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US-20260123777-A1 - INJECTION MOLDED CUTLERY

US20260123777A1US 20260123777 A1US20260123777 A1US 20260123777A1US-20260123777-A1

Abstract

Aspects of the present disclosure relate to injection molded cutlery having a body defining a handle portion and a utensil portion, with an injection gate mark located at a center section of the body. The body can be made from a bio-material injected at a pressure that is less than 60% of an injection pressure required for injection at an end of the body.

Inventors

  • Daniel A. Blundy
  • Gregory A. Warner
  • MARCUS JEFFERY NORMAN
  • Kyle Coutchie

Assignees

  • DART CONTAINER CORPORATION

Dates

Publication Date
20260507
Application Date
20260107

Claims (20)

  1. 1 . A piece of injection molded cutlery having a body defining a handle portion and a utensil portion, with an injection gate mark located at a volumetric center section of the body, and the body is made from a bio-material injected at a pressure that is less than 60% of an injection pressure required for injection at an end of the body.
  2. 2 . The piece of injection molded cutlery of claim 1 wherein the volumetric center section comprises 20% or less of a total volume of the body.
  3. 3 . The piece of injection molded cutlery of claim 2 wherein the volumetric center section comprises 15% or less of the total volume of the cavity.
  4. 4 . The piece of injection molded cutlery of claim 3 wherein the volumetric center section comprises 10% or less of the total volume of the cavity.
  5. 5 . The piece of injection molded cutlery of claim 4 wherein the volumetric center section comprises 5% or less of the total volume of the cavity.
  6. 6 . The piece of injection molded cutlery of claim 2 wherein the body has a volume to surface area ratio of 0.0242 or less.
  7. 7 . The piece of injection molded cutlery of claim 6 wherein the body has a thickness of 0.0450 inches to 0.0508.
  8. 8 . The piece of injection molded cutlery of claim 6 wherein the bio-material comprises Polyhydroxyalkanoate (PHA).
  9. 9 . The piece of injection molded cutlery of claim 8 wherein the center section includes a section of the handle portion; and wherein the injection gate mark is located in the section of the handle portion.
  10. 10 . The piece of injection molded cutlery of claim 1 wherein the body is compostable.
  11. 11 . The piece of injection molded cutlery of claim 1 wherein the body is biodegradable by at least 90% within twelve months in an environment having a temperature range of 20 to 30 degrees Celsius.
  12. 12 . The piece of injection molded cutlery of claim 1 wherein the body is formed with a clamping pressure of 3 tons per square inch or less and the body is at least 5.5 inches long.
  13. 13 . A piece of injection molded cutlery having a body defining a handle portion and a utensil portion, with an injection gate mark located at a volumetric center section of the body, and the body is made from a bio-material injected in the volumetric center section.
  14. 14 . The piece of injection molded cutlery of claim 13 wherein the volumetric center section comprises 20% or less of a total volume of the body.
  15. 15 . The piece of injection molded cutlery of claim 14 wherein the volumetric center section comprises 15% or less of the total volume of the cavity.
  16. 16 . The piece of injection molded cutlery of claim 15 wherein the volumetric center section comprises 10% or less of the total volume of the cavity.
  17. 17 . The piece of injection molded cutlery of claim 16 wherein the volumetric center section comprises 5% or less of the total volume of the cavity.
  18. 18 . The piece of injection molded cutlery of claim 13 wherein the injection gate mark is located at a volumetric center of the body.
  19. 19 . The piece of injection molded cutlery of claim 18 wherein the body has a thickness of 0.0450 inches to 0.0508.
  20. 20 . The piece of injection molded cutlery of claim 19 wherein the body is formed with a clamping pressure of 3 tons per square inch or less and the body is at least 5.5 inches long.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisional of U.S. patent application Ser. No. 18/417,371, filed Jan. 19, 2024, now allowed, which claims priority to and the benefit of U.S. Provisional Ser. No. 63/455,708 filed Mar. 30, 2023, both of which are incorporated herein by reference in their entirety. BACKGROUND Plastic cutlery or utensils, such as forks, knives, and spoons, are widely used, and typically made by injection molding, which is based on a mold set defining multiple cavities in the shape of the utensil being made. The molten plastic is injected into each of the cavities, typically at an end portion of the cavity forming a handle for the utensil, at an injection pressure to ensure the plastic will flow from the one end of the cavity to the other to fill the cavity. Injection molding machines generally include an injector, platen, and press. The platen generally has a fixed platen coupled to the injector and supports a first part of the mold, and a moveable platen driven by the press toward the fixed platen and supporting a second part of the mold, where the first and second mold parts come together to form the cavity. The press applies a counter force to the injection pressure from the injector to keep the mold parts closed. The injection molding machines come in standard sizes, which are normally rated based on the pressure generated by the press, with the sizing being categorized in terms of “tons of pressure” or “tonnage”, for example, a “5 ton machine”. The platens tend to be of a fixed size and can only accommodate a mold or multiple molds of a certain physical size. The number of utensils that can be formed in a single cycle of operation of the injection molding machine is a function of the needed injection pressure, the tonnage rating of the press, and the area on the platen. SUMMARY According to one aspect, a piece of injection molded cutlery having a body defining a handle portion and a utensil portion, with an injection gate mark located at a volumetric center section of the body, and the body is made from a bio-material injected at a pressure that is less than 60% of an injection pressure required for injection at an end of the body. In another aspect, A piece of injection molded cutlery having a body defining a handle portion and a utensil portion, with an injection gate mark located at a volumetric center section of the body, and the body is made from a bio-material injected in the volumetric center section. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a schematic view of an exemplary system for injection molding cutlery according to an aspect of the disclosure. FIG. 2 is a cross-sectional view of an exemplary mold portion for injection molding cutlery according to an aspect of the disclosure. FIG. 3 is a flow diagram of an exemplary method for injection molding cutlery according to an aspect of the disclosure. FIGS. 4-6 are perspective views of an exemplary mold cavity prior to injection, during injection, and after injection, respectively, according to an aspect of the disclosure. FIGS. 7 and 8 are perspective views of injection molded cutlery according to an aspect of the disclosure. FIGS. 9 and 10 are cross-sectional views of injection molded cutlery according to an aspect of the disclosure. FIG. 11 is a schematic view of an exemplary system for injection molding cutlery according to an aspect of the disclosure. DETAILED DESCRIPTION Injection molding machines rely on a press to applying a clamping force (tons or tonnage) to hold the mold parts together against the injection pressure of the molten plastic. The injection pressure is provided by an extruder that feeds the molten plastic to the mold. The platens of the injection molding machine are normally sized to accommodate different size molds and/or multiple molds. The size and/or number of molds are limited by the area of the platen, the injection pressure required by the plastic for the given mold, and the tonnage of the injection molding machine. The clamping force of the injection molding machine has to be greater than the injection pressure as applied to the one or more molds. As injection pressure increases, the number of mold cavities will decrease, all other things being equal. The injection molding of plastic cutlery historically used polypropylene or polystyrene as the plastic, which was injected at the end of the handle and flowed to the tip of the cutlery. Polypropylene and polystyrene are not considered biodegradable plastics. When switching to biodegradable plastics, which have a much higher viscosity, it was found that the injection pressure was almost double that required for the non-biodegradable plastics. All things being equal, the doubling of the injection pressure when using biodegradable plastics would result in an inverse reduction in the number of pieces of cutlery that could be molded in a single cycle of the injection molding machine compared to when the machine