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Author Archives: Doug Billings

  1. Benefits of Recycling Plastic for Injection Molding

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    Regrind - recycled plasticScientists estimate that there are 5 trillion tons of plastic in the world’s oceans. FIVE TRILLION!* It’s hard to wrap your head around that number, isn’t it? Couple that with the ever-increasing global demand for plastic, and the oil it is derived from, and you have a perfect storm. Thankfully, plastic is recyclable. Today we’ll look at some approaches to plastic recycling, and dive into the benefits.

    First, let’s consider the use of plastics during the plastic injection molding process. For parts to be formed, molten material must travel through channels known as runners into the mold’s cavities. Once the parts have set, the plastic strip-like pieces formed within the runners, ironically also known as runners, have served their purpose. This excess plastic may be as much as 50% of the job’s material usage! That creates a tremendous amount of plastic that’s ripe for recycling.  

    How Do Injection Molders Recycle Plastic?

    A robotic arm picks up the runners, and feeds them into the grinder.

    A robotic arm picks up the runners, and feeds them into the grinder for in-line recycling.

    There are several ways a manufacturer can handle this excess material. In many cases, they will simply collect it, and send it out for recycling. A third party will take the plastic, which will eventually be recycled. To complete the cycle, the fabricator may buy recycled plastic to use as raw material for production. While this does help conserve resources, the processes to properly recycle plastic are complex, costly and demand more natural resources.

    Alternatively, plastic shops may recycle in-house. There are two main methods of doing this: 

    1. They collect the excess material during production, then send it to another part of the facility for regrind and reuse. 
    2. In modern automated shops, like Plastic Design, the material is collected, reground and reused in-line, as part of an extremely efficient plastic injection process.

    So, why go through all this effort to recycle plastic?

    Resource Conservation 

    It’s pretty simple. Using recycled material helps conserve valuable natural resources such as oil. By keeping waste out of landfills, the manufacturer is contributing to a circular economy, giving materials a second life. 

    Waste Reduction

    Keep in mind that about half of the material used in the plastic injection molding process doesn’t make it into the finished components. By capturing and recycling this plastic, significant amounts of waste are avoided, along with the costs it takes to handle, store and dispose of it. Putting less waste into the environment results in a much more sustainable manufacturing process. 

    Cost Reduction

    While recycled plastic tends to cost more than virgin material, utilizing an optimal in-line recycling process actually drives material costs down. This is due to the many operational efficiencies it brings, across many departments. Think about it for a moment – it costs nothing to ship material that’s already in the building. There’s less handling required on the shop floor, thanks to automation. Since little disposal is required, associated fees are greatly reduced as well. The purchasing team also has less buying to do. There’s less raw material to stock, which means lower carrying costs. 

    Most industries can benefit from working with injection molders that are committed to a sensible recycling program. There are certainly some exceptions, such as the medical field or others that have strict requirements aimed at avoiding contamination. Otherwise, recycling plastics within the injection molding process brings many benefits to manufacturers, the environment, and, yes, the bottom line.

    Can You Benefit from Using Recycled Plastics?

    We’ve helped lots of brands reduce their carbon footprint and help keep plastic injection molding prices in check. Contact us now to see how we can assist you.

    *SOURCE: National Geographic

  2. 5 Ways to Reduce Plastic Injection Molded Part Costs

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    Reduce Plastic Injection Molded Part CostsThere’s one question that comes up in practically every call we have with prospects and customers lately. You’ve probably guessed it already: “How can we reduce cost?”

    It’s a fact. Every buyer wants to pay less for their injection molded parts, but without sacrificing quality. Thankfully, for many jobs, this is achievable if you know where to look. But you must be careful to preserve the part’s quality and integrity in the process, otherwise it could cost you in the long run. As the old saying goes, don’t be penny wise but pound-foolish.

    There are several areas worth examining to help reduce injection molded part costs. These include part and tooling design, material, and manufacturing process considerations. Let’s take a look at these to see how successful cost reduction can be achieved:

    Part and Tooling Design

    The first place to start is with part design. Ultimately, your goal is to simplify the part wherever possible, Or, as we say here in the shop, KISS, or keep it super simple. Technically speaking, this translates to simplifying the geometry, minimizing undercuts, and eliminating unneeded features. When design is properly optimized, less material will be consumed and cycle time reduced. Less design complexity leads to lower tooling costs.

    Additional cost saving opportunities may be found in the tool design and construction. Optimizing cooling channels, or conducting a mold flow analysis to identify areas for improvement. You should also consider options for using standardized mold components. By optimizing the gating system and cooling channels, you may be able to further cut cycle time and reduce material waste.

    Are You Using the Best Material?

    Material selection presents another potentially large opportunity for cost reduction. In our experience, the material is often over-spec’d. For instance, it is not unusual to see a job that calls for a resin that is say $10 or $20/lbs., when it could be made from a commodity material costing just a few dollars per pound. For medium and larger runs, this adds up to significant savings. Of course, you must be certain that the new material still meets the required specifications and operating conditions for the part. But there is no benefit in over specifying, it is sort of like installing stainless steel muffler on the Yugo.

    Process Considerations

    To keep production costs in check, it is critical to be sure that the process is optimized during process development stage. Reducing cycle time has a major impact on part cost. It is also a good idea to routinely revisit and verify that your process is at its optimum, study quality data, and eliminate any sources of waste or defects.

    Automation and Robotics to the Rescue!

    Another cost-saving process enhancement is to utilize automation and robotics when possible. As we explored in our previous blog, automation brings many cost-cutting benefits. It is especially useful when complex assemblies may be faithfully produced with the help of reliable automation. This reduces labor costs, material waste and cycle time.

    Don’t Forgot About the Economies of Scale!

    When practical, consider ordering in larger volumes. It is a simple principle. As run size increases, unit cost decreases. When coupled with reliable forecasting, this could lead to healthy savings. Don’t have a lot of space to store components that you don’t need yet? Many shops will offer stocking programs to help with warehousing. Though do keep in mind that carrying inventory is not free, so consider these costs when weighing against the benefits of longer production runs.

    As you can see, there are plenty of ways to reduce injection molded part costs. It all comes down to reducing labor costs and cycle time while increasing process efficiency. As we mentioned earlier though, please be cautious. While saving money is certainly a good thing, you don’t want to sacrifice the part’s required properties in the process, especially for mission or safety-critical applications.

    Want to see if we can help you reduce molded part costs?

    Give us a call, tell us about your part, or send a drawing. We’ll be happy to review it and let you know what find!