Mold flow simulation is a crucial part of engineering and producing molded plastics for a range of purposes. Molded products requiring custom injection should always have a simulation done before producing a prototype, as this increases the chances of a successful product. With advances in technology, the in-house engineering team of a molded plastic manufacturer is able to easily provide the simulation at an early stage in the design process. This step offers numerous benefits in addition to ensuring the product meets all requirements.
Understanding Mold Flow Simulation
Not all buying agents or managers thoroughly understand the process of mold flow simulation. This is a method of using advanced technology and software to simulate the process of filling a part made of molded plastic as well as the packing and cooling of the component. It is used as a diagnostic tool to detect potential issues with the mold flow design at an early stage in the process. The simulation essentially provides in-house engineers with a visual representation of the way in which the mold will fill.
Simulation Provides Important Information
The simulation of the mold flow provides important information regarding how the mold will fill during production. It allows the design team and engineers to see if any areas of the mold will not fill completely with plastic. It additionally demonstrates where in the part weld lines will develop and whether these welded points will be considered structurally sound.
Advanced simulations of mold flow can even analyze cooling lines as well as their effects. Engineers can analyze this process through multiple cycles or the entirety of a single cycle to determine cooling lines and determine whether warpage at these points is a concern.
Simulation Saves Time and Costs
Conducting a mold flow simulation allows engineers to save time during the development process, cutting costs significantly. These financial savings are then passed onto the company purchasing agent, who boosts sales by offering more affordable pricing to buyers. The simulation process is able to save time in a number of ways. It allows the product to be analyzed nearly instantly to ensure it can be manufactured. This prevents the risk of an issue not becoming apparent until the mold tool has been created. If a problem is noticed at this late stage, it can be more time-consuming and expensive to correct.
Additionally, the mold flow simulation process allows in-house engineers to predict any potential issues regarding the quality, ranging from inadequate draft angles to flow lines. This allows for immediate adjustment before time is spent working off the design or resources are used creating it.
In the majority of cases, the new mold flow simulation technology will be used when designing new parts. It is versatile enough, however, to assist with existing parts as well. In this case, in-house engineers can use the simulation to determine how molding conditions and part quality will be affected. This is particularly important for existing parts that engineers are adjusting to make thinner and lighter. By determining the effects ahead of time, it is possible to avoid making costly changes that will not function as predicted.
Mold flow analysis: optimize the injection molding process,
Mitigate risk before production begins
Mold flow analysis helps to mitigate risk and create a successful mold from the start. It helps designers to:
correct potential cosmetic and structural problems
determine the appropriate wall thickness
troubleshoot potential problem areas of the mold
identify optimal gate locations
adjust for ample corner radius
create even and clean edges
identify the best material for the desired outcome
create a successful mold from the start
Mold flow analysis diagnostic reports
The analysis generates color-coded reports to illustrate how the plastic would perform in the mold. Reports include Fiber Orientation, Average Temperature, Knit Lines, Air Traps, Confidence of Fill, Sink and Warp, and Fill Time Result.
We’ll examine elements of two reports: Fill Time Result and Confidence of Fill.
Fill Time Result
The Fill Time Result report presents the position of the flow front at regular intervals as the mold cavity fills. A balanced flow of plastic pattern indicates the plastic part has a good fill time.
How to read the results
The designer evaluates the image for flow paths that finish and reach the edges at the same time. Evenly spaced contours indicate the speed at which the plastic is flowing. Widely spaced contours indicate rapid flow; narrow contours indicate the part is filling slowly.
