Technické správy
Mletie
Powerful Cutting Mill
The SM 300 excels especially in the tough jobs where other cutting mills fail. It has a freely selectable speed range from 700 to 3,000 rpm with high torque. The mill is convenient to operate and easy to clean. Reliable and extremely efficient sample preparation in the laboratory is now guaranteed with the SM 300.
Perfect Homogenization with the GRINDOMIX GM 300
The diversity of foodstuffs with their often very different product properties represents a real challenge for food testing laboratories. Before the actual analysis, the sample materials – which can vary strongly with regards to hardness and moisture – need to be homogenized and reduced to a sufficiently small particle size. RETSCH’s GRINDOMIX knife mills are the ideal tools to meet the complex requirements of sample preparation of food. The model GM 200 has proven itself for the homogenization of smaller sample volumes of up to 700 ml. For larger volumes RETSCH now offers the new GRINDOMIX GM 300 with a grinding chamber volume of 5,000 ml.
Preparation of Elastic Plastics for the Detection of PAH
Polycyclic aromatic hydrocarbons, short PAH, are usually a by-product of combustion and can be found, for example, in cigarette smoke or oil-based products. Mineral oil containing PAH is often used in rubber products as plasticizer, especially in black-coloured products such as car tyres, rubber grips of tools or rubber shoe soles. It was discovered that some polycyclic aromatic hydrocarbons are carcinogenic, so that maximum permissible values have been determined for the concentration of PAH in consumer products.
Size reduction of elastic plastics with volatile components
Neutral-to-analysis sample preparation for the detection of PAH and phthalates
Using the CryoMill for samples with volatile substances
For the size reduction of many materials it is more suitable to use a cryogenic mill than a laboratory mill which operates at room temperature. The sample is embrittled by liquid nitrogen which improves its breaking behavior when submitted to impact, pressure and friction; moreover, volatile components of the sample are preserved. The RETSCH CryoMill is not only the most modern and safest cryogenic mill in the market, it also provides excellent grinding results.
Cutting Mill SM 300 - Refinement of a well-proven grinding principle
Cutting mills are used in many different areas of sample preparation for subsequent analyses. Typical applications include the size reduction of secondary fuels, the processing of biomass for renewable energy research, the control of products in the context of RoHS and WEEE regulations or the recovery of precious metals – the variety of sample materials is huge.
Paddle Blender PB 100 for microbiological food testing
The Paddle Blender PB 100 is designed for sample preparation for subsequent microbiological food testing. The homogenization of the sample is produced by a combination of mechanical effects. The paddles crush the sample during the first 3 seconds with maximum speed; this is complemented by a peristaltic mixing of the sample which guarantees optimum sample preparation (patented SMASH effect).
Renewable raw materials are gaining ground
The representative sample preparation of plants requires experience
Toxic analyses of biological samples
Cryogenic grinding facilitates the preparation of animal samples
Efficient Grinding at –196 °C
RETSCH’s New CryoMill for Safe and Reproducible Grinding with Liquid Nitrogen
Milling of Samples in a Fertilizer Laboratory
The fertilizer laboratory of the Division of Regulatory Services at the University of Kentucky uses the Retsch ZM 200 ultra centrifugal mill for milling fertilizer samples.
Tracking Down Fake Cashmere
Cashmere wool is the best known precious wool. It is won from the cashmere goat which originates from the high mountain region of the same name. Due to its properties such as softness and warmth, cashmere wool gains more and more popularity in the manufacture of clothing. Genuine cashmere is won solely from the goat’s downy hair and must possess a certain hair structure with an exactly defined length and thickness.
Preparation of Soil, Sewage Sludge and Sediment Samples in a Wastewater Treatment Laboratory
The preparation of a mixture of organic and inorganic samples holds some difficulties: whereas sand, clay and stones can usually be ground to homogeneous samples with suitable laboratory mills, the high energy input can cause samples with organic components such as fat or starch to cake. Carsten Bunn, a laboratory technician at the waste water treatment laboratory BRW, has to deal with this problem every day. He treats samples which are taken from the sand traps of the wastewater treatment plants and consist of exactly that mixture. The sediments of household and industry waste water not only contain sand, clay or leaves but anything that people nowadays dispose of through the sewer system: cellulose, hair and especially food residues.
Fast and Reproducible Sample Preparation with a Vibratory Disc Mill
The Vibratory Disc Mill RS 200 from Retsch is used for the quick, loss-free grinding of hard, brittle and fibrous materials to analytical fineness.
