When it comes to the use of aluminum thermoforming, it refers to a process by which tools are produced from machined billet plates of aluminum under both certain temperatures and pressures. While many elect to use wood for this purpose, aluminum serves as the go-to option for lasting design and functionality purposes.
Thermoform tooling, when combined with advanced finishing techniques, is thought to produce results not all that different from what would be expected of injection molding. No matter the medium used, thermoform tooling is particularly effective because of its ability to offer close tolerances, tight specifications, and sharp detail.
Aluminum thermoforming is a particularly desirable option as opposed to injection molding as well because of the relative ease of using it to produce any number of parts of a particular size and shape.
Did You Know?
6061 has been a long time staple for use as a thermoform tooling material, but alloys like Duramold 2, Duramold 5, M1, M5, ATP-5, and K100S are now offering some superior characteristics that improve the thermoforming process.
In addition, unlike injection molding, aluminum thermoforming allows designers to test for design flaws and to better understand customer acceptance of the design prior to mass production of it.
Thermoforming has the ability to replace more expensive and time-consuming injection molds for design purposes. This can be attributed to its vacuum fixture, which is necessary when a part needs trimming. Vacuum fixtures not only serve the purpose of helping make a reverse impression of the part, but aid with the mounting of this impression into the vacuum box. This is important because the trim fixture is responsible for holding the part being trimmed under vacuum pressure as a way of ensuring consistent results.
This is particularly important given the various uses of thermoformed products in the construction of large panels, housings, and enclosures, many of which require further refining of their design for optimal performance.
For example, aluminum thermoforming allows for design for one-sided parts more easily than does injection molding. Whereas, moveable features requiring trimming, fabrication, or assembly might be suited for other modeling techniques or approaches.
In this case, thermoforming only works on controlled sides because of this technique’s strict adherence to close tolerances. This means that the side away from the mold cannot be controlled despite being able to successfully predict what will happen on the uncontrolled side.
Mold Formation Specifications
According to a United States-based thermoform mold manufacturer, Associated Thermoform Inc., when working with aluminum or any other material to create a mold, the desired thickness of that medium is .040” to .500”.
Using mediums of this thickness most allow the manufacturer to capture both sharp and crisp details with close tolerances including undercuts, formed-in textures, formed-in logos, formed-in hardware, as well as custom coloring.
What’s more, if the design calls for a multi-dimensional design, then two individual sheets are joined together to form a twin sheet form to capture double-walled parts, similar to what would be produced if a roto-mold were made, featuring both better cosmetics and more details.
Types of Aluminum Thermoforming Molds
There are several different kinds of thermoforming molds; Machined, Cast Aluminum, and Composite Molds. Each of these different type molds serves a different purpose, whether one’s looking for a textured or multi-dimensional design, whether one is looking to have a prototype created for future refining or if the design is more set in stone and one’s looking for a mole that can go the distance.
Each of the molds varies in its effectiveness of use depending on their intended purpose as follows:
- Machined Aluminum Molds
This type mold is most typically constructed for shallow parts with small draw ratios. Aluminum is most often used in constructing these type molds because of their ability to hold cost to tolerances. When being constructed, the molds they are mounted on a control base as a way of controlling the mold temperature as the mold is formed. A number of different mold types can be machined using aluminum molds including male and female molds and vacuum- and pressure-form molds. The preferred medium for these type molds is aluminum specifically because of its ability to offer texturing as well as features including both loose and pneumatic cores and inserts.
- Cast Aluminum Molds
These type molds are generally cast using a composite material at a foundry using a pre-designed pattern. Generally built for parts, these molds feature large draw ratios. Much like Machined Aluminum Molds, Cast Aluminum Molds, can take the form of male or female molds and be vacuum- or pressure-formed. At the foundry, temperature controls are cast into both the back and sides of the molds. This allows the molds to be easily adapted for the purposes of adding texture, loose or pneumatic cores, or inserts.
- Composite Molds
These type molds are most appropriate for either prototyping or smaller scale productions. In constructing these molds, cost-effective composite materials are utilized to build the mold. Parts produced by Composite Molds are more basic in design than those produced by either the Machined or Cast Aluminum Molds. This means that they are particularly effective in evaluating fit, form, and function in deciding whether design changes are necessary. Unlike the aforementioned molds, although these molds are vacuum forming, they are not temperature controlled and have a limited lifespan.
Whichever type mold is selected, aluminum thermoform molding is a durable choice as opposed to wood molds. Aluminum molds are effective in making sure molds are close to tolerances, tight specifications, and sharp details. Aluminum thermoforming is a particularly desirable option as opposed to injection molding as well because of the relative ease of using it to produce any number of parts of a particular size and shape.
They also serve as a particularly flexible choice when trying to create a number of prototypes, each with their own degrees of functionality because of the variability of design offered by this type medium mold. This makes aluminum a particularly desirable option when deciding between more solid and temporary construction choices. And, aside from being most cost efficient than injection molding just in terms of sheer design, aluminum thermoforming allows designers to test for design flaws and to better understand customer acceptance of the design prior to mass production of it, which also saves money.