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这并不总是那么容易，但不要使它比需要更难。从3D打印到注射成型不像仅使用不同设备的计算机辅助设计（CAD）文件那样简单。由于3D打印提供的设计自由度比注射模型更大，因此您可能需要修改CAD文件并指定其他信息。但是，让我们不要超越自己，尤其是考虑到涉及的时间和金钱。

从3D打印to injection molding is usually a financial decision that’s based on production volumes. You may also need to consider the timing of expected demand. Preparing your part for injection molding is especially critical, and there are plenty of questions to ask and answer. If you’re a part designer or an engineer who’s looking for help, use this article as a checklist to determine if you’re ready to move from 3D printing to injection molding.

准备您的零件设计

If your design isn’t ready for injection molding, it really doesn’t matter how many parts you’d like to mold. Design for manufacturing (DFM) is critical because 3D printing supports part features that are difficult, expensive, or impossible to achieve with injection molding. Some features that aren’t in your 3D printed part can be molded, but with extra costs and longer timelines. Other features, such as lattice-like structures, can be 3D printed but not injection molded.

To assess your injection molding readiness, ask yourself the following questions.

  • 部分几何和表面是否可以实现？注射成型不能产生复杂的零件几何形状和弯曲表面，因此起点是DFM。如果您无法降低零件的复杂性或改变其形状，请考虑加工而不是成型。例如，5轴CNCmachining can achieve intricate geometries with limited setups.CNC车床转动可以在加工时间有限的情况下创建弯曲表面。
有机形状的3D模型在紫色背景下
CAD file for 3D printed part. Injection molding can’t produce curved surfaces.
  • 您是否替换了复杂的填充图案？虽然填充图案可以提高3D打印零件的强度，无法通过注射成型复制。取而代之的是，使用肋骨和毛刺，即垂直于墙壁或平面的特征。
  • Are you using a large enough radii?Otherwise, voids and warpage caused by uneven shrinking may occur. Often, this happens where ribs or gussets meet an adjacent feature or wall. As a rule, the minimum inside radius is the thickness times one. At the corners, however, the inside radius is 0.5 times the material thickness and the outside radius is 1.5 times the material thickness.
  • What about wall thickness?注射模压零件对陨石坑状的水槽标记更敏感，因此请保持壁厚相对均匀。如果您需要同时使用较薄的墙壁和较厚的墙壁，请设计平滑的过渡。
  • Did you round sharp corners?它们倾向于使霉菌释放复杂化，因此最好使用fillets反而。例外是何时拐角也是模具的分开线。

如果您在不考虑注射成型的情况下设计了自己的零件，则还需要回答这些问题。

  • What are the draft angles?Draft, a small amount of taper, facilitates mold release and helps to avoid part damage. A minimum amount of draft is also needed to achieve a specific surface finish on your mold.
  • 那表面饰面呢？与许多3D印刷零件不同，注射模压零件是光滑的。平滑度是模具如何表面完成的函数，并且对应于您需要提供的等级或类别。
  • 什么是允许的闪光灯？Injection molding produces parts with some amount of flash, unwanted material that overflows from the mold cavity. Because flash isn’t an issue in 3D printing, you may need to think about flash location, thickness, and extension for the first time.
  • 您需要调整零件公差吗？Dimensional deviations in 3D printing are greater than in injection molding. Therefore, you could tighten your tolerances. Remember, however, that close-tolerance parts are more expensive.

在最终确定零件设计的同时，根据您的应用程序要求评估材料也很重要。这是因为3D打印的聚合物与注射成型的塑料具有相同的最终用途特性。例如，3D打印的ABS对注射模压的ABS没有相同的抗击能力。对于身体面板来说，这可能很重要，但对医疗设备而言并不重要。

确定交叉体积

注射成型通常使用加工钢或“硬”工具，费用为2,000美元至20,000美元；但是，大型模具的成本远不止于此。不过，仅零件尺寸并不能决定霉菌成本。您需要的精度也会影响成本，这决定了注入成型的体积成本效益。您也需要评估销售预测。如果您不希望出售大量的零件，那么注射成型可能会过滤。

接触案件，使用注塑成型制成的塑料制成
Injection molding is ideal for high-volumes of standard parts like these contact lens cases.

跨界量是注塑成型比3D打印更好的财务意义。通过将注射模具的成本扩散到​​大量的零件中，您可以降低模具的每单位成本，并更快地摊销工具成本。考虑这些一般准则。

  • 标准零件具有通常在低矮的跨界量。
  • 小精确零件have a higher crossover volume because their molds require more complex machining operations. This volume can be in the tens of thousands.
  • Large parts还具有比标准零件更高的交叉量。那是因为模具需要更多的金属和更长的加工时间。

时机也很重要。如果您需要初次运行的快速零件，那么等待金属注射模具的数周是没有意义的。要发布产品，您需要知道何时开始成型。如果成本而不是速度是一个限制因素，聚氨酯铸件could be a better option since the tooling is significantly less expensive and can support runs up to 500 pieces. You could also use a “soft” injection mold that’s made fromaluminum甚至是非金属材料，可以持续数量有限的周期。

用于注入成型的模具的图像
这样的模具可能需要几个月的时间才能花费数千美元。

If you need low-cost parts across a high volume of identical units, however, there’s no substitute for injection molding with hard tooling. To determine if you’re really ready to make the move from 3D printing, gather these numbers to find out when you’ll see a return on investment (ROI).

  • 总所需数量：您在项目期间需要的零件数量。
  • Initial Order Quantity:The number of parts in your first order.
  • 年订单数量：The number of parts you’ll need in a given year. For multi-year projects, this number may increase or decrease over time.

将模具的成本除以总所需数量，可为您带来单位成本。但是，生产所有这些部分需要多长时间，并需要数年才能获得投资回报率？

您的3D打印零件是否可以进行注射成型？

Hopefully after reading this article, you can determine your readiness for moving from3D打印to注射成型。经济学通常会推动这一决定，但是零件设计师和工程师也使用针对注射成型进行优化的部分设计引导了这一过程。如果您准备好进行即时注射造型报价，创建一个帐户与我们一起上传您的设计。要在您的收件箱中获取更多工程内容，请在下面订阅我们的新闻通讯！