GB/T 40271-2021 PDF EnglishUS$165.00 · In stock · Download in 9 seconds
GB/T 40271-2021: Test method for identification of textile fibers - Differential scanning calorimetry(DSC) Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid
Similar standardsGB/T 40271-2021: Test method for identification of textile fibers - Differential scanning calorimetry(DSC)---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT40271-2021 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 59.080.01 CCS W 04 Test Method for Identification of Textile Fibers - Differential Scanning Calorimetry (DSC) ISSUED ON: MAY 21, 2021 IMPLEMENTED ON: DECEMBER 1, 2021 Issued by: State Administration for Market Regulation; Standardization Administration of the People’s Republic of China. Table of ContentsForeword ... 3 1 Scope ... 4 2 Normative References ... 4 3 Terms and Definitions ... 4 4 Test Principle ... 5 5 Equipment and Materials ... 6 6 Sample ... 7 7 Test Procedures ... 7 8 Result Expression ... 8 9 Test Report ... 9 Appendix A (informative) Calibration Method ... 10 Appendix B (informative) Standard Samples ... 11 Appendix C (informative) Melting Peak Temperature and Enthalpy of Fusion of Synthetic Fibers ... 12 Bibliography ... 13 Test Method for Identification of Textile Fibers - Differential Scanning Calorimetry (DSC)1 ScopeThis Standard describes a test method for the identification of textile fibers through a differential scanning calorimeter. This Standard is applicable to textile fibers with an obvious melting peak temperature, which is lower than decomposition temperature. NOTE: the differential scanning calorimetry is generally not used alone, but by determining the melting peak temperature and enthalpy of fusion of fibers to assist in the identification of the fibers.2 Normative ReferencesThe content of the following documents constitutes indispensable clauses of this document through normative references in the text. In terms of references with a specified date, only versions with a specified date are applicable to this document. In terms of references without a specified date, the latest version (including all the modifications) is applicable to this document. FZ/T 01057.1 Test Method for Identification of Textile Fibers - Part 1: General Introduction3 Terms and DefinitionsThe following terms and definitions are applicable to this document. 3.1 Melting Melting refers to the transition from a solid state of a completely crystalline or partially crystalline substance to a liquid state with different viscosities. [source: GB/T 6425-2008, 3.5.5.1] 3.2 Enthalpy of Fusion Enthalpy of fusion refers to the quantity of heat required for material melting under a constant pressure. NOTE: it is expressed in kJ/kg or J/g. [source: GB/T 19466.3-2004, 3.3, modified] 3.3 Differential Scanning Calorimetry Differential scanning calorimetry refers to a technique of determining the relationship between the heat flow rate or heating power (difference) delivered to the specimen and the reference substance, and temperature or time under program control temperature and certain atmosphere. [source: GB/T 6425-2008, 3.2.9] 3.4 Differential Scanning Calorimetry Curve (DSC curve) Differential scanning calorimetry curve (DSC curve) refers to a graphical representation of the relationship curve between the heat flow rate or heating power (difference) delivered to the specimen and the reference substance measured by the differential scanning calorimeter, and temperature or time. NOTE: the y-coordinate of the curve is heat flow rate, which is also known as heat flow and expressed in mW (mJ s-1); the x-coordinate is temperature or time. [source: GB/T 6425-2008, 3.2.10, modified] 3.5 Calibration Calibration refers to a set of operations of determining the relationship between the indicated value of the measuring instrument or measuring system and the already- known value corresponding to the measured value under specified conditions. 3.6 Instrument Baseline Instrument baseline refers to a thermal analysis curve measured with empty sample cuvettes of the same mass and material, and without the use of specimen. [source: GB/T 6425-2008, 3.5.3.1 a), modified]4 Test PrincipleUnder certain conditions, adopt the differential scanning calorimetry to determine and obtain the DSC curve of the fiber, as it is shown in Figure 1. In this Figure, Tpm is the melting peak temperature of the fiber; the connection points Tim and Tfm are used to draw a baseline; the area between it and the melting peak is the enthalpy of fusion of the fiber. Different types of synthetic fibers have different melting peak temperatures, based on which, the category of fibers can be identified. the sealed empty sample cuvettes into the sample holder. In accordance with the actual test conditions, test the instrument baseline. 7.4 Take another sample cuvette (see 5.2); use the balance (see 5.4) to weigh its mass, accurate to 0.01 mg. Put the specimen into the sample cuvette; put on the cap and tightly seal it. Then, re-weigh the sample cuvette which holds the specimen, accurate to 0.01 mg. 7.5 Put the sample cuvette which holds the specimen into the sample holder at the designated position of the instrument; put the sealed empty sample cuvette into the other position as a reference. 