Regular observations shall be maintained during production runs for gross closure defects. Any such defects shall be recorded and corrective action taken and recorded. The operator, closure supervisor, or other container closure inspection person shall visually examine either the top seam of a can randomly selected from each seaming head or the closure of any other type of container being used. These examinations and a record of the observations shall be made at intervals of sufficient frequency to ensure proper closure. Additional visual closure inspections shall be made immediately following a jam in a closing machine, after closing machine adjustment, or after startup of a machine following a prolonged shutdown, All pertinent observations shall be recorded. When irregularities are found, the corrective action shall be recorded.
(1) Teardown examinations for double-seam cans shall be performed and the results shall be recorded at intervals of sufficent frequency on enough containers from each seaming station to ensure maintenance of seam integrity. The results of the teardown examinations shall be recorded and the corrective action taken, if any, shall be noted.
(a) Required can seam measurements:
(i) Micrometer measurements are required for covered hook, body hook, width, tightness for wrinkle and thickness.
(ii) Seam scope or projector measurements are required for body hook, overlap tightness for wrinkles, and thickness by micrometer.
(iii) Double seam can terminology:
(a) Crossover means the portion of a double seam at the lap.
(b) Cutover means a fracture, sharp bend, or break in the metal at the top of the inside portion of the double seam.
(c) Deadhead means a seam which is incomplete due to chuck spinning in the countersink.
(d) Droop means smooth projection of double seam below bottom of normal seam.
(e) False seam means a small seam breakdown where the cover hook and the body hook are not overlapped.
(f) Lap means two thicknesses of material bonded together.
(b) Two measurements at different locations, excluding the sideseam, shall be made for each double seam characteristic if a seam scope or seam projector is used. When a micrometer is used, three measurements shall be made at points approximately one hundred twenty degrees apart, excluding the sideseam.
(c) Overlap length can be calculated by the following formula:
Theoretical overlap length = ch+bh+t-w, where ch=cover hook; bh=body hook; t=cover thickness; and w=seam width (height, length).
(2) For glass containers with vacuum closures, capper efficiency shall be checked by a measurement of the cold water vacuum. This shall be done before actual filling operations, and the results shall be recorded.
(3) For closures other than double seams and glass containers, appropriate detailed inspections and tests shall be conducted at intervals of sufficient frequency to ensure proper closing machine performance and consistently reliable hermetic seal production. Records of such tests shall be maintained.
(B) Cooling water.
Container cooling water shall be chlorinated or otherwise sanitized as necessary for cooling canals and for recirculated water supplies.
(1) Each hermetically sealed container of low-acid processed food shall be marked with an identifying code that shall be permanently visible to the naked eye.
(2) The required identification shall identify in code the establishment where packed, the product contained therein, the year packed, the day packed, and the period during which packed.
(3) The packing period code shall be changed with sufficient frequency to enable ready identification of lots during their sale and distribution.
(4) Codes may be changed on the basis of one of the following intervals:
(a) Four to five hours.
(b) Personnel shift changes; or
(c) Batches, as long as the containers that constitute the batch do not extend over a period of more than one personnel shift.