Extrusion prototyping is a process of prototype creation where soft metals are confined and then shrunk within a space while leaving only a small opening for the material to escape. The material retains the shape of the opening it passes through. Therefore, what you get is called an extrusion prototype. Once the prototype is approved, one can further proceed with the process of bulk production to manufacture extrusions that match with the approved prototype.
The extrusion technique is an excellent way of converting materials into desired shapes with complex and useful features. Especially when you are producing parts of aluminum, extrusions have a perfect blend of strength, low weight, and fine geometric features that are functional and also appealing.
Aluminum extrusions are generally utilized in different kinds of assemblies where portions are exposed outside of a product for aesthetic purposes and other functional sides of the same part are strictly hidden inside. Since aluminum is naturally corrosion-resistant and excellent for various surface treatment options, aluminum extrusions can be used in more places than you can imagine.
How to design an extrusion prototype?
Designing an extrusion prototype is all about defining its two-dimensional shape and its cross-section. A traditional approach starts by laying out an array of anchor dimensions or reference points and then involves connecting the dots to join the features together in line with manufacturability guidelines. When that shape is stretched into three-dimensions using perspective and shading techniques, then it shows what the physical part will look like after extrusion.
The strategy engineers use for extrusions:
Engineers further refine the product with precision and optimization. The important thing is to make sure the profile is balanced. An unbalanced profile makes it very difficult to turn it into a product. Sometimes, manufacturers even directly refuse to work on unbalanced profiles if they feel the risk is too great.
Here, by “balanced”, we mean consistent wall thickness throughout the profile and symmetry in multiple directions. During the production process, balanced profiles allow the material to flow evenly and straight through the die and stay relatively straight as they come out. This evenness in the product enhances the life of the extrusion. Therefore, good design extrusion practices help you protect your investment.
Besides, it is not only the shape that determines the properties of an extrusion product. Let’s take an example of chocolate chip cookies. The ingredients in the batter will determine the flavor and texture of the cookie. When you want chewy and soft cookies, keep the time and temperature low. If you want cookies that are good for dunking in a cold glass of milk, keep the time long and temperature moderate. In case you want chewy centers with barely crisp edges, then you need high temperature and short baking time.
In the same way, aluminum extrusions have different properties based on their specific alloy composition and temper that helps to determine the part’s strength, corrosion resistance, machinability, and workability. In this case, the temper or heat temperature can be thought of as the baking process. In the case of aluminum extrusions, by changing temperature, you are transforming the metallurgical structure of strength and hardness.