ASTM D1076 : 15

Standard Specification for Rubber—Concentrated, Ammonia Preserved, Creamed, and Centrifuged Natural Latex

Standard Details

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

(A) Dry rubber content by definition and use is the acid coagulable portion of latex after washing and drying.

(B) It is accepted that KOH numbers for boric acid preserved latices will be higher than normal, equivalent to the amount of boric acid in the latex.

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.

Category 4—Centrifuged, 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 5—Centrifuged 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:

	Section
Sampling	6 and 7
Total Solids	8
Dry Rubber Content	9
Protein Content	10
Total Alkalinity	11
Viscosity	12
Sludge Content	13
Coagulum Content	14
KOH Number	15
pH	16
Mechanical Stability	17
Copper and Manganese	18
Density	19 – 31
Volatile Fatty Acids	32 – 36
Boric Acid	37
Dry Films	38
Precision for All Test Methods	39