Method of forming paperboard containers

• US 5,096,650 A
• Filed: 02/28/1991
• Issued: 03/17/1992
• Est. Priority Date: 02/28/1991
• Status: Expired due to Fees

• Current Assignee: Network Graphics Incorporated
• Original Assignee: Network Graphics Incorporated
• Inventors: Renna, Douglas J.
• Primary Examiner(s): Lowe, James
• Application Number:
  US07/662,488
• Time in Patent Office: 383 Days
• Field of Search: 264/320, 264/324, 264/322, 229/2.5 R, 162/218, 162/223, 162/225, 162/226, 162/227
• US Class Current: 264/322
• CPC Class Codes: B29C 51/08 Deep drawing or matched-mould forming, i.e. using mechanical means only
• CPC Class Codes: B29K 2001/00 Use of cellulose, modified cellulose or cellulose derivatives, e.g. viscose, as moulding material
• CPC Class Codes: B29K 2105/0064 Latex, emulsion or dispersion
• CPC Class Codes: B29K 2105/256 Sheets, plates, blanks or films
• CPC Class Codes: B29K 2711/126 Impregnated
• CPC Class Codes: B29K 2995/0059 Degradable
• CPC Class Codes: B31B 50/59 Shaping sheet material under pressure by folding B31B50/26; embossing B31B50/88
• CPC Class Codes: B31F 1/0077 Shaping by methods analogous to moulding, e.g. deep drawing techniques
• CPC Class Codes: B65D 65/466 Bio- or photodegradable packaging materials
• CPC Class Codes: Y02W 90/10 Bio-packaging, e.g. packing containers made from renewable resources or bio-plastics

Abstract

A paperboard, containing a major portion of cellulose and a minor portion of an uncured biodegradable latex polymer, is molded into a shaped packaging form.

Claims

1. A process for preparing a formed paperboard body comprising the steps of providing a paperboard sheet having a major portion of cellulose fibers and a minor portion of an uncured latex polymer;

heating said sheet to approximately the glass transition point of the polymer, but below that temperature at which the polymer coverts to a non-soluble state;

introducing said sheet into a mold having the shape of the desired body and subjecting said heated sheet within said mold to pressure for a period of time sufficient to form said body and set said latex into fixed form;

removing said body from said mold; and

cooling said body.

2. The process according to claim 1, wherein said paperboard is formed from an aqueous slurry of between 60 and 80 percent cellulose fibers and about 20 to 40 percent latex polymer.

3. The process according to claim 2, wherein said latex polymer is selected from the group consisting of styrene/butadiene copolymers, vinyl acetate polyvinyl chloride, polyacrylate esters, and polymethacrylate esters.

4. The process according to claim 1, wherein said paperboard in said mold is held at a temperature of between 150 and 300 degrees Farenheit, the pressure is held between 300 and 400 pounds per square inch, and the time of molding is between 5 seconds and 1 minute.