Summary: Aluminum injection molds are finally gaining a foothold in the plastic injection industry, which can no longer ignore its benefits over traditional metals.
In the injection molding industry, poor tooling practices and selection of aluminum alloys have given rise to the widespread myth that aluminum is ‘prototyping-only tooling’.
However, this is changing rapidly, and aluminum along with 3D printed molds are competing with traditional metals in the plastic injection market.
The modern aluminum injection mold offers superior quality with less scrap, faster turnaround times, tighter tolerances, and process consistency, leading to significant savings in production costs. The range of applications for aluminum in the manufacture of injection molded plastics is limitless.
How to make aluminum injection molds?
Aluminum injection molds are gaining prominence as they help reduce costs. Also, since aluminum tends to cool at a uniform rate, cycle times are decreased, allowing for faster production. Aluminum molds are generally less expensive compared to steel ones and have a faster build time.
Aluminum CNC machining has become the predominant method for manufacturing molds with varying degrees of complexity, precise detail, and shorter turnaround times.
In some cases where cavities need to have sharp corners, the process may require additional EDM (Electrical Discharge Machining) as regular milling may not help achieve this.
The basic injection molding process involves two halves of the mold being separated at the end of the cycle to eject the part. With this simple structure, the part cannot have undercut or protruding features, as the mold halves would snag each other when separated.
When the mold is used to make complex plastic parts, additional complexity is added. Slides are added to the mold to accommodate such features. General processing is mainly based on machines; there is no heat processing or specialized tooling involved. An aluminum injection mold takes on average 10-15 days to complete.
How much does an aluminum injection mold cost?
The cost of an aluminum injection mold can vary based on a number of factors. High-quality molds with tighter tolerances, longer tool life, and more cavities would take longer to build and cost more. However, a higher quality mold offers considerable savings in the long run that outweigh the initial cost. These molds last longer and require less maintenance compared to poor quality tools.
Aluminum mold for plastic injection
Injection molders find aluminum an attractive option for plastic injection because it can speed up mold construction, greatly reduce cycle times and lower tooling costs.
An application in an aluminum mold works 20 to 40 percent faster than the same part in a steel mold. This efficiency is making the plastic injection industry increasingly competitive worldwide.
This means that the inherent efficiencies brought about by using aluminum in injection molding can ensure that you never lose orders or contracts with traditional steel-based plastic injection molders with similar offers. Steel mold operators cannot compete with aluminum ones under similar conditions and requirements.
Molders may be initially surprised at how quickly an aluminum mold reaches its processing temperature due to its high thermal conductivity. This means you not only get more parts produced per shift, but you also reduce machine downtime to change molds.
With increased machine utilization, you can produce more parts with less equipment. Mold operators can also save time at different points during plastic injection, since aluminum heats up and cools down faster.
Aluminum injection mold life expectancy
The life expectancy of an injection mold is of great interest to tool makers and injection molders. With proper care and maintenance, aluminum injection molding can reach the million shot mark with multiple resins and in different situations. While there is no single set of guidelines for aluminum tool maintenance, each tool needs a customized maintenance plan that depends on numerous factors.
Some of the most important factors to consider when determining a maintenance schedule for an injection mold include the type of resin, mechanical actions, the presence of coating, and the type of gate.
Several material-related precautions must be practiced to prolong the life of an aluminum injection mold. A Nibore coating is a popular method of preventing door area wear from filled resins. The coating also reduces rust on the tool to further extend tool life.
There are some molding parameters that affect the maintenance of the aluminum mold. Excessive temperatures and pressures during an injection can quickly damage the tool and shorten its life.
As part of a regular maintenance routine, the aluminum mold should be thoroughly cleaned after each run of pieces and resin residue. Often it can run for 5-7 days before you need to clean it, but in some cases, it may need cleaning every 2-3 days for different reasons.
Regardless of the length of the run, aluminum molds must be cleaned after coming off the press and before being stored for the next order. Routine maintenance should also include regular checking for wear and gouges. Regular care also promotes part quality and optimal mold performance. This consideration and the thermal benefits make aluminum the preferred choice for many injection molds today.
Conclusion
In the hyper-competitive business environment we live in today, cost savings and efficiencies, however insignificant, can no longer be ignored. Such competitive forces are finally forcing injection mold operators to move away from the status quo and seek alternatives to traditional methods.
With this, the time for widespread acceptance of aluminum tooling has finally arrived, and thanks to numerous improvements in the classification of aluminum alloys and effective tooling and forming practices, there’s never been a better time to make the transition.
Categories: Technology
Source: SCHOOL TRANG DAI
