Apr 26, 2013
Electronics and Engineering Application Guide
This Application Guide is a focused version of the Engineering Selection Guide that is organized by application or use. Key materials were chosen and linked to where they are most commonly used.
Dec 3, 2012
Heat Curable Silicone Marking Inks
NuSil Technology’s MED-6613-X family of silicone marking inks is
specifically designed for printing healthcare devices, including those
intended for long-term implant applications.
Sep 25, 2012
Due to their unique chemistry which results in a large amount of free volume within the polymer/filler
matrix, silicones are ideal candidates for incorporating additional fillers or additives. One such method for incorporating a filler into a formulated silicone is via a masterbatch. A masterbatch is
a highly filled or concentrated component. For a barium sulfate masterbatch, the amount of masterbatch to be added can be calculated based on the percentage of barium
sulfate (BaSO4) in the master batch and the ultimate desired loading of BaSO4 in the final elastomer
Sep 6, 2012
Optical Gel Encapsulants Designed for Phosphor Dispersions
NuSil Technology has specifically designed higher viscosity silicone Optical
Gel Encapsulants to keep the phosphor powders suspended for extended
periods of time during dispensing. They are excellent for low to high power
LED applications and are available in refractive indices ranging from 1.51 to
Sep 5, 2012
Solvent Resistant Silicones
NuSil Technology is a cutting-edge manufacturer of silicone
materials for industries requiring precise and predictable custom
formulations. Our standard solvent resistant materials
are cost effective alternatives to custom development. NuSil’s
line of fluorosilicone based silicones consists of encapsulants,
adhesives, gels, foams and dispersion fluids.
Jun 25, 2012
Working with High Consistency Rubbers
A high consistency rubber, or HCR, consists of a high molecular weight polymer combined with reinforcing filler to produce a material that can be molded, extruded, or calendered into a useful end product. An HCR has the consistency of clay when uncured and is primarily formulated in a one- or two-part system (peroxide and platinum catalysts respectively). Known for high mechanical strength, HCRs are also sometimes referred to as high tear rubbers or high tear elastomers (HTRs or HTEs). This application note will cover potential applications for HCRs, typical properties, cure chemistries, and processing HCRs.
Feb 27, 2012
Optically Clear Materials for Healthcare Applications
NuSil’s optically clear elastomers for healthcare applications are all
highly processed materials that crosslink via an addition cure
mechanism. Optically clear, or transparent, means that light waves are
partially reflected and partially refracted (transmitted through the
material). Refractive index (RI) is defined as the ratio of the velocity of
light in a vacuum to the velocity of light in a material1. The high
refractive indexes of the products listed below indicate that they are
highly responsive to light. These restricted healthcare materials meet
all USP Class VI and many ISO-10993 test requirements for
biocompatibility. For more information on NuSil’s restricted and
unrestricted materials, please visit www.nusil.com or refer to the
Dec 9, 2011
Adhesion and Silicone Adhesives
Most silicone adhesives are made of silica-filled silicone polymers that cure in place by crosslinking. The overall mechanical strength is known as cohesive strength. The strongest bonds are those which occur between atoms from chemical bonding; however, adhesion is not limited to chemical bonding. Conversely, materials can have the ability to form a strong “bond” when brought into contact with another surface for a short time (seconds) under light pressure. This short-term, pressure-induced attachment is known as tack2. Tack and adhesion are influenced by how a force (and how much of it) is applied to the bond, as well as the bond thickness (thinner can be better)1.
Dec 8, 2011
Choosing a Silicone Primer / Adhesive System for Healthcare Applications
Silane primers are used to promote adhesion between two non-bonding surfaces. Although designed for use with silicone adhesives, they can also be used with other adhesives, such as epoxies. The primers usually consist of one or more reactive silanes, a condensation catalyst and some type of solvent carrier. The reactive silanes typically have two different reactive groups; one compatible with the substrate and the other with the adhesive. These different groups form a compatible interface between the incompatible substrates and promote adhesion. The reactive silanes are usually added as moisture sensitive alkoxy silanes and, in the presence of water and a condensation catalyst, form the priming surface. The silanes and the condensation catalysts form a very thin polymeric film on the surface of the substrate; the silanes begin hydrolyzing with atmospheric moisture and the condensation catalyst starts joining all the hydrolyzed groups to form a primer film on the substrate.