Cement - representative sample preparation is important
To produce high-quality cement, the mineralogical and chemical composition of raw materials as well as intermediate and finished products has to be determined. At each stage of the production, samples have to be taken, processed and analysed to ensure quality control without gaps. Retsch offers a range of instruments that are used for sample preparation during the complete production process, from the quarrying of the raw materials to the final product. The typical sample preparation process involves preliminary size reduction, sample division and fine size reduction before the sample can be submitted to further analyses....
Green Chemistry in the Lab
Mechanochemistry is a very effective method to carry out syntheses without solvents and by-products. The technical literature describes a great number of reactions where a conversion of 100% is achieved. A precondition for the establishment of mechanochemistry in the industrial sector is the availability of suitable laboratory mills. A decisive factor is that – similar to conventional preparative chemistry – ambient parameters such as pressure and temperature can be documented and monitored. The Planetary Ball Mills and Mixer Mills from Retsch fulfill these requirements.
Tracking down hazardous substances (RoHS/WEEE)
Preparing electronic waste for obtaining representative analytical samples.
A solution for converting an electrical appliance into a meaningful analytical sample is described using a remote-controlled toy car as an example.
Size reduction within the context of sample preparation
In general “size reduction” is taken to mean the disintegration of solid substances by mechanical forces without altering their state.
Sample Preparation of Electronic Scrap in the Context of RoHS and WEEE
Since August 2004 new EU directives for the disposal of used electrical and electronic appliances as well as the restricted use of certain hazardous substances in these devices have become effective.
Making Whole Cell Extract of Saccharomyces cerevisiae
Preparation at the Courtesy of the Staley Lab at the University of Chicago
Consistent Milling on a Nano Scale
Planetary ball mills are helping scientists and engineers advance nanotechnology by providing a consistent way to produce nanoscale powders.
Bigger is not Better
There is a trend towards smaller samples that have more controlled particle size and yet remain representative of the material being analyzed.
Increasing the development efficiency of ceramic materials
The development of high-performance ceramics is determined by a large number of influencing factors. In addition to material-specific aspects, such as the chemical purity of the initial raw materials, particle size reproducibility and uniformity of particle morphology, production-specific factors also determine the final properties of ceramics.
Sample Preparation of Plastics for X-Ray-Fluorescence Analysis
The elemental analysis of plastics has become more and more important. EC directive 91/338/EWG regulates the ban of cadmium in PVC, EC directive 94/62/EC defines limits for cadmium, lead, chromium and mercury in packing materials and EC directive 2000/53/EC defines limits for the same elements in end-of-life vehicles. This has created a strong need for a rapid and reliable testing method.
Cryogenic Preparation of Sample Materials
Within the context of sample preparation, size reduction plays an important role as it has a substantial influence on the results of the subsequent analysis. If the particles are too coarse or non-homogeneous the results of the analysis may turn out to be incorrect, especially if there is only a very small amount of sample material which represents the total amount.
Cryogenic disruption of yeast cells
The MM 301 can be used for cell disruption applications. In this case, yeast cells were embrittled with liquid nitrogen.
Sample preparation of electronic scrap with SM 2000 and ZM 200
RETSCH mills in the context of RoHS and WEEE
Reliable sample preparation in food technology
An efficient sample preparation procedure for rapid, reliable and reproducible analytical results is becoming increasingly important today. Ever more stringent requirements are being set both in research and production, e.g. for product monitoring and quality control.
Analysis of cadmium in plastics
In recent years, mass media have focused on the topics of the environment and environmental conservation. With the advancement in scientific technology, resource development has progressed.
Sample Preparation of Solid Materials for the XRF-analysis
X-Ray fluorescence is one of the most versatile methods to determine elements in a sample. The material is exposed to x-rays that cause each element to emit its own unique fluorescent x-ray. The subsequent analysis of the results is based on comparisons to standard samples with given chemical composition.
The Representative Sample Preparation of Waste
Now that a certain environmental awareness has developed in the population over the past few years, our efforts are geared not only to avoiding waste, but also to reducing the mountains of waste which still arise by means of raw material recovery and the reintroduction of secondary raw materials into the industrial cycle.