7.6 Set the program of the instrument; deduct the instrument baseline. Under the condition of at least 50 °C lower than the melting peak temperature, at a rate of 10 °C/min, start to raise the temperature, until it is at least 30 °C higher than the extrapolated final temperature (Tefm), or 20 °C ~ 30 °C lower than the thermal decomposition temperature; record the DSC curve. For some new types of fibers and some fibers obtained through certain special processing, they may be heated up for the first time to eliminate the thermal history of the fiber processing process, then, heated up again for the observation of the DSC curve. NOTE: other temperature-raising rates may also be adopted; the temperature-raising rate should not exceed 20 °C/min. 7.7 Cool down the instrument to room temperature; take out the sample cuvette; observe whether the sample cuvette is deformed, or whether the specimen overflows. If it is found that the sample cuvette is deformed or the specimen overflows, then, the test shall be invalidated and re-conducted. 7.8 Repeat steps 7.4 ~ 7.7 to test the other two specimens.8 Result Expression8.1 Melting Peak Temperature The test curve of the melting peak temperature is shown in Figure 1. From the Figure, respectively read the melting peak temperature (Tpm) of each specimen; the result shall be accurate to 0.1 °C. Take the average value of all specimens as the melting peak temperature of the sample; the result shall be rounded off to an integer. If the second temperature-raising is performed, take the value measured after the second temperature-raising as the test result. The melting peak temperature of synthetic fibers is shown in Appendix C. 8.2 Enthalpy of Fusion The test curve of the enthalpy of fusion is shown in Figure 1. Take the area betweenAppendix A(informative) Calibration Method A.1 General Rules of Calibration The differential scanning calorimeter is a sensitive thermal analysis instrument, which requires regular temperature and heat calibration. Under the circumstances of changing test temperature range, changing air source and flow rate, changing refrigeration system or being idle for a long time, before use, at least two standard samples shall be used for the calibration of temperature and heat. See Appendix B for commonly used standard samples. NOTE: other calibration requirements of the instrument may comply with the recommendations by the manufacturer, or with the assistance of the manufacturer in the implementation. A.2 Temperature Calibration A.2.1 Select at least two standard samples with the same mass as the specimen to be tested and whose extrapolated initial temperature is at or close to the temperature range to be tested. A.2.2 Under the same test conditions as the specimen to be tested, determine the extrapolated initial temperature of the standard samples and record it. A.2.3 By comparing the standard value and the recorded value of the standard samples, determine the temperature correction coefficient for calibration. Alternatively, the computer system may automatically compare and calibrate in accordance with the standard value and the recorded value. A.3 Heat Calibration A.3.1 Select at least two standard samples with the same mass as the specimen to be tested and whose extrapolated initial temperature is at or close to the temperature range to be tested. A.3.2 Under the same test conditions as the specimen to be tested, determine the enthalpy of fusion of the standard samples and record it. A.3.3 By comparing the standard value and the recorded value of the standard samples, determine the heat correction coefficient for calibration. Alternatively, the computer system may automatically compare and calibrate in accordance with the standard value and the recorded value. ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of GB/T 40271-2021 be delivered?Answer: The full copy PDF of English version of GB/T 40271-2021 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of GB/T 40271-2021_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 40271-2021_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. www.ChineseStandard.us -- GB/T 40271-2021 -- Click this link and select your country/currency to pay, the exact amount in your currency will be printed on the invoice. Full PDF will also be downloaded/emailed in 9 seconds.How to buy and download a true PDF of English version of GB/T 40271-2021?A step-by-step guide to download PDF of GB/T 40271-2021_EnglishStep 1: Visit website https://www.ChineseStandard.net (Pay in USD), or https://www.ChineseStandard.us (Pay in any currencies such as Euro, KRW, JPY, AUD).Step 2: Search keyword "GB/T 40271-2021". Step 3: Click "Add to Cart". If multiple PDFs are required, repeat steps 2 and 3 to add up to 12 PDFs to cart. Step 4: Select payment option (Via payment agents Stripe or PayPal). Step 5: Customize Tax Invoice -- Fill up your email etc. Step 6: Click "Checkout". Step 7: Make payment by credit card, PayPal, Google Pay etc. After the payment is completed and in 9 seconds, you will receive 2 emails attached with the purchased PDFs and PDF-invoice, respectively. Step 8: Optional -- Go to download PDF. Step 9: Optional -- Click Open/Download PDF to download PDFs and invoice. See screenshots for above steps: Steps 1~3 Steps 4~6 Step 7 Step 8 Step 9 |
