TAPPI T 244 cm-11

VIP免费

史蒂文 2024-12-18 29 38.5KB 3 页 12星币

侵权投诉

T 244 cm-11

SUGGESTED METHOD − 1970

OFFICIAL STANDARD − 1977

OFFICIAL TEST METHOD − 1983

REVISED − 1988

REVISED − 1993

CLASSICAL METHOD − 1999

REVISED − 2011

The information and data contained in this document were prepared

by a technical committee of the Association. The committee and the

Association assume no liability or responsibility in connection with

the use of such information or data, including but not limited to any

liability or responsibility under patent, copyright, or trade secret laws.

The user is responsible for determining that this document is the

most recent edition published.

Approved by the Standard-Specific Interest Group for the Standard

TAPPI

CAUTION:

This method may require the use, disposal, or both, of chemicals which may present serious health hazards to humans. Procedures for the handling

of such substances are set forth on Material Safety Data Sheets which must be developed by all manufacturers and importers of potentially

hazardous chemicals and maintained by all distributors of potentially hazardous chemicals. Prior to the use of this test method, the user should

determine whether any of the chemicals to be used or disposed of are potentially hazardous and, if so, must follow strictly the procedures specified

by both the manufacturer, as well as local, state, and federal authorities for safe use and disposal of these chemicals.

Acid-insoluble ash in wood, pulp, paper, and

paperboard

1. Scope and summary

1.1 This method describes a procedure for determining the acid-insoluble ash content of cellulose samples.

1.2 The sample is dry-ashed and the residue treated with hydrochloric acid. The insoluble residue is filtered,

washed, ignited, and weighed.

1.3 This method measures all acid insoluble material. It is a faster and less accurate method than other

referenced methods. For a more accurate but time-consuming wet-ash procedure for determining the silicates and silica

content of pulp, see TAPPI T 245 “Silicates and Silica in Pulp (Wet Ash Method).”

2. Significance

Silica or silicates, the major components of the acid-insoluble ash, are normally present in wood and pulp in very

small quantities. If excessive amounts are present and carried into the finished paper, particularly of “fine” or specialty

grades, they may cause undesirable abrasion of metal repeatedly applied to the paper, such as punches, dies, knives, or

type. Paper and paperboard may be filled or coated with clay (alumino-silicates) making the acid-insoluble ash content

considerably higher.

3. Apparatus1

3.1 Platinum crucible, or dish, 50 mL.

3.2 Muffle furnace, maintained at 525 ± 25°C.

3.3 Filter paper, ash-free, double acid-washed, higher retention, of a type recommended for use with the finest

precipitates.

1Names of suppliers of testing equipment and materials for this method may be found on the Test Equipment Suppliers list, available

as part of the CD or printed set of Standards, or on the TAPPI website general Standards page..

T 244 cm-11 Acid-insoluble ash in wood, pulp, paper, and paperboard / 2

4. Reagents

Hydrochloric acid, 6M. Carefully add one volume concentrated HCl to one volume distilled water. Use caution in

making and handling of this reagent.

5. Sampling

5.1 Sampling wood: Obtain, grind, and screen a sample of wood in accordance with TAPPI T 257 “Sampling

and Preparing Wood for Analysis” and TAPPI T 264 “Preparation of Wood for Chemical Analysis” or a sample of pulp

in accordance with TAPPI T 210 “Weighing, Sampling, and Testing Pulp for Moisture.” Do not take cut edges or other

parts of pulp where mineral contamination may have occurred.

5.2 Sampling pulp: Obtain a sample of pulp in accordance with TAPPI T 210 “Weighing, Sampling, and Testing

Pulp for Moisture.” Do not take cut edges or other parts of pulp where mineral contamination may have occurred.

5.3 Sampling paper or paperboard: Obtain a sample of paper or paperboard in accordance with TAPPI T 400

“Sampling and Accepting a Single Lot of Paper, Paperboard, Containerboard, or Related Product.”

6. Test specimen

The size of the specimen, approximately 25 g, depends on the ash content and should be adjusted so that the weight

of the acid-insoluble ash will be at least 10 mg. Tear pulp, paper, and paperboard samples into small pieces. For wood,

use approximately 25 g of the ground and screened material prepared in 5.1. Weigh duplicate specimens to the nearest

0.01g.

