Injection molded cutlery and method and system therefor

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Solution Overview

Problem

Injection molding machines face inefficiencies when switching from non-biodegradable plastics like polypropylene or polystyrene to biodegradable plastics due to significantly higher injection pressures, leading to reduced production capacity and the need for more robust machinery or increased clamping forces.

Innovation Solution

By injecting biodegradable plastics into the center section of the mold cavity instead of the end, reducing the required injection pressure to levels comparable to non-biodegradable plastics, while maintaining similar injection times, thus allowing the use of existing machinery and increasing production efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If biodegradable plastic is injected at the end of the cavity like conventional plastic, then the injection process follows standard procedure, but the injection pressure becomes excessively high (more than double that of conventional plastic)

Engineering Contradiction:

Improveinjection process standardizationVSAvoidinjection pressure

Core Design Contradiction:

Ease of manufactureVSStress or pressure

Solution Approach 1:

The patent inverts the conventional injection approach by injecting molten biodegradable plastic at the center section of the cavity rather than at the end. This reverse injection strategy allows the material to flow outward in multiple directions simultaneously, dramatically reducing the injection pressure from more than double conventional levels to acceptable ranges, while still achieving complete cavity fill.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent transitions from one-dimensional end injection to multi-dimensional center injection. By positioning the injection gate at the center section, the molten plastic flows radially in multiple directions simultaneously, effectively utilizing three-dimensional space for material distribution and reducing pressure requirements.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If biodegradable plastic is injected at high pressure to fill the cavity, then the cavity can be filled completely, but the number of pieces that can be molded in a single cycle decreases

Engineering Contradiction:

Improvecavity fill completenessVSAvoidproduction rate

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

By inverting the injection location from end to center, the patent achieves complete cavity fill at lower pressures, which maintains manufacturing precision while enabling higher production rates by reducing the robustness requirements of the injection molding machine.

Inventive Principle:

Principle #13The other way round (Inversion)

3Stress or pressure

If high injection pressure is used for biodegradable plastic, then the material can be forced into the cavity, but more robust (larger) injection molding machines are required

Engineering Contradiction:

Improveinjection pressureVSAvoidmachine robustness

Core Design Contradiction:

Stress or pressureVSDevice complexity

Solution Approach 1:

The patent applies the inversion principle by changing the injection location from end to center, which reduces the required injection pressure to levels similar to conventional plastics. This allows existing standard-sized injection molding machines to produce biodegradable cutlery without requiring more robust, larger, or more expensive equipment.

Inventive Principle:

Principle #13The other way round (Inversion)

4Ease of manufacture

If injection is performed at the end of the cavity, then the process follows conventional methods, but the clamping force requirements increase

Engineering Contradiction:

Improveprocess conventionalityVSAvoidclamping force

Core Design Contradiction:

Ease of manufactureVSForce

Solution Approach 1:

By inverting the injection approach to center injection, the patent distributes the molten plastic flow more evenly throughout the cavity, reducing peak pressures and consequently lowering the clamping force requirements compared to conventional end injection methods.

Inventive Principle:

Principle #13The other way round (Inversion)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables the production of biodegradable cutlery at the same rate as non-biodegradable cutlery using existing injection molding machines, without the need for new, higher-tonnage equipment, and maintains production efficiency.

Implementation Method 1

The injector assembly is coupled to the mold to provide the bio-material to the plurality of utensil-shaped cavities via the plurality of gates

Methodology Applied

Scientific EffectInjection pressure: Pressure Increase

Data Source

PatentUS12611061B2Injection molded cutlery and method and system therefor

Publication Date: 2026.04.28 DART CONTAINER CORP

AI summary

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.