At some point, an injection molding tool reaches a stage where neither routine maintenance nor targeted measures to extend its service life are sufficient to maintain the required production quality. It may also happen that production requirements change so significantly that the existing tool no longer meets the need.
In both cases, the question arises: Is renovation or upgrading the right answer, or is a new tool the better solution?
Renovation and upgrading are not the same as starting from scratch. They involve a systematic assessment and reconstruction of an existing system with the aim of restoring or improving its performance. This approach assumes that the basic structure is still serviceable and that the interventions are well-defined and economically sound.
The difference between renovation and upgrading
These terms are often used interchangeably, but they refer to different types of procedures.
Refurbishment involves restoring a tool to its original performance level. It is appropriate when wear, damage, or dimensional deviations have reduced the tool’s quality below acceptable standards. The goal is to restore the tool to the condition for which it was designed.
Upgrading involves improving a tool beyond its original specifications. This is necessary when production requirements have changed and the existing tool no longer meets them. This may involve increasing the number of cavities, modifying the geometry, improving cooling, or integrating new components.
In practice, the two are often combined. A machine that needs to be refurbished is upgraded at the same time if production requirements have changed.
When is renovation or upgrading appropriate?
It’s not always clear when maintenance and life extension measures have reached their limits. However, there are typical situations where renovation or upgrading becomes the natural next step.
Widespread wear: When wear is no longer limited to individual components but is widespread across form holes, cores, mating surfaces, and moving parts, targeted interventions are insufficient. In this case, a comprehensive overhaul makes more sense than attempting to solve the problems individually. This is the situation that distinguishes overhaul from service life extension. [INTERNAL LINK → Service life extension of injection molding tools]
Changed production requirements: If part geometry, material selection, or volume projections have changed significantly since the original design, upgrading may be the most effective approach rather than investing in an entirely new tool.
Damage resulting from incidents: Manufacturing defects, improper handling, or mechanical incidents can cause damage that requires more than routine maintenance. In such cases, a structured refurbishment process is necessary to ensure that all consequences of the incident are identified and rectified. Read more about this topic in the article: Preventive Maintenance of Injection Molding Tools
Documented service life limit: A mold that has reached its practical service life limit—based on cycles, dimensional deviation, and maintenance history—is an obvious candidate for a comprehensive assessment. Learn more about this in the article: What determines the service life of an injection molding tool?
What a renovation entails
A thorough renovation typically follows a structured process that begins with a condition assessment and ends with the validation of the renovated tool.
Condition Assessment and Inspection: Before work begins, the tool’s current condition is systematically assessed. This includes dimensional measurement of critical tolerances, visual and tactile inspection of surfaces, and a review of maintenance documentation. Without this baseline, it is not possible to accurately determine the scope of the refurbishment.
Disassembly and component evaluation: The tool is disassembled, and each component is evaluated individually. Some components are reused, others are repaired, and worn parts are replaced. This also provides an opportunity to inspect areas that are not accessible during normal operation.
Machining and straightening: Worn or deformed surfaces are machined to the correct dimensions. This may require welding, followed by CNC machining and polishing, depending on the nature of the damage and the requirements for the finished surface.
Surface treatment: When renovating, it is natural to consider whether surface treatment can improve durability in the future. The choice of treatment depends on the type of steel and the stresses to which the tool is subjected. [INTERNAL LINK → Steel types for injection molding tools – selection of tool steel]
Assembly and Adjustment: Once all components are prepared, the tool is assembled, and all interfaces, movements, and functions are adjusted. This step requires experience and precision, as the interaction between components is crucial to the overall result.
Test run and validation: The refurbished tool undergoes a controlled test run, during which parts are inspected and measured against specifications. Only when production is stable and within tolerances is the refurbishment considered complete. The same process applies to new tools. [INTERNAL LINK → Test run, break-in, and validation]
Upgrade as a structural improvement
An upgrade differs from a renovation in that structural changes are made to the equipment rather than simply restoring it to its original condition.
Typical upgrades include:
- Increased number of cavities to achieve higher productivity
- Modification of the inlet system or cooling configuration to reduce cycle time
- Geometry adjustments due to product changes
- Incorporation of interchangeable inserts to increase flexibility in the future
An upgrade requires that the design be thoroughly re-evaluated with the new requirements in mind. In principle, this constitutes a partial redesign of the mold and should be approached with the same level of thoroughness as the initial design phase. This perspective is described in: [INTERNAL LINK → Design for Manufacturing in Injection Molding Tools]
The economic assessment
The decision to refurbish, upgrade, or invest in new equipment is largely a financial consideration. There is no single right answer, but there are a number of factors that should be taken into account.
Renovation is typically the most cost-effective solution when:
- The basic design is robust and well-documented
- Wear and tear is widespread, but not structurally damaging
- The production requirements that the tool must meet remain unchanged
- The expected remaining service life after renovation can be estimated with reasonable accuracy
A new mold is often the better investment when production requirements have changed fundamentally, or when the total cost of refurbishment approaches the price of a new mold without offering a comparable service life. The full picture of what a new mold costs is described in: [INTERNAL LINK → How much does an injection mold cost?]
Summary
Renovation and upgrading are appropriate solutions when maintenance and life extension are no longer sufficient, or when production requirements have changed.
A refurbishment restores a tool’s original performance through systematic inspection, machining, and replacement of components. An upgrade enhances the tool beyond its original specifications and requires a design-oriented approach similar to the original development process.
The key to a successful outcome is an accurate assessment of the current condition, a well-documented maintenance history, and a clear definition of the performance that the refurbished or upgraded equipment is expected to deliver.
Frequently Asked Questions
Refurbishment restores a tool’s original performance by repairing wear and damage. Upgrading improves the tool beyond its original specifications, typically because production requirements have changed.
Renovation is typically the most sensible solution when the basic structure is still sound, wear and tear is widespread but not structurally damaging, and production requirements remain unchanged. If requirements have changed fundamentally, or if the cost of renovation approaches the price of a new machine, both alternatives should be evaluated.
A condition assessment includes dimensional measurements of critical tolerances, visual and tactile inspections of surfaces and components, and a review of maintenance documentation. This forms the basis for accurately defining the scope of the renovation.
Yes. In practice, refurbishment and upgrades are often combined. Since a tool is already disassembled and being worked on, it makes sense to implement improvements that enhance performance or adapt the tool to changing production requirements.
A refurbishment is completed with a controlled test run and validation, during which components are inspected and measured against specifications. The refurbishment is not considered complete until production is stable and within the defined tolerances.
