Norm

ASTM D7474 - 17 en

Standard Practice for Determining Residual Stresses in Extruded or Molded Sulfone Plastic (SP) Parts by Immersion in Various Chemical Reagents

45,11 54,58 Incl BTW

Over deze norm

Status Definitief
Aantal pagina's 4
Gepubliceerd op 15-08-2017
Taal Engels

1.1 This practice covers the evaluation of residual stresses in extruded profile or molded SP parts. The presence and relative magnitude of residual stresses are indicated by the crazing of the specimen part upon immersion in one or more of a series of chemical reagents. The specified chemical reagents were previously calibrated by use of Environmental Stress Cracking (ESC) techniques to cause crazing in sulfone plastics (SP) at specified stress levels.

1.2 This practice applies only to unfilled injection molding and extrusion grade materials of high molecular weight as indicated by the following melt flow rates: PSU 9 g/10 min, max., PESU 30 g/10 m, max, and PPSU 25 g/10 min, max. Lower molecular weight (higher melt flow) materials will craze at lower stress levels than indicated in Tables 1-3. (See Specification D6394 for melt flow rate conditions.)

TABLE 1 Liquid Reagents for Residual Stress Test for PSU

Mixture

Mixture Composition

Critical Stress, MPa (psi)

% by volume Ethanol

% by volume Ethyl Acetate

1

50

50

15.2 (2200)

2

43

57

12.1 (1750)

3

37

63

9.0 (1300)

4

25

75

5.5 (800)

TABLE 2 Liquid Reagents for Residual Stress Test for PESU

Mixture

Mixture Composition

Critical Stress, MPa (psi)

% by volume Ethanol

% by volume MEK

1

50

50

17.9 (2600)

2

40

60

10.3 (1500)

3

20

80

6.9 (1000)

4

0

100

5.9 (850)

TABLE 3 Liquid Reagents for Residual Stress Test for PPSU

Mixture

Mixture Composition

Critical Stress, MPa (psi)

% by volume Ethanol

% by volume MEK

1

50

50

22.8 (3300)

2

25

75

13.8 (2000)

3

10

90

9.0 (1300)

4

0

100

8.0 (1150)

1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

Note 1: There is no known ISO equivalent for this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Details

ICS-code 83.080.01
Engelse titel Standard Practice for Determining Residual Stresses in Extruded or Molded Sulfone Plastic (SP) Parts by Immersion in Various Chemical Reagents
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