Texture in Aluminum Tooling
Prototype Plastic surface finishes for rapid prototyping in Aluminum tooling do not have to be limited. Texture is an important part of selling any product. Appearances matter. Our IPP ™ process allows for all SPI, Mold-Tech and Roehlen standard Finish levels.
There are many reasons for adding texture to a plastic prototype. Textures can be varied from a very fine A – 1 surface finish used on a highly aesthetic plastic part like a clear optical component to a D – 3 surface on a part that will most likely be never seen by the end user.
Diamond finishes for SPI#1 or A – 1 classes are generally labor intensive as they require hand polishing, but this does not effect our Aluminum Tooling prototype lead times, you will still receive your prototype(s) in 3 weeks or less.
Texture in Product Perception
Plastic parts not only benefit from designs that are pleasing to the eye, they also benefit from touch. Smooth as glass, or rough to indicate strength and durability. A prototype is a tool to help you see not only your concept in reality, but to objectively decide how it will fare in the marketplace. Texture plays a huge part in product perception. Learn more about the role psychology plays in design and plastic prototypes.
Texture on a prototype can be a functional component of its design. Imperfect parts can be camouflaged by the right texture. Is the prototype designed for frequent handling? Texture can be used to hide finger prints and improve the gripe for the end user. Texture can also be used to reduce part wear from friction. But most often, texture is used for aesthetic reasons.
The proper term for the science of friction is Tribology. Rubbing two sticks together to build a fire is an example of friction. We can take the principle and apply it to the injection molding process in order to improve cycle times by reducing friction upon the moving parts. Less friction equaling a faster process.
You can use this premise to benefit your design. In an effort to reduce wear from friction you can’t apply a lubricant to a frequently handled product like a tool or handle like you can to an internal component.
The only solution to reduce visible wear upon a frequently touched product is by applying either rough or smooth texture. An uneven surface can distract the eye from obvious wear resulting in a product that has a longer life cycle of perceived value by the end user.
Or you can apply a highly polished Diamond finish to create increased ‘slip’ so the use results in less friction by decreased surface texture.
Mold Texture Concerns and Benefits
A word of warning when texture classes D 1 – 3 prototype parts are required. Bead blasting is just that, the mold is blasted with tiny glass or aluminum oxide beads to get the effect.
Because of this, parts of the mold – Aluminum or Steel – might be too small to be uniformly textured by this method. During the design review process, if this is a possible issue we will work with you to find the best solution that doesn’t compromise your design’s integrity.
Another concern is ejection. Heavily textured Class D plastic part’s often do not make the smoothest transition out of the mold. We can help with that by working to ensure a minimum of “drag” marks. If the part is not an aesthetic component, ‘drag’ may not be much of a concern. There are proper draft guidelines to follow per the depth of texture.
1º of draft for every .001 of texture depth is a standard guideline to follow.
However, on the flip side… adding texture to a mold cavity often can help a Class A surface part. Class A’s are meant to be sleek and smooth. You would think that something so sleek would just “pop” right out of a mold. Not so. The little bit of texture gives the part just enough ‘tooth’ to allow the proper resin fill and ejection, but not so much that it compromises the surface quality. This ‘Tooth’ can also prevent possible sink marks, scuffs and drag marks that would render an otherwise Class A prototype a quality control failure. Forgive the play on words, but improper ejection can lead to a prototypes rejection.
Class A Prototypes
Class A plastic parts tend to be the drama queens of the plastic world. If conditions aren’t perfect… you will know it. Which is why most rapid prototype shops won’t do them. The lead time is perceived as too short to find fixes for all the little goofy nuances that can occur from any number of conditions… hence the drama queen visual.
Add in all the attention to detail and good tooling practices required to run production quality Aluminum Tooling, most standard mold tooling shops won’t bother with Class A Aluminum Tooling.
Though if Class A plastic prototypes are done correctly the outcome is smooth sailing, batting 1000. There are so many little tricks of the trade that no one person can know them all. That is why it takes an experienced team to bring the project in on time and done right. We hedge our bets by using Scientific Molding principles along with our IPP™ process and over 30 years of experience in traditional tool making. You can trust your prototype needs will be fulfilled with PHOENIX PROTO