Sleeve-type closures for dispenser nozzles

Abstract

Reusable sleeve closures comprising a flexible thin sleeve of film grade plastic which seals the nozzle of a partially used sealant, mastic or caulk-dispensing cartridge or squeeze tube to substantially retard the hardening of the remaining tube contents. The plastic film provides a vapor barrier against exit of water or organic solvent from the sealant composition, and/or retards diffusion of oxygen that could cause the composition to set. The film is preferably somewhat stretchable and without creep over time, so that the sleeve provides an extremely tight seal for a substantial distance along the nozzle, e.g. film grade polyolefin or polyvinylidene chloride copolymer plastic film. The sleeve length is preferably long enough to provide a head space for a visual and tactile indicator of content condition. Sleeves may be packaged with the cartridge, or provided after-market. A 4-mil film polyolefin sleeve preserves water-based acrylic caulk over 9 months.

Description

[0001] The benefit is claimed under 35 USC .sctn. 119 (e) of the filing date of Provisional Application Ser. No. 60 / 179,585 filed Feb. 1, 2000 under the same title by the same inventor.FIELD[0002] The invention relates to closures for nozzles of dispensing cartridges and squeeze tubes, more particularly to a flexible sleeve of plastic film that hermetically seals the nozzle of a fresh or partially-used sealant, mastic, adhesive, glazing or caulk-dispensing cartridge or squeeze tube so that the remaining unused contents do not set. The sleeve(s) may be packaged with the cartridge, or may be provided as an after-market replacement used alone or in combination with ordinary nozzle caps.[0003] It is common practice to package sealant, mastic, adhesive, glazing, caulk and glue compositions in plastic or metal squeeze tubes, or plastic or plastic coated or impregnated paper cartridges which are adapted to be loaded into extrusion devices, ordinarily called caulking guns, in order to dispe...

AI Technical Summary

Benefits of technology

0013] The invention comprises a flexible sleeve of plastic film which tightly fits over the open nozzle of sealant dispenser cartridges and squeeze tubes to provide a hermetic seal to prevent or substantially retard, on a long term basis, the hardening of the remaining contents of the cartridge or tube after its initial use. The plastic film may range widely in composition and thickness including multi-layer and copolymer film, so long as it has the functionality of providing a vapor barrier against exit of water or organic solvent from the sealant composition, and prevent or retard diffusion thereinto of such quantities of oxygen as would cause the composition to set in the case of air-settable compositions. The plastic film is preferably heat sealable, somewhat stretchable and not subject to substantial relaxation or creep over time, so that when the sleeve is inserted over the open nozzle and pulled or pushed downwardly thereon, it provides an extremely tight seal for a substantial distance along its length.

Problems solved by technology

In addition to being uneconomic, disposal of excess composition represents a considerable waste of resources and is highly undesirable for environmental reasons.

At present, there is no known recycling available for the wide variety of sealant and mastic compositions being distributed today.

However, since the plastic of which the caps and nozzles are made has very low tensile strength, it is easy to over-tighten the screw caps, causing them to split.

Likewise, a bead and groove does not provide a hermetic seal for any substantial length of time.

These solutions are temporary at best and typically do not prevent drying out of the contents for more than a few weeks, especially when there is residual pressure on the contents, which results in pushing off the cap.

However, most tubes do not fit in Ziploc.RTM. bags, the plastic is thin (on the order of 1 mil or less), and the bags with the cartridge in them contain so much air as to defeat the purpose.

The wrapping approach simply does not provide an adequate seal.

However, they also suffer from the problem of the caps splitting when they are screwed down too tightly, or not providing a good hermetic seal when the threads, beads or grooves become clogged with partially set or dried sealant material.

Finally, this class of packaging also suffers from the same types of poor cap fit problems as the more common caulk tube type dispensing cartridges.

Thus, in both classes of sealant and mastic packaging (cartridges and squeeze tubes), where the contents of the cartridge or tube are not entirely dispensed during a particular caulking or gluing operation, if precautions are not taken to carefully and redundantly reseal the nozzle, the remaining caulking compound will harden, due to exposure to the atmosphere.

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