This specification establishes the requirements for first grade concentrated natural rubber latex of the following categories: Category 1, centrifuged Hevea natural latex preserved with ammonia only or by formaldehyde followed by ammonia; Category 2, creamed Hevea natural latex preserved with ammonia only or by formaldehyde followed by ammonia; Category 3, centrifuged Hevea natural latex preserved with low ammonia with other necessary preservatives; and Category 4, centrifuged, or centrifuged and creamed, guayule latex, or other natural rubber latex, containing a specified dry weight amount of latex, with ammonia or other hydroxide, with other necessary preservatives and stabilizers. This specification applies to natural latex sources other than Hevea brasiliensis but does not apply to compounded latex concentrates. Materials shall be tested by analytical procedures that determine the following chemical properties an substances: total solids; dry rubber content; protein content; total alkalinity; viscosity; sludge content; coagulum content; KOH number; pH; mechanical stability; copper and manganese; density; volatile fatty acids; boric acid; and dry films.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

Significance and Use

This specification denotes limits on the 4 categories of latex as defined in the scope and defines the test methods to use for the specified properties. These test methods may be used for production control or for referee purposes.

1. Scope

1.1 This specification covers requirements for first grade concentrated natural rubber latex (see Table 1) of the following categories:

Category 1Centrifuged Hevea natural latex preserved with ammonia only or by formaldehyde followed by ammonia.

Category 2Creamed Hevea natural latex preserved with ammonia only or by formaldehyde followed by ammonia.

Category 3Centrifuged Hevea natural latex preserved with low ammonia with other necessary preservatives.

Category 4Centrifuged, or centrifuged and creamed, guayule latex, or other natural rubber latex, containing less than 200 µg total protein per gram dry weight of latex, with ammonia or other hydroxide, with other necessary preservatives and stabilizers.

Category 5Centrifuged Hevea natural latex treated with aluminum hydroxide or by other means, preserved with ammonia only or by formaldehyde followed by ammonia containing less than 0.5 % non-rubber content.

1.2 This specification is not necessarily applicable to latices prepared or preserved by other methods, and shall not be construed as limiting the desirability or usefulness of other categories of latices. It does apply to natural latex sources other than Hevea brasiliensis but does not apply to compounded latex concentrates.

1.3 The analytical procedures applicable to the specifications are included and appear in the following order:

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

Keywords

Acidity, alkalinity, pH--rubber materials/applications; Boric acid content; Coagulum content; Density--rubber; Dry rubber content; Fatty acids content; KOH number; Mechanical stability; Natural rubber (NR) latex--specifications; Rubber--specifications; Sludge; Solids content; Viscosity--rubber; Volatile fatty acids content ;

ICS Code

ICS Number Code 83.040.10 (Latex and raw rubber)

Citing ASTM Standards

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