Textured Mold Surface for Implantable Device Manufacturing

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Solution Overview

Problem

Existing methods for manufacturing implantable medical devices with textured surfaces often result in inconsistent surface textures and contamination risks, as they involve direct projection of particles into non-crosslinked polymers, which can lead to variations in surface state and contamination of controlled manufacturing areas.

Innovation Solution

A method using a mold with a textured surface created by shot-blasting with corundum particles to produce a negative replica of the device, allowing for the application and cross-linking of polymers, resulting in a consistent textured surface without additional mold integrations, and can be applied to various implant shapes and materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If direct projection of particles into non-crosslinked polymers is used to texture the surface, then the textured surface can be created, but the surface texture becomes inconsistent and contamination risks increase

Engineering Contradiction:
Improvesurface texture consistencyVSAvoidcontamination risk
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The mold surface is textured by shot-blasting with corundum particles before the polymer application step. This preliminary texturing of the mold creates a consistent negative replica that is then transferred to the polymer during molding, eliminating the need for direct particle projection onto the polymer and ensuring uniform surface texture while reducing contamination risks.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The textured mold acts as an intermediary tool between the shot-blasting process and the final polymer implant. The mold surface captures the textured pattern from shot-blasting and transfers it to the polymer during molding, serving as a mediator that decouples the particle projection process from the polymer processing, thereby ensuring consistency and reducing contamination.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If additional elements are integrated on the mold to achieve texturing, then the surface texture can be improved, but the device complexity increases

Engineering Contradiction:
Improvesurface texture qualityVSAvoidmold complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The texturing function is extracted from the mold structure itself and implemented as a separate pre-processing step using shot-blasting. Instead of integrating complex texturing mechanisms into the mold, the mold surface is simply subjected to external particle bombardment before polymer application, thereby maintaining mold simplicity while achieving high surface texture quality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The texturing operation is performed as a preliminary action on the mold surface before polymer molding. By preparing the mold surface in advance through shot-blasting, the complex texturing effect is achieved without requiring complex integrated structures during the actual molding process, thus reducing overall device complexity.

Inventive Principle:
Principle #10Preliminary action

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 method ensures reproducible, consistent surface textures for implantable medical devices, reduces contamination risks, and is simpler and cost-effective compared to other techniques like atomic particle irradiation, facilitating better integration with surrounding tissues.

Implementation Method 1

texturing said surface of the mold by shot-blasting with solid particles of defined material and size, at defined pressure

Methodology Applied
Scientific EffectShot-blasting:

Implementation Method 2

cross-linking said polymer applied to the mould

Methodology Applied
Scientific EffectCross-linking: Chemical Bonding

Data Source

PatentEP1847369B1Method of manufacturing implantable medical devices with textured surface
Publication Date: 2008.12.31 CEREPLAS
  • EP1847369B1 patent drawingFigure 1~4

AI summary

A combined dosing and feed unit (15) with flow and return channels (1-6) is provided for the two or more reactive components of the plastic. Each component alternatively has its own, separate dosing and supply unit. The mixing chamber (16) in the mold (19) is at least partially encased by a plastic molding (18). The mixing chamber is formed in and by a plastic molding, made in a prior production stage. It is separately interposed between the dosing and feed unit and the cavity, during the filling operation through a casting gate zone (17). The plastic molding containing the mixing chamber is extracted from the mold, together with the finished product. Its two connected halves, form the mixing chamber (16). The connections are a film hinge and clips opposite it, which hold the halves closed. The nozzle unit (13) intervenes between the dosing and feed unit, and the mixing chamber. Its openings (11, 12) correspond in number with the supply channels (5, 6), to which they are connected. A replaceable intermediate unit (14) intervenes between the dosing and supply unit, and the nozzle unit; this too, has a corresponding number of connecting channels. It also has a further feed device allowing additional components to be supplied to the mixing chamber. Further details of the design are provided, based on the foregoing principles.An independent claim IS INCLUDED FOR the corresponding method.