Milling FAQ

Frequently Asked Milling Questions

Most Popular Questions

Who is Quadro?

Quadro invented The Original Conical Screen Mill - the Comil® in 1976. A revolutionary concept at the time, the Comil® has since proven to be one of the most durable and imitated advances in particle processing and size reduction technology available within the marketplace.

How do you ensure quality?

We believe that quality itself is a process that cannot stand still. Continuous improvement continues to be Quadro's focus, with investments in R&D as well as the ongoing refinement of the Comil® design. This is what reinforces Quadro's position as a market leader.

Why is Quadro different?

When you choose Quadro, you can rely on superior engineering and manufacturing capabilities, thereby ensuring maximum uptime and yield. What's more, Quadro products are backed by the highest levels of application and technical support.

About Quadro
What differentiates Quadro from their competitors?

Founded in 1976, Quadro has earned the respect and trust of customers worldwide via our commitment to improve the performance of powder processing and milling operations. We are recognized as manufacturers of specialized process equipment, with over 40,000 machines installed globally as well as decades of experience with problem-solving and product innovation. We set the standards by which others are measured.

How does Quadro support projects globally?

As well as our own IDEX-affiliated regional offices, we are supported by a network of Agents & Distributors, who enable us to provide quality customer service anywhere in the world.

With customers in more than 80 countries, we have both the ability and competency with which to provide whatever level of support may be required.

What testing facilities do you have available?

Process / Application Testing

Quadro® has an extensive database linking to our equipment capabilities with various processes and applications, across a broad range of industries.

Our industry-leading global test facility is located at our Head Office in Waterloo, Canada, and features a full range of the latest lab equipment, a product preparation area and a state-of-the-art analysis area. Testing is also available at our facilities in India and China.

Our knowledge, expertise and facilities are available to evaluate all potential applications.

In addition, our rental fleet enables customers to test their application prior to purchase, thereby ensuring the suitability of our equipment for specific process requirements.

Site Acceptance Testing / Start-up Assistance

We offer full on-site start-up assistance for both purchased and rental machines to enable you to get your Quadro® equipment up and running. This service includes machine set-up, standard IQ/OQ (Installation Qualification/Operational Qualification) Performance Qualifications and Site Acceptance Testing, all of which aid in the validation of your process.

Technical Training

Focused, professional training programs are  available either at our facility or yours for engineers, technologists, operators and maintenance personnel. Training is comprehensive, covering everything from basic equipment operation and best practice to more advanced programs relating to equipment theory, optimization and troubleshooting.

Do you provide a spare parts service?

We have a dedicated aftermarket team who will assist you promptly with any requests for Quadro replacement parts or technical service support in order to keep your equipment running smoothly and efficiently, thereby reducing unscheduled downtime and minimizing impact on production.

Contact our Aftermarket Team to learn more.

Quadro Milling Equipment
What is a Comil?

Quadro Engineering developed, designed and engineered the original cone or conical mill in 1976 for achieving:

  • Uniform size reduction (wet and dry)
  • Sieving/screening
  • Deagglomeration
  • Homogeneous dispersion and mixing

It is now widely recognized as the powder milling technology of choice, respected by global manufacturing leaders across a range of industries including  Pharmaceutical, Food, Chemical and Personal Care/Cosmetics.

The Quadro Comil® delivers optimum process efficiency and product consistency and is fully scalable from R&D to large production volumes with accuracy and repeatability of results.

Typical applications include:

  • Granulation of dry powders
  • Size reduction and milling of wet/soaked products to produce liquid with wet suspended particulates
  • Powders into paste
  • Wet blending
  • Uniform sizing of wet granulation for tablet manufacturing
  • Lump-free homogenous blending to precise size requirements
  • Reducing sticky agglomerates into uniformly-sized powders
  • Product reclaim

What is the difference between an Overdriven and Underdriven Comil?

The Overdriven Comil is the simplest and most economical Comil to maintain and operate.

Available in four models, the Overdriven Comil has the widest capacity range - up to 120,000 lb/hr (54,500 kg/hr). And with the largest number of screen and impeller options available in the market and many specialized tools, almost any process requirements can be achieved.

The Underdriven Comil has a smaller footprint, inline design and extremely short head height, easily integrating into processing environments where space is limited. A large diameter infeed and 'straight through' housing promote unhindered inline product flow for quicker discharge.