7. Procedure

7.1 As directed in TAPPI T 211 “Ash in Wood and Pulp, Paper, and Paperboard: Combustion at 525°C,”

determine moisture level in the sample and ash the pulp in portions in a platinum dish, previously ignited in the muffle

furnace to a constant weight (to the nearest 0.1 mg). Ignite the sample at 525°C in the muffle furnace until the residue is

free from black carbon particles.

NOTE 1: This method may also be applied to the ash resulting when T 413 (ashing at 900°C) is utilized, in which case this must be noted in

the report.

Cool the dish to room temperature, add 5 mL 6M HCl, and evaporate carefully to dryness on a steam bath. Add a second

5-mL portion of 6M HCl and again evaporate to dryness. Add a third 5-mL portion of 6M HCl to the residue, heat on the

steam bath, and dilute with 20 mL of distilled water.

7.2 Filter the solution through the ash-free filter paper, being careful to remove all the residue from the dish by

means of a rubber policeman, and wash the residue several times with hot distilled water until the filtrate is free from

chloride ions (check with silver nitrate solution).

NOTE 2: The filtrate resulting when this method is used on pulp or paper and paperboard may be utilized for the determination of trace metals

such as Cu, Fe, Mn, and Ca where their determination on an ashed sample is required. In such cases, collect the filtrate in a

volumetric of suitable size (50 ml in most cases) and follow the analysis method of the trace metal procedure being used. Such

procedure should not be followed when using this method for wood, as the grinding and screening procedures (see 5.1) may

contaminate the sample with trace amounts of metals.

7.3 Place the filter paper containing the insoluble residue in the platinum dish. Heat very carefully until the

water has evaporated, and then ignite the residue in the muffle furnace at 525ºC until free from carbon. Allow the dish to

cool in a desiccator and weigh to the nearest 0.1 mg.

8. Calculation

Calculate the acid-insoluble ash content as:

3 / Acid-insoluble ash in wood, pulp, paper, and paperboard T 244 cm-11

a × 1000

Acid-insoluble ash, ppm =

where

a = weight of insoluble residue, mg

m = weight of the oven-dry sample, g

9. Report

Report the average result for the acid-insoluble ash as parts per million (milligrams per kilogram), to the nearest 5

parts per million.

10. Precision

10.1 Repeatability (within a laboratory) = 70 ppm

10.2 Reproducibility (between laboratories) = not known

10.3 These terms are in accordance with the definitions in TAPPI T 1200 “Interlaboratory evaluation of test

methods to determine TAPPI repeatability and reproducibility.”

11. Keywords

Wood, Pulp, Paper, Paperboard, Ash content, Acid insolubles, Silicates, Silica, Impurities, Ash

12. Additional information

12.1 Effective date of issue: September 27, 2011.

12.2 Related methods: ISO Standard 776; BS 4496.

12.3 This method was made classical by committee action in 1999. This method was revised and reconfirmed

in 2011 to make editorial corrections for better clarity.

Your comments and suggestions on this procedure are earnestly requested and should be sent to the TAPPI Standards

Department. g

文档加载中……请稍候！
如果长时间未打开，您也可以点击刷新试试。

下载文档到电脑，查找使用更方便

亲，本站95%以上的标准规范都面向会员免费，办理VIP会员下载更省钱，平均每篇不到2元

立即下载 VIP免费下载

已全部加载

摘要：

TAPPI T 244 cm-11 是美国纸浆与造纸工业技术协会（TAPPI）发布的标准测试方法，专门用于测定纸浆中酸不溶木素（Klason lignin）的含量。该标准为造纸行业、木材化学与生物质研究领域提供了关键的技术规范，适用于各类化学浆、机械浆及未漂浆的分析。通过准确测量残留木素比例，用户可评估纸浆的漂白效率、纤维纯度及加工适宜性。TAPPI T 244 cm-11 详细规定了样品制备、酸水解步骤、过滤与称重流程，确保结果具有重复性和可比性。对于从事纸浆质量管控、制浆工艺优化或生物质能研

展开>> 收起<<

TAPPI T 244 cm-11.pdf

共3页,预览3页

还剩页未读，继续阅读

声明：本文档系会员上传，若文档所含内容侵犯了您的版权或隐私，请立即通知，我们立即给予侵权申诉删除！

TAPPI T 244 cm-11

相关推荐

开通VIP享超值会员特权

相关内容

热门标签

举报选择: