can sealing compound, Application Compound It is impossible to include a comprehensive discussion of sealing compounds in this booklet.
However, due to the Previous references, a few comments about their application are acceptable.
To achieve a hermetic seal, the appropriate sealant must be selected. There is no single compound that is optimal for all types of packs; therefore,
it is essential to use the correct one. Engineers from Grace’s sales team can help you choose the ideal sealing compound.
Before it can be applied to the can end, the sealing compound must be prepared properly.
Grace also offers technical bulletins containing comprehensive instructions for the compound’s preparation. In addition,
there are audio-visual programs detailing the precise instructions for preparing the compound.
Using conventional lining equipment, the compound can now be applied to the end of the can. For many sanitary cans,
the sealing compound is lined in a sanitary open-top placement, with the sealing compound beginning at 0-4/64 “(0-1.58 mm)
from the cut edge inward to the start of the seaming panel radius (Figure 46). For many beer and beverage can ends,
the compound is lined in a flat top beer or soft drink can placement with the sealing compound 0-4/64 inches thick “(0-1.58 mm)
from the cut edge to the curl height on the shoulder of the can end.
The amount of compound to be utilized depends on the can end diameter, pack, process, and can style.
Local Grace representatives can provide specific recommendations pertaining to these parameters.
One or two turn linings can be utilized to apply the compound. There is no preference between a one- or two-turn lining if both are well-made.
If the one turn lining is poorly made, resulting in skips, voids, or lack of uniformity, the two turn lining is likely to provide a more uniform,
even application and, consequently, a superior hermetic seal.
After the lining has been completed, quality checks are performed to ensure that the correct film weight is obtained
and that the compound is distributed in the desired manner.
Before being double-seamed onto can odies, freshly-lined ends must be kept for twenty-four to forty-eight hours.
Before storage or use, the ends of water-based compounds are oven-dried.

Double Seamer Modifications A double seamer can be modified in numerous ways to produce commercially acceptable hermetic double seams.
Many of these adjustments are beyond the scope of this manual and are typically covered in detail in the manuals that come with the double seamers.
Three of the most frequent adjustments are illustrated in the following images.
These are the adjustments for base plate pressure and first and second operation roll tightness.
If one or more are out of alignment, a variety of problems may ensue. The images below depict the outcomes of tight,
normal, and loose base plate pressures combined with tight, normal, and loose first and second operation roll adjustments.
These seams were created on a Continental Can Company 415-CR1 seamer using A12000 and A12001 seaming rolls for the first and second seaming operations,
respectively. 303 x 406 (80.971113 mr) double sliver notch cans with 60 pound double cold reduced plain tinplate bodies and 85 pound conventional tinplate C enameled ends were utilized.
These ends were lined with a commercial sanitary compound at a film volume of 56 cubic millimeters with a two-turn lining in sanitary open top placement.

Double Seamer Adjustments. There are numerous adjustments which can be made to a double seamer to make commercially acceptable hermetic double seams.
Many of these adjustments are beyond the scope of this booklet and are frequently covered in detail in the manuals supplied with the double seamers. Three of the
more common adjustments are referred to in detail inㆍ the following pictures. These are base plate pressure and first and second operation roll tightness
adjustments. If any one or more get out of adjustment, various problems may result. The following pictures illustrate the results of tight, normal, and loose base
plate pressures in combination with tight, normal and loose first and second operation roll adjustments.
These seams were made on a Continental Can Company 415-CR1 seamer using A12000 and A12001
first and second operation seaming rolls. 303 x 406 (80.971113 mr.) couble sliver notch cans consisling
of 60 pound double cold reduced plain tinplate bodies and 85 pound conventional tinplate C enameled ends
were used. A comimnercial sanitary compound was lined in these ends at a film volume of 56 cubic millimeters in
a two turn lining in sanitary open top placement.

