Double Tray System Rigidity via Groove Deepening

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Solution Overview

Problem

The existing plastic double tray system for plant cultivation lacks sufficient rigidity, causing it to sag excessively when supported at two opposite ends, which limits its capacity for heavier loads and variety of plant sizes, and does not provide adequate support for stable use in floating conditions.

Innovation Solution

The double tray system incorporates a bottom tray with frustum-shaped support elements and a groove-shaped deepening on the baseplate, thermoformed to enhance rigidity, where the groove-shaped deepening increases bending stiffness and provides a flat bottom surface to prevent sagging and allow floating use without additional components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the double tray system is supported at two opposite ends on a framework, then the structure is simple and easy to implement, but the rigidity is insufficient causing excessive sagging in the middle region

Engineering Contradiction:
ImproverigidityVSAvoidstructure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The bottom tray is segmented into multiple regions: a middle region with increased wall thickness for central support, and side regions with support elements for lateral stability. This segmentation allows the structure to maintain rigidity without adding complex external components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wall thickness of the bottom tray is not uniform but varies locally: the middle region has increased wall thickness to prevent sagging, while other regions maintain standard thickness. This local quality enhancement provides rigidity exactly where needed without unnecessary material usage.

Inventive Principle:
Principle #3Local quality

2Strength

If the wall thickness of the bottom tray is increased to prevent sagging, then the rigidity is improved, but the manufacturing cost and material usage increase

Engineering Contradiction:
ImproverigidityVSAvoidmaterial usage
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

Instead of uniformly increasing wall thickness throughout the entire bottom tray, the invention applies increased thickness only to the middle region where sagging occurs. This localized approach provides the necessary rigidity while minimizing material consumption and manufacturing cost.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention applies partial action by reinforcing only the critical middle region rather than the entire structure. This partial reinforcement is sufficient to prevent sagging without the excessive material usage that would result from full-tray thickening.

Inventive Principle:
Principle #16Partial or excessive action

3Strength

If support elements are added to the bottom tray to increase rigidity, then the structural stability is improved, but the device complexity and manufacturing steps increase

Engineering Contradiction:
Improvestructural stabilityVSAvoidnumber of components
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The support elements are merged with the bottom tray itself, forming an integrated structure where the support elements and the tray base are made as a single piece. This eliminates the need for separate support components and reduces assembly steps while maintaining structural stability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bottom tray provides its own support functionality through integrated support elements that are part of its structure. The tray serves dual purposes: containing the seedlings and providing structural support, eliminating the need for separate support components.

Inventive Principle:
Principle #25Self-service

4Ease of manufacture

If the bottom tray is designed with a flat bottom surface, then the manufacturing is simplified, but the rigidity is reduced causing the tray to hang down between supports

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidrigidity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The bottom tray maintains a flat bottom surface for most of its area to ensure ease of manufacture and stable placement, but incorporates a localized raised middle region with increased wall thickness. This local quality variation provides rigidity where needed while preserving the overall flat surface for manufacturing simplicity.

Inventive Principle:
Principle #3Local quality

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

The enhanced rigidity allows the double tray system to support a larger variety of plants and prevent excessive sagging, enabling heavier loads and easy transport, while maintaining a low-cost, competitive product with integrated reinforcement.

Implementation Method 1

the groove shaped deepening increases bending stiffness and provides a flat bottom surface to prevent sagging

Methodology Applied
Scientific EffectGeometric reinforcement: Geometry

Implementation Method 2

a plastic sheet is heated to a pliable forming temperature, formed to a specific shape in a mold, and trimmed to create a usable product

Methodology Applied
Scientific EffectThermal softening: Heating

Implementation Method 3

the double tray system is manufactured by thermoforming

Methodology Applied
Scientific EffectThermoforming:

Data Source

PatentEP2975925B1Double tray system for seed sowing or seedling transplantation
Publication Date: 2020.07.01 D T SYST INT LTD
  • EP2975925B1 patent drawingFigure 1A~1B
  • EP2975925B1 patent drawingFigure 2A~2B
  • EP2975925B1 patent drawingFigure 2C~2D

AI summary

Thermoformed double tray system for cultivation of plants including a top tray which is stacked with a bottom tray. The top tray has cells for receiving a substrate. The bottom tray provides rigidity to the double tray system. The bottom tray has a baseplate which is provided with support elements to support the top tray. The baseplate has an outer edge which defines the outer contour of the bottom tray. A groove shaped deepening in the baseplate is extending in parallel with the outer edge. The deepening increases a bending stiffness of the bottom tray and provides rigidity to the double tray system. The deepening is provided with a reinforcing ribs which cross the deepening.