No matter what parts you are creating, working with metal can be a tedious process. However, there are several ways to expedite production, and one of those ways is to use releasing agents.
Incorporating releasing agents into your manufacturing process can help produce high-quality parts, extend the life expectancy of molds, and even shorten the casting cycle time.
There are many environmental and economical requirements that releasing agents must meet before they can be used.
In this post, we will go over everything you need to know about using releasing agents in your production process.
What Are Releasing Agents?
Releasing agents are water-based solutions that are used to form a barrier between the casting and the metal material. What this does is cool the casting and prevent damage. A good example would be aluminum.
Casting an aluminum part requires temperatures up to 932°F (500°C). Without a releasing agent, high temperatures like this can cause extreme wear on the casting and shorten its lifespan drastically.
To prevent damage to the casting, a releasing agent made of wax and water emulsion is first sprayed onto the casting surface. The water will evaporate, cooling the casting in the process. Meanwhile, the wax remains on the surface of the casting and creates a barrier.
The remaining wax prevents the metal from adhering to the casting, and it also helps the finished part be easily removed. Please note that the releasing agents work best when they are used between every casting cycle.
Releasing agents do so much more than cool down the mold and help metal pieces pop out. These solutions also contain other complex properties that make the production process go a lot faster.
They remain chemically stable at high temperatures, they have a good wetting capacity, and they comply with environmental and economical policies. One example of this would be that releasing agents must not clog the nozzles or tubing systems of spraying machines.
If the realizing agent is water-based, then it also contains chemical additives such as biocide that keep the solution stable at all times. Biocide helps to protect the solution itself from decomposition due to microbiological assault. This helps to prevent corrosion inside the castings.
The best releasing agents also need to be resource-efficient. That means that each new casting cycle should only require a small amount of the releasing agent solution. Micro-spraying technology is preferred.
Not only does it cut down on material waste, it also helps to protect the environment and reduce water waste.
Difference Between Water-Based and Water-Free Solutions
While many releasing agents are water-based solutions, there are a few other water-free solutions to consider as well. For the purpose of die casting, water-based and water-free releasing agents can be separated into three unique groups – oils, waxes, and R-polysiloxanes.
Group 1 is made up of raw (ester) oils, mineral oils, semi-synthetic oils, and fully-synthetic oils. The main benefit of using an oil-based releasing agent is its ability to spread evenly across a casting.
Another beneficial property is that ester oils affect the CO2 balance favorably. The disadvantage that some metalworking facilities find with oil-based releasing agents is that they have lower temperature thresholds. The maximum casting temperatures can exceed the limit of the oil-based solution and cause it to break down.
Group 2 consists of synthetic wax-based releasing agents. These are manufactured using crude oil. The main benefit to wax-based releasing agents is optimal adhesion to the casting and the promotion of enhanced molten metal flow.
In other words, these agents stick to the casting and allow the extremely hot metal to flow into the mold smoothly. As a result, the metal is easier to remove from the casting once the process is complete. Another benefit of using wax releasing agents is that they can withstand higher temperatures than oil. The downside is that they can leave behind wax deposits.
Group 3 is made up of the newest addition to the relating agent lineup known as R-polysiloxanes. These adhere very well to the castings, and they ensure that molten metal flows into the mold smoothly.
They also allow for the production of high-quality metal pieces that can be easily removed from the casting even while the temperature is still high.
R-polysiloxanes releasing agents leave behind some residue as well, but the deposits are caused by decomposition. That makes the residue easier to remove than the wax-based releasing agents.
What Is Micro-Spraying?
As we mentioned briefly before, micro-spraying is the preferred delivery method for releasing agents. When a releasing agent is applied to a casting, evaporation causes the casting to cool rapidly.
This can result in cracking along the surface of the mold, which will cause the quality of the metal products to plummet. We call this the cooling effect, and it can be minimized by selectively applying small amounts of water-based releasing agent solutions.
Micro-spraying does just that. It applies only the necessary amount of releasing agent solution to the casting. This reduces the thermal load, cuts down on production costs, and helps to enhance the lifespan of the casting.
Another added benefit to micro-spraying is that it also prevents the buildup of residue, which results in high-quality products.
Lubricants and Cleaning Solvents
Releasing agents are not the only liquids that you will need to run a productive metalworking shop. Every machine on the floor needs to be regularly lubricated with the appropriate oils, and a cleaning schedule needs to be kept.
Finding the right lubricants and cleaning products can be challenging if you have a lot of different metalworking machines. That’s why we provide guidance to enable you to find the right ones. Check out this blog for lubricant information, and take a look at this one for cleaning solutions.
Still have questions? Get in touch with our team of experts here at Dake today.