Mack Prototype’s 25th Anniversary Open House
Mack Prototype turned 25 this year and on Aug. 8, 2024, our complex prototyping and low-volume production division opened its doors to customers, vendors, community members, colleagues and retirees. Catch a glimpse of the festivities and some of Mack Proto’s exciting technologies in this new video from Mack Molding.
Understanding the Relationship Between Gate Location and Flow Ratio in Injection Molding
In the world of injection molding, optimizing the quality of molded parts is paramount. Two critical factors that play a significant role in this optimization process are gate location and flow ratio. Properly understanding and managing these elements can make the difference between a successful, high-quality part and having an incomplete part that can’t be filled. Let’s delve into how gate location and flow ratio interact, and why careful consideration of these factors is essential.
The Importance of Gating in Injection Molding
Figure 1: A direct sprue on a simple panel.
Injection molding commonly utilizes six types of gates, each with its unique application:
- Direct Sprue
- Edge-/Tab-gate
- Fan-gate
- Sub-/Cashew-/Banana-gate
- Diaphragm
- Pinpoint (for hot drops)
The location of these gates can significantly impact the quality of the final product. For example, improper gate placement might cause early freeze-off, leading to short-shots or improper filling due to inadequate machine pressure. To mitigate these issues, it’s crucial to follow specific guidelines when determining gate placement:
- Place the gate at the part’s largest wall thickness.
- Ensure the gate is positioned to minimize the flow length.
- Consider the cosmetic implications of gate placement.
By adhering to these guidelines, the risk of defects is minimized, resulting in a higher-quality product.
Understanding Flow Ratio and Its Implications
Flow ratio, defined as the distance between the gate and the farthest point of the part in relation to wall thickness, is a key metric in ensuring proper part filling (Equation 1). Choosing the best gate type, location and quantity minimizes the flow length and optimizes the flow ratio. The industry standard, as provided by RJG, suggests that the flow ratio should be kept under 150. At Mack, however, a stricter standard of 100 is applied to provide an increased factor of safety.
Equation 1: Flow Ratio = Flow Length / Wall Thickness
A poor flow ratio can lead to several issues, including:
- Longer fill times
- Pressure spikes
- Compromised part strength
- Formation of knit lines or seams, creating weak points
For instance, consider Figure 2, a part with a flow length of 21.753 inches and a wall thickness of 0.16 inches, resulting in a flow ratio of 135.97 . This falls within the industry standard, but to meet Mack’s more stringent requirement, a second gate might be added to lower the ratio below 100. In contrast, Figure 3 is a part with a 36.08-inch flow length would result in a flow ratio of 225, which is well outside acceptable standards and would require significant adjustments.
Balancing Gate Location and Flow Ratio
In some cases, sub-optimal gating methods or locations are necessary to preserve the cosmetic quality of the part or accommodate complex geometries. However, these compromises often lead to increased flow ratios. So, how can this challenge be addressed?
One solution is the use of flow leaders. These are raised paths—typically 1 inch wide and 1 millimeter (0.0394 inches) high with heavy drafting—that help manage the flow of material through the mold. Flow leaders reduce unwanted shear and air pockets, eliminate the need for multiple gates, and increase wall thickness, thereby lowering the flow ratio and reducing pressure spikes.
Improper gate placement, on the other hand, can cause several issues, including fill imbalance, air pockets, uneven cooling, shrinking, warping, and short-shots. The use of Moldex simulations can provide valuable insights into how different gate placements and flow leaders impact the filling process, helping engineers make informed decisions.
Figure 4: A gradient showing the flow length/wall thickness for each scenario: good sprue placement, good sprue placement with flow leaders, bad sprue placement, and bad sprue placement with flow leaders, respectively.
Conclusion
Understanding the relationship between gate location and flow ratio is critical in injection molding. By carefully considering gate placement, flow ratio, and the use of flow leaders, engineers can significantly improve the quality of molded parts. At Mack, we prioritize these factors to ensure that our products not only meet industry standards but exceed them, delivering high-quality, defect-free parts to our customers.
For more information on this topic, or any of your plastic injection molding needs, please feel free to reach out to us!
This article was written by Mack Intern Jonas Paquette. A senior at Rensselaer Polytechnic Institute (RPI), majoring in mechanical engineering, Jonas recently interned in Mack’s Application Development Center where he developed no-code apps using Tulip Software, created part models in SolidWorks, assisted with tool sampling, and reviewed client CAD models.
Three Mack Leaders Named to Plastics News’ Women Breaking the Mold
Mack Molding has long been recognized for its contributions to the plastics industry, and this year, the spotlight shines brightly on three remarkable women who have been named among the Plastics News’ Women Breaking the Mold winners: Dwalin DeBoer, Casey Tsougranis and Ann Wedell. These women have not only excelled in their respective roles but have also broken barriers and set new standards for leadership in a traditionally male-dominated industry.
Dwalin DeBoer: Leading with Expertise and Passion
Dwalin DeBoer’s journey into the plastics industry began with a love for chemistry in high school, which led her to pursue a degree in chemical engineering at Worcester Polytechnic Institute. Her early hands-on experience at Monsanto Plastics solidified her passion for polymers, setting the stage for a successful career. Today, DeBoer leads a 13-person business unit at Mack Molding, overseeing account management, program management, and customer service for 51 clients.
Her role involves guiding customers through the complexities of plastic injection molding, ensuring that designs are manufacturable and that processes are robust and repeatable. DeBoer’s leadership has been instrumental in managing relationships and technical challenges, all while maintaining the highest standards of quality and customer satisfaction. Recognized as a “Rising Star” by Vermont Business Magazine in 2012, DeBoer continues to pave the way for other women in leadership roles, balancing a demanding career with a fulfilling family life. Read more from Plastics News.