Things to look for
The Fill Time Result report provides insight into the following:
Short shot: A part is short shot when the flow of plastic does not completely fill the mold cavity, thereby resulting in an incomplete part
Hesitation: Hesitation occurs when the flow of plastic stops or slows down resulting in asymmetrical and unpredictable flow patterns
Overpacking: The result of one flow path finishing before others. Overpacking can result in high part weight, warp, and non-uniform density distribution
Weld lines: Also known as knit lines, these are molding defects that occur when two flow fronts meet without the ability to “weld”
Air traps: A bubble of air trapped when plastic flow fronts coincide. Air traps can cause structural and visual defects
Racetrack effect: Occurs when the flow races through the thick areas of a mold cavity before the thin sections have filled
Mold Flow Analysis Guide
Download our guide to help interpret results generated by mold flow analysis.
Confidence of Fill Result
Confidence of Fill Result report addresses the probability of the plastic filling the mold cavity.
The colors displayed in the Confidence of Fill indicate:
All green: Plastic fills the part easily and the part quality will likely be acceptable.
Some yellow: The part can be difficult to mold, or quality is probably not acceptable. As the percentage of yellow increases, the difficulty in molding the part increases, and the part quality decreases.
Some yellow and red: The part is difficult to fill, or quality is probably unacceptable. As the percentages of yellow and red increase, the difficulty in molding the part increase, and the part quality decreases.
Any translucent: The part cannot be molded because a short shot will occur.
Results help to determine the probability of molding a quality part
One way to use the results to determine whether you can mold a quality part is to consider how much of each color is displayed. The results could indicate a need to:
change the design to better balance flow paths
choose a different injection location to ensure the part is completely filled
re-evaluate the material selection
change the processing conditions
How can mold flow analysis improve plastic injection molding?
Optimize Gate Positioning
Identify and Predict Fill Patterns
Predict Part Deformation
Improve Overall Product Quality
Create New Design Adjustments and Solutions
The plastic injection molding process allows manufacturers to create a wide array of high-quality processes. It can also give you the ability to mass-produce products in large numbers and at a shorter period of time. It is important to maintain this process as any problem or mistake can compromise the whole process entirely. This is where Mold Flow Analysis comes in.
At times, most of the problems stem from the mold design process as there can be issues that can greatly affect the quality of the final product. It is important to solve these problems as soon as possible, and the best solution is to make use of systems like Mold Flow Analysis.
What is Mold Flow Analysis?
A man’s hand holding a mouse
Mold Flow Analysis is a software that is designed to predict and simulate the flow of plastic during the injection molding process. It enables plastic manufacturers to see the effectiveness of their mold design and see how it all flows together before even trying it out on the machine itself.
Creating and designing a plastic product is a process that requires a good amount of testing and experimentation before manufacturing. Having software such as Mold Flow Analysis helps save more time, resources, and production costs by having the ability to analyze the success and effectiveness of a plastic mold.
We’ll step back a little bit further in the mold making process. Sometimes, I use MFA when I get a request to quote and we haven’t been awarded the job yet. So, I’ll use that to help give us a better idea of: Will the part fill? Is their design bad and we just can’t fill it? Then, maybe at the RFQ, we’ll go back to them at their time of quote and say, Hey, we’ve quoted this way, but we see this issue or two that need to be addressed first.
Now, we typically only do that for customers with whom we’ve had a longstanding relationship. We don’t always want to give our engineering work away for free, but if we have a good working relationship with a customer, then we’re more receptive to do that at no cost to them. Now, if we are awarded the job, then yes, we immediately start into: Is the part moldable? Where are we going to gate it? Are we sure it’s going to gate okay? Some of these items are very simple that we know it’s going to fill just from experience in the wall thickness and the material or the plastic. However, there are times when there’s a red flag, Hey, I better run an analysis on this just to make sure we can fill it.
We perform a complete mold flow analysis on every new injection mold we build. The moldflow software today is very accurate at predicting potential injection molding problems and bring benefits. By optimizing the cooling circuitry valuable cycle time can be reduced. Warpage data can be used to play critical features steel safe or modify the part model by adding windage. Injection molders and mold makers who neglect this important step are losing a lot of potential profit in lost time and wasted material.
