A very important aspect of project planning is assessing the design and providing design considerations for part manufacturability. During this phase, Elite Plastics program managers and engineers are looking for anything that might cause problems in the molding process including both cosmetic and dimensional issues. Typical issues include wall thickness, wall to rib ratio, draft angles, boss diameters, undercuts, weld line locations, and texture choices. Elite Plastics solves this problem with years of experience and state-of-the-art software simulators that allow engineers to get a closer look at the part by dissecting it into smaller pieces. These tools can help identify these issues so that they can be solved prior to production.
One of the main issues faced during project development is wall thickness. The wall thickness depends on many factors and there is no density that works universally for all projects, so it must be customized per part. Wall thickness is important because it affects processing of the part and depending on how far the material needs to flow, this can affect both cosmetics and dimensions. If the walls are too thin than the melted plastic moves slowly through the tool, which makes it difficult to fill. On the other hand, if the walls are too thick than it takes longer for the plastic to cool, which can cause part shrinkage. This happens because the areas of plastic on the outside cool more quickly than the inside, which can cave in. Where possible, there needs to be even wall thickness and smooth transitions for the material to flow through correctly.
Wall to rib ratios are another important consideration during part design. Ribs are commonly used in plastics manufacturing as a way to increase the strength of the part structurally. It’s important to note that rib thickness must be 60% or less than the wall thickness of the part or the ribs will sink and be seen through the other side of the part.
One of the main considerations during injection molding manufacturing is the part draft angles. This is because the part needs to be able to get out of the tool and to do this there cannot be a 0 degree, or exactly perpendicular, draft. A 0 degree draft angle would cause the part to get stuck inside the tool. A part with heavy texture will need to increase the draft angles even more because the plastic is more likely to stick to the tool. The key takeaway here is that correct draft angles will make the part look good without getting stuck.
Boss diameters, the holes where screws are inserted, are important to consider too. The boss diameter needs to be the right size because it typically holds a metal insert which needs to fit in correctly. If the boss wall is too thick, there will be sinking on the other side of the part. If the diameter is too small, the insert will not fit in the hole. There are industry specific standards based on each manufacturer.
An undercut can be defined as a recessed area of the part, and in terms of molding this means that the undercut area makes the part unable to release out of the tool. The plastic is injected around the undercut feature and the part cannot be ejected because the shape curves inward. The part is stuck because the plastic has formed around the tool which causes problems during production.
Weld lines are a cosmetic issue for consideration. A weld line occurs when the material wraps around a feature and comes back together around an obstruction while filling the tool. When this happens, a small line is formed called a weld, or knit, line. This needs to be considered during part design because the weld line is tricky to hide. When determining the location of a weld line it is important to look at the plastic temperature, gate location, speed of flowing plastic, gate thickness, gate location, and gate height.
Texture can be used to hide molding flaws. For example, when the part design will give you sink a heavier texture can help to hide this. Using texture like this has a lot of tradeoffs in design and many customer negotiations occur.
During the stage of project planning when part design occurs, all of these factors are critical to build a successful part that meets customer specifications. The main issues to consider in regards to part design include wall thickness, wall to rib ratio, draft angles, boss diameters, undercuts, weld lines, and texture.
At Elite Plastics, we go beyond the standard injection and compression molding processes to offer full solutions to our customers through secondary processes. Within these secondary processes, we offer a range of plastic decorating capabilities in-house in our Beaverton, Oregon facility. These decorative technologies include pad printing, screen printing, hot stamping, vacuum metallization, painting and laser etching, and insert mold decorating.
One of the standard decorative technologies at Elite Plastics is pad printing. Through this printing process, ink is transferred from the cliché and is applied to the part via the pad. To do this, the artwork is etched onto the cliché, a flat plate, and ink is deposited into the grooves of the image. From there, the pad comes down on the cliché and picks up the image before transferring it to the part. At Elite Plastics, there are two types of pad printing machines including a programmable micro printer and standard pad printers. The difference between the two types is that the standard machine is equipped with stationary fixtures while the programmable printer is able to move the fixture so that the part can be printed on at multiple angles. Another major strength of pad printing compared to other decorative processes is the ability to print multiple colors during one set-up rather than through individual set-ups per color. This saves crucial time and money for the program. Pad printing is able to achieve fine print graphics as well.