Oct 6, 2011
Case Study-Increasing Silicones Resistance to Thermal Degradation
Silicones can withstand high temperatures for extended periods of time; however, thermal degradation remains a concern. Depending on the application and requirements of the end user, thermal degradation may be combated by the incorporation of phenyl into the polymer structure or the addition of a thermal stability additive (filler). The incorporation of both phenyl and fillers will provide the best resistance to thermal degradation; however, fillers would not be an option for transparent material. As an alternative, increasing phenyl content would then be necessary in transparent materials to provide resistance to thermal degradation.
Sep 20, 2011
Self-Lubricating Silicone Rubber
The surface of cured silicone elastomers are often characterized by a high
coefficient of friction, some degree of tackiness and a tendency for blocking
sticking to themselves by virtue of chemical affinity). All of these inherent
features may be problematic for applications requiring a molded or extruded silicone component which needs to move or slide with minimal friction.
Historically, silicone lubricants have been used to alleviate this friction on
silicone molded parts, rubber stoppers, and O-rings that require frictionless
surfaces that are durable and long lasting for repeated use.
Sep 15, 2011
Choosing a Silicone Primer / Adhesive System for Engineering Applicaitons
Silane primers are used to promote adhesion between two non-bonding surfaces. Although designed for use with silicone adhesives, they can also be used with other adhesives, such as epoxies. This document outlines the procedures that are recommended when using primers and presents adhesion test results for various adhesives, primers and substrates.
Jul 22, 2011
Conductive Silicones in Elevated Temperatures
With silicone’s insulative nature and large Coefficient of Thermal Expansion (CTE), sustaining conductivity as temperatures rise requires a special understanding of silicone chemistry and filler technology. Conductivity can be maintained by adjusting the type, amount, and the particle size and distribution of filler in the silicone matrix. This Application Note discusses the trade-offs one should expect when customizing silicone to remain conductive in elevated temperatures and help explain why changes occur.
May 5, 2011
Custom Molded Parts for Aircraft and Aerospace Applications
Utilizing state-of-the-art Computer
Numerical Controlled (CNC) machines NuSil engineers have the capacity to
make one-cavity molds as large as 84" x 40" x 30" for these specialty parts.
Additionally, with the ability to compression mold in a 500 ton press or a 5 ton press, NuSil has the flexibility to process small or large parts.
Apr 1, 2011
ASTM E595 Test Method
adhere to NASA’s requirements for a low outgassing material, NuSil
Technology utilizes ASTM’s Test Method E595 as a standard, lot-to-lot test
for their controlled volatility (CV- and SCV-) silicones.
Apr 1, 2011
Thermally Conductive Silicones for Healthcare Applications
In the healthcare industry thermal
management of medical devices is crucial and often times, applications surrounded by silicone such as pacemakers
require generated heat to be dispersed. In these cases, a build up of heat would leave the device inoperable and thus,
ineffective. To address this, NuSil Technology has used silicone’s natural molecular free volume to add filler that in turn allows for thermal conductivity. By manipulating silicone, medical grade silicone can be developed to be used in
conjunction with such devices and allow for long term implant or continual use.
Mar 4, 2011
Moisture Permeability of Silicone Systems-Case Study 2
The purpose of this Case Study is to further clarify the relationship between Water Vapor Transmission Rates (WVTR) and select silicones. This study will assist with product selection when moisture permeability is of interest for specific applications. An analysis of how various fillers and durometers influence WVTR is provided.
Mar 3, 2011
Case Study-Aging Study of Silicone Materials in Simulated Gastric Fluid
An evaluation of the properties of silicones in what is deemed to be the harshest environment of the human body: gastric acid. In this investigation, dimethyl, diphenyl, and trifluoropropyl silicones were tested and the changes in the product’s physical properties such as elongation and tensile strength were recorded and evaluated.
Dec 29, 2010
Silicone Colored Inks
The R-1008-X silicone ink series is non-corrosive and features excellent adhesion to a variety of substrates, especially to other silicones. The unique
materials are one-part, flowable silicone dispersions that cure rapidly at room temperature when exposed to
Dec 1, 2010
A Guide to Silicone Dispersions- Strategies for Processing and Troubleshooting
This application note will summarize important properties and characteristics of dispersions, present guidelines for applying a dispersion and offer suggestions for troubleshooting.
Oct 21, 2010
Production Methods for Manufacturing Chewable Tablets-Oral Form
Simethicone has been used for many years as a pharmaceutical antifoam to treat discomfort associated with gas buildup in the stomach or the large intestine. Simethicone works by causing small gas bubbles to coalesce into larger bubbles, making them easier to pass, by either belching or flatulence. Simethicone does not keep gas from forming, but rather allows a person to easily pass the built-up gases. This paper will address the production methods for manufacturing chewable tablets - oral form.
