Method of extrusion blow-molding container having upper and lower sections of different thickness
OwnerEdward S. Robbins, IIIinventor
Life of this patent
Estimating the term…
Abstract
A method of forming a container having upper and lower portions, the lower portion having self-supporting side walls and a bottom wall. The upper portion is flexible and non-self-supporting. Preferably, the upper and lower portions are formed of plastic material with the upper portion forming a integral continuation of the lower portion. The entire container may be formed using blow molding techniques or other conventional means such as co-extrusion.
Claims17
A method of making a plastic container comprising an enclosure having integral upper and lower portions, said lower portion being generally tubular and including side walls of a plastic material of a predetermined thickness and a bottom wall, and said upper portion being a tubular extension of said lower portion, and having an open upper end, and being of a flexible, gatherable, and non-self-supporting thin film plastic material of a predetermined thickness substantially less than the thickness of the plastic material forming said lower portion, whereby the container may stand in an upright orientation with the side wall supporting said upper and lower portions, the steps comprising forming said upper and lower portions by extruding sequentially continuous first and second portion of a parison having first and second wall thicknesses, one thickness being substantially less than other, disposing said first and second parison portions in a blow mold having mold walls, urging the first and second parison portions into conformance with the mold walls to form the container, the parison portion of substantially less thickness forming said upper container portion, and removing a part of said upper portion to form said open upper end.
A method of making a plastic enclosure comprising the steps of:
- substantially simultaneously forming integral first and second generally tubular enclosure portions in a single continuous process, said first enclosure portion including side walls and a bottom wall closing one end thereof, the step of forming said first enclosure portion comprising the step of forming said side walls of a plastic material of predetermined thickness such that said side walls are self-supporting;
- and forming said second enclosure portion from a flexible, gatherable and non-self-supporting thin film plastic material of a predetermined thickness less than the thickness of the plastic material forming the side walls of said first enclosure portion and extending integrally as a tubular extension of an end of said first enclosure portion remote from said bottom wall, said second enclosure portion having an open upper end, the steps of forming said first and second enclosure portions in a single continuous process comprising extruding sequentially continuous first and second portions of a parison having first and second wall thicknesses, one thickness being substantially less than the other, disposing said first and second parison portions in a blow mold having mold walls, urging the first and second parsion portions into conformance with the mold walls to form the enclosure, the parison portion of substantially less thickness forming said second enclosure portion and, removing a part of said second enclosure portion to form said open upper end.
A method of making a plastic enclosure comprising the steps of:
- substantially simultaneously forming integral first and second generally tubular enclosure portions in a single continuous process, said first enclosure portion including side walls and a bottom wall closing one end thereof, the step of forming said first enclosure portion comprising the step of forming said side walls of a plastic material of predetermined thickness such that said side walls are self-supporting;
- and,
- forming said second enclosure portion from plastic material integral with and of a predetermined thickness less than the thickness of the plastic material forming the side walls of said first enclosure portion and extending integrally as a tubular extension of said first enclosure portion adjacent an end of said first enclosure portion remote from said bottom wall such that the second portion is flexible, gatherable, non-self-supporting, and comprised of thin film plastic material, said second enclosure portion having an open upper end, the steps of forming said first and second enclosure portions comprising extruding sequentially continuous first and second portions of a parison having first and second wall thicknesses, one thickness being substantially less than the other, disposing said first and second parison portions in a blow mold having mold walls, urging the first and second parison portions into conformance with the mold walls to form the enclosure, the parison portion of substantially less thickness forming said second enclosure portion, and removing a part of said second enclosure portion to form said open upper end.
Dependencies are inferred from the claim text.