Considerations when evaluating pad printing as a decorative option include the type of plastic material and the size of the artwork. If the plastic material being printed on has a heavy textured finish, the ink may not print as crisply or thoroughly as it would on a smooth material. Some plastic materials aren’t cohesive with inks and require a pre-treatment to ensure good adhesion. After production, a post-treatment is done to ensure that the ink is cured quickly. Despite these considerations, pad printing technology is highly recommended for its ability to achieve multiple colors and angles in one run.
In our next article we will discuss screen printing technology and its application for plastic parts.
In simple terms, annealing is a manufacturing process of heating a material up for a period of time before allowing it to cool down. This capability can be applied to all three types of basic materials, ceramic, metal, and polymer, but we focus on plastic material here at Elite Plastics. In the plastics industry specifically, annealing is the process of heating a plastic part up to half of the melt temperature for a moderate period of time before letting the plastic cool back down. When the part is reheated like this, the material relaxes and the molded stress is reduced. Annealing is a secondary operation, specifically a heat treatment, and isn’t typically done for all plastics parts or even in most plastic industries, but it is an important technology here at Elite Plastics.
This is an important step of the molding process because most plastic materials are poor conductors of heat which can lead to part damage. Because the plastic parts are heated up to high temperatures through annealing, the material is able to relax so that it does not react to stress caused by molding when it is in its final application or shape. These stresses typically include tension or compression (built-in stress or molded stress).
The purpose of annealing can vary for different plastic materials, but Elite Plastics uses it to ensure part stability over time. This is important for two main reasons. First, by reducing the stress, the plastic part will have better mechanical and thermal properties because there are fewer sites in the polymer that could propagate a crack or expand the part. Secondly, because most of the plastic parts that Elite Plastics produces are painted, a crack would be very visible against the paint. This is because the part material will contract and expand over time and if it has not already experienced this fluctuation at a more extreme condition through annealing, it will noticeably crack.
While the annealing process is not used in every plastic industry, Elite Plastics is committed to utilizing the technology to ensure plastic part quality over time.
There are many different types of plastic materials being used in the manufacturing industry and with so many choices out there it can be difficult to select a specific solution. A few of the most common materials include polyethylene (PE), polypropylene (PP), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), and various engineering polymers.
While polyethylene and polypropylene are different resins, both have similar properties within their plastic family because they are buoyant materials and are hydrophobic, meaning they do not absorb water. These two commodity plastics are commonly used within the injection molding industry because they are lower in cost, easy to obtain, come in a wide variety of colors, and are favored for their resistance to many chemical solvents, acids, and bases. The material density allows them to float, which can be an advantage or disadvantage depending on the application. Typically, polyethylene and polypropylene materials are used for small, cheap and lightweight products such as reusable water bottles, containers, children’s toys, and are commonly found in packaging such as plastic bags and films. These materials are not as hard as other plastics and don’t hold up as well to ultra violet (UV) light exposure. On the other hand, these materials can withstand an impact without shattering because they aren’t brittle like glass.
ABS is another favorite within the injection molding industry and is used widely at Elite Plastics, a division of GM Nameplate. The reason for this is due to the chemical composition of this material and the versatility associated with its physical and chemical properties. For example, ABS has great impact resistance, toughness, and heat resistance, which makes it a great option for housing and bezels because it can handle some impact without breaking. This material can also be processed with additives to improve UV resistance, gloss, and can be found in a wide variety of colors. The price point for ABS is also reasonable. While ABS is a strong material, it doesn’t stand up against high temperatures or external elements as well as other material options.
Polycarbonate is the top choice for most projects because it is reasonably priced, can infuse UV resistant additives, is a good electrical insulator, and has good fire retardant and heat-resistant properties. While polycarbonate is very popular, it isn’t the best choice for a part that has strict flammability restrictions because the piece can shatter if it gets hot enough.
Even though Elite Plastics is experienced in working with the plastic materials above, they also excel in manufacturing parts that are required to be made of engineering polymers. In this case, engineering polymers are injection molding grade plastics that have exceptional toughness, stiffness, chemical resistivity, and highest heat-resistant and flame-retardant properties. Some common engineering polymers include poly ether ketone (PEEK), polyetherimide (PEI), and polysulfone (PSU). While these materials may have impressive numbers to back them up, they are very expensive to obtain.
To mark the two decades since GM Nameplate acquired its plastic division in Beaverton, Oregon, the employees of the Beaverton Division gathered for an internal celebration. In 1995, GM Nameplate bought Danegon Plastics, now known as Elite Plastics, and after 20 successful years, the facility has grown larger than ever. Joining GMN allowed Danegon Plastics to become a custom manufacturer and in turn, offered GMN the plastic injection molding capabilities it needed.
GMN’s plastic division is a facility solely dedicated to plastic manufacturing. Plastic injection molding is the foundation of our plastic manufacturing expertise and after 20 years, the division’s capabilities have grown to encompass a huge range of technologies. These include plastic decorating, plastic tooling, plastic machining, and assembly, in addition to injection and compression molding. In an effort to offer our customers full solutions, our plastic division plays a crucial role in value-added assemblies and custom manufactured parts.
To learn more about GMN’s plastic division, click here.
Last year, GMN Plastics adopted a new employee training system known as Paulson training. For the past year, every employee at GMN Plastics has used the program and it has now been implemented as one of the first steps of new hire job training.
The program has been very effective in helping employees understand basic safety on the molding floor, common manufacturing problems and how to overcome them. The Paulson training has educated our employees with extensive industry specific vocabulary as well. Employees need to pass the training before they can operate machinery to produce parts and this is a good way to identify when people are ready to handle the equipment and begin production work. This training is very important because it has been found to lower product defects and boost overall quality which is a key standard at GMN Plastics.
There is a huge opportunity to grow with this program as the GMN Plastics business builds. The system has helped support the growth at GMN Plastics as more employees are hired and more shifts are added to production.
Dan Thurmond, President of GMN Plastics, has been working in the plastics industry for his entire career and at GMN Plastics for the past 30 years beginning when he started the business. Dan’s plastic experience began in high school when he took a plastics course and continued after graduation at the LA Trade Technical College where he studied plastics manufacturing. During this time he was involved with The Society of Plastic Engineers, a group he is still a member of today, and had his first apprenticeship with an affiliate company in 1969.
How did Dan go from an apprenticeship to starting his own business? He worked his way up through the plastics industry and eventually started two different plastics manufacturing companies. Dan started his first business, T&T Plastic Molding, in California and built it up before selling it four years later. He then moved to the Pacific Northwest where he began working at View-Master, the producer of stereoscopic children’s toys, where he gained experience running the molding, painting, and tooling operations there.
In 1985, Dan started Danegon Plastics with Egon Steinborn in Oregon. As the business grew, they eventually began working with GM Nameplate (GMN). GMN had been looking for a plastic injection molder as it transitioned from all sheet stock materials to injection molded nameplates that would snap into housing components. After a year and a half working as a subcontractor, GMN bought Danegon Plastics in 1995. From there, Danegon Plastics became GMN Oregon and was eventually rebranded as GMN Plastics, the name it currently holds today. While Dan stayed at the company, Egon Steinborn decided to sell his share of the company and went on to own a tool shop that continues to work with Elite Plastics today.
Dan agreed to stay at GMN Plastics for three years to ensure that the company was up and running. After working with GMN, he decided that there was, and still is, no better place to work and has been here ever since.
Chris Passanante, GMN’s product line manager of plastics, explains that, “Dan is a wonderful person, his compassion and family values carry over to relationships with his employees. He has a wealth of industry knowledge and experience, always open to suggestions and values all of his teams input. I have been very fortunate to be part of Dan’s team for the last 14 years; he has been a great mentor and friend.”
Dan Thurmond is a huge contributor to the success of GMN Plastics and GMN as a whole. He has grown the business as technologies have evolved over time and brings a positive experience to everyone who has the opportunity to work with him. We want to thank Dan for 30 years of commitment to GMN Plastics.
This January we celebrate 20 years since GM Nameplate (GMN) acquired its plastic division. In 1995, GMN bought Danegon Plastics, which became GMN Oregon and was eventually rebranded as GMN Plastics, the current business name.
Danegon Plastics was started in 1985 by Dan Thurmond, current GMN Plastics president, and Egon Steinborn. Before GMN bought Danegon Plastics, the business was run inside of a barn, two horse stalls, and two storage containers with a makeshift roof built in between. When this space had grown too small for the business, Thurmond purchased a large army tent to expand into. As the business grew, Danegon Plastics began to supply GMN with injection molded nameplates as a plastic injection molder. GMN bought Danegon Plastics 10 years after the business was started, in 1995, after working with the company for a year and a half. When GMN bought the business it was moved into a new facility where GMN Plastics currently resides today.
Danegon Plastics had been producing its own line of standard plastic lids for a variety of customers. As the marketplace changed to custom products Danegon Plastics needed to shift with the trend. Dan knew that Danegon Plastics had grown as much as it could on its own and by joining GMN, the business was able to expand to all that it is now. As Dan says, “a business can’t stay at the same level, it needs to grow and for us, GMN was the next big growth opportunity. It took us in a whole new direction. We had previously focused on plastic screw lids, and with GMN we began to focus on nameplates and branding.”
GMN had the resources that Danegon Plastics needed including a wide range of nameplate capabilities and key contacts in large US companies. Danegon Plastics had the plastic molding capabilities that GMN needed as well. By coming together, the two companies were able to grow together with complementary technologies. This shift helped GMN Plastics expand into other areas of plastic injection molding including plastic decorating, thermoforming, welding, and much more.
GMN Plastics has come a long way since it operated out of a storage facility in the 1980’s. Today, GMN Plastics is recognized as a leader in servicing highly regulated industries with comprehensive injection and compression molded products, sub-assemblies, highly decorated parts, and plastic machining. With a 60,000 square foot state-of-the-art facility, GMN Plastics serves the medical, automotive, aerospace, and industrial industries. After 20 years, we have grown to 150 employees and continue to expand year after year. At GMN Plastics we are proud of our history and continued growth.
Two new ultrasonic welding machines have been added to the equipment list in the GMN Plastics facility. Ultrasonic welding is a process in which sound vibration is used to adhere an insert to plastic or plastic to plastic. This technology has many advantages over other processes and is typically chosen because it is more precise, has faster cycle times, is easier to set-up for production, the tooling involved is less expensive, the machines are smaller, and it can be done either as a standalone operation or at the molding machine during the molding process.
Because ultrasonic welding is used for a wide variety of applications, there are many variables to consider when determining whether this technology should be chosen. To decide whether ultrasonic welding is the right option for a project, the team at GMN Plastics looks at factors of the part design including part function, material, cosmetic requirements, and part size.
A good example of the advanced capabilities of ultrasonic welding can be seen through a plastic bezel that GMN Plastics manufactured for a large medical technology corporation. This complex piece used four different inserting operations, each with different heights and locations. Ultrasonic welding was able to meet the customer’s project requirements with reduced set-up times, reduced handling and movement, one piece flow operation (also known as lean manufacturing), and better quality.
When Toyota and their tier one supplier needed a gear shift indicator to match the sleek interior of their Camry line of vehicles, GMN stepped in. It was decided that the piece would be a glossy shade of piano black with a backlighting solution. A difficult combination to achieve, GMN’s plastic division GMN Plastics, was able to provide Toyota with an ideal solution through an extensive painting system and laser etching technology.
Learn more about this ongoing program for Toyota in our case study here.
To watch how this part was made, click play on the video below.