One of the biggest advantages of using Mold Flow Analysis is that you will be able to improve the quality of your products. Having the ability to predict how plastic flows through your mold allows you to make the necessary adjustments and create improved designs before production even starts.
Plastic injection molding allows you to create a huge number of high-quality products on a consistent basis. Using Mold Flow Analysis will help make sure that this process remains streamlined and efficient, which in turn lessens the number of errors and issues present.
Mold Flow Analysis is a software that helps you minimize the number of mistakes and errors during the mold design process. This allows you to create products that have the highest quality. This means that you have the ability to create a diverse array of new designs. Easily find new adjustments and solutions that help improve your final design.
The implementation of Mold Flow Analysis has helped improve the plastic injection molding industry. It has provided a set of advantages and functions that help optimize how plastic products are manufactured. There are many ways that you can utilize Mold Flow Analysis in your manufacturing and design process. Here are some of the ways it can improve your overall manufacturing capabilities.
The main reason to complete a mold flow analysis is the ability to predict where the current mold will have complications and offer a visual representation of where to focus resources to create fast, efficient, and consistent injection molded parts.
These are results that you can expect after an analysis identifies all areas needed for improvement:
Faster cycle times – You can expect your mold to run faster as it will be able to fill the parts quicker and more consistently after an anlysis that optimizes the injection molding process.
Reduce clamp tonnage – An optimized mold will reduce all restrictions and require only a miminum clamp load to secure the mold closed during the injection process.
Produce better quality parts – Your mold will offer consistency from part to part, whether that runs in the hundreds or millions. A properly designed mold will yield very minimal variance.
Speed up overall project progress – A mold flow analysis takes the guess work out of optimization and offers your tooling maker the resulting design that requires little to no modification to make optimized parts. Development time it minimized, which will also save you investment cost.
Reduce the number of mold test cycles – In early years of injection molding, development could take months to find the optimum design through trial and error. A computerized analysis removes most or all of the trial time, and allows the first use of the tool to produce optimized parts.
Reduce your delivery time on parts – An optimized mold will be ready to produce production parts sooner than ever before. As analysis modeling and software continually become better at creating accurate models, molds require less design and tooling changes before production can begin.
One best benefit from a mold analysis it to predict the strength and structure for each part cavity. This prediction will allow the designer to adjust the part design, mold design, or molding conditions to ensure the parts produced meet your design structure needs. The FEA analysis predicts the weak points (as well as the strongest points), which can be further enhanced for break points, fracture points, and durability over the lifecycle. From there material / resin selection, part designs, molding processes, and assembly processes can be refined to offer a part at a reduced cost with maximum functionality.
Mold Flow Analysis (MFA) is a software that is used to simulate the flow of molten plastic material into the injection mold crate, allowing the manufacturer to elevate mold and part design in order to create products that are of the highest quality.
The MFA is quite the handy software that not only increases the chances of creating the best products that the molding process can produce but it also gives you a preview of what and how your end product will look and behave. This insight allows you the space and time to make adjustments beforehand in order to reduce wastage and create the best quality that the machine and the technology can manage.
The benefits of using mold flow analysis are unlimited, and only the surface has been scratched so far. They simply add a level of efficiency that is unrivaled, and this is why it has become a very important tool of manufacturing that every injection molding plant makes use of to increase its productivity. Getting the chance to simulate everything beforehand allows the luxury to make changes on the spot, and this leads to saving costs, time, and labor.
The mold flow analysis has brought a lot of benefits to the injection molding model. There is a reason why many manufacturers in the injection molding industry are turning to MFA in large numbers.
Why simulate? Under perfect conditions, an experienced mold designer can render an efficient mold that works first shot, every shot. Those perfect conditions generally include good symmetry in the mold both in and between cavities, with consistent and equal runner lengths and perfectly uniform cooling throughout the mold. Hot runner systems help, but the real world is rarely so perfect.