Examination of the Double Seam The countersink depth is measured with a gauge which is calibrated in
lenths, hundredlhs and thousandihs of an inch or in tenths and hundredths of a millimeter. One typical gauge
is shown in Figure 30. To make the counlersink measurement, the bar ol the gauge is placed on top of the double seam so that it
straddles the diameter of the can end. The foot or point of the gauge, which is connecled to the indicators, is
positioned on the can end at the base of the chuck wall and at the lowest point or at the greatest depth adjacent
to the chuck wall. The countersink gauge in Figure 30 has two dials, each with an indicator — a small indicator on a 0 to 7
small inner scale indicating tenths of an inch, and a larger indicator on a 0 to 99 large outer scale indicating
hundredths — .01, and thousandths — .001 of an inch.
At least three readings should be taken at equidistant points around the seam. The minimum and maximum
roadings are rocorded to provide a range for the countersink. No readings should be taken within a half

inch of the side seam, and the bar of the gauge should not be allowed to rest on the high point of the seam at
the side scam when a rcading is being taken. Periodically, the countersink gauge should be
calibrated. First, the foot or point should be checked to see that it is tight in its shaft. Second, the knurled screw
near the top of the dial must be loosened to allow the indicator to be turned. The bar of the gauge is then
placed on a llat surface, preferably a block of machined steel. With the gauge in this position, the foot is at a zu ro
position. The outer scale is rotated until the zero and the indicator coincide. Finally, the knurled screw is
tightened to lock the gauge at the zero position.

The countersink is an extremely important measurement and is only as reliable as the gauge and
the technique used with it. seam Many seam measurements are made with a can
micrometer, Figure 31, This micrometer is read in thousandths of an inch with provisions for reading
hundredths — .01 and tenths.1 of an inch. Some seam micrometers read in metric units.
The can seam micrometer is a piece of test equipment and if used and cared for properly will be a useful and
accurate instrument. The barrel of the can seam micrometer is divided by numbered lines in tenths of an inch, 0.1″, from zero to
one-half an inch — 0-0.5″. Between the numbered lines there are three intermediate lines at .025″, .050″ and
.075″. The thimble of the micrometer is rotatable and has numbered graduations around it from 0 to 24. Each
graduation indicates one thousandth of an inch — ㆍ.001″. Each revolution of the thimble is equal to .025″.

For measurements between O and .025″, the reading comes directly from the thimble — the number on the
line of the thimble which comes closest to the long line on the barrel. For readings over .025″, the reading on
the thimble is added to the reading on’he barrel. If three lines past zero on the barrel were exposed (no numbered
graduations on the barrel were showing) and the five graduation on the thimble coincides with th e long line on
the barrel, the reading would be .080″ (.025 + ,025 + . .025 + .005) as shown in Figure 33. There is no vernier
on this micrometer. The barrel of the metric system can seam micrometer is divided in half millimeter increments, 0.5 mm., from
zero to thirteen millimeters — 0-13 mm. Only the zero, . 5 and 10 millimeter lines on the barrel are numbered,
with nine intermediate lines in 0.5 mm. increments between each of the numbered lines. The rotatable
thimble has fifty graduations around it from 0 to 49. Each graduation indicates one hundredth millimeter.
Every fifth graduation on the thimble is numbered. Each complete revolution of the thimble is equal to 0.5 mm.

On the metric micrometer, for measurements between 0 and 0.5 mm., the ieading comes directly from the
thimble – the number on the line of the thimble which comes closest to the long line on the barrel. For readings
over 0.5 mm., the reading on the thimble is added to the reading on the barrel. If three lines past zero on the
barrel were exposed (no numbered gradualions on the barrel were showing) and the forty-one (41) graduation
on the thimble coincides with the long line on the barrel, the reading would be 1.91 mm. (0.5 + 0.5 + 0.5 +.41)
as shown in Figure 32. There is no vernier on this micrometer. any can seam micrometer-have a projectio
pointed shaft at the anvil end of the micrometer. This can be used to measure the countersink depth. However, the
previously described countersink gauge of Figure 30 is much easier to read and is more accurate.
Periodically, the micrometer should be checked for a correct zero setting. The anvil and spindle surfaces
should be cleaned with a piece of paper, no abrasive.