Casey Tsougranis: Driving Growth and Innovation
Casey Tsougranis, the Director of Business Development at Mack Prototype Inc., exemplifies the blend of technical expertise and business acumen required to succeed in the plastics industry. After earning her degree in management engineering with a concentration in chemistry, Tsougranis joined Mack Molding as a business development manager. Her internship in program management provided her with invaluable exposure to the validation processes of the orthopedic industry, which fueled her interest in molding processes.
In 2022, Tsougranis was promoted to her current role, where she leads new business development at Mack Prototype, a division focused on rapid prototyping and low-volume manufacturing. Her responsibilities include driving sales growth, building customer relationships, and developing marketing strategies. Despite the challenges of establishing brand recognition in a competitive market, Tsougranis has successfully positioned Mack Prototype as a trusted partner in the industry. Her achievements are a testament to her perseverance and her ability to navigate a male-dominated field with confidence and expertise. Read more from Plastics News.
Ann Wedell: Mastering the Art of Materials Management
As the Materials Manager at Mack Molding, Ann Wedell plays a crucial role in ensuring the smooth flow of materials and the timely delivery of products. Wedell’s career began in the pulp and paper industry, where she honed her skills as a process engineer before transitioning to the plastics industry. At Mack Molding, she has held various roles, including quality engineer and manufacturing engineer, before stepping into her current position.
Wedell’s team is responsible for inventory accuracy, scheduling, and materials planning, all of which are critical to meeting customer demands. She has been instrumental in streamlining the planning process and optimizing the use of the company’s ERP system to drive on-time delivery. As a mother of young children, Wedell is breaking the mold by demonstrating that it is possible to achieve success in a demanding career while also being an engaged parent. Read more from Plastics News.
Breaking the Mold and Inspiring the Next Generation
DeBoer, Tsougranis, and Wedell are not just leaders in their field; they are role models for the next generation of women in the plastics industry. Their achievements underscore the importance of diversity in leadership and the value of different perspectives in driving innovation and growth. As Mack Molding continues to thrive, it does so with the knowledge that it is in capable hands—hands that are not only shaping the future of the company but also inspiring countless others to follow in their footsteps.
Meet Mack at D2P New England
The Mack team headed to Design-2-Part (D2P) New England Oct. 16-17, 2024, at the Royal Plaza Trade Center in Marlborough, Mass. Be sure to visit us at Booth 319, where representatives from Mack Molding and Mack Prototype will be available to meet with you in one convenient location.
D2P is the region’s largest design and contract manufacturing show, featuring over 240 exhibitors across more than 300 manufacturing and service categories. Don’t miss this opportunity to learn about everything Mack has to offer—plus, enjoy the perks of free admission and parking.
Founded in 1920, the Mack Group has grown beyond its roots in plastic injection molding to become a vertically integrated product development and manufacturing partner. Today, Mack Molding, Mack Prototype, Synectic Engineering and Mack Technologies are all part of a comprehensive solution that can take your ideas from concept through prototyping to full-scale manufacturing. Our services are designed to reduce costs, shorten time-to-market, and support your business throughout the product life cycle.
Mack Molding specializes in design, prototyping, injection molding, sheet metal fabrication, and machining. Mack Prototype focuses on rapid manufacturing services, including 3D printing, cast urethane molding, plastic injection molding, CNC machining, and an NPI Launch Lab to transition products from prototype to production, while Synectic Engineering provides full-service product design, prototype development, and manufacturing. Mack Technologies offers printed circuit board assembly and turnkey assembly services.
If you’d like to schedule a meeting at our booth, please reach out to your business development manager or contact Jon Whitney, Vice President of Business Development, at jon.whitney@mack.com or (802) 375-0714.
VISIT MACK AT MD&M SOUTH
Use promo code SPECIAL24 for a free expo pass and 20% off a 2-day conference pass
The Mack Molding team is in Charlotte, N.C., for MD&M South. It is part of IME South – a six-in-one advanced design and manufacturing expo focused on giving attendees a comprehensive view of the product lifecycle, from prototype to production. We are excited to be part at Booth 2223, where our experts are ready to discuss how Mack’s plastic injection molding and contract manufacturing can help bring your programs to fruition.
Taking place June 4-6, 2024, at the Charlotte Convention Center, MD&M South brings together more than 300 suppliers and 3,000 industry professionals to explore the latest insights and solutions spanning medtech, packaging, automation, plastics, design, and processing. With Mack locations in Statesville, N.C., and Inman, S.C., this is right in our neighborhood and a great opportunity to learn more about our offering.
Please join Mack by using the promo code SPECIAL24 when you register online to get a free expo pass or save 20% on the conference. Once you are on site make sure to stop by and see the Mack team at Booth No. 2223. We would love the opportunity to discuss our abilities as a full-service contract manufacturer with specialties in plastics design, prototyping, plastic injection molding, sheet metal fabrication, machining and turnkey system assembly.
Mack Molding’s roots may be in plastic injection molding, but today it is so much more. As a vertically-integrated product development and manufacturing partner, Mack is prepared to take your ideas from inception through prototyping to manufacturing. Whether you are interested in Mack Medical, Mack Molding, Mack Technologies, Mack Prototype or Synectic Product Development, the design function is part of a total product development solution geared toward reducing cost and time-to-market and our vertically integrated services have been organized to benefit your business throughout the product life cycle.
If you would like to schedule a specific meeting time in our booth, please contact your business development manager, or Jon Whitney, Vice President of Business Development at jon.whitney@mack.com or (802) 375-0714.
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