Frequently Asked Questions

Can the Aximill process wet materials?
This depends on the material. For example some minerals (ie. zeolite) can be processed to a fine, dry powder with a starting moisture content of up to 40 percent. Fibrous materials such as wet grass can also be processed to a dry powder. Similarly, vegetables can be processed to powders, depending on their sugar content, method of preparation (eg. grated or cubed)and the humidity of the processing air or gas. But, milling fresh vegetables is basically milling water.

Drying vegetables conventionally with warm air results in a scale of diminishing return, where the first 50 to 60 percent of moisture can be removed quickly, while the remaining moisture can consume up to 80 percent of the total drying energy. However, after the initial conventional drying step, the Aximill is the more efficient way of removing the remaining moisture at low temperatures, because the milling process exposes a large surface area of the material to the aforementioned air or gas. This drying is a side-effect of the milling process.

What temperatures are products subjected to in the Aximill?
This depends on the moisture content of the material. Products with a high moisture content tend to remain cool because of the latent heat of vaporisation. Because the Aximill has efficient water jacketing and the cooling water can be chilled, the product can generally be kept under 45 degrees C.

On the other hand, if the water flow is turned off, and the machine is used to produce a very fine product, temperatures of over 100 degrees C can be achieved.

Can the Aximill be used as a spray dryer?
No. The Aximill is more suited to products that require micronising, as well as drying.

How difficult is the Aximill to clean?
The smaller models require little physical effort to dismantle and clean, and special tools are provided to simplify the task. Typically, the Aximill 250 can be stripped and reassembled in one hour. As the models get bigger, the time increases. However, spray rings can be fitted, and the machines can be hot water washed internally without dismantling.

What is the smallest sample volume that can be run through an Aximill?
In a laboratory environment, in order to break samples down for analysis, volumes as small as 50 cc give good results in the smallest model of Aximill (the Aximill 250). However, if the aim is to get the smallest possible particle size, there are always a few tailings at the end of the run that are larger. There has to be a large enough volume in the machine for efficient micronization to occur.

I regularly use broadbean flour in my kitchen. It contains unsightly brown flecks and particles which I am told is the skin of the broadbean, which customers don't like. Can Aximill solve this problem?
Yes. We at Aximill are able to mill the flour so fine that the skin is undetectable. We were asked the same question about millet, and solved the problem the same way.

Can the Aximill be used to dry fresh herbs?
Yes. To date we have processed a wide spectrum of herbs. The important thing is to not overwork the herb. There is a limit to how fine some herbs can be milled before losing essential oils and volatiles. For example, fresh bayleaf can be milled to approximately 60 micron without loss of aromatics, while retaining a beautiful colour and fresh flavour.

To have your questions answered, please contact Aximill

Page last updated: 15 April 2015