We love the process of invention and design development and seeing concepts come together, iteratively worked through prototypes, and end up with a design that is just right and meets all of the technical and aesthetic requirements, but do you know what we love even more than that?See your designs in full production.
However, aesthetically pleasing designs that are also functionally sound are only half the battle; for the majority of plastic parts, you will Nylon CNC Machining also need to design them for injection molding, which is the most common and cost-effective method for producing high volumes of plastic parts. Milling very specific geometries on parts with CNC is uncommon because it typically results in a cost that is between 50 and 100 times higher per part than CNC. This presents its own unique set of requirements, and by adhering to the design guidelines that are provided below, you can reduce the amount of money spent on tooling while maintaining the quality of your designs to the same level as before.
Let's take a look at the manufacturing process before we get into Aluminum Extrusion the specifics of how to tune a 3D printed design for injection molding. How exactly does the process of injection molding work?The Fundamentals of Injection MoldingIn its most fundamental form, injection molding is a straightforward process. First, two large metal mold halves are brought together; then, a material made of plastic or rubber is injected into the cavity they form; finally, after everything has cooled, the part is ejected simultaneously with the two halves of the mold; this completes the process. separate. After repeating the process 10,000 times, you will have a batch of parts that are finished and ready to sell.
In general, even though the injected plastic materials are melted, they are not actually heated: the material is forced through a large auger into the injection port. This can actually make things more complicated. The material will begin to heat up as it is compressed, and as it does so, it will begin to flow into the mold. The mold itself has to be the negative of the part that is going to be molded, and the geometries involved can get quite complicated. You can see how the geometry of one half of the mold is used to form the inside of the mug, while the other half of the mold is used to form the outside of the mug if you examine a very basic red mug, like the kind we used to play beer pong in college. If you do this, you will be able to see how the mug is formed. That shouldn't be too difficult seeing as how you already have a large cone protruding from one side into the other.
Imagine a simple plastic coffee mug instead of the traditional red mug. This is an example of how molds need Precision Parts to adapt as the shapes produced become more complex. The handle is made from a separate mold than the body, but the body and the inside are both made from molds. If the part geometry that two dies are trying to form cannot be formed in a straight line, then the dies will need action slides or screws. The action of dies can form extremely complicated shapes, such as the threads found in nuts and screws. But there is a cost associated with this versatility:There is typically a price difference of 10 times between simple dies that have "straight pull" and dies that have action.
Avoiding undercutting, which is when one part of a geometry is under another, when a part of that geometry cannot be formed with a mold half, or when the part gets stuck in the mold, is the most important principle for reducing tooling costs. Undercutting occurs when one part of a geometry is under another. Take, for instance, the example of a standard snap fit. Because the underside of the snap cannot be accessed from the bottom and the rest of the housing is in the way, the snap on the left in this case cannot be simply injection molded. As shown on the right-hand side of the image, we can fix this problem by cutting out a small section of the case's material, which can subsequently be easily shaped into a snap.
When we are evaluating a design, we frequently picture the object being placed on a glass table with one beam of light shining from below and another beam of light shining from above. If the light shines on every side of the piece, then it is simple to form; on the other hand, if there is a section that is shaded, then it is an undercut. When molding, there is one more thing to think about, and that is how easy it will be to remove the part from the mold after it has cooled and the mold has separated. Several different geometries have the potential to make it difficult to remove parts from the mold, CNC finishing complicate the molding process, lengthen the cycle time, and ultimately drive up the cost per part.
However, if the component has some regions that are extremely thick and other regions that are extremely thin, the thin regions will cool and harden first while the thick regions will continue to cool. Because the thin area around this geometry has already cooled, and a skin has formed on the surface of the part, when the molten center cools and shrinks, it sucks the surface down, creating a sink mark on the smooth surface of the part, which makes it appear unattractive. Sink marks can be avoided by maintaining a relatively uniform thickness of the material throughout the entire part, keeping the ratio between thin and thick sections to no more than 2:3, and making sure that the transition from thin to thick areas is not made all of a sudden.
We did not attempt to mold the entire head as a single piece; rather, we cut the head geometry into three separate parts and then ultrasonically welded them together after the molding process was complete. The latch die of the bracket is pulled in the same direction as the shaft, and the bottom of the machine head and the seat for the shaft are integrally constructed as a single piece. The surface, the cutting line, and the mounting barrel for the outer edge counterweight all make up a separate part. The die pull is positioned in a direction that is perpendicular to the surface, and the top of the housing constitutes a third component of the machine.
Although it may appear to be a difficult design problem at first glance, dividing the components in this manner is frequently the only way to ensure that a design is both aesthetically pleasing and functionally sound. Even if there are three pieces instead of one, it will still be more cost effective to mold and mold than it will be to design a single mold that requires a dozen different actions. When you make such a significant alteration to your design, it is only natural that you will need to create brand-new prototypes in order to test the new geometry.
The prototype testing phase of 3D printing is followed by the full-scale manufacturing phase, and in between these two phases, there is a pleasing medium polyurethane casting. The procedure is very similar to injection molding in that the two halves of the mold are brought together, material is injected into the cavity, and the finished product is expelled; however, room temperature materials and flexible molds are utilized in this process. The tools, on the other hand, are typically a tenth of the price, and you can make any small parts that you like. This presents a significant difference.