What is the best mixer for fragile materials? In industrial production, the handling of fragile materials has always been a great concern for producers. If you need to mix fragile materials, you need to consider more factors; how to ensure the integrity of the material at the same time, to achieve the effect of full mixing? As a professional manufacturer with 17 years of experience, HONGDI Machinery recommends that you consider double cone mixer and drum mixer.
Double Cone Mixer
Working Principle of double cone mixer
Double cone mixer consists of two conical cylinders connected by a cylindrical section in the middle, the whole is a “double cone” structure. Its working principle is based on gravity diffusion and convection mixing, the mixing process relies only on gravity and inertial force, shear force is very low, suitable for fragile materials.
Advantages of double cone mixer
- Low shear: no mechanical agitation, avoiding particle breakage (e.g. tablet coating, brittle catalysts).
- High homogeneity: combination of diffusion and convection, suitable for homogeneous mixing of powders and particles.
- Easy to clean and no pollution: smooth inner wall with no dead space, in line with GMP standard (pharmaceutical and food industry). Material can be stainless steel or coated to avoid metal contamination of sensitive materials.
Disadvantages of double cone mixer
- Viscous materials are limited: if the viscosity of the material is too high, it is easy to be agglomerated or adhered to the inner wall, and the mixing efficiency will be reduced.
- Strict requirements on filling rate: it is suggested that the filling rate is 30%~70%, excessive or insufficient will affect the mixing effect.
Applicable materials of double cone mixer
Coated granules and micro-pills in the pharmaceutical industry; fluorescent powder/magnetic powder in the electronic material; pearlescent pigment/microcapsules in the cosmetic industry; porous catalyst carrier in the chemical industry; and mixing of fragile grains and cereals in the food industry.
HONGDI Machinery Real Case:
With its low shear, high cleanliness and stable mixing effect, the double cone mixer has become one of the preferred equipment for mixing fragile materials and is irreplaceable especially in high standard industries.
Drum Mixer
Working Principle of Drum Mixer
The drum mixer consists of cylindrical drums installed horizontally or inclined and driven by a motor to rotate around a central axis. Its working principle is based on gravity slip and diffusion mixing. Material with the drum wall up to a certain height, due to gravity naturally slides down, forming a continuous “waterfall” flow. The inner wall can be equipped with baffles or paddles to enhance the tumbling and diffusion effect of the materials.
Advantages of Drum Mixer
- Low shear force: only rely on gravity sliding and particle friction, suitable for fragile materials (such as puffed food, nuts).
- Simple structure: no complex internal components, easy to clean and maintain.
- High capacity for large particles: suitable for brittle particles with a diameter of several millimeters to tens of millimeters (e.g. cereals, tablets).
- Customizable:Interior walls can be retrofitted with baffles or coatings (e.g., polyurethane) to minimize material adhesion or abrasion. Rollers can be customized for liquid spraying, powder spraying, drying, etc., which is very suitable for food processing flavoring
Disadvantages of Drum Mixer
- Filling rate limitation: 30%~50% filling rate is recommended, too much will reduce the fluidity.
- Large floor space: Due to low filling rate, large drums require large installation space, especially for continuous production lines.
Applicable materials of Drum Mixer
Puffed snacks, nuts, grains in food industry; tablet granules, coated micro-pills in pharmaceutical industry; puffed feed granules, seed coating in agriculture and feed industry; pearlescent pigments, loose granules in daily chemical industry.
HONGDI Machinery Real Case:
With its simple structure and low-damage characteristics, the roller mixer has become a classic choice for mixing large and fragile materials, especially widely used in industries that do not require harsh mixing uniformity.
Since the double cone mixer and drum mixer can mix friable materials, then in the actual production of how to determine which I am more suitable for the choice of mixer? Take a look at HONGDI Machinery’s experience treasure trove.
How do you make a choice?
1. According to the material characteristics to choose
Particle size:
- Drum mixer: priority for large particles (such as nuts, puffed feed).
- Double cone mixer: priority selection of small particles or powder (such as pharmaceutical powder, nanomaterials)
Degree of friability:
Both are suitable for friable materials, but the double cone mixer is better at ultra-brittle fine powders (e.g., phosphor), and the drum mixer is suitable for large particles of friable materials (e.g., potato chips).
Adhesion:
- Drum mixer: baffles or coatings can be added to reduce wall sticking, suitable for slightly sticky (e.g. chocolate coating).
- Double cone mixer: closed structure is suitable for dust control, but high viscous materials are easy to agglomerate.
2. According to the production needs to choose
Production capacity:
- Drum mixer: suitable for medium and large continuous production (such as feed, food industry).
- Double cone mixer: suitable for small and medium-sized high-precision batch production (such as pharmaceuticals, electronic materials).
Hygiene standards:
- Drum mixer: open and easy to clean, suitable for food and feed industry.
- Double cone mixer: closed anti-pollution, suitable for pharmaceutical, chemical high cleanliness scene.
Mixing uniformity requirements:
- Drum mixer: uniformity requirements ≤ 5% difference is applicable (such as seasoning coating).
- Double cone mixer: preferred when the uniformity requirement is ≤2% difference (e.g. mixing of active ingredients of drugs).
3. According to the industry and cost to choose
- Pharmaceutical/electronics industry: priority double cone mixer (high uniformity, anti-pollution).
- Food / feed industry: priority drum mixer (large capacity, low cost).
HONGDI Machinery suggests that: in the selection of machines need to take into account the characteristics of materials, production scale, industry norms and costs, if necessary, through a small test to prove the mixing effect and breakage rate. Or contact us, our professionals will be based on your needs for you to customize the right program.