机械研磨的方法合成纳米晶体Al-Si-Fe-X合金粉末
Mechanical milling and field assisted sintering consolidation of nanocrystalline Al-Si-Fe-X alloy powder
通过声波显微镜研究纯金属钛粉和钛粉以及铁-铜合金的纳米晶体机械性能
Determination of mechanical properties of nanocrystalline materials by means of acoustic microscopy : application of pure elements (Fe and Ti) and alloys (Fe-Cu)
Die neue Power Generation
Planeten-Kugelmühlen haben seit jeher einen festen Platz in der täglichen Laborpraxis zur Feinzerkleinerung unterschiedlichster Materialien. Neben dem Mischen und Zerkleinern hat sich in den letzten Jahren auch im mechanischen Legieren z.B. thermoelektrischer oder hochkoerzitiver Materialien ein weiteres Anwendungsgebiet ergeben.
Effektive Zerkleinerung mit Schlagrotormühlen
Die reproduzierbare und kontaminationsneutrale Probenaufbereitung spielt eine entscheidende Rolle im Hinblick auf zuverlässige Analysenergebnisse. Ein wichtiger Schritt ist die Homogenisierung und Zerkleinerung der Probe auf eine definierte Feinheit mit Hilfe von Labormühlen. Neben der Zerkleinerung auf Analysenfeinheit können die Schlagrotormühlen von Retsch auch für die Kleinproduktion, Herstellung von Musterchargen und in der Forschung und Entwicklung von neuen Produkten eingesetzt werden.
Herstellung von Nanopartikel mit der Planeten-Kugelmühle
Die Herstellung von Nanopartikeln, deren Größe im Bereich von 1 Mikron und kleiner liegt, ist in vielen technischen Bereichen immer mehr auf dem Vormarsch, denn sie ermöglichen die gezielte Veränderung von Materialeigenschaften.
Los especial del pigmento
Debido a la ilimitada variedad de colores y texturas que ofrencen los recubrimientos en polvo; muchos de los nuevos recubrimientosde aplicación especifica se crean en el laboratorio en pequeñas cantidades que luego se le envían al cliente para su aplicación y aprobación.
Molienda ultrarrápida y ultrafina
El nuevo molino ultracentrífugo ZM 200 de RETSCH es un molino de rotor no sólo extremadamente rápido y cuidadoso con el material molido, sino también de uso universal gracias a su amplia gama de accesorios.
Perfekte Homogenisierung von Lebensmittelproben
Nahrungsmittel treten in sehr unterschiedlichen Formen und Konsistenzen auf und sind in der Regel inhomogen. Für die Analytik werden jedoch homogene und repräsentative Proben benötigt, um aussagekräftige Ergebnisse zu erzielen. Für diese Aufgabe sind die Messermühlen Grindomix GM 200 und GM 300 von RETSCH die idealen Instrumente.
Preparación de muestras altamente heterogéneas para el control de calidad
El agotamiento de los recursos y el aumento del precio de los combustibles primarios tales como el petróleo, el gas o el carbón han obligado a la industria del cemento a buscar fuentes alternativas de energía. Otro factor contribuyente es, sin duda, el comercio de emisiones que hace todavía más rentable el cambio a fuentes de energía con un balance neutro de CO2, en su mayoría combustibles no fósiles. En los últimos años, se ha registrado un incremento en el uso de fuentes de energía alternativas, especialmente por aquellas industrias con una alta demanda energética. En consecuencia, viene ganando cada vez más importancia el empleo de combustibles secundarios o alternativos, que en su mayoría son extraídos de residuos urbanos e industriales – es decir, residuos urbanos que no han podido ser recuperados ni reciclados.
Probenvorbereitung von Böden
In Industrienationen mit hoher Besiedlungsdichte und einem begrenzten Angebot an Industrie- und Gewerbegebieten unterliegt die Nutzung von Gebäuden und Flächen einem dauerhaften Wandel. Daher sind Bodenuntersuchungen für Investoren, Behörden und Privatpersonen unumgänglich. Umweltanalytische Untersuchungen bilden die Basis, um Gefährdungen aufzuzeigen und damit Menschen und eingesetztes Kapital zu schützen. Bei SGS Institut Fresenius in Herten werden bis zu 400 Bodenproben am Tag aufgearbeitet und analysiert. Hierbei wird sehr genau darauf geachtet, dass geltende Normen und Verordnungen eingehalten werden. In Deutschland gilt die BbodSchV, wobei die Analytik auch auf die Vorschriften anderer Länder angepasst wird.
Thermoelektrische Wandler - Eine Technologie aus der Raumfahrt
Mechanisches Legieren von thermoeletrischen Materialien für die Raumfahrt, entwickelt vom Institut für Werkstoff-Forschung in Köln, Arbeitsgruppe "Thermoelektrische Materialien".
