Injection moulding dates back to the 1920s when a man named John Wesley Hyatt used celluloid (an early plastic) in a mould and used heat and pressure. This was the first injection moulding machine, and out popped the first ever injection moulded part. It wasn’t until the 1940s, when World War II happened, that everyone scrambled to try and find efficient ways to mass-produce parts, and injection moulding came back to the forefront.
Today, injection moulding is the unsung hero of the manufacturing world. Most everyday plastic parts around your house and workplace are injection moulded, from your toothpaste cap to the dashboard in your car. When injection moulding entered the game, it didn’t just change it; it became the MVP (most valuable player).
So, what is an injection mould made from? Traditional mould materials for injection moulding have evolved over the years. Now, your choice of mould material depends on various factors such as the types of plastic being used, production volume and desired characteristics of the final product.
The most common choices for injection moulded moulds are steel alloys and aluminium alloys. At Protolabs, we tend to lean towards Aluminium moulds for several reasons, which we will go into in more detail shortly, but to summarise, aluminium moulds are lighter, offer faster heat dissipation, and are cost-effective for lower production volumes and prototyping. If you wish to use our on-demand production service and are worried about the longevity of your mould, please bear in mind that with our production offering, we also provide a lifetime guarantee for your tool. Quite simply, we will fix or replace as necessary.
What makes Aluminium Moulding a popular choice?
Unsurprisingly, the popularity of aluminium moulding is a result of its endless advantages.
Lightweight – Aluminium is significantly lighter than the traditionally used steel. This makes it easier to handle and change, which is particularly advantageous during setup and maintenance operations, reducing labour and equipment requirements.
Rapid Cooling – Aluminium has excellent thermal conductivity. This means it can absorb and transfer heat more efficiently than other materials. Rapid cooling is crucial in injection moulding; it not only shortens cycle times, but it also enhances productivity and improves the overall efficiency of the process.
Cost-Efficiency – Aluminium moulds are more cost-effective than their steel counterparts. Whilst aluminium may have a higher initial cost, its lower weight and faster cooling times can lead to massive cost savings over the lifetime of the mould, especially in lower production volume scenarios.
Improved Cycle Times – The combination of aluminium being lightweight and its superior thermal conductivity all leads to reduced cycle times, increasing overall production output
Enhanced Surface Finish – Aluminium moulds can provide a smoother surface finish due to a number of reasons, including their smooth surface, high machinability, and thermal conductivity.
Durability and Longevity – Whilst Aluminium is not as hard as some steel alloys, advancements in alloy formulations and treatments have improved the durability of aluminium moulds.
Corrosion Resistance – Aluminium naturally forms a protective oxide layer that makes it corrosion-resistant. This is beneficial, especially in environments where exposure to moisture or corrosive substances is a concern.
Precision and Tight Tolerances – Aluminium moulds can be machined with high precision, producing parts with tight tolerances. It is essential for applications where precise dimensions are critical.
So, why is aluminium moulding gaining popularity? The answer is all of the above, mixed with the fact that constant enhancements are being made, making aluminium a preferable option. Also, with consumer demands shifting towards sustainable practices, environmental considerations come to the fore, and aluminium is highly recyclable.
What are the applications and industries of aluminium mould tools?
The versatility of aluminium moulds makes them suitable for a range of applications and industries, particularly where cost-effectiveness, lightweight construction, and rapid production are prioritised. Whilst they may not be suitable for all scenarios, advancements in aluminium alloys have expanded their use across diverse manufacturing fields such as aerospace, automotive, medical, electronics, packaging and more.
What are the key considerations and limitations of aluminium mould tools?
There are some things to consider when using aluminium moulds, such as their limited hardness and heat resistance. This can be a disadvantage when the mould needs to withstand high pressures or prolonged exposure to high temperatures.
Other limitations can include their wear and durability and, consequently, the increased need for maintenance or replacement.
Aluminium moulds may also not be suitable for certain processes such as injecting a mould with abrasive or corrosive materials. Also, their compatibility with certain materials, can lead to issues such as chemical reactions or poor release characteristics.
In summary, whilst aluminium moulds have many benefits, it is also important to consider their limitations.
What is needed for proper maintenance of aluminium mould tools?
There are many things you can do to ensure aluminium moulds are properly maintained and last as long as possible. Things to be mindful of are regular cleaning, inspection for wear and damage (to ensure further damage and deformation are prevented early), lubrication (to prevent friction wear and ensure smooth operation), proper storage, correct handling (during installation, removal and maintenance), temperature control, surface protection, correct injection parameters (avoid excessive wear and stress by optimising parameters), documentation (keeping a record of maintenance or issues observed), timely repairs and ensuring operators receive the correct training.
By implementing these maintenance practices, the lifespan and performance of an aluminium mould tool can be maximised and contribute to the overall product quality and operational efficiency.
So, are you sold on aluminium tools? If you have any further questions about aluminium moulds or any of the tools we use at Protolabs, please do not hesitate to contact us and speak to one of our Sales representatives or applications engineers on +44(0) 1952 683047 or email us [email protected]