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  • White Paper Sieve Analysis - Different methods for a variety of applications

    The determination and knowledge of the particle size distribution is an essential part of the quality control process for industrial products. From incoming and production control to research and development sieve analyses are used to determine a number of parameters or simply the particle size. Easy handling, low investment cost and high accuracy make sieve analysis one of the most frequently used procedures for measuring the particle size. This white paper gives an overview of the different sieving techniques and describes the necessary steps to ensure reliable results.
  • White Paper: Cryogenic Preparation of Sample Materials

    A solid sample material should always be sufficiently prepared by size reduction and homogenization before it is subjected to chemical or physical analysis. Care should be taken that the analysis sample fully represents the original material and that the sample preparation process is carried out reproducibly. Only then are meaningful results guaranteed. Most sample materials can be reduced to the required analytical fineness at room temperature by choosing a mill with a suitable size reduction principle (impact, pressure, friction, shearing, cutting).
  • White Paper: How to minimize standard deviations by correct sample preparation

    Modern analytical methods increase precision and push detection limits to make even the smallest traces of sample components detectable. Despite this development sample preparation, which is carried out prior to the actual analysis, is frequently neglected. Errors caused by lacking accuracy in sample preparation have a much bigger impact than errors made during analysis. Just like an iceberg which is mostly hidden under water, only a small part of the sum of errors is perceived whereas the major part of potential errors is not taken into account (fig. 1). One of the reasons may be the fact that sampling and sample preparation have always been done in a traditional way which has become a routine over the years and is no longer considered as having a critical influence on the subsequent analyses.
  • White Paper: Ultrafine Grinding with Laboratory Ball Mills

    How are nano particles produced? The “Bottom-Up” method synthesizes particles from atoms or molecules. The “Top-Down” method involves reducing the size of larger particles to nanoscale, for example with laboratory mills. Due to their significantly enlarged surface in relation to the volume, small particles are drawn to each other by their electrostatic charges. Nano particles are produced by colloidal grinding which involves dispersion of the particles in liquid to neutralize the surface charges. Both water and alcohol can be used as dispersion medium, depending on the sample material. Factors such as energy input and size reduction principle make ball mills the best choice for the production of nanoparticles.

Müşteri Dergisi " örnek " (2)

  • No. 38

    INTRODUCING VERDER SCIENTIFIC DIVISION
  • No. 38

    DIE VERDER SCIENTIFIC DIVISION STELLT SICH VOR

Uygulama raporları (36)

  • 環境負荷物質の検出(RoHS/WEEE)

    電子部品廃棄物の試料調製 ラジコンカーの分析用試料調製の方法を説明しています。  プラスチックの顔料に含まれるカドミウム、ハンダ中の鉛、ケーブルの難燃材に含まれるPBBなど、電子部品の中には有害物質が含まれている可能性が数多くあります。EUの有害物質規制に関する指令(WEEE/RoHS)が2006年7月に発令されて以来、機器メーカー、部品メーカー、材料メーカー、およびリサイクル業者は、その対応に迫られています。
  • Mulino a taglienti SM 300 – Affinamento di un sistema di macinazione ben affermato

    I mulini a taglienti vengono utilizzati in diverse aree della preparazione dl campione alle analisi successive. Tipiche applicazioni includono la riduzione di combustibili da rifiuto, la macinazione di campioni di biomasse per ricerche nell’ambito delle energie rinnovabili, il controllo dei prodotti nell’abito delle normative RoHS and WEEE, o nel recupero dei materiali preziosi – la varietà di campione è notevole.
  • Plastica – un materiale con molte variazioni

    Grazie alla varietà quasi illimitata di materie plastiche, i loro campi di applicazione sono vasti. Abbreviazioni come PE, PET, PC, PP, PBT o ABS non descrivono solamente un semplice materiale, ma un’intera classe di prodotti con molte caratteristiche differenti. A seconda della destinazione d’uso, la plastica deve essere, per esempio, resistente agli urti, a prova di rottura, resistente al calore o resistente ai solventi.
  • Utilizzo del Cryomill per campioni con componenti volatili

    Per la riduzione di dimensioni di molti materiali è consigliabile utilizzare un mulino criogenico invece di un mulino che opera a temperature ambiente. Il campione viene infragilito con l'azoto liquido che migliora il suo comportamento di rottura quando viene sottoposto a impatto, pressione e attrito. Inoltre, in questo modo vengono conservati i componenti volatili del campione. Il mulino Cryomill non solo è il mulino criogenico più sicuro e moderno sul mercato ma fornisce anche eccellenti risultati di macinazione.
  • La Fragmentación

