Click here to make tpub.com your Home Page

Page Title: Quality controls for each molding compound batch for housing or plug.
Back | Up | Next

Click here for thousands of PDF manuals

Google


Web
www.tpub.com

Home

   
Information Categories
.... Administration
Advancement
Aerographer
Automotive
Aviation
Construction
Diving
Draftsman
Engineering
Electronics
Food and Cooking
Logistics
Math
Medical
Music
Nuclear Fundamentals
Photography
Religion
   
   

 




img
MIL-M-70779 (AR)
If welding is stopped for one (1) hour or longer, the
equipment shall be subjected to the qualification test prior to
use in production.
All welding equipment removed from production because of some
fault may, after reworking, be returned to production, providing
it passes the qualification test above.
The contractor may use coupons of the same material and
thickness as the parts being welded subject to approval of the
Contracting Officer.
4.5.7 Qualtiy controls for each molding compound batch for
housing or plug.
4.5.7.1 Resin/hardener weight ratio control.  At the
beginning of production and at least once each four hours of
production, or portion thereof, the inspector shall draw two (2)
test shots with the mixer set to expel the hardener and resin
separately.  The hardener and resin of each shot shall be weighed
individually to verify that the ratio is between 1.8/1 and 2.2/1.
If either shot fails to meet the requirement, all items filled
since the last acceptable check shall be rejected.  Further, the
mixer shall be corrected and shall pass the above test before
being returned to use.
4.5.7.2 Mixing and cure control.  One (1) test bar from each
batch of molding compound (see 4.5.7.1) shall be molded at the
same time the batch is used to mold housings or plugs, or bond
plugs to housings for lot acceptance testing. Vibration and
evacuation as necessary may be used to mold the bar.  The mix
ratio limits shall be 2.0/1.0 + 10% (1.8/1 to 2.2/1) . The test
bar shall be processed with the items molded from the batch of
molding compound which the bar represents; i.e., the bar shall be
cured in the same ovens and subjected to the same temperatures for
the same periods as the time it represents.  After completion of
the cure,- the bar shall be tested for ultimate compressive
strength, as specified in ASTM-D-695(85) except that the specimen
dimensions shall be 0.5 inch by 0.5 inch by 1.0 inch or 0.5 inch
diameter by 1.0 inch long.  The ends shall be flat and parallel to
within .003 inch, and shall be perpendicular to the long axis of
the specimen.  Speed of testing shall be as specified in the ASTM.
4.5.8 Temperature control during molding/cure operations.
Whenever the preform assembly, the housing, or the munition is
subjected to heating in ovens, temperature records shall be
maintained and reviewed to assure that the minimum temperature has
been reached and that the maximum temperature has not been
exceeded.  If any units have been subjected to temperatures beyond
the maximum limit at anytime, regardless of duration  they shall
be rejected.  Temperature measuring instruments shall be approved
and calibrated in-accordance with 4.4.4.
48

Privacy Statement - Press Release - Copyright Information. - Contact Us

Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business