Aug 6, 2010
Low Durometer Silicones Designed for Soft Tissue Implant Applications
Silicone gels and elastomers have been used in soft tissue implant applications for decades because gels offer softness and silicone elastomers offer increased cohesive strength. However, they both offer these unique benefits independent of the other.
Jun 23, 2010
Thermally Stable Silicones for Space and Aircraft Applications
thermal stability at high operating temperatures, as high as 300°C depending
on the exposure time. Silicones can be incorporated with iron oxide fillers that
can impart increased thermal stability at elevated temperatures. These same
silicones can also be modified for low outgassing or fuel resistance to handle
the rigorous demands of aerospace and aircraft technologies.
Jun 21, 2010
NuSil’s line of fluorosilicones comprises adhesives, sealants
and coatings. Fluorosilicones resist degradation when exposed
to jet fuel, solvents, gasoline, or crude oil and operate in a
broad range of temperatures.
May 28, 2010
Working with Liquid Silicone Rubbers - Best Practices from Prototype to Large Scale Production
This whitepaper characterizes Liquid Silicone Rubbers (LSRs) and their typical properties and gives guidelines for obtaining the best results from initial design to prototyping to full scale production
May 25, 2010
Low Coefficient of Friction Silicone Coating (R-2182)
The R-2182 is a two-part, addition
cure silicone coating dispersed in xylene and the R-1182 is a one part,
condensation cure system dispersed in Tert Butyl Acetate.Once cured, these coatings chemically bond to the silicone elastomer substrate and mimic the mechanical properties thereof, resisting abrasion and eliminating the concern of migration commonly associated with
lubricants such as fluids and greases.
Jan 28, 2010
Low Coefficient of Friction Silicone Coating (MED-6670)
MED-6670 is a two-part, low coefficient of friction silicone coating dispersed in
xylene specifically designed to coat molded or extruded silicone parts and
overcome the inherent tackiness and a tendency for blocking (sticking to
themselves by virtue of chemical affinity) of silicone.
Dec 16, 2009
Mixing and De airing Addition Cure Silicones
Silicone and air mixtures are very complex and dynamic systems, however this article’s purpose is not to discuss fluid dynamics and laminar flow, but rather the basics of how air can be introduced into a system, common methods of mixing and de-airing, and packaging options when specialized mixing and dispensing equipment is not available.
Dec 10, 2009
Correlation Between Moisture Permeability of Phenyl Substitution on Dimethicone and Performance as a Moisture Shield in Haircare Products
Studies have revealed that high humidity leads to higher moisture levels in the hair and despite the desire to be moisturized the high moisture
content results in a negative perception of the feel and appearance of the hair. For this reason NuSil Technology chose to measure the water
permeability of silicones with varying degrees of phenyl substitution in addition to characterizing hair tresses treated with the same silicones and
subjected to high humidity levels.
Dec 7, 2009
Tacky Gels for Healthcare Applications
Silicone tacky gels are ideal for processing into sheets or pads for various topical applications requiring a temporary adhesive. Silicone gels have a history of biocompatibility, are non-allergenic, and offer superior breathability.
Sep 15, 2009
Silicones for Thermal Management
NuSil understands the difficulties that occur when bonding hybrid packages and offers a wide variety of thermally conductive silicones for potting, encapsulating and adhering all levels of packaging. Silicones offer thermal stability at high operating temperatures that other adhesives are unable to sustain. NuSil’s thermally conductive silicone adhesives and encapsulants aid in the removal of heat without adding additional stress to the device during thermal cycling.
Sep 9, 2009
Case Study: The Influence of Primer on Adhesion of Silicone to Silver and Gold Substrates
This case study investigates the influence primer has on the adhesion of a standard silica filled methyl silicone to silver and gold substrates.
Jul 28, 2009
Colored Silicones for Healthcare Applications
NuSil Technology has the capability to provide pre-colored silicone materials available to the healthcare market. NuSil can provide colored versions of our Liquid Silicone Rubbers (LSR), High Consistency Rubbers (HCR), Low Consistency Elastomers (LCE) and adhesives, pigmenting these materials to be either translucent or opaque.
Jul 28, 2009
Silicone Ice-phobic Coatings
Ice build up has major economic impact on the aircraft industry, resulting in multiple efforts to understand
and resolve the problem. When compared to other commercially marketed ice-phobic coatings and
non-stick materials such as Tefon®, NuSil’s silicone coatings show significantly improved reduction in ice
adhesion when applied on aluminum surfaces.