These two surfaces should be brought into contact with normal pressure. Then, while holding the frame in one
hand, insert the wrench supplied with the micrometer into the hole in the barreI sloeve and turn the barrol
sleeve until the parallel line coincides with the zero line on the thimble.
The seam thickness may be measured with the can seam micrometer. The micrometer is placed on top of
he double seam so that the seam lies between th and the spindle screw. The can seam micrometer should
be balanced directly over the seam using the index finger to hold the micrometer. The tip of the micrometer
should not be the holding point, for the anvil will not be able to conform to the taper of the chuck wall and an
erroneously high reading will be obtained. The thimble is turned clockwise until the double seam is snugly held
between the anvil and the spindle screw, Figure 34. The thimble should be snug, but not too tight. The reading is
then taken as previously described on pages 24-25. At least three measurements should be taken around the
double seam, and the seam thickness recorded as a ange ㅡ minimum to maximum.

The can searn micrometer may also be used to measure the seam length as illustrated in Figure 35. The
tip of the micrometer is rested on the body of the can so the anvil is at the cover hook radius. The thimble is
turned clockwise until the length of the double seam is held snugly between the anvil and the thimble screw.
The lines on the micrometer barrel and the thimble are read to give the seam length measurement. As stated in
“‘Evaluating the Double Scam,” the scam length for sanitary cans should be approximately .120″ (3.05 mm.).
The seam length measurement is read to the nearest thousandth of an inch or hundredth of a millimeler and
is made at a minimum of three places around the seam. It should be recorded as a range, the minimum to the
maximum.

The overlap measurement is made on a section cut from the double seam. A power driven, high speed saw
with a sharp, fine tooth, thin blade does the best job. One such saw is shown in Figure 36. With this saw the
can is laid on its side, and two parallel cuts are made

through the seam, one by each blade of this two bladed saw. Only one of these cuts is made on the diameter of
the can, and it is this cut which is used for the overlap measurement. The section is removed from the can with
tin snips or nippers. With the single blade saw shown in Figurc 37, the can s laid on its side and an initial cut is made on a dia
of the can. To allow removal of the section, a second cut is inadc on a 45” angle to and intersecting with the lirsl.
(A frequently used saw blade is 4 inches in diameter, .014 inch thick with approximately 25 teeth to the
inch.) An additional section should be cut through the seam at the thickest part of the cross over. In this section
heavy solder and dangerously reduced overlaps are readily found if present, making this one of the most
critical observations and measurements of the entire seam examination.
The section may then be placed in the small vise of the seam projector or held up to the light source of the

through the seam, one by each blade of this two bladed saw. Only one of these cuts is made on the diameter of
the can, and it is this cut which is used for the overlap measurement. The section is removed from the can with
tin snips or nippers. With the single blade saw shown in Figurc 37, the can s laid on its side and an initial cut is made on a dia
of the can. To allow removal of the section, a second cut is inadc on a 45” angle to and intersecting with the lirsl.
(A frequently used saw blade is 4 inches in diameter,
.014 inch thick with approximately 25 teeth to the
inch.) An additional section should be cut through the seam at the thickest part of the cross over. In this section
heavy solder and dangerously reduced overlaps are readily found if present, making this one of the most
critical observations and measurements of the entire seam examination.

The can seam micrometer is then used to measure the cover hook at a minimum of three equidistant points
around its circumference. The cover hook is held between the anvil and the thimble screw, with the anvil
at the cut edge of the cover hook, and the thimble screw at the cover hook radius. The cover hook should be
parallel to the main axis of the micrometer to obtain an undistorted measurement as shown in Figure 44. The
cover hook is measured to the nearest .001″ or 0.01 mm. and is reported as a range from minimum to maximum.
The cover hook should be wiped clean using a brush or cloth with solvent to remove dirt, grease, pack or
compound before the wrinkle and juncture ratings are made. The methods used for making these ratings are
discussed in ”Evaluating the Double Seam,” pages 10-22. The end and body plate thickness measurements are
made with a thickness micrometer like the one in Figure 45. This one has pointed anvil and thimble screw tips.

UBIS: Compound is an adhesive sealant technology for metal packaging and its key function is to prevent leakage between the can and its lid.
Compound should also prevent any external contamination thereby extending shelf life of the product packed

Benefits and Importance of Sealants
• To prevent void space and leakage on metal packaging seams
• To prevent contamination
• To maintain internal air pressure
• Prolong shelf-life