Every new product has to define the surface finish required for visual appeal and/or a technical function. The question is always what will work best to create the product that every customer wants. Surface finish is one of the smaller details, but it can make a large impact in development cost and long-term success if done incorrectly.
Understanding the intention and function of your product and how the customer will use it may help to determine what surface finish you should be choose. You should be selecting a surface finish that offers flexibility while meeting your customer’s visual expectation. That expectation may serve as a representation of the value in the product, and what initially attracts them to your product. Multiple surface options can offer a texture and finish that will be durable and visually appealing, and still meet the performance requirements needed to serve the customer demands. These are some of the initial discussion points you should be having with your mold designer concerning surface finish:
What is the Purpose of Your Surface Finish?
Before you start the search for surface finish options, you should know what the purpose of the finish is. Will it be added for visual appeal, or does it provide some function? It may be as simple as one of those options, or it could be a combination of both. Before you pick the final surface finish, you should know what class of mold you will need based on production volume and what material the mold will be made from. A steel mold will be harder than an aluminum mold and offer more options for surface finish. Steel has the advantage that it can be polished for a smoother surface finish too. That can also be advantageous for painting or another secondary turnkey operation to enhance your product.
Some of the surface finishes available include:
- Geometric or patterned shapes – These shapes can be limited to certain sections of the product, or offer complete and unique coverage.
- Leathery texture simulating grain – The goal is to mimic texture found on natural products like leather or rawhide.
- Prepared for painting or secondary graphics – this type of finish will be very simple and flat. It’s a blank canvas for something to be added.
- Etched with a logo – The goal with etching is to provide a logo for your brand or business to standout. The logo could be placed once or multiple times to give your product a little extra exposure.
- Blasted for a rough uniform texture – The uniform texture isn’t a unique pattern, but a constant rough texture on the surface.
- Gloss, matte, or satin polish – This finish will be somewhat reflective but can also be a flat texture that does not reflect much depending on the choice between gloss or matte.
- Mirror or lens finish – This type of finish will be very reflective.
What Advantages Does Surface Finish Offer?
Adding a surface finish has multiple advantages including being used to make undercuts and hide parting lines formed during the molding process. Depending how the mold is designed and created, there may be multiple slides that move in and out to inject and release the part. Each of those adjoining areas form parting lines that may or may not be visually appealing to the product and customer. A strategic texture or finish in those areas can blend or hide the parting lines. Beyond visual appeal, texture can improve grip, offer improved paint adhesion, and can allow gases to escape the mold during the injection process.
When Should Surface Finish Be Determined?
Surface finish may seem like a small detail to discuss with your mold designer, but if left as an after-thought it can cause delays in mold creation and costly development changes. At the initial discussion of the project, your designer will also ask about resin selection. The resin you choose can be affected by the surface finish on your product. Both need to work together to properly form an injection molded part. Selecting one without regard for the other can affect resin flow through the mold. You’ll want to have your mold analyzed through the design process to guarantee your selected resin will fill the cavity correctly during injection.
What Else Should Be Considered When Choosing a Surface Finish?
Choosing the correct resin for your product is just the beginning of the design considerations to be discussed. Surface finish can hamper the capability to add any type of embossing, pad printing, or hot stamping with a logo or visual pattern. There are basic two categories of resins; amorphous and semi-crystalline, and there are sub-categories to each main category. Your product may need additives or fillers to meet certain design criteria, it may need a determined fill rate inside the mold, a pressure requirement, and/or a determined temperature to completely fill the injection mold. All of these variables are connected and it can be confusing to know what should be determined first, second, and so on.
Your goal is to design and develop a product that your customer wants to purchase. It needs to have visual appeal and also meet their functional requirements. Choosing each detail to ensure that happens is one of the more critical stages to get through. When you need a resource to design your mold, help and select an appropriate resin, and a supporting surface finish with all the parameters needed for a successful product, we’re here to help. For more information on SEA-LECT’s production opportunities, call (425) 339-0288 or email us at email@example.com
Matthias Poischbeg was born and raised in Hamburg, Germany. Matt moved to Everett, Wash., after finishing his bachelor’s degree in business in 1995 to work for Sea-Dog Corporation, a manufacturer, and distributor of marine and rigging hardware established in 1923.
In 1999, Matt took over the reins at Sea-Lect Plastics Corporation, a sister company of Sea-Dog and a manufacturer of plastic injection molded products with an in-house tool & die shop. Matthias Poischbeg is also a contributor to Grit Daily.