From liquid wax to candle –
the stirring process as the key process

Our latest case study is about what is probably the most comfortable light in the world. Especially now, as we approach Christmas, we like to remember the warm glow of a candle and one or the other finds a place on our tables and shelves.

Our customer, the Barmherzigen Brüder Saffig, makes candles by hand. The wax is heated, colors and essential oils are added, and then the wax is poured into jars. But what is the big challenge when pouring candles?

Unwanted air inclucions

The head of production, Stefan Sausen, explains: “The special thing [when stirring wax (editor’s note)] is that stirring is guaranteed without air being introduced. And that with a wide variety of filling levels in the wax container.”

Air inclusions are not only a problem for waxes, but also, for example, for paints for further processing. In the case of wax, the air inclusions are undesirable from a purely visual point of view. In addition, the customer wants to buy 100% homogeneous wax. The air pockets therefore significantly reduce the quality of the product. For the Barmherzige Brüder, however, the biggest problem lies elsewhere:

Essential oils are added to the candles. If the air pockets rise to the surface of the heated wax and burst open there, the essential oils spread at the production site and not just at the customer’s.

The stirring process as a key process

Once the air pockets have formed, it is very time-consuming to get rid of them. Therefore, the only option is not to let them arise in the first place. And this is where the secret lies in the upstream stirring process: Only gentle, constant stirring that is adapted to the fill level in the container and the medium prevents air from being drawn in from the surface. The wax is removed via an outlet tap on the bottom of the mixing tank.

Since using the PTM agitator on a traverse, the quality of the wax has been impeccable and air pockets have not occurred since then. The essential oils are also no longer released during the production process. Our customer can adjust the stirring behavior at any time directly on the agitator and adapt it to changing circumstances.

Homogeneous temperature

Thanks to the stable, continuous stirring behavior of the agitator, Stefan Sausen also maintains the right temperature in the entire wax container: “The wax container is quite high… but with the funnel we get circulation from top to bottom, so that we have a temperature difference in the kettle of below 1° Celsius. Absolutely perfect.”

And Stefan Sausen tells us another advantage of our agitator: “As a workshop for disabled people, noise emissions were extremely important to us.” In contrast to other drive types, such as electric motors or vane motors, pneumatic PTM agitators are quiet and can be used in noise-sensitive environments without any problems.

Advice & contact

Would you also like advice on your application in order to achieve your perfect mixing result? In our test laboratory we simulate your application under real conditions. And then put together your solution from our large product range. You can find direct contact to us here.