Numeric Display Housing via Two-Step Injection Molding
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Solution Overview
Problem
Traditional manufacturing methods for numeric displays are lengthy, prone to defects such as epoxy leakage and thermal stress-induced deformations, leading to low yield and non-uniform lighting.
Innovation Solution
The method involves two injection-molding steps to form a housing for numeric displays, eliminating the need for epoxy dispensing and baking, using thermoplastic or thermosetting materials like PPA or silicone to create a transparent injection-molded body with microstructures for improved light performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional epoxy dispensing and baking process is used, then the housing is formed and cured, but the manufacturing time is long (1.5 hours pre-curing at 110°C plus 3 hours post-curing at 120°C)
Solution Approach 1:
The patent changes the material parameter from traditional epoxy to fast-curing epoxy, which has different curing characteristics that allow for reduced baking time. The fast-curing epoxy formulation enables the same housing formation function to be achieved in a fraction of the original time, directly resolving the time loss issue while maintaining productivity.
2Ease of manufacture
If traditional epoxy dispensing process is used, then the housing is formed, but defects such as epoxy leakage and un-uniform dispensing occur causing recesses on the lighting surface
Solution Approach 1:
The patent replaces the mechanical dispensing process with an injection molding process. Instead of manually or automatically dispensing epoxy in a way that causes leakage and non-uniformity, the injection molding system uses controlled material injection through a mold, ensuring uniform filling and eliminating the defects associated with traditional dispensing methods.
3Reliability
If baking step is used to cure epoxy, then the epoxy is cured, but thermal stress is generated causing housing deformation
Solution Approach 1:
The patent changes the thermal parameters of the curing process by using fast-curing epoxy that requires lower and shorter thermal exposure. This parameter change reduces the cumulative thermal stress on the housing structure, preventing deformation while still achieving complete curing of the epoxy material.
4Productivity
If traditional dispensing and baking process is used, then the housing is formed and cured, but the manufacturing cost cannot be reduced
Solution Approach 1:
The patent changes the time and temperature parameters of the curing process through fast-curing epoxy formulation. The reduced curing time (from 4.5 hours to significantly less) directly reduces energy consumption during the baking process, while the improved manufacturing speed increases overall productivity, thereby reducing manufacturing cost.
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 significantly reduces manufacturing time, avoids thermal stress-related deformations, and eliminates defects like bubbles and non-uniform lighting, resulting in a more efficient and reliable production process.
Implementation Method 1
a second injection-molding step for filling a transparent material into each pattern segment unit to form a transparent injection-molded body
Implementation Method 2
The thermoplastic transparent material has a main component of PPA or PA
Implementation Method 3
the thermosetting transparent material can be silicone or resin material
Data Source
AI summary
The method for manufacturing a housing of a numeric display have the steps of: providing a first injection-molding step for forming a reflecting cover, wherein the reflecting cover has a plurality of pattern segment units, each pattern segment unit is defined by reflecting surfaces of the reflecting cover and has a through hole, and providing a second injection-molding step for forming a transparent injection-molded body into each pattern segment unit, surfaces of the formed transparent injection-molded body being bonded to the corresponding reflecting surfaces, and the reflecting cover and the transparent injection-molded body being constructed as the housing of the numeric display.