Integrated Erasing Tip Ballpoint Pen Double Injection Molding
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Solution Overview
Problem
Conventional ballpoint pens face difficulties in erasing written content due to cumbersome assembly processes, weakened structural support, and unstable coupling between the erasing tip and the pen body, leading to inefficient erasing and potential contamination from elastomer erasers.
Innovation Solution
A writing instrument with a single, integrated design where the tip erasing body is formed on the outer surface of the lower body through double injection molding, eliminating the need for separate assembly and ensuring a strong, gap-free bond, using a polymer composition that includes hydrogenated styrene isoprene butadiene block copolymer, hydro-treated heavy paraffinic, benzotriazole, zinc distearate, polyethylene, and ethylene-propylene copolymer for effective erasing without additional elastomer erasers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a separate elastomer eraser is attached to the opposite end of the ballpoint pen tip, then the erasing function is achieved through friction heat, but the writing instrument must be reversed to erase, making the correction work cumbersome and causing loss of instantaneous ideas
Solution Approach 1:
The patent combines the erasing function and writing function into a single integrated tip structure. The erasing body is formed integrally with the lower body through double injection molding, allowing both writing and erasing operations to be performed from the same end of the pen, eliminating the need to reverse the instrument for corrections
Solution Approach 2:
The tip assembly serves multiple functions: the ballpoint pen tip performs writing while the integrated erasing body performs erasing. This multi-functional design allows the single instrument to handle both writing and correction tasks without requiring separate tools or orientation changes
2Adaptability or versatility
If a separate elastomer eraser is used, then erasing is achieved, but eraser residue is generated and contaminates the surroundings, and the eraser volume is reduced due to wear, making it unusable later
Solution Approach 1:
The patent changes the material composition of the erasing body from traditional elastomer to a specific resin composition containing polypropylene, ethylene-propylene copolymer, and other additives. This material parameter change eliminates residue generation while maintaining effective erasing capability through controlled friction
Solution Approach 2:
The erasing body is made from a composite resin material consisting of multiple components including polypropylene, ethylene-propylene copolymer, hydrogenated styrene isoprene butadiene block copolymer, and various functional additives. This composite material provides both erasing effectiveness and resistance to residue generation and wear
3Adaptability or versatility
If the tip erasing body and lower body are manufactured separately and then assembled, then the erasing function is integrated, but the assembly process is difficult and cumbersome, resulting in very low productivity
Solution Approach 1:
The patent merges the manufacturing process of the erasing body and lower body into a single double injection molding operation. The erasing body is formed as an integral part of the lower body in one continuous manufacturing step, eliminating all subsequent assembly operations and dramatically improving productivity
Solution Approach 2:
The erasing body is formed during the injection molding process itself, with the material and shape prepared in advance during molding. This preliminary formation eliminates the need for separate assembly steps, as the erasing function is already integrated into the final product structure
4Adaptability or versatility
If the tip erasing body is inserted and fixed inside the lower body, then the erasing function is integrated, but the thickness of the lower body must be relatively thinner, weakening the external shape support and making the pen feel unstable
Solution Approach 1:
The erasing body and lower body are merged into a single integral structure through double injection molding. This merging allows the full thickness of the lower body to be maintained for structural support, while the erasing function is incorporated as an integral surface feature rather than an inserted component
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
Simplifies manufacturing, enhances structural integrity, and allows for seamless erasing without altering the writing direction, preventing residue and improving productivity by integrating the erasing function directly into the pen body.
Implementation Method 1
The operating principle of today's erased ballpoint pen can be explained by the friction heat use method and the friction force use method. The above friction heat use method is to write words or shapes on paper using thermal ink and discolor the color of the thermal ink by friction heat so that the above words or shapes disappear from view.
Implementation Method 2
the above friction force use method does not use the above thermal discoloration ink, but instead uses an adhesive ink with a certain adhesive force on the ground subject to writing work. If a user wants to erase words or shapes already written, the user contacts an eraser on the written words or shapes, rubs the words or shapes with the eraser, pushes the words or shapes written in adhesive ink on the paper by friction between them, and removes them from the paper.
Data Source
AI summary
A writing instrument having a removal function of a handwritten content is provided where a tip erasing body that erases incorrectly written words or pictures is formed on the outer peripheral surface of a lower body, and the tip erasing body and the lower body are formed by a double injection molding method. An integrated one body prevents any form of gap between the tip erasing body and the lower body. Since the tip erasing body is integrally made with the lower body, when a user wants to erase incorrect contents, an unstable state like a conventional product can be overcome.