Keeping Up with Technology: Mold-filling Simulations for Manufacturers
Injection molding is one of the most common modern methods used for manufacturing parts. It’s a great technology for producing high volumes of parts, in a multitude of materials – metals (called die-casting), glasses, elastomers, and polymers. It’s simple, really – the heated material is forced into a mold that is shaped like the part you need. The material is cooled, hardens and…voila’… you have your part.
As simple as the process is, parts to be injection molded must be very carefully designed. The material used for the part, the desired shape and features of the part, the material of the mold, and the properties of the molding machine must all be considered.
That’s where mold-filling simulations come in.
One of the reasons that mold-filling simulation is widely used to design parts and molds is because of a large number of parts that are produced in plastics today.
As Mr. McGuire said in the 1967 film, The Graduate “There’s a great future in plastics. “
Plastics are more affordable and ensure lighter parts, less scrap, and greater design capability. The use of plastic injection-molding manufacturing processes has expanded every year for the past half-century. It has become a sophisticated process for making a variety of components and products of increasing complexity in industries ranging from automotive, medical, and aerospace to consumer products, toys, and packaging.
As more of today’s leading manufacturers look to plastic materials to produce better alternatives to conventionally machined metal parts, the efficiency and quality of injection molding processes become critically important because more than 80 percent of plastic parts must be injection molded. Traditionally, this has meant prototyping. A prototype is an early sample, model, or release of a mold built to test design and learn what changes need to be made.
The problem with prototyping is that — while it enables manufacturers to resolve manufacturability and tooling issues that can lead to defects (air traps, voids, poorly placed parting lines, shrinkage, warpage, surface blemishes, structural weaknesses, and large part deformation) — it also adds time and cost to the process. What’s really needed to streamline injection-molded component and tooling development is the ability to perform the trial-and-error-driven prototyping process in an accurate, virtual environment.
New software technologies have eliminated the need for the tedious, iterative prototyping trial and error. 3D CAD software and the models that can be created with it, enable manufacturers to simulate the mold-filling process in a virtual world.
With this virtual simulation, they are able to determine such things as (1) the optimal temperature of the melted plastic that is injected into the mold; as well as that of the mold itself; (2) determine whether the cooling channels are adequate to support these temperatures, and if not, how should they be re-configured; (3) the best thermoplastic material to use for a specific design; (4) the pressure and flow rate that should be used to inject plastic material into the mold to facilitate filling and packing; (5) length of time the part should be left in the mold to solidify before ejection; (6) whether specialized tooling—inserts, side actions, additional injection gates, secondary operations, or innovative cooling channel layouts will shorten cycle times or eliminate defects.
Using a 3D CAD Service for Injection Mold Simulation
When manufacturers are under time constraints to produce molds and parts, they need the answers to these questions fast, in order to produce tooling that minimizes quality issues.
Often, injection-molding professionals rely on upon outsourcing services to provide accurate simulations. Outsourcing is a cost-effective way for them to predict how the many variables that influence production affect shooting, cooling, and ejecting a particular part.
Inject Mold Simulation Outsourcing serves two purposes:
- The manufacturers don’t have to invest the time and money associated with iterative prototyping
- They have unbiased outside source that runs the simulations and makes recommendations for mold changes
Accurate mold-filling simulations performed by an experienced 3D CAD service company supports the same trial-and-error process that prototyping provides, but is a faster, less expensive way for manufacturers to discover the right combination of variables required to produce quality injection-molded parts.