    Por lo general se asocia a la noción "fragmentación", el machacamiento, de sustancias sólidas mediante fuerza mecánica. Pero también la división de líquidos en gotas o de gases en bollas representa un proceso de fragmentación.
  • La nueva generación de molinas planetarios de bolas

    Los más precisos resultados de trituración en el más breve tiempo se consiguen con los nuevos molinos planetarios de bolas, de Retsch. Con el PM100 y el PM200, Retsch presenta una nueva generación de molinos planetarios de bolas con uno o dos unidades de trituración, que establecen nuevos estándares de rendimiento en este segmento de la producción.
  • 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.
  • Materias primas renovables a la vanguardia

    Particularidades de la preparación de plantas
  • Metales pesados en juguetes

    De la trituración al análisis
  • 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.
  • Eiskalt Zerkleinert

    Die meisten Probenmaterialien lassen sich durch die Wahl des geeigneten Zerkleinerungsgerätes problemlos mahlen. Die Beanspruchungsmechanismen wie Prall, Druck, Scherung, Schneiden, Reibung reichen bei Raumtemperatur aus, um das Material auf die benötigte Partikelgröße zu zerkleinern. Was aber kann man tun, wenn die mechanische Beanspruchung allein nicht ausreicht, um das Probenmaterial in möglichst kleine Partikel zu überführen? Eine Lösung dieser Problematik bietet der Einsatz von Flüssigstickstoff, der das Bruchverhalten solcher Materialien begünstigt.
  • Kolloidvermahlungen zur Erzeugung von Nanopartikeln

    Nanoteilchen, d.h. Partikel mit einem Durchmesser von weniger als 100 Nanometer, werden seit vielen Jahren von Wissenschaftlern erforscht. Zum einen lassen sie sich im „Bottom-up“ Verfahren aus Atomen oder Molekülen synthetisieren. Im “Top-Down“ Verfahren hingegen werden größere Partikel, z.B. mit Hilfe von Labormühlen, zerkleinert. Kleine Partikel weisen durch das extrem vergrößerte Verhältnis von Oberfläche zu Volumen erhöhte Oberflächenladungen auf, so dass die Partikel elektrostatisch zueinander gezogen werden. Daher können Nanopartikel nur durch Nassvermahlung (Kolloidvermahlung) erzeugt werden.
  • Outdoorbekleidung: Natur pur oder dem Gift auf der Spur?

    Freizeitaktivitäten in der Natur wie Wandern, Radfahren oder Klettern erfreuen sich großer Beliebtheit. Die Textilindustrie bietet hierfür eine große Bandbreite an Funktionskleidung aus synthetischen High-Tech Materialien, die in der Regel wind- und wasserfest sind sowie atmungsaktiv. Wie Greenpeace in einer Studie von 2013[1] nachweisen konnte, finden sich in wetterfesten Textilien immer wieder Gefahrstoffe wie per-oder polyfluorierte Chemikalien (PFC), welche z. B. zum Schutz vor Wasser und Schmutz in die Kleidung eingearbeitet werden.
  • Probenvorbereitung für die Analyse von PET Verpackungen

    PET Flaschen sind als leichte und stabile Getränkeverpackung beliebt und weit verbreitet. Mineralwasser und andere Getränke in diesen Flaschen können jedoch Spuren der gesundheitsschädlichen Verbindung Acetaldehyd enthalten. Der Stoff wirkt sich schon in geringen Spuren negativ auf die Geschmacksqualität aus. Zur Qualitätssicherung sind daher für Verpackungshersteller und Getränkeabfüller aufwändige quantitative Prüfverfahren erforderlich. Da Acetaldehyd eine leicht flüchtige Verbindung ist, muss eine thermische Belastung der PET Probe im Vorfeld der Analyse in jedem Fall verhindert werden. Die Kryogenvermahlung bei -196 °C ist eine Methode zur schonenden, reproduzierbaren Zerkleinerung elastischer Materialien. Das Verfahren eignet sich für die Probenvorbereitung im Rahmen chromatographischer Routinekontrollen im zertifizierten Prüflabor.
  • Schnell und schonend zerkleinern

    In zahlreichen Labors werden täglich viele unterschiedliche Probenmaterialien aufbereitet. Für die Zerkleinerung von Feststoffproben auf Analysenfeinheit wird eine Mühle benötigt, die nicht nur vielseitig einsetzbar und leicht zu reinigen ist, sondern die auch eine reproduzierbare Probenvorbereitung – und damit zuverlässige Analysenergebnisse - garantiert.
    Mit der Ultra-Zentrifugalmühle ZM 200 bietet RETSCH eine Rotormühle an, die nicht nur sehr schnell, sondern auch äußerst materialschonend zerkleinert und, dank einer umfangreichen Zubehörpalette, universell einsetzbar ist. Mit ihrem kraftvollen Powerdrive-Antrieb vermahlt die ZM 200 weiche bis mittelharte und faserige Materialien extrem schnell auf Endfeinheiten bis unter 100 µm und steigert so den Probendurchsatz im Labor.
  • Emax - faster, finer, cooler

    The biggest challenge when developing a high energy ball mill is controlling the temperature. The very high energy produced by ball milling leads to an extreme heat increase inside the grinding jars. RETSCH solved this problem by creating an innovative integrated water-cooling system. Grinding breaks for cooling, which are unavoidable in conventional ball mills even after only 30 minutes grinding at moderate speed, are usually not necessary when using the High Energy Ball Mill Emax.
  • Sample preparation of PET preforms for subsequent analytics

    In the beverage industry plastic bottles – or rather their performs - are analyzed for their acetaldehyde content to prevent any health risk for consumers. The acetaldehyde must be extracted from the preforms prior to analysis. To ensure correct results, the bottles first have to be crushed and homogenized by laboratory mills. Care must be taken that the volatile substance acetaldehyde does not escape during the process due to heat build-up inside the grinding chamber. To preserve the acetaldehyde, part of the sample preparation is carried out under cryogenic conditions.
  • Toxic substances in our daily life

    Plastic is an inherent part of our everyday lives; it is used in a huge variety of things such as, for example, packaging, furniture, clothing or electronic devices. Though the utility of the material is undoubted, consumers are increasingly unsettled by recurring news about hazardous substances detected in plastics.
    Substances such as plasticizers, which are not firmly bound in the material, are absorbed via the skin and can influence the hormonal balance. Plasticizers contained in food packaging, for example, penetrate into the food and thus into the human body when the food is eaten. Plasticizers in toys are a particularly serious problem; children tend to take toys into their mouths thus absorbing the dangerous chemicals.  Equally hazardous are polycyclic aromatic hydrocarbons (PAH). The family of PAH comprises more than 100 compounds most of which have been found to be carcinogenic.
  • Emax - The Revolution in Ultrafine Grinding

    The Emax is an entirely new type of ball mill which was specifically designed by RETSCH for high energy milling. The impressive speed of 2,000 min-1, so far unrivaled in a ball mill, in combination with the special grinding jar design generates a vast amount of size reduction energy. The unique combination of impact, friction and circulating grinding jar movement results in ultrafine particle sizes in the shortest amount of time. Thanks to the new liquid cooling system, excess thermal energy is quickly discharged preventing both sample and mill from overheating, even after long grinding times.
  • Outdoor clothing: Pure nature or traces of poison?

    Outdoor activities such as hiking, biking or climbing are very popular. As a result, the textile industry offers a huge variety of functional outdoor clothing made from synthetic high-tech materials which are wind- and waterproof as well as breathable. In 2013 Greenpeace published a study proving that hazardous substances such as perfluorinated and polyfluorinated chemicals (PFC) were used in weatherproof clothing as protection against water or dirt. This article describes the sample preparation process with cutting mills and cryogenic mills of high-tech fibres.
  • White Paper: Representative Analysis Results Require Adequate Sample Preparation

    A faultless and comparable analysis is closely linked to an accurate sample handling. Only a sample representative of the initial material can provide meaningful analysis results. Rotating dividers and rotary tube dividers are an important means to ensure the representativeness of a sample and thus the reproducibility of the analysis. Correct sample handling consequently minimizes the probability of a production stop due to incorrect analysis results. Thus correct sample handling is the key to effective quality control.
  • CryoMill - Cryogenic grinding was never more convenient or efficient

    Some sample materials have properties which make size reduction at ambient temperature impossible. If, for example, very elastic materials need to be ground or volatile components have to be preserved for further analysis, it is essential to carry out cryogenic grinding. The use of liquid nitrogen helps to embrittle the sample, thus improving its breaking properties, and preventing volatile substances from escaping due to the frictional heat produced by the grinding process.
  • Secondary fuels – Energy for the cement industry

    Due to decreasing resources and increasing market prices for primary fuels like oil, gas or coal, it is paramount for the cement industry to search for alternative energy sources. With regard to the CO2 emissions trading, a switch to energy sources which have a neutral CO2 balance can be rather profitable. Usually, these are non-fossil fuels. Industries with high energy consumption have made increasing use of alternative fuels during the last years. Accordingly, the use of so called secondary fuels (also waste derived fuels/wdf or refuse derived fuels/rdf) has gained importance. These are mostly combustible fractions of domestic or industrial waste which cannot be recycled.
  • 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.
  • 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
  • Sick with Dolls

    Traces of Heavy Metals in Toys
  • 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.
  • 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.
  • 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.
  • 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.
  • 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.
  • 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.
  • 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.

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