Manufacturing method for writing instruments by injection molding
By injection molding writing instruments with a 50% inorganic filler content, particularly using calcium carbonate, the challenge of single-use medical instruments contributing to plastic waste is addressed, enabling combustible disposal and reducing waste volume.
JP2026096745APending Publication Date: 2026-06-15MORI TRUST HLDG INC +1
Patent Information
- Application Number
- JP2024210566
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-12-03
- Publication Date
- 2026-06-15
AI Technical Summary
Technical Problem
Existing writing instruments, particularly medical ones, contribute significantly to plastic waste due to their single-use nature and are not easily disposable as combustible waste, failing to meet the requirements of reducing plastic waste volume.
Method used
Manufacturing writing instruments by injection molding using a mixture of inorganic filler and thermoplastic resin, with a minimum 50% inorganic filler content, specifically utilizing calcium carbonate particles, to enable combustible waste disposal.
Benefits of technology
The method allows for the production of writing instruments suitable for combustible waste disposal, reducing plastic waste volume effectively and making them suitable for medical use.
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Abstract
The objective is to provide a method for manufacturing writing instruments by injection molding that is not significantly different from that of ordinary writing instruments, can be disposed of as combustible waste, and is particularly suitable as medical writing instruments. [Solution] A method for manufacturing a writing instrument consisting of a barrel 1, a cap 2, and a lead holder 3 fitted into the barrel 1 with a lead inserted, by injection molding, wherein the cap 2 and lead holder 3 are injection molded using only thermoplastic resin, and the barrel 1 is injection molded using a mixture of inorganic filler and thermoplastic resin, with the inorganic filler content in the entire writing instrument set to be 50% by mass or more.
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Citation Information
Patent Citations
Writing utensil
JP2000272286A