Arc-Shaped Drainage Grid Injection Molding Process
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Solution Overview
Problem
Existing plastic drainage grids, produced through injection molding, lack sufficient resistance to support higher loads, limiting their use to pedestrian areas due to their rectangular section design, whereas metal grids can handle higher loads like class C250, necessitating a more durable and stable plastic solution.
Innovation Solution
An injection molding process and apparatus that create drainage grids with an arc-shaped cross-section and inverted T-ribs, where the imprint is primarily in the movable matrix and the molten material is contained in the fixed matrix, allowing for a more robust structure with increased resistance by concentrating material in the cylindrical body and optimizing rib design for load distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If plastic drainage grids are made with a rectangular section design, then they are easier to manufacture through injection molding, but they lack sufficient resistance to support higher loads
Solution Approach 1:
The patent applies curvature by transitioning from a rectangular cross-section to an arc-shaped cross-section for the drainage grid. The grid features a curved profile with a crown (highest point) and extrados/intrados surfaces, which provides superior mechanical strength and load-bearing capacity compared to straight rectangular designs, while still being manufacturable through injection molding processes
2Ease of manufacture
If plastic materials are used for drainage grids, then the production cost is reduced, but the resistance and durability are insufficient compared to metal grids
Solution Approach 1:
The patent changes the geometric parameters of the grid structure, specifically implementing an arc-shaped cross-section with optimized curvature radius, crown height, and rib thickness. These parameter changes enable plastic materials to achieve load-bearing capacities comparable to metal grids while maintaining the cost advantages of plastic manufacturing
3Ease of operation
If the imprint of the cavity is obtained entirely in the movable matrix, then the extraction of the article is easier, but the molten material containment and injection control become more difficult
Solution Approach 1:
The patent segments the cavity formation between the two matrices: the movable matrix forms the extrados surface and through-holes (imprint), while the fixed matrix forms the intrados surface and contains the molten material during injection. This segmentation allows easy extraction of the grid from the movable matrix while maintaining effective material containment and injection control through the fixed matrix
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 resulting drainage grids exhibit improved tensile strength and resistance, enabling them to support loads comparable to metal grids of class C250, while being lighter and more cost-effective, thus suitable for areas with occasional vehicle passage.
Implementation Method 1
plastic articles can be produced through an injection molding process in which a plastic material, usually a thermoplastic material, is molten and then injected under pressure into a mold formed by two matrices
Implementation Method 2
waiting for the solidification of the plastic material in the one or more cavities on obtaining a drainage grid for each of the one or more cavities
Data Source
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AI summary
An injection molding process to mold an element and an apparatus for the realization of said process. More particularly, an injection molding process and an apparatus for the realization of a drainage grid (10) comprising a rectangular element showing four sides (12, 14, 16, 18), an upper face (17) and a lower face (19), the cross-section being shaped like an arc at the lower face (19), said rectangular element comprising at least three longitudinal ribs (30) and at least three transverse ribs (26, 28, 30, 32, 34, 36, 38).