Method of packaging a thermoplastic composition with a film having a low complex viscosity and corresponding packaged article

The present invention relates to an improvement in the method of packaging thermoplastic compositions, particularly hot melt adhesive compositions. The method comprises substantially surrounding a portion of adhesive composition with a plastic packaging film having a relatively low complex viscosity at low temperatures. The packaging material is meltable together with the adhesive composition, blendable into the molten adhesive composition, and does not adversely affect the adhesive properties to the extent that it is unnecessary to remove the packaging material from the hot melt adhesive composition prior to usage. The invention is particularly useful for certain low viscosity pressure sensitive adhesive compositions, that are typically applied by melting the packaged adhesive composition in a melt tank. More particularly, the invention is useful for hot melt adhesives that are applied by application means that are very sensitive to inhomogeneity of the combination of molten hot melt adhesive and molten packaging material such as spraying, screen printing, bead applicators and gravure coating hot melt application techniques. The present inventors have discovered that an easily measured property, namely complex viscosity, directly relates to physical film compatibility and have further identified a class of polyolefin materials, which are particularly amenable to exhibiting such properties. It is important to note that this discovery assumes that the film material is first chemically compatible with the thermoplastic composition to be packaged.The invention is particularly useful for low viscosity thermoplastic compositions having a Brookfield viscosity of less than about 10,000 cPs at 350° F., such as pressure sensitive hot melt adhesive compositions which are typically applied by melting the packaged adhesive composition in a melt tank wherein the melt tank lacks an active mixing means. The invention is also useful for hot melt adhesives that are applied by application means that are very sensitive to inhomogeneity of the combination of molten hot melt adhesive and molten packaging material such as spraying, screen printing, foaming and gravure coating hot melt application techniques.