With four models to choose from, the Underdriven Comil is scalable in capacity from several ounces to 35,000 lb/hr (15,900 kg/hr). The innovative spacer less design allows for quick changeover of impellers and screens.

Is the Flexsift a screener or a sifter?

The Quadro® FlexSift delivers high capacity, inline security screening and gentle deagglomeration and delumping. This means that only uniform, appropriately sized particles can enter the processing stream. The Quadro® FlexSift effectively deagglomerates materials without damaging the powder particles. Learn more with this overview.

What are the key advantages of a greaseless gearbox?

A greaseless gearbox gives operators the flexibility to modify their maintenance schedules or save money by eliminating oil, lubricator components and system maintenance.

Ensuring that motors are regularly oiled can be costly, cumbersome and, in some applications, not even an acceptable option.

A greaseless gearbox provides the following application benefits:

  • Mitigates product contamination.
  • Low energy input reduces overall product temperature.
  • Noise exposure levels reduced.
  • Easily accessible to perform preventative maintenance.

Milling advice & guidance
How can I achieve a higher milling capacity?

At Quadro® we have a wide range of mill sizes and configurations, from Lab scale to full-size high-capacity machines, inclusive of several Overdriven and Underdriven design models.

Equipment selection will be dependent upon your application and material properties (particle size, moisture content, temperature sensitivity, hardness and other physical and chemical properties). A full evaluation of your requirements will be carried out before recommending the equipment and process that most efficiently and effectively achieves your specific size-reduction requirements.  With a large choice of screens and impellers available, we will have the right solution for you.

The Overdriven Comil has the widest capacity range - up to 120,000 lb/hr (54,500 kg/hr) whilst the Underdriven Comil is scalable in capacity from several ounces to 35,000 lb/hr (15,900 kg/hr).

How can I achieve a tight particle size distribution (PSD)?

Achieving the target particle size at a tight particle size distribution is vital in producing a quality product no matter what industry you are operating in.

Cone Milling(or conical milling), and Hammer Milling are widely used milling methods in the industry. Selecting which milling process to use ultimately depends on the target particle size trying to be achieved.

However, it is not just about the mill, but also the screen type and impeller that are selected too. We help our customers with their options by sharing our Particle Size Card’- this sizing chart ties the target particle size to the mill type and the size of round or grater hole screen required in partnership.

For each type of particle or powder, we also evaluate if any special coatings are needed, and of course look at the RPM and tip speed, to mill your product and achieve the exact PSD you require.

What factors help to optimize particle size?

We have a wide range of screens and impellers available with screen openings ranging between 0.150mm (0.006”) and 38mm (1.5”). Screen types include round and square perforations, wire mesh, and grater (or Conidur) options.

There are dozens of profiled impellers designed to suit specific requirements including basic versions with round, square or beveled arms, as well as more aggressive profiles. Impellers can be further customized with special add-ons and/or finishes.

We will help you navigate through the choices of screens/impellers and after reviewing your mill feeding method, e.g. a pneumatic conveying system, we will match your product with the precise RPM and tip speed necessary to achieve consistent and scalable PSD results.

Once this set of parameters is established, you will not only be able to accurately achieve the PSD you need, you will also be able to quickly scale up from lab-sized equipment to full capacity production utilizing those exact same operating parameters.

What are the key components of fine grinding?

When precision grinding is paramount to your milling process, the Quadro® F10 Fine Grind Model or H20 High Energy Comil® represent a perfect alternative.

With the capability to deliver D90 targets in the 20 – 60 µm range, Quadro’s results provide the highest percentage within target of any fine mill technology and come as a complete station, eliminating the need for auxiliary equipment. These machines give you the capability to control PSDs with an integrated variable-frequency drive for responsive milling speed/torque adjustments, thus ensuring enhanced on-target PSD results.

The Quadro® F10 Fine Grind Model offers unparalleled portability and process flexibility and benefits from low heat production, reduced noise output and low power/air consumption.

The Quadro® H20 High-Energy Comil® achieves PSDs that are 30-70% finer than those achieved by competing conical mills.

Our experienced team will help you with your tooling selection i.e. screen and impeller, and review your mill feeding method, which is key, particularly for the H20 High-Energy Comil®. We will match your product with the precise RPM and impeller tip speed to enable you to achieve consistent and scalable PSD results.

Do you have a specific question that is not answered here?

Type your question for our team below.