Working principle
- Pre-cooling and tempering: Liquid nitrogen (-196 °C) rapidly cools the sample below the glass transition temperature, increasing internal stress and sharply reducing toughness, resulting in a "brittle" state.
- Low-temperature grinding: In a sealed grinding chamber maintained below -150 °C, the tempered sample is subjected to impact/shear through methods such as high-frequency oscillating ball milling, electromagnetic colliders, or rotating blades. Powders as fine as 5 µm or even sub-micron levels can be formed in one step.
- Sublimation drying (optional in-line): For samples containing water, they can first be frozen in the chamber, and then vacuumed to cause the ice to sublimate, achieving "freeze-drying + grinding" in one step, avoiding subsequent secondary moisture absorption.
Process flow
Raw material preparation
Cleaning and drying: After harvesting, guar beans need to be washed to remove impurities and then dried to reduce their moisture content. Shell removal and screening: After drying, the guar beans undergo shell removal. After removing the shells, the seeds are screened and graded to ensure the consistency of raw material quality and uniform particle size.
Crush
Using mechanical grinding equipment, the selected guar bean seeds are processed into fine powder to prepare for the subsequent extraction of guar bean gum.
Extract
The extraction process of guar gum usually involves a combination of chemical and mechanical methods. Guar bean powder is mixed with water to form a slurry, and then an appropriate amount of chemical reagents (such as alkaline solution) is added to facilitate the dissolution and release of guar gum. Through a series of filtration and centrifugal separation steps, the insoluble impurities in the slurry were removed, resulting in a relatively pure guar gum solution.