ふるい分析のふるい分け方法

Sieve analysis

Sieve analyses are indispensable for production and quality control of powdery and granular bulk materials in many industries (including food, pharmaceutical, and chemical). Advantages of sieve analysis include:

• easy handling 
• low investment costs 
• rapid delivery of precise and reproducible results 
• the ability to obtain individual particle size fractions 

Therefore, this method can certainly compete with modern analytical techniques such as laser light scattering or image analysis methods.

To ensure high reproducibility and reliability, the sieve shaker and accessories must meet stringent requirements that comply with (inter)national standards. RETSCH analytical sieves and sieve shakers, as well as all other measuring equipment (e.g., balances) needed for characterizing particle size distribution, are therefore calibratable and are subject to test equipment monitoring as part of quality management systems. For comprehensive process reliability, careful sample preparation is also essential. Only in combination can sieving results be achieved that enable reliable characterization of your products.

Different Requirements, Different Sieving Parameters

The optimal parameter settings depend on the respective material. Depending on the chosen sieve shaker, interval, speed, sieving time, amplitude, or even negative pressure may come into play. Although numerous (inter)national standards and guidelines exist for product-specific sieve analysis parameters, for some materials, suitable parameters must be determined experimentally. We are happy to assist you.

Take advantage of our offer for a free test sieving!

Horizontal sieving:
For flakes, sticks...
-> Long particles stay on the sieve

Vibratory sieving:
Lenghtwise passing of the particles through the pores.
-> Sample seems to be finer

Different sieving methods lead to different sieving results, which can be reflected in the particle size distribution. The diagrams illustrate how the horizontal sieving method and the vibratory sieving method each affect the particle size fractions. While the horizontal method achieves specific sorting through uniform movements, the vibratory sieving method utilizes 3D throwing motions for alternative separation. This results in different particle distributions, clearly shown in the diagrams.

Both times an identical sample of wood pieces was sieved

Sieving is a comparative method. Every particle that can pass through the mesh is accordingly smaller than the mesh size. Sieving usually considers the volume or mass fractions of a sample. Number (Q₀), length (Q₁), or area (Q₂) are usually determined by optical methods (e.g., Camsizer). The problem: Camsizers only capture the measurement parameters without being able to fractionate the sample.

In most cases, the Q₃ dimension (volume) is suitable as a parameter for reliable quantification of particle size distribution. This is because volume is directly proportional to mass and thus the simplest property to use to reliably determine particle size distribution with minimal effort.

Only optical instruments provide information about particle shape

• Dependening on the falling orientation of the particles, it can be detected in different ways.
• Sticks might be detected as spheres or coins. 

光学的粒子特性評価

粒度分析は、光学測定技術を使用して実施することもできる。測定のバリエーションによっては、粒子形状に関する記述も可能です。測定範囲は、システムによって0.3nmから30mmです。粒子の特性評価は、懸濁液、エマルション、コロイド系、粉末、顆粒、バルク材料で実施できます。

当社の姉妹会社であるMICROTRACは、広範なグローバルネットワークと粒子特性評価における比類のないサービスを提供するテクノロジーリーダーです。

RETSCH Sieve Shakers for Reproducible Results

RETSCH sieve shakers cover a comprehensive measurement and application range for your requirements. Different sieving movements and sieve sizes enable you to use the appropriate RETSCH sieve shaker for every material that can be sieved. This ensures you always obtain exact and reproducible results – naturally in accordance with test equipment monitoring (DIN EN ISO 9001ff).