MIL-DTL-11891G(AT)
4.5.2 In-process inspection. In-process inspections listed in tables III and IV shall be
performed on unvulcanized bushing, track roadwheel path and ground pad compound batches as
soon as possible after they are final (all ingredients are added to the compounds). This effort will
minimize production of large quantities of defective compounds which may result in the
production of defective track components.
4.5.2.1 Sampling for in-process inspection.
4.5.2.1.1 Bushings. The samples for in-process inspection shall be selected and tested in
accordance with table III.
4.5.2.1.2 Roadwheel path and ground path. The samples for in-process inspection shall
be selected and tested in accordance with table IV.
4.5.2.2 Rework (workaway). Rubber track compounds that are defective or
miscompounded shall not be used for rework (workaway) to fabricate any track components.
Rework will be limited to conforming compounds that are generated during processing. Rework
will consist of compounds being reworked into the same compounds using the lowest practical
level in order to avoid process, compound and finished product variation. This level shall be
established by the contractor and shall not affect the rubber properties or result in processing
difficulties. Rubber compounds for rework would normally be limited to the following:
a. Non-defective compounds being worked into themselves at the rate indicated
above.
b. Excess rubber left on the mills after extrusion, provided it is sheeted off promptly,
identified and kept clean.
c. Extruded rubber that failed to meet dimensions, provided the extruded rubber is
milled, cooled and identified.
d. Rubber used to warm up the tuber, but has not been contaminated with other
rubber compound or scorched material.
4.5.2.3 Material weight tolerances. The ingredients shall be properly weighed on
calibrated scales and controlled by inspections to assure compliance to the tolerances and
inspection frequencies established by the contractor. The weights of all ingredients for the master
batches, remills (if any), and final batches shall be inspected to assure process control.
4.5.2.4 Vulcanization time, pressure and temperature. The vulcanization time,
temperature, pressure and other cure conditions will be those established by contractors to assure
that track components have acceptable properties. These established cure conditions and
tolerances will continue to produce components with acceptable properties and will meet the
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