Cutting Grinder

What is the Cutting Grinder?

A cutting grinder shears material with rotating blades against fixed counter knives. It suits soft, fibrous, elastic and moist samples that impact grinders cannot break cleanly, such as plants, food and polymers.

Overview

A cutting grinder uses a rotor fitted with hardened blades that pass close to fixed counter knives in the chamber, cutting the sample rather than crushing it. The cut material falls through a sieve or screen that sets the final particle size, and is collected in a vessel. The cutting action handles fibrous, soft, elastic and moist materials that would smear or jam in an impact mill, and produces a reasonably uniform product. Rotor speed, blade design, screen size and feed rate control the result. A push ram or gravity feed delivers the sample to the rotor, and the chamber can be removed for cleaning between samples.

How does it work?

Grinders reduce particle size by different mechanisms. Mortar grinders rub the sample between a pestle and a bowl, producing a fine product with little contamination when agate is used. Cutting grinders shear material between rotating blades and fixed counter knives, which suits fibrous, soft and elastic samples. Disc grinders press material between rotating discs and give a controlled particle size. Rotor beater grinders use rapidly moving beaters to shatter brittle and medium-hard material, and cryogenic grinders embrittle the sample with liquid nitrogen before impact so that heat-sensitive or sticky samples grind cleanly. Particle size, throughput and contamination depend on the mechanism, the tool material and the grinding time.

What are the key features?

• Rotor blades cutting against fixed counter knives
• Interchangeable screens for particle size
• Handles fibrous, soft and elastic samples
• Removable chamber for easy cleaning
• Push ram or gravity feed option

What are the technical specifications?

A typical cutting grinder configuration offers final particle size of 0.5–10 mm, screen dependent, sample capacity of Up to 5 L per batch, rotor speed of 200–3,000 rpm, blade material of Hardened stainless steel, screen options of 0.5, 1, 2, 4 mm and feed type of Gravity with push ram. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Cutting Grinder is used in plant and agricultural material grinding, food and feed sample preparation, polymer and rubber sample cutting and waste and biomass processing. Across the wider Grinders class, laboratories also deploy it for food and feed sample homogenisation, soil, sediment and rock preparation and plant and biomass material grinding.

Which standards and certifications apply?

Relevant standards and methods include ISO 3310-1, ASTM E11, ISO 2591-1, EPA 3050B and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Clean the grinding set thoroughly between samples to prevent cross-contamination, and pre-grind a portion of the sample or an inert material to condition the surfaces when trace work demands it. Do not overfill the grinding chamber, since excess sample reduces efficiency and raises temperature. Allow heat-sensitive samples to cool, or use cryogenic grinding, to avoid loss of volatiles and changes in composition. Inspect blades, discs and pestles for wear, and replace them on schedule to keep particle size reproducible. Follow the electrical safety requirements of IEC 61010-1 and, for cryogenic work, handle liquid nitrogen with appropriate ventilation and protection.

How do I select the right Cutting Grinder?

Select a cutting grinder for soft, fibrous, elastic or moist samples. Confirm the screen range gives the required particle size and that the rotor and blade design suit the material. In an RFQ state the sample type and moisture, capacity per batch, target particle size and cleaning requirements.

How does it compare with other Grinders variants?

Choose a grinder according to the sample properties and the required final particle size. Hard, brittle material suits a disc or rotor grinder; fibrous, soft and elastic material suits a cutting grinder; and fine, homogeneous powder for trace analysis favours a mortar grinder with an agate set. Heat-sensitive, sticky or volatile samples suit cryogenic grinding with liquid nitrogen. Confirm the final particle size range, sample capacity and throughput, and that the grinding set material does not introduce the elements being analyzed. Consider cleaning between samples, noise and dust, and whether the method requires a defined particle size distribution.