Packaging foods in glass
Practical Action
Figure 11: Hand operated ROPP machine
Figure 12: Motorised ROPP machine
Plastic snap-on caps are fitted over the neck of the bottle and sealed by a capping machine
(Figure 13).
Corks are mostly used to seal wine bottles and hand operated corkers which both squeeze the
cork and insert it into the bottle are available (Figure 14). Corks are first wetted to make
them slip more easily into the bottle and they then expand to give an airtight, waterproof seal.
As corks may be contaminated by microorganisms, it is important that the soaking water
contains either a few drops of bleach per litre or sodium metabisulphite at approximately one
teaspoonful per 5 litres.
Figure 13: Capping machine
Figure 14: Hand operated corking
Jars machine
Push-on lids are still used for sealing jars (Figure 15) although these are increasingly being
replaced by twist-on-twist-off (TOTO) lids. Small equipment is available for each of these
types of closure.
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