The hot fill process in most bottling situations brings certain problems that are inherent in this method of filling and cooling.
Generally, while the process is sanitary, the subsequent activities of cooling and packaging may bring about a situation wherein such bottles carry water beneath their caps.
This water is generally a potential breeding ground for
bacteria which may grow thereon, and cause a
diminution in product quality.
Such water is generally economically impossible to remove, as the
drying of that water would require either the removal of the cap (typically causing the breaking of a sanitary or security seal) and physical
drying of the
bottle, followed by recapping, or the use of
high heat drying equipment, which may cause deformation in the
bottle and cap or degradation of the bottled product.
Further, containers of such products, and other products, are subjected to considerable jostling in every stage of their existence.
Even after a container is unsealed and put into everyday use the container is subjected to every manner of assault on its integrity.
While a container generally survives jostling, the product inside, and / or the seals or liners used to protect the product are often imparted with considerable splashing or dusting from their surroundings, so as to leave the liner or, when the seal is removed or otherwise impaired, the product adulterated, contaminated or soiled beyond
usability.
Products such as
medicine and food or drink that are bottled and capped under sanitary conditions are often times quickly contaminated by the splashing of liquid or
powder (often times the same substance that has been placed in the container, but which has spilled during filling or from other containers previously filled, or overfilled).
While containers may be wiped clean if such splash up occurs prior to the capping and or the sealing of the container, once the container is capped and / or sealed (with a liner or otherwise), splash up that causes adulterating substances to rise to the neck or mouth of the capped container cannot be cleaned up without great cost in time and lost production.
Further, the removal of the cap of a tamper resistant or tamper evident container of the types in common use, so as to clean off splash up, is likely to destroy the tamper evident seal causing the loss of the container and / or the closure.
Further, capped products may also be contaminated, in this same manner or through
contamination by any other substance on or around the container, during transportation, either from the manufacturer to the
distributor, or from the
distributor to the product's final destination.
Closed containers may also be contaminated at anytime during the life of the product and the container.
For example, a bottle of milk may be contaminated by the splash up of spilled milk, water, or cleaning products on the
assembly line, may be contaminated by the splash up of liquid condensation (which may form on the bottle as a result of temperature changes during transit), or may be dropped into the sink, or onto any splashable substance, while the
consumer is attempting to open or after closing the container.
In all of these situations, and particularly in those situations where liners have already been removed from the container, the product is likely to be ruined by the splashing of any substance under the cap, onto the neck, and into the mouth of the container.
Further, even when a liner exists over the container's mouth, a
consumer is apt to be displeased and return the sealed products if he finds that the liner is wet or dirty upon opening the container for the first time.
While the liner may have prevented the product inside the container from having been contaminated, the proximity of a contaminant to the neck and mouth of a container may lead, at a later time, to
contamination of the product via the consumer's hands or by other means.
However, such protection is generally effective only after the likelihood of splash up during the container filling process on the
assembly line has passed and is only useful until the
plastic film is removed by the consumer prior to use.
However, such container and closure combinations only seal the mouth of the container and do not protect the neck of the container.
Liner-less closures cannot prevent the
contamination of the neck of the container and the concomitant problems of product contamination from the soiling of the consumer's hands after contact with an unclean container neck.
Further, liner-less closures cannot prevent the migration of the contaminant from the container neck to the container mouth (and subsequently to the product inside the container).