Three Tips for Controlling Tooling Costs in Injection Molding

Posted on 05-04-2017

Optimize Plastic Part and Tool Design

Tooling is an essential part of any injection molding program, but it is also part of the expense. Your goal when beginning a new molding project is to achieve the best cost per part as well as the best ROI on your tooling investment. By working with your supplier early in the design process, you can often find ways to make both the plastic part and tool more cost effective.

Your supplier will consider several factors that can affect mold cost, including:

  • Part complexity
  • Hourly output / yearly part volume
  • Material selection (for both part and tooling)
  • Quality requirements
  • Cycle time
  • Gate location
  • Mold cooling

It is also important that your supplier understands the secondary operations, final assembly, and intended application of your part. This knowledge can help them optimize the plastic part design and determine what other value-added cost-saving strategies to employ.

 

3 Tips for Controlling Tooling Costs

Part design, mold design, and mold build are three primary forces that drive tooling cost.

1. Part Design

Making the part easier to manufacture is one of the best ways to lower the overall cost of production. The complexity of the part design will then drive the tool design. Various design decisions affect cost, including:

  • Under cuts
  • Texture
  • Threading (internal or external)
  • Resin
  • Slides
  • Servo hydraulics
  • In-mold labeling
  • Insert molding

If engaged early enough in the product development process, your supplier’s engineering team can often suggest a design or redesign to make the part easier to mold—and keep the finished part cost as competitive as possible.

2. Mold Design

The two main types of plastic injection molds are cold-runner and hot-runner molds. Cold-runner mold designs are usually simpler, and the tool is less expensive; however, the cost per part is often higher. Hot-runner mold designs are typically more complex and more expensive, but the part cost is lower. Further savings can be had by utilizing design tools such a Moldflow help to confirm proper cooling channels and effective gating locations.

Choosing the right cooling method can reduce cycle time and improve part quality. Empire reviews all options for cooling, including but not limited to standard mold cooling, hot steam or oil, and conformal cooling options. The geometry of the part and the resin being used play a large role in what method is chosen. Understanding the cost of added cavitation helps to balance upfront tooling investment and evaluate an ROI that works best for your tooling budget.

3. Mold Build

The construction of the tooling will also impact the overall cost. Important factors include:

  • Material (steel, aluminum, etc.)
  • Specification (Class 101, 102, 103, etc.)
  • Configuration (traditional 3-plate design, MUD unit, etc.)

By communicating and collaborating with your supplier early on, you can determine which options will make the most sense for your project.

 

Design for Longevity

A well-designed tool is easier to set up and to start, has lower rejection rates and a predictable cycle time, and will perform beyond its required life expectancy. This allows your supplier to provide reliable quality, cost, and delivery for your program. On the other hand, an unreliable tool impedes production and requires extra money, time, and effort to repair.

Empire strives to understand all aspects of your project up front in order to achieve the lowest cost, even when we’re only building the tool and not producing the part. This information helps us increase the longevity of the tool and avoid residual costs, such as repair expenses, that can crop up through continued use of the tool.

To learn more about improving part quality and cost through tooling, download our free guide.

The best value for a program is often achieved when a supplier works closely with you as a strategic partner. Whether you require tooling services only or tooling for full production, Empire’s experienced team can help you make the most of your tooling investment. Contact us to discuss your latest project.