of Used Milking Machine Inflations
Synthetic Rubber v. Silicone Rubber
Dr. Richard Heckmann
Analyze the surface of two types of milking machine inflations;
one composed of silicone rubber and the second a synthetic rubber
following use. The silicone rubber inflation had been used for approximately
6,000 cow milkings while the formulated rubber product had been
used for 1,200 cow milkings.
of each were attached to specimen studs, coated with gold in a mini-coater
sputter apparatus and viewed with a high resolution scanning electrom
microscope (SEM) for accurate evaluation of the inflation surface.
The SEM was operating at 5 KV and representative pictures were taken
at 2200x, 600x, and 220x for both specimens and viewed at other
magnifications. Permanent records were recorded on the micrographs
with a digital data keyboard entry system attached to the SEM. An
X-ray microprobe scan (EDAX) was completed on each sample to determine
elemental composition. The EDAX unit is attached to the SEM.
Results: (figures shown below)
Figures 1 to 10 represent the results of the SEM and X-ray probe
scans of the two types of inflations for cow milking machines. Figure
1A, 1B, and 1C represent scanning electron micrographs taken at
three magnifications; 220x, 600x, and 2200x of the surface of the
used (1200 cow milkings) formulated rubber milking machine inflations.
Note the deep cracks and depressions (arrows) in the surface of
the inflation that could harbor harmful virus and disease causing
bacteria. The size of the cracks and spaces can be measured using
the micron bar (100, 50, 10 µm) at the right hand side of
the caption. These pictures were prepared using an SEM at 5 kv.
Following the 1A, B, C micrographs are the "full page"
prints of the preparation. Figures 2A, 2B, and 2C represent another
sample from the same set of inflations as used for 1A, 1B, and 1C.
Bacteria are visible for 2C. Again the full page prints follow the
composite represented by 2A, 2B, and 2C.
rubber inflations are represented by Figure 3A, 3B, and 3C with
the second sample labeled 4A, 4B, and 4C. The second series (4A,
4B, and 4C) are highly representative of the inflation surface after
extensive use. This inflation had been used for 6,000 cow milkings
and showed no cracks, depressions, or tears. Appeared similar to
when it was formulated and extruded. The full page SEM micrographs
following the composite for each sample. Three magnification levels
were used again; 220x, 600x, and 220x with a 5 kv operating voltage.
The next series, 5A, 6A, 7A, represent a comparison between the
two inflations. Figure 5A and 5B are at 220x magnification with
5A representing formulated rubber and 5Bsilicone rubber. Note the
difference in the number of breaks and depressions in the surface
of the two products. Figures 6A and 6B represent 600x magnification
while 7A and 7B represent 2,200x magnification. As was the case
for Figures 5A and 5B, the A figure is formulated rubber while B
is silicone rubber.
Results of this project show that a silicone rubber inflation is
much better than a formulated synthetic rubber inflation even after
5 times more cow milkings. The surface of formulated rubber inflation
after 1,200 cow milkings is riddled with cracks, holes, and depressions.
The "breaks" in the rubber inflation can harbor harmful
bacteria and alter microorganisms as well as chemicals used in udder
Based on these
data, the silicone rubber inflation is the best product.
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