Disposable, microwaveable containers having suitable food contact compatible olfactory properties and process for their manufacture
AssigneeFort James Corporation
InventorsRonald L. Cochran II, Mark B. Littlejohn, Donald C. McCarthy, Cristian M. Neculescu, Robert Patterson, Anthony J. Swiontek
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Abstract
Low-odor microwaveable polypropylene/mica food contact articles are disclosed. The articles are prepared by low temperature processing and typically include odor-suppressing basic organic or inorganic compounds. Preferably, the articles are substantially free from C8 and C9 organic ketones associated with undesirable odors. Further improvements to the articles include crack-resistant embodiments with synergistic amounts of polyethylene and titanium dioxide.
Claims84
A microwaveable, disposable food contact article having food contact compatible olfactory properties formed from a melt-processed polyolefin/mica composition wherein said composition includes from about 40 to about 90 percent by weight of a polypropylene polymer and from about 10 to about 50 percent by weight mica and wherein said melt processed composition exhibits a relative aroma intensity index of less than about 1.6.
A microwaveable, disposable food contact article having food contact compatible olfactory properties formed of a melt-processed polyolefin/mica composition wherein said composition includes from about 40 to about 90 percent by weight of a polypropylene polymer and from about 10 to about 50 percent by weight mica and a basic organic or inorganic compound comprising the reaction product of an alkali metal or alkaline earth element with carbonates, phosphates, carboxylic acids as well as alkali metal and alkaline earth element oxides, hydroxides or silicates and basic metal oxides, including mixtures of silicone dioxide with one or more of the following oxides:
- magnesium oxide, calcium oxide, barium oxide, and mixtures thereof.
A low temperature compounding process for preparing polypropylene/mica melt compounded product which includes a basic odor-suppressing agent having olfactory properties suitable for food contact applications comprising the sequential steps of:
- (a) preheating a polypropylene polymer while maintaining the polymer below a maximum temperature of about 350° F.;
- followed by (b) admixing mica to said pre-heated polymer in an amount from about 10 to about 50 percent by weight based on the combined weight of resin and mica;
- followed by (c) extruding said mixture.
A process for forming a microwaveable, disposable, rigid and strong, mica and basic inorganic or organic compound filled polyolefin container having food contact compatible olfactory properties, said polyolefin being selected from the group consisting of polypropylene and polypropylene polyethylene copolymer or blend, and a mixture of these wherein the inorganic or organic compound is selected from the group consisting of calcium carbonate, sodium carbonate, potassium carbonate, barium carbonate, aluminum oxide, sodium silicate, sodium borosilicate, magnesium oxide, strontium oxide, barium oxide, zeolites, sodium phosphate, potassium phosphate, magnesium phosphate, sodium stearate, calcium stearate, potassium stearate, sodium citrate, potassium citrate, hydroxides of these elements, and mixtures of these organic compounds, mixtures of silicon dioxide with one or more of the following oxides:
- magnesium oxide, calcium oxide, barium oxide, and mixtures of one or more of the basic inorganic or organic compounds set forth herein, comprising the steps of:
- (a) forming an extrudable admixture of the polyolefin resin, mica, and the basic inorganic compound or basic organic compound;
- (b) extruding said extrudable admixture of the polyolefin resin, mica, and the basic inorganic compound or the basic organic compound at elevated temperature;
- (c) passing the resulting extruded admixture of the polyolefin resin and mica and the basic inorganic compound or the basic organic compound through a multiple roll stack, at least one roll of said stack having a matte finish;
- (d) thermoforming said extruded admixture of the polyolefin, resin, mica, and the basic inorganic compound or organic compound;
- and
- (e) recovering a container having a micronodular surface and exhibiting a melting point of no less than 250° F., said container being dimensionally stable and resistant to grease, sugar, and water at temperatures up to about 220° F. and having sufficient toughness to be resistant to cutting by serrated flatware wherein the amount of the basic inorganic compound or basic organic compound added is sufficient to reduce carbonyl moiety containing decomposition products to provide containers with suitable food contact compatible olfactory properties.
A process for forming a microwaveable, disposable, rigid and strong, mica and basic inorganic or organic compound filled polyolefin container having food contact compatible olfactory properties, said polyolefin being selected from the group consisting of polypropylene and polypropylene polyethylene copolymer or blend, and a mixture of these wherein the inorganic or organic compound is selected from the group consisting of calcium carbonate, sodium carbonate, potassium carbonate, barium carbonate, aluminum oxide, sodium silicate, sodium borosilicate, magnesium oxide, strontium oxide, barium oxide, zeolites, sodium phosphate, potassium phosphate, magnesium phosphate, sodium stearate, calcium stearate, potassium stearate, sodium citrate, potassium citrate, corresponding hydroxides of the foregoing elements and mixtures of these organic compounds, mixtures of silicon dioxide with one or more of the following oxides:
- magnesium oxide, calcium oxide, barium oxide, and mixtures of one or more of the basic inorganic or organic compounds set forth herein, comprising the steps of:
- (a) forming an extrudable admixture of the polyolefin resin, mica, and the basic inorganic compound or basic organic compound;
- (b) extruding said extrudable admixture of the polyolefin resin, mica and the basic inorganic compound or the basic organic compound at elevated temperature;
- (c) passing the resulting extruded admixture of the polyolefin resin and mica and the basic inorganic compound or the basic organic compound through a multiple roll stack, at least one roll of said stack having a matte finish;
- (d) passing said extruded admixture of the polyolefin resin, mica, and basic inorganic compound or the basic organic compound at least partially around said roll having a matte finish;
- (e) controlling the speed of said extrusion process, the size, temperature and configuration of said roll stack such that the surface of said extruded admixture of the polyolefin resin, mica, and the basic inorganic or organic compound not in contact with said matte roll has a coarse-grained structure;
- (f) thermoforming said extruded admixture of the polyolefin, resin, mica, and the basic inorganic compound or organic compound;
- and
- (g) recovering a container having a micronodular surface and a rough surface and exhibiting a melting point of no less than 250° F., said container being dimensionally stable and resistant to grease, sugar, and water at temperatures up to about 220° F. and having sufficient toughness to be resistant to cutting by serrated flatware wherein the amount of the basic inorganic compound or basic organic compound added is sufficient to reduce carbonyl moiety containing decomposition products associated with odor to provide containers with suitable food contact compatible olfactory properties.
A crack-resistant, theromoformed food contact article having a wall thickness from about 10 to about 80 mils consisting essentially of from about 40 to about 90 percent by weight of a polypropylene polymer, from about 10 to about 50 percent by weight mica, from about 1 to about 15 percent by weight polyethylene, from about 0.1 to about 5 weight percent titanium dioxide and optionally including a basic organic or inorganic compound comprising the reaction product of an alkali metal or alkaline earth element with carbonates, phosphates, carboxylic acids as well as alkali metal and alkaline earth element oxides, hydroxides, or silicates and basic metal oxides, including mixtures of silicone dioxide with one or more of the following oxides:
- magnesium oxide, calcium oxide, barium oxide, and mixtures thereof.
Dependencies are inferred from the claim text.