Hairbrush Bristle Flash-Free Molding via Multi-Part Segmentation
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Solution Overview
Problem
Existing hairbrush bristle production methods are inefficient, leading to bristles that are not gentle on hair and scalp, are costly, and produce significant waste, with flash formation causing hygiene issues and requiring labor-intensive deflashing processes.
Innovation Solution
A method using a multi-part mold system that allows for optimized molding of bristle shafts and feet with separate cavities, enabling flash-free production and resilient mounting, along with the option for different material combinations and bristle head coverings for enhanced gentleness and hygiene.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a multi-part mold part is used to mold bristle shafts, then the bristles can be produced with complex shapes and optimized mold cavities, but flash formation occurs on the bristle shaft which damages hair and creates hygiene issues
Solution Approach 1:
The mold is divided into multiple separable parts (first mold part for bristle shaft, second and third mold parts for bristle foot) that can be independently opened and closed. This segmentation allows the bristle shaft to be molded in a flash-free environment while still enabling complex bristle foot geometries through the multi-part configuration.
Solution Approach 2:
The bristle shaft molding is extracted from the bristle foot molding process. The bristle shaft is molded first in a separate mold cavity formed by the first mold part, then the second and third mold parts are added to complete the bristle foot. This extraction eliminates flash formation on the bristle shaft while preserving the ability to create complex bristle foot shapes.
2Ease of manufacture
If traditional molding methods are used, then production is simpler, but the process is labor-intensive and produces significant waste
Solution Approach 1:
The molding of the bristle shaft and bristle foot is merged into a single integrated process using the multi-part mold system. Both components are molded simultaneously in one injection cycle, eliminating the need for separate molding operations and post-assembly steps, thereby improving productivity without sacrificing manufacturing simplicity.
Solution Approach 2:
The multi-part mold design enables easy removal and recovery of the molded bristles without damage. The mold parts can be separated and reused for the next production cycle with minimal maintenance, reducing waste and improving production efficiency compared to traditional single-piece molds that require complex ejection mechanisms.
3Productivity
If bristle shafts are molded with flash, then production is faster, but deflashing processes are required which are time-consuming and expensive
Solution Approach 1:
The design accepts that multi-part molding can produce flash, but strategically directs this flash formation to occur only on the bristle foot portion where it does not contact hair. The bristle shaft is molded in a flash-free zone, converting the potential harm of flash into a beneficial arrangement where flash is isolated to non-critical areas.
Solution Approach 2:
Different quality requirements are applied to different parts of the bristle. The bristle shaft requires flash-free surfaces for hygiene and hair gentleness, while the bristle foot can tolerate flash as it does not contact hair. The multi-part mold system enables this local quality differentiation by controlling flash formation in specific mold cavities.
4Temperature
If aliphatic polyamides are used for bristles, then heat resistance is improved for use with hot air styling, but flash formation is enhanced due to material flow characteristics
Solution Approach 1:
The molding parameters for aliphatic polyamides are optimized to control material flow. By adjusting injection pressure, temperature, and mold cavity design, the material flow is directed to fill the bristle foot cavity completely while minimizing flash formation. This parameter optimization allows the use of heat-resistant aliphatic polyamides without the excessive flash formation that normally accompanies their good flow characteristics.
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 method enables cost-effective, mass-producible bristles with reduced waste and improved gentleness, allowing for complex shapes that promote resilient mounting and reduced flash formation, enhancing the hygiene and usability of hairbrushes.
Implementation Method 1
The mold cavity will usually taper away from the feed opening, i.e. the mold cavity has a smaller cross-section at a point further away from the feed opening. Accordingly the bristle shaft blank is generally molded in such a way that it tapers in the direction of the bristle head.
Data Source
AI summary
The invention relates to a hairbrush, bristles for use in a hairbrush and a method of producing a hairbrush and such bristles. The invention discloses in particular a method of producing a bristle, in which mouldable material is introduced into a multi-part mould which can be separated into its individual parts, and a bristle having a bristle head, a bristle shank and a bristle foot is produced and a bristle shank is moulded using a first mould part, wherein mouldable material is introduced into a first cavity of the first mould part and subsequently removed from the first cavity of the first mould part, wherein the first cavity of the first mould part is maintained and the bristle foot is moulded using a second mould part and a third mould part, wherein the second and third mould parts together form a second cavity, of which the shape corresponds essentially to the shape of the bristle foot which is to be moulded, and the second cavity is filled with the mouldable material and the second and the third mould parts are subsequently separated, and the bristle head is moulded using a fourth mould part and fifth mould part, wherein the fourth and fifth mould parts together form a third cavity, of which the shape corresponds essentially to the shape of the bristle head which is to be moulded, and the third cavity is filled with the mouldable material and the fourth and the fifth mould parts are subsequently separated.