Jul 21, 2009
Application and Storage Recommendations for NuSil’s Primers
Adhesion is a critical property for numerous applications involving silicone materials. Silicone primers
are often used to improve adhesion between silicones and various substrates. The proper handling and
application of silicone primers can enhance the overall strength and consistency of bonds. This document outlines the procedures that are recommended for best bonding results.
Jun 24, 2009
Moisture Permeability of Silicone Systems- Case Study #1
The healthcare, electronics and aerospace industries use silicone elastomers and adhesives in a broad range of applications. Humidity control is an important parameter of concern for these applications. For instance, wound dressings must “breathe” similar to our skin to accelerate the healing process. In other applications moisture permeability can cause premature failure due to corrosion of electronic components or other means. An example would be moisture sensitive fillers and humid environments can alter the performance of the functional fillers. In Light Emitting Diodes (LEDs), phosphors added to the silicone encapsulant to make white light may absorb moisture over time, which could alter the light output of the LED.
Jun 15, 2009
Silicone for Healthcare Balloon Applications
Silicone elastomers possess unique properties making them an ideal material
choice for balloon healthcare applications. Urological catheters, intra aortic
angioplasty devices, and anchors for drug ports or feeding devices all
commonly use silicone balloons. In addition to a proven history of being
non-allergenic and biocompatible, silicone elastomers’ physical properties
contribute to a balloon’s function and desired performance, including key
properties such as modulus, tensile set, and recovery after inflation.
Jun 15, 2009
Silicone Materials for Food Contact
This document includes NuSil’s product listing of cured (as prescribed on the
product certification) and washed elastomers that meet the extraction
requirements of 21 CFR 177.2600 for Rubber Articles Intended for Repeated
Use. Most of NuSil’s (material) elastomers can be tested per this requirement.
May 18, 2009
Ultra Low Outgassing Silicone Materials
Silicone adhesives and coatings have been used for over five decades because of their ability to retain elasticity and low modulus over a broad temperature range, thus reducing shear stress during thermal cycling. These properties provide excellent utility in space and terrestrial environments, where spacecrafts and sensitive electronics are repeatedly exposed to these extreme temperatures.
Apr 29, 2009
Fast-Cure Silicone Adhesives for Medical Device Applications
NuSil’s line of fast-cure silicone adhesives are two-part, platinum catalyzed, addition cure systems that provide excellent mechanical properties including high peel strength. The Unrestricted adhesives (MEDX-4213) may be considered for use in long-term implantable (>29 days) medical device applications, and the Restricted adhesives (MEDX-4013) may be used for short-term implant (=29 days) or external applications. These adhesives are typically used to bond silicones to metals, plastics, urethanes, ceramics, glass or other silicones – frequently without the use of primer.
Apr 29, 2009
Adjustable Cure Silicone Adhesives for Various Assembly Applications
NuSil’s R31-2186,R32-2186 and R33-2186 are two-part, adjustable cure,
high strength silicone adhesives. Thisseries of adhesives is designed to allow the engineer to accelerate the cure time with heat to allow more
efficient processing times and reduce production costs. R31-2186 and R33-2186 are designed to cure at low temperatures for situations where higher cure temperatures can’t be used due to equipment limitations or heat sensitive materials within the assembly.
Apr 29, 2009
Two-Part, Side by Side Kit Adapter Instructions
EQ049/047 is an adapter that can be used to dispense material from a side by side (sxs) kit, also known as a dual cartridge. In place of using the standard extruder gun for the sxs kit, the EQ049/047 is used in conjunction with a standard caulking gun.
Feb 18, 2009
Silicones for Solar Module Assembly
NuSil Technology is a global leader in formulating custom silicone materials and has a wide range of silicones useful for solar module assembly. We can chemically modify silicone to a variety of refractive indices to minimize light loss at optical interfaces. For decades NuSil has been supplying silicones for satellite solar arrayassemblies and refractive index matching in Light Emitting Diodes (LEDs).
Feb 2, 2009
Silicone for Specialized LCD Screens
LCD screens are specialized assemblies comprised of many fragile components and materials. With LCD screens becoming smaller and smaller, they are being incorporated into many high-end devices such as PDAs or GPS systems that require use in rugged and extreme environments. NuSil offers the curable silicone gel LS-3252 for use in LCD screens. LS-3252 is an encapsulation material designed for protection of sensitive photonics assemblies.
Jan 26, 2009
Optical Properties of Radiation Resistant Silicone
Silicones do not degrade at continuous high operating conditions up to 200