Diseñando con materiales de silicona

The Designing With Silicone Materials Series
The following document focuses on product design with silicone materials. This document uses the technical knowledge and experience of NuSil Technology’s staff and provides links to additional online resources. The table of contents is listed below.

Table of Contents
Getting Started: Basic Design Methods/Concepts – Focuses on project initiationand touches on concepts like “beginning with the end in mind,” as well as key relationships and arrangements with suppliers. Material Requirements – Covers fabrication, processes and end-material properties. Material - Process - Device Fit – Outlines the nature of silicones, variations in properties and unknowns in product design with silicone. Prototyping and Production – Details fabricationissues, inhibitors and other issues. Supply Issues – Focuses on supplier communication, JIT issues and change management. Next-Generation Designs – Discusses how silicone materials fit into next-generation designs, including the evolution of materials to meet future needs.

Getting Started: Basic Design Concepts / Methods
Designing a device from a technical standpoint is unquestionably complex andfraught with pitfalls. Planning the development of a device requires the design engineer to consider what is needed and when it is needed. Time contingencies are always factors, as designs are now expected to undergo several iterations before the final version makes it to the production line. Beginning with the end in mind, a concept coined and popularized by Stephen Covey, doesn’t always cover theunanticipated challenges and problems in the design process. While NuSil Technology does not purport to be design experts, we do have a wealth of materials and business knowledge that cover many challenges faced by materials in the design phase. The process typically begins in two places, either with an entirely new and novel device or an improvement to an existing device. In both instances, abrainstorming process yields a quantity of ideas that are funneled into a few “top prospects.” Taking these top prospects and researching similar devices and the materials used in those devices can be a

timesaver. The use of AutoCAD and simulation software provided by companies like UGS and MSC Software can provide critical, front-end virtual testing to determine the best design, as well asprofiles of promising materials for construction. At this point, the material-evaluation process begins. Often, materials are selected because they meet multiple objectives not identified in the virtual design. Considerations beyond physical properties include: • • • Device aesthetics Regulatory concerns Production and assembly concerns

Critical to this process is a relationship with a supplier thataids in the design and development process. Issues like business confidentiality, development agreements and supplier competencies can, when unresolved, stall the design process. Open communications of supplier expectations at the onset of the relationship is critical to a successful design process.

Materials Requirements
In the design process, applications that are needed for the device areidentified. Moving parts in the design may mandate the need for a lubrication solution, separate parts of the device may require the use of an adhesive for bonding, and so on. Silicone may be considered as candidates for the following types of applications: • • • • Lubrication Adhesion Encapsulation/protection Solid forms

Within these applications, the engineer begins to focus on the device’sspecific requirements. Property requirements that are most often considered are: • • Cured physical properties Uncured physical properties

The cured physical properties that most engineers consider, particularly in adhesion, encapsulation and solid-form applications, are durometer, tensile, tear, elongation and stress at strain. Other properties such as appearance, chemical resistance,...