Thermoset Polymer Utility Vault Lid Mold With Textured Surface

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Solution Overview

Problem

Existing utility vault and pit covers are heavy, difficult to remove, and lack sufficient load-bearing capacity and slip resistance, posing safety risks to workers and limiting their applicability in high-traffic areas.

Innovation Solution

A mold for manufacturing a fiber reinforced polymer material utility vault lid with a textured surface and bosses of varying heights, designed for improved slip resistance, using a low-pressure molding process with a steam pot to enhance strength and UV characteristics, and incorporating a lid ejection mechanism for easy removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If heavy materials like concrete, polymer concrete, or cast iron are used for vault covers to withstand substantial loads, then load-bearing capacity is improved, but weight increases making them difficult to remove and reinstallation

Engineering Contradiction:
Improveload-bearing capacityVSAvoidweight of cover
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent uses fiber-reinforced polymer composite materials combining glass fibers with thermoset polymer resin to create a cover that is both lightweight and strong. The composite structure provides high strength-to-weight ratio, achieving load-bearing capacity comparable to heavy materials while weighing significantly less, thus resolving the contradiction between strength and weight.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameters by using fiber-reinforced polymers with specific fiber orientations and resin formulations to achieve the required mechanical properties. By adjusting fiber content, fiber length, and resin type, the cover achieves adequate load-bearing capacity with reduced weight.

Inventive Principle:
Principle #35Parameter changes

2Weight of moving object

If plastic lids are used to reduce weight, then ease of handling is improved, but load-bearing capacity and slip resistance deteriorate

Engineering Contradiction:
Improveweight of coverVSAvoidload-bearing capacity
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent enhances plain plastic by incorporating fiber reinforcement (glass fibers) into the polymer matrix, creating a composite material that maintains the lightweight advantage of plastics while dramatically improving load-bearing capacity and surface friction properties.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent creates local quality variations by incorporating textured surfaces and patterns on the cover surface to improve slip resistance, while the fiber reinforcement provides localized strength enhancement in areas subjected to high loads.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If smooth surfaces are used on polymer covers, then manufacturing simplicity is improved, but slip resistance deteriorates when wet

Engineering Contradiction:
Improvesurface simplicityVSAvoidslip resistance
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies textured surfaces and patterns only on the top surface of the cover where slip resistance is needed, while keeping other surfaces smooth for manufacturing simplicity. This localized texturing provides improved grip when wet without complicating the overall manufacturing process.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent incorporates surface textures and patterns directly into the mold cavity, so the slip-resistant surface is formed automatically during the molding process without requiring additional post-manufacturing steps, thus maintaining manufacturing simplicity while achieving improved slip resistance.

Inventive Principle:
Principle #10Preliminary action

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 solution results in a lightweight, durable cover that withstands substantial loads, provides improved slip resistance, and is easier to install and remove, while maintaining UV stability and reduced material costs.

Implementation Method 1

using a low-pressure molding process with a steam pot to enhance strength and UV characteristics

Methodology Applied
Scientific EffectThermal heating: Heating

Data Source

PatentEP3711918B1Mold for manufacturing a thermoset polymer utility vault lid
Publication Date: 2025.06.25 CHANNELL COMML CORP
  • EP3711918B1 patent drawingFigure 1
  • EP3711918B1 patent drawingFigure 2
  • EP3711918B1 patent drawingFigure 3~4

AI summary

A method of manufacturing a fiber reinforced composite material lid for an utility vault including mixing an unsaturated polyester thermosetting matrix in to a resin paste, compounding the resin paste into a fiber reinforced composite material, maturing the compounded fiber reinforced composite material, cutting the matured compound into a charge pattern, molding the charge pattern in a mold cavity of a heated mold under low pressure to form the lid and cooling and machining the lid. The mold includes a cavity die and a core die having a shear angle for interfacing the core die within the cavity die and a steam pot for heating the cavity die and the core die, wherein the lid is molded between the cavity die and the core die and removed from the mold by a lid ejection mechanism.