Logo

ASTM D7050-04

Current Revision

Standard Practice for Rubber from Natural Sources—Sampling and Sorting Bales Based on Predicted Processing Properties

$73.00

$73.00

$131.40


Sub Total (1 Item(s))

$ 0.00

Estimated Shipping

$ 0.00

Total (Pre-Tax)

$ 0.00


Stay effortlessly up-to-date with the latest standard revisions. When new versions are released, they're automatically charged and delivered to you, ensuring seamless compliance.

...

1.1 This practice covers the sorting of natural rubber bales of TSR10 or TSR20 in the factory according to their predicted processing performance based on differences in viscoelastic properties.

1.2 This practice determines which bales should be used in factory compounds which benefit from using "soft" natural rubber versus which work better with "hard" natural rubber.


In accordance with Specification D 2227, shipments of TSR10 and TSR20 must meet a minimum initial Wallace plasticity (Po) of 30 to be accepted. However, even with this minimum restriction, the uncured viscoelastic or processability properties are allowed to vary greatly. This variation in properties can significantly affect the quality and efficiency of a factory operation.

Bales of TSR10 or TSR20 which are lower in their uncured elastic quality (soft rubber) in some cases may impart better processing properties to tire innerliners, cushion gums, and sidewalls. Soft bales sometimes impart better building tack, better mold flow, and lower extrusion die swell with better dimensional stability. Also, these soft rubber bales may dissolve faster in solvents for adhesion dipping.

Bales of TSR10 or TSR20 that are higher in their uncured elastic quality (hard rubber) in some cases generate greater shearing during the initial stages of a factory mix, which result in a faster breakdown and a shorter mix cycle.

Therefore, in a factory operation, sometimes segregating TSR10 or TSR20 shipments into soft and hard categories can improve the efficiency and quality of a factory operation.

SDO ASTM: ASTM International
Document Number D7050
Publication Date June 1, 2004
Language en - English
Page Count 2
Revision Level 04
Supercedes
Committee D11.22
Publish Date Document Id Type View
June 1, 2004 D7050-04 Revision
May 1, 2019 D7050-04R19 Reaffirmation
May 1, 2014 D7050-04R14 Reaffirmation
Sept. 1, 2009 D7050-04R09 Reaffirmation