Design for manufacturing (DFM) is an approach to product development that emphasizes the importance of designing a product in such a way that it is easy to manufacture. Also known as design for manufacturability, it is used in a wide range of engineering disciplines, including the injection molding of small plastic parts. Through the smart application of DFM principles to everything from the raw materials used to dimensional tolerances to the number of components in a finished part, companies can often produce more parts faster and at a lower cost.
Nylon is a synthetic thermoplastic that is extremely versatile and resistance to many chemicals. In our decades of small plastic parts manufacturing in Colorado, we have used it in a wide variety of ways. It is a material that is naturally very strong, but in some applications, glass is added to create greater structure and rigidity. What is referred to as “glass-filled nylon” provides many benefits to manufacturers, but there are also some cautions to keep in mind if you choose to work with it.
One of the keys to the accurate and efficient creation of small plastic parts is having a mold that is perfectly designed for the task at hand. There was a time when toolmakers were generalists who could create a mold to meet any specs. Today, however, with advances in everything from the design of parts to the materials used to make them, that’s no longer the case.
There are two truths that are clear in virtually every industry today: capital can be hard to come by and companies are under intense pressure to control costs in order to maximize profits. Organizations that use plastic injection molding to produce parts for their products may be tempted by the lure of cheap tooling. However, as a leading molder of small plastic parts in the Denver area, we know that the reality is that sometimes lower-cost alternatives can end up costing more in the long run.
It takes some time and effort to establish a good working relationship with a small plastic part injection molder. As a result, you may be reluctant to move on to a different provider, even if the current relationship starts to deteriorate.
A number of questions will likely come to mind — things like:
- What are the signs that it’s time to leave?
- What are we risking if we decide to stay?
- If we choose to leave, what is involved in moving our processes to a new injection molding shop?
One of the more interesting challenges we get at our small part plastic injection molding operation in the Denver area is how to design a plastic parts manufacturing process in a way that produces the best assemblies. When two or more finished parts must fit together properly to make one assembly, there are a number of factors to keep in mind.
Historically, small plastic part injection molding has been performed primarily with steel molds. There are many advantages to steel, including:
Nylon is a synthetic thermoplastic first produced in 1935 and introduced as a fabric during the 1939 New York World's Fair. You will also see Nylon referred to by its chemical designation “PA.” It is commonly available in black, white, and off-white or beige, which is its natural color. Nylon can be produced as fibers, filaments, sheet stock, and films, and also as the raw material for injection molding.
Acetal is the common name for polyoxymethylene (POM), a white semi-crystalline thermoplastic. It is strong, abrasion and impact resistant, and tolerates many organic chemical compounds. It has a low coefficient of friction and durable stiffness, so it is often used in moving parts. Because it is widely available in sheet and block form, many machined prototypes are made of acetal. Examples of items made from acetal include a variety of large and small plastic parts:
Polycarbonates (PC) are a group of strong, impact-resistant, heat-resistant, thermoplastics. They are naturally transparent, with the raw material capable of transmitting light as well as glass—and they are much lighter than glass. While they are clear by default, PC plastics are commercially available in many colors.