Von der Probe zum Pressling – Probenvorbereitung von Feststoffen für die Röntgenfluoreszenz
Aufgrund der Einfachheit der eigentlichen RFA-Messung wird häufig der Aspekt der optimalen Probenvorbereitung übersehen, was sich dann in mangelnder Reproduzierbarkeit bis hin zu falschen Ergebnissen auswirken kann.
What Hair Reveals
The detection of illegal drugs and pharmaceuticals plays a role in various fields, for example in forensic science, road traffic accidents, in competitive sports or at the workplace. Chemical substances can be detected in blood, saliva, urine and in hair. Hair has the great advantage of storing the substances for a long period, which means that detection is still possible several months after consumption of the drug. In addition to the detection of drugs, hair samples are also used for DNA analysis as well as for the analysis of heavy metals and minerals.
Zerkleinern von Proben in einem Düngemittellabor
Für die genaue und reproduzierbare Analyse von Düngernährstoff, Spurennährstoffen und Spurenmineralien ist das vorherige Zerkleinern der Probe unverzichtbar. Das Düngerlabor der Division of Regulatory Services der University of Kentucky verwendet zum Homogenisieren der Proben die Ultra-Zentrifugalmühle ZM 200 von Retsch.
Zusammenspiel der Kräfte
Planeten-Kugelmühlen ermöglichen mechanisches Legieren dank ihrer hohen Zerkleinerungsenergie
Mechanisch legierte Werkstoffe haben schon längst ihren Einzug in die moderne Werkstofftechnik gehalten. Viele neue Werkstoffe und Werkstoffkomposite wurden in den letzten Jahren durch intensive Forschung entwickelt und werden bereits industriell hergestellt. Mechanisches Legieren ist ein gängiges Verfahren, um Werkstoffpaarungen oder Komposite zu synthetisieren, die auf konventionellem Wege nicht realisierbar wären, wie z. B. das Verbinden von Natur aus unmischbarer Legierungspartner. Das Werkzeug der Wahl dafür sind Planeten-Kugelmühlen.
Preosievanie
Sieving of agglomerating powders with the air jet sieving machine AS 200 jet
Air jet sieving is usually the method of choice for dry sieving of materials with particle sizes below 40 microns. However, it is also a faster alternative to vibratory sieving of materials of up to 250 microns.
Separation of large sample volumes with the AS 450 control
Particle analysis of large quantities of bulk goods is usually done by vibratory sieving. In most vibratory sieve shakers in the market the sieve stack is mounted
on springs which oscillate vertically. However, to evenly distribute the material
over the entire sieve surface, the so called 3D vibratory sieving as it is used in the AS 450 control is the most suitable method. This is characterized by a circular
motion superimposing the vertical throwing motion so that the sample material
is moved over the whole sieve.
Air Jet Sieving of Bulk Materials
Particle size analysis and particle size distribution are important criteria for the quality control of bulk materials. In a running production process, the results of a quality check must be available quickly to allow for immediate adjustment of the production parameters. Depending on the expected particle size and sample volume, different sieving methods and sieving machines are suitable for analysis. The method used for particle size analysis is primarily determined by the fineness of the material to be sieved. For dry sieving of samples with particle sizes below 40 microns, air jet sieving is the method of choice.
The Basic Principles of Sieve Analysis
Many natural and manufactured materials occur in a disperse form, which means that they consist of differently shaped and sized particles. The particle size distribution, i.e. the number of particles of different sizes, is responsible for important physical and chemical properties.
Reproducible Sieving in the Shortest Possible Time
Despite the rapid development of modern optical particle measuring techniques, classical sieving analysis is still at the forefront for the practical quality assurance of bulk goods.
Fine Tuning Sieve Analysis for Accurate Particle Size Measurement
All to often, this useful method is overlooked. But if followed, these principles deliver accurate and reliable results at an affordable price.
Put the squeeze on
Sieving is cost effective for particle sizes greater than 75 μ, although the technique can be used for some materials of smaller size if the method can be validated. Assuming the relevant standards and clean, wellmaintained equipment that conforms to the standards are used, sieving can provide an accurate and reproducible measure of particle size distribution within a sample.
Investigation of the reproducibility of projection sieving operations
In a development project the task was to reduce the production-related effort of the vibration drives of sieve shakers for the different mains frequencies of 50 Hz and 60 Hz respectively.
Análisis por tamizado - El "patito feo" del laboratorio moderno
Con el equipo y el software adecuado, el análisis por tamizado es una técnica analítica que va más allá de proveer datos granulométricos rápidos, exactos y reproducibles.
Wenn sich das Siebgut optimal bewegt
Die Kenntnis von Korngröße und Kornverteilung bei dispersen Feststoffen ist für Forschung und Entwicklung, Verarbeitung und Qualitätssicherung äußerst wichtig. .
Asistencia
Representative results require adequate sample preparation
The following situation is typical for many production plants: After a routine quality check, the production process is stopped or an already produced batch is suspended, because the analysis results were not within the relevant critical values. But does the tested product really deviate from the specifications? The quality control managers are convinced of this because modern analysis instruments provide results with very low tolerances. The sample in question was tested several times and the result was confirmed. The question is why the product does not match the specifications although the production parameters have not been changed in any way.
The possibility that the tested product is indeed deficient cannot be excluded. However, it is often not the product itself which causes irregular analysis results but a lack of understanding of the steps which come before the analysis.
Comparative investigations on spinning rifflers
The influence of the degree of mixing of the material and the influence of the operating data of the apparatus were investigated in two spinning rifflers.
Fine Tuning Sieve Analysis for Accurate Particle Size Measurement
All to often, this useful method is overlooked. But if followed, these principles deliver accurate and reliable results at an affordable price.
Put the squeeze on
Sieving is cost effective for particle sizes greater than 75 μ, although the technique can be used for some materials of smaller size if the method can be validated. Assuming the relevant standards and clean, wellmaintained equipment that conforms to the standards are used, sieving can provide an accurate and reproducible measure of particle size distribution within a sample.
Cement - representative sample preparation is important
To produce high-quality cement, the mineralogical and chemical composition of raw materials as well as intermediate and finished products has to be determined. At each stage of the production, samples have to be taken, processed and analysed to ensure quality control without gaps. Retsch offers a range of instruments that are used for sample preparation during the complete production process, from the quarrying of the raw materials to the final product. The typical sample preparation process involves preliminary size reduction, sample division and fine size reduction before the sample can be submitted to further analyses....
Sample Preparation of Plastics for X-Ray-Fluorescence Analysis
The elemental analysis of plastics has become more and more important. EC directive 91/338/EWG regulates the ban of cadmium in PVC, EC directive 94/62/EC defines limits for cadmium, lead, chromium and mercury in packing materials and EC directive 2000/53/EC defines limits for the same elements in end-of-life vehicles. This has created a strong need for a rapid and reliable testing method.
Sample Preparation of Solid Materials for the XRF-analysis
X-Ray fluorescence is one of the most versatile methods to determine elements in a sample. The material is exposed to x-rays that cause each element to emit its own unique fluorescent x-ray. The subsequent analysis of the results is based on comparisons to standard samples with given chemical composition.
The Representative Sample Preparation of Waste
Now that a certain environmental awareness has developed in the population over the past few years, our efforts are geared not only to avoiding waste, but also to reducing the mountains of waste which still arise by means of raw material recovery and the reintroduction of secondary raw materials into the industrial cycle.
Probenvorbereitung von Böden
In Industrienationen mit hoher Besiedlungsdichte und einem begrenzten Angebot an Industrie- und Gewerbegebieten unterliegt die Nutzung von Gebäuden und Flächen einem dauerhaften Wandel. Daher sind Bodenuntersuchungen für Investoren, Behörden und Privatpersonen unumgänglich. Umweltanalytische Untersuchungen bilden die Basis, um Gefährdungen aufzuzeigen und damit Menschen und eingesetztes Kapital zu schützen. Bei SGS Institut Fresenius in Herten werden bis zu 400 Bodenproben am Tag aufgearbeitet und analysiert. Hierbei wird sehr genau darauf geachtet, dass geltende Normen und Verordnungen eingehalten werden. In Deutschland gilt die BbodSchV, wobei die Analytik auch auf die Vorschriften anderer Länder angepasst wird.
Vergleichende Betrachtung zweier Rotationsprobenteiler-Prinzipien
Zur Qualitätssicherung und Steuerung einer Produktion beschränkt man sich auf die Untersuchung von Teilmengen (Analysenmengen). Ziel der Probenteilung muß es daher sein, die in der Gesamtmenge eines zu untersuchenden Stoffes heterogen verteilten Eigenschaften repräsentativ in den einzelnen Teil- oder Analysenmengen wiederzufinden.
Von der Probe zum Pressling – Probenvorbereitung von Feststoffen für die Röntgenfluoreszenz
Aufgrund der Einfachheit der eigentlichen RFA-Messung wird häufig der Aspekt der optimalen Probenvorbereitung übersehen, was sich dann in mangelnder Reproduzierbarkeit bis hin zu falschen Ergebnissen auswirken kann.
