Two-Component Toothbrush Head Over-Molding for Secure Embedding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing toothbrushes with elastomeric cleaning elements lack design flexibility, secure fastening, and material variety, often requiring elastomeric elements to be made from the same material as the brush head, which limits properties and handling efficiency.
Innovation Solution
A method involving two-component (2K) cleaning elements, where one component is over-molded with a harder plastic material to create an undercut, allowing for secure embedding within the toothbrush head and enabling greater design flexibility and material choice, along with the integration of bristle tufts for enhanced functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If elastomeric cleaning elements are directly over-molded with the brush head material, then the manufacturing process is simplified, but the design flexibility and material selection are limited
Solution Approach 1:
The cleaning element is divided into two separate components: a first component (elastomeric cleaning element) and a second component (harder plastic material). This segmentation allows each component to be optimized independently - the first component provides cleaning functionality with elastomeric properties, while the second component enables secure fastening through undercut formation during over-molding, thus resolving the contradiction between manufacturing simplicity and design flexibility
Solution Approach 2:
The cleaning element uses a composite structure combining two different materials with distinct properties. The first component uses elastomeric material for cleaning performance, while the second component uses harder plastic material for structural support and anchoring. This composite approach enables both ease of manufacture through over-molding and versatility in material selection and design flexibility
2Ease of manufacture
If elastomeric cleaning elements are made from the same material as the brush head, then the manufacturing process is simplified, but the properties and handling efficiency are reduced
Solution Approach 1:
Different regions of the cleaning element have different material properties tailored to their specific functions. The first component (elastomeric) provides local quality for cleaning contact with soft tissues, while the second component (harder plastic) provides local quality for mechanical resistance and secure anchoring in the brush head, thus resolving the contradiction between material consistency and handling efficiency
3Manufacturing precision
If elastomeric cleaning elements are arranged at the outer surface of the cleaning element field, then the geometric requirements are met, but the design flexibility is reduced
Solution Approach 1:
The second component extends in a direction perpendicular to the brush head surface, creating a three-dimensional structure that allows the cleaning element to be embedded within the brush head rather than constrained to the outer surface. This dimensional change enables flexible arrangement options including embedded, surface-level, or protruding configurations, resolving the contradiction between geometric precision and design flexibility
4Productivity
If downstream over-molding techniques are applied to elastomeric cleaning elements, then the brush head is formed, but the elastomeric cleaning elements are negatively influenced
Solution Approach 1:
The second component with undercut structure is prepared in advance during the first over-molding step, creating a protective and anchoring structure before the final brush head formation. This preliminary action protects the elastomeric first component from degradation during downstream processing while enabling secure fastening, thus resolving the contradiction between productivity and element integrity
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 allows for secure fastening and enhanced handling of elastomeric cleaning elements, offering improved design flexibility and material options while maintaining mechanical resistance and ease of processing, thus improving the manufacturing efficiency of toothbrushes.
Implementation Method 1
the second component is over-molded with a harder plastic material to create an undercut, allowing for secure embedding within the toothbrush head
Data Source
Figure 1A~1J
Figure 2a~2f
Figure 3a~3f
AI summary
Brush heads, in particular toothbrush heads comprising bristle tuft cleaning elements and two-component-(2K)-cleaning elements can be produced by injection molding. In order to achieve high design flexibility regarding the arrangement of the 2K-cleaning elements and regarding the material choice, the 2K-cleaning elements may be manufactured separately or in an upstream molding step. Then the 2K-cleaning elements together with the bristle tuft(s) may be over-molded with plastic material in order to form the brush head or a part thereof.