain competitive positioning. Conclusion Successful injection molding tool transfer programs require a comprehensive approach that addresses the unique technical, quality, and operational challenges of plastics manufacturing. While each transfer presents specific challenges, organizations that develop systematic capabilities and follow proven practices will achieve significantly better outcomes in terms of downtime, quality, and cost. The key to success lies in recognizing that tooling transfers are not simply a matter of moving equipment, but rather a process that involves machine compatibility, process optimization, quality validation, and regulatory compliance. By addressing all these elements systematically and maintaining focus on part quality and production efficiency, manufacturers can transform tool transfers from sources of risk and disruption into opportunities for process improvement and operational excellence. Remember that successful tool transfers ultimately enable production teams to manufacture high-quality parts efficiently and consistently, regardless of which machine or facility is used. Keep this objective at the center of your transfer planning, and the technical and logistical challenges become much more manageable. Contact EnTech Plastics today to discuss your project and how we can assist with a smooth transition.
When bringing a new product to market, manufacturers face critical decisions about which production methods to use at different stages of development. Two approaches that often come up in discussions are low volume injection molding and rapid prototyping. While both serve important roles in product development, they address fundamentally different needs and offer distinct advantages depending on your specific requirements. Understanding the differences between these manufacturing approaches can save significant time, money, and resources while ensuring your product reaches the market successfully. What is Rapid Prototyping? Rapid prototyping encompasses various additive manufacturing technologies designed to quickly create physical models of parts and products directly from digital designs. The primary purpose of rapid prototyping is to enable fast iteration during the design phase. Engineers and designers can test form, fit, and basic function without the time and expense of creating production tooling. Changes can be made quickly by simply modifying the digital file and printing a new version. What is Low Volume Injection Molding? Low volume injection molding uses the same fundamental process as traditional high-volume injection molding but is optimized for smaller production runs , typically ranging from 100 to 10,000 parts. This approach uses simplified tooling, often made from aluminum rather than steel, and may employ rapid tooling techniques to reduce lead times and costs. The goal is to produce parts that meet the part specifications while keeping tooling investments reasonable for smaller quantities. This makes it an attractive option for products with naturally low volume requirements. Key Differences Between the Two Approaches Purpose and Development Stage Rapid prototyping primarily serves the design verification phase. It's ideal for testing concepts, validating designs, and communicating ideas to stakeholders. The focus is on speed and iteration rather than production-ready parts. Low volume injection molding, however, is used when you've moved beyond concept validation and need parts for market testing, pilot production, or limited commercial release. Material Properties and Quality This represents perhaps the most significant difference between the two approaches. Rapid prototyping materials, while continuously improving, still have limitations compared to production injection molding resins, such as: Anisotropic properties (different strength in different directions) Lack of chemical resistance Lack of UV stability Low volume injection molding uses the same materials available for high-volume production, including engineering plastics with specific properties like flame retardancy, chemical resistance, or biocompatibility. Parts produced through low volume injection molding exhibit consistent properties throughout and meet the required performance characteristics but they are produced in small-volume production runs. Surface Finish and Aesthetics Rapid prototyping typically produces parts with visible layer lines or surface textures that may require post-processing to achieve acceptable aesthetics. While techniques exist to improve surface finish, they add time and cost to the process. Low volume injection molded parts can achieve surface finishes ranging from textured to mirror-like, depending on the mold design. The surface quality is consistent and repeatable, making it suitable for customer-facing applications or parts requiring specific aesthetic standards. Dimensional Accuracy and Tolerances Most rapid prototyping technologies can achieve reasonable dimensional accuracy for conceptual work, but may struggle with tight tolerances required for functional assemblies. Factors like material shrinkage, warping, and support structure placement can affect final dimensions. Low volume injection molding provide much tighter tolerances depending on part geometry and material. This precision is crucial for parts that must interface with other components or meet specific functional requirements. Lead Times and Flexibility Rapid prototyping excels in speed for initial parts. Simple components can be produced within hours or days of design completion. Changes are easily accommodated by modifying the digital file. Low volume injection molding requires time for tool design and manufacturing, typically several weeks depending on complexity. However, once tooling is complete, parts can be produced quickly. Making the Right Choice for Your Project While rapid prototyping has its place in early concept validation, low volume injection molding emerges as the clear winner when you need parts that truly perform. The superior material properties, consistent quality, and production-ready performance make it the smart choice for initial low volume production runs of functional parts.. The initial tooling investment quickly pays for itself through lower per-part costs, especially when you factor in the time saved from not having to reprocess parts due to material limitations or quality issues. More importantly, low volume injection molding gives you confidence that your parts will perform exactly as intended in real-world applications. When you're ready to move beyond basic prototypes and create parts that meet your actual performance requirements, low volume injection molding provides the reliability, quality, and cost-effectiveness that rapid prototyping simply cannot match. Don't let the allure of "quick and cheap" prototyping derail your product's success when production-quality parts are within reach. Ready to Experience the Low Volume Injection Molding Advantage? EnTech Plastics specializes in low volume custom injection molding solutions ; our experienced team can help you evaluate your project requirements and determine the most cost-effective approach for your specific needs. With state-of-the-art equipment and decades of expertise, we deliver production-quality parts with the flexibility and speed your project demands. Contact EnTech Plastics today to discuss how low volume injection molding can accelerate your product development and ensure market-ready performance from day one.