One of the primary costs of an injection molding project is the tooling. Given the size of the initial investment in the injection mold, OEMs want the mold to last as long as possible and often wonder how long the mold will last. It is important to understand that the lifetime of injection molds is typically measured in production cycles as opposed to time. This approach allows OEMs to determine when the initial tooling cost will be paid off, and if the cost of the tooling is justified based on the number of parts the mold is expected to manufacture.

There are several factors that play a part in injection mold longevity. One key design criteria that predicts tooling life span is mold class, which is indicative of the life expectancy of the mold based on the number of cycles it is designed for.

What is Tooling Mold Class?

The tooling mold class as defined by the Plastics Industry Association sets standards on the physical tool construction and life expectancy. To determine which mold class to proceed with, designers often start with the desired life expectancy and the tool material. For example, if the project has a short life expectancy with a commodity grade material or an engineered grade that is not abrasive, designers can likely start at Class 105 or “prototyping” mold class. As expected, the more cycles required of tooling, the more robust the mold must be, thus, driving up the overall tooling cost. By selecting the appropriate mold class for your application, you can save a significant amount of costs by not over-engineering the tool. Below are descriptions of different mold classes. It should be noted that the following are only general guidelines and OEMs should consult with a trusted injection molding partner, like ProMed, to ensure the right design criteria, including mold class, are selected for your specific project.

  • Mold Class 101: this class is for high volumes and is rated for 1,000,000+ cycles. These molds typically operate with very fast cycle times. Due to the high-volume requirements, these molds are made with the highest quality materials and are the most expensive. These molds can tolerate harsh materials and operating conditions, and are able to achieve tight tolerances.
  • Mold Class 102: this class is rated for no more than one million cycles. This tool is for medium to high volume production and is usually a good option for abrasive materials as well as close tolerance products.
  • Mold Class 103: this mold class is rated for under 500,000 cycles. This is a common mold for low to medium volume production.
  • Mold Class 104: this mold class is rated for under 100,000 Cycles. This tooling is a good option for lower production volumes with non-abrasive materials.
  • Mold Class 105: this class is rated for no more than 500 cycles and is typically for prototype purposes. This tooling is the least expensive.

What Impacts Mold Longevity?

Although mold class is a good basis for designing tooling longevity, there is no method to determine exactly how many cycles a mold will last. However, the factors below each impact the life span of a mold and the life can be maximized for molds that are well cared for.

  • Materials – the life span of an injection mold is significantly impacted by the material of the injection molded products as well as the material of the tooling itself. Molds made of a softer metal, like aluminum, do not generally last as long as harder metal molds such as stainless steel. As for the silicone blend being molded, some formulations contain abrasive or corrosive ingredients, which can wear down the tooling and decrease the life span.
  • Conditions – injection molding manufacturing occurs under a range of operating conditions and some environments are tougher on equipment than others. Additionally, cleanliness and the likelihood for contaminants such as moisture, dust, and debris also impact the life cycle of tooling.
  • Length of Cycles – As a rule of thumb, injection molds tend to last longer when they operate under longer cycle times compared to high-speed production cycles.
  • Proper Maintenance – this is one of the key elements that impact tooling life span yet it is often overlooked. Preventative maintenance and the associated inspections are vital to maximizing the life of injection molds.

ProMed’s Silicone Injection Molding Capabilities

ProMed was founded in 1989 to address an industry need for cleanroom manufacturing of silicone components, specifically those having a medical application. We have garnered a reputation as the world benchmark of implantable silicone components and assemblies – and are one of few companies in the world to provide contract manufacturing of drug-eluting products.

ProMed has expertise in working with the full spectrum of silicones covering a wide range of properties and characteristics. We will assist in your material selection to help ensure all design requirements are met. Our manufacturing facilities and equipment are designed for a single purpose—to mold medical and implantable silicone, combination components, and bio-material grade plastics with uncompromising quality and service. We currently have four divisions that are located within two manufacturing sites. All are certified class 10,000 / ISO Class 7 cleanrooms.

We can identify the right manufacturing solution for any project. We have extensive experience in a wide range of injection molding techniques including:

  • Automated Injection Molding
  • Multi-cavity tooling
  • Micro molds and micro molding
  • Servo-controlled de-molding capabilities
  • Insert molds, overmolds, and automation integration
  • Transfer molding
  • Compression molding

Contact ProMed today at 763-331-3800 to discuss your next medical molding project.

Summary
How Long Do Injection Molds Last?
Article Name
How Long Do Injection Molds Last?
Description
Overview of how long injection molds last including mold classes and factors that impact tooling life span such as materials and maintenance.
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ProMed Molding
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