Tough Black (Loctite Henkel 3843) and Ceramic-Filled (BASF 3280) are two new advanced photopolymer materials now available for 3D printing.

The third check in SOLIDWORKS for injection molding is Undercut Analysis. More undercuts mean a more complex multipart tool rather than a simple two-piece tool. More complexity means more added expense and manufacturing time because of features like side-actions. Undercut Analysis is right beneath Draft Analysis and once again, select the pull direction for the option to use the adjustment triad if you haven’t explored all possibilities yet. To make it easier to see these undercut faces, you can toggle the display of each type of face by clicking the hide/show Eye icon next to each face type.

The next consideration helps ensure the material flows nice and evenly into the mold. For this to happen, we want as close to constant wall thickness as possible. This can be especially challenging where we add bosses, clips, and ribs. To highlight any problem areas, we can call upon the Thickness Analysis in SOLIDWORKS. This is found on the Evaluate tab of the CommandManager but is also under the Tools drop-down menu.

In our first of three blog posts, let’s take a look at some useful design checks available in SOLIDWORKS for injection molding.

Our helpful design aid demonstrates part features that are too thin or too thick, bad bosses, right and wrong ribs, and other considerations to be mindful of while designing parts for injection molding.

The first thing you want to check for is draft. Without that, parts are not going to eject from the mold cleanly and easily. The molding process is typically engineered around speed and volume so the easier the parts come out, the faster they can be produced and the less chance those parts will incur any cosmetic defects.

Our digital factories create prototypes and low-volume parts fast, while our manufacturing network, offers advanced capabilities and volume pricing.

One of the most important aspects of the part design process is design for manufacturing (DFM). A good place to start, as with most things in life, is Wikipedia. It defines DFM as “the process of designing or engineering a product in order to facilitate the manufacturing process in order to reduce its manufacturing costs. DFM will allow potential problems to be fixed in the design phase, which is the least expensive phase in which to address them.”

For extra help, SOLIDWORKS can count all the faces based on whether they are positive, negative, or require draft. To do this, simply click the Face Classification box. If you are not exactly sure the angle of the direction of pull, use the adjustment triad to play around with different pull directions.

Check back next week for part two of our SOLIDWORKS blog series when we look at tips for improving DFM on machined parts.

Multi-material injection molding has become increasingly popular across many different product applications, allowing us to create complex plastic products which take advantage of more than one material. For example, on handheld products, handles, and grips, we can use a much sturdier base material overmolded with a soft, ergonomic plastic to drastically improve comfort and the overall end user experience.

For more organic shaped parts, you may want to call upon the gradual transition option, which uses a gradient display rather than discrete colors.

Of course, if you want to really be sure your injection-molded part is going to successfully be manufactured, go one stage further and simulate it with SOLIDWORKS Plastics. This will highlight many more things all at once versus running individual checks, so running design checks with a full injection mold simulation is the best approach—especially if you want to get your design right early in the development process.

Mark Rushton is a product portfolio manager for SOLIDWORKS, in the Desktop products team, focused on additive manufacturing. He has been involved with 3D CAD and 3D printing for over 15 years in several capacities from research to consulting for the likes of Rolls Royce, GE, JCB, and Dyson.

When you run it, you need to tell SOLIDWORKS the direction of pull and what angle of draft you want to look for as acceptable. In most situations, 2 degrees is the amount to look for. For shut offs or if there is a texture required on the face, you should apply at least 3 degrees.

AIM Processing is an experienced American manufacturer specializing in custom injection molding services and multi-material molding solutions. An ISO 9001:2015 registered domestic manufacturer based in the Denver, Colorado region, our company is committed to uncompromising quality, consistency, and responsive customer service.

Topics: Plastic Injection Molding Defects, Plastic Types, Quality, Texture, Choosing the right plastic injection molder

If you hover the mouse cursor over any of the part’s faces, it will give you a dynamic update of the draft on the face you are over. Exiting the command also allows the colors to stay displayed on the part. This makes it easy for you to make any changes to the part and see the colors update as you make changes.

SOLIDWORKS will then highlight positive draft in green, faces requiring draft in yellow, and negative draft in red (assuming they are all set to default colors). When viewing the part from both sides of the direction of pull, it should be all green from one side and all red from the other. Any yellow faces, need draft added.

Essentially, multi-material molding services let us combine multiple optimized plastics in a single molding product. There are three primary methods for multi-material injection molding, which we discuss below along with some of the advantages of each.Of course, choosing the most suitable method depends on the specific application requirements, material compatibility, and production considerations. Get in touch with the experts at AIM Processing and we’ll help you choose the most efficient, cost-effective method for your unique products.

Plastic overmolding services are widely used for combining materials with disparate properties – such as hard and soft plastics, or metal and plastic combinations. The primary advantage with overmolding is the ability to create products with improved ergonomic features, enhanced aesthetics, and optimized strength for the given application.From consumer electronics and mobile devices to automotive interiors and hand tools, overmolding is an extremely popular method for enhancing molded products for comfort, usability, and longevity. Plastic overmolding is essentially the two-shot molding operation, but completed in two separate molding runs: the first for the substrate material, the second for the secondary material. While this method still requires two tools, they are typically of a reduced cost & complexity when compared to two-shot molding.

Enter a value based on the overall thickness of the part (what you want the thickness to be). Choosing the Show Thin Regions will color code all the faces of the part thinner than that value. Thin walls means the flow of polymer is restricted and could cause a short shot. Choose the Show Thick Regions radio button and SOLIDWORKS will color code all faces thicker and thinner than the target value. Much like Draft Analysis, hovering the cursor over the model shows the thickness in that spot. If the walls are too thick, you could end up with sink marks or warpage.

Get machined parts anodized and chromate plated with our quick-turn finishing option. Eligible materials include aluminum 6061/6082 and 7075.

Ideal thickness for injection-molded parts varies on material but can be anything from 0.5mm to 25mm, but most engineering plastics fit between approximately 1mm and 4mm.

To run the Draft Analysis tool in SOLIDWORKS, you will find it on the Evaluate tab of the CommandManager, or if you want to go another route, it can also be found under the drop-down menus in View > Display > Draft Analysis.

Luckily, the accessibility of 3D CAD in recent years has brought a multitude of checking tools to “spell check” your design based on DFM rules. Note that specific guidelines such as recommended draft angles or wall thickness are manufacturer dependent. But using these tools can reduce manufacturing costs, a lot of back and forth with the shop floor, time to market, and even save your reputation as a good engineering designer.

Proto Labs, Inc. 5540 Pioneer Creek Dr. Maple Plain, MN 55359 United States P: 877-479-3680 F: 763-479-2679 E: [email protected]

Couldn’t have said it better myself.  Should be pretty straightforward, right? Well, form can often compete with function and design compromises have to be made when factoring in business decisions. Furthermore, the more complex your design become, the more taxing it is to check that every feature is fit to manufacture.