Smoked sheet

Recipe, in parts by wt smoked sheets, 100.00 zinc oxide, 5.00 filler, as indicated nondiscoloring antioxidant, 1.00 MBTS, 1.00 TMTD, 0.10 sulfur, 2.75 stearic acid, 3.00. 

Two subgrades of SMR 5 are SMR 5RSS and SMR 5ADS, which are prepared by direct baling of ribbed smoked sheet and air-dried sheet (ADS), respectively. 

TSR 5. Within the Malaysian scheme SMR 5 is restricted to mbber derived from sheet material prepared by conventional processes, ie, ribbed smoked sheet (RSS), air-dried sheet (ADS), and unsmoked sheet (USS) and presented in small bale form. Other countries may source different raw materials, eg, Indonesia produces SIR 5 from thin latex coagulum (14). SMR 5 prepared by pressing dry-sheet material into standard bales must be identified by the type of sheet material, eg, SMR 5RSS, on the test certificate as well as on the wrapping. 

Comminuted and other new process rubbers. In these cases the coagulum is broken up and then dried. The rubber is then packed in flat bales similar in size to those used for the major synthetic rubbers (70-75 lb) unlike the heavier square bales used with smoked sheet and crepe rubbers. 

In solid form, the natural rubber is graded according to the content of dirt remaining from the precipitation of latex at the plantation. Eight basic NR types have been traditionally recognized internationally. Only the so-called ribbed smoked sheets and the pale crepes are normally used for adhesives. The predominant grade system, the Standard Malaysian Rubber system, has been used since 1965. 

A grade of natural rubber inferior to estate brown crepe and formerly known as thick remilled brown crepe cuttings removed in the inspection of smoked sheet rubber are washed, creped and designated smoked blanket crepe . 

Plantation rubber in the form of sheets which have been dried in an atmosphere of wood smoke and finally sheeted in a mill having rolls engraved with a ribbed design. Ribbed smoked sheet comprises about 60% of the output of a plantation. See Plantation Rubber. 

Ribbed smoke sheets White and pale crepes Estate brown crepes Compo crepes Thin brown crepes Thick blanket crepes Flat bark crepes Pure smoked crepe... 

Smoked sheet, 40 lamp black, 1 phenyl-/ -naphthylamine, 3.5 dicumyl peroxide 50 min at 140° C Methyl methacrylate 52 — 96 96... 

Smoked sheets and N330 carbon black 50 500 19.6 (2,842) Irradiated in air... 

Gum rubber (SMR-5L) plus o-dichlorobenzene Gum rubber (Smoked Sheets)... 

Smoked Sheets and N330 Carbon black plus octyl acrylate Smoked Sheets and N330 Carbon black plus tetramethylene diacrylate Smoked Sheets and N330 Carbon black plus glyceryl triacrylate Pale Crepe and N330 Carbon black Pale Crepe and N330 Carbon black plus octyl acrylate... 

Raw rubber can be either natural or synthetic. The standard grades of natural rubber are smoked sheets and pale crepe. For high grade products, first grade smoked sheets, namely RMAIX or Pale Crepe, is used. Pale Crepe is practically colourless and is preferred in products where delicate colour, extreme whiteness or transparency... 

The percentage sulphur (determined in the un-vulcanized reclaim) and the available rubber hydrocarbon are taken into consideration while evolving the compound formulation. It should be noted that reclaimed rubber is not all rubber. In arriving at the total rubber content in the rubber formulation containing reclaim, allowance must be made for its rubber content. For example in the following blend of smoked sheet and whole tyre reclaim, the total rubber content is to be considered as 100 parts instead of 125 parts as below and the proportion of other ingredients should be worked out accordingly on "parts per hundred rubber" (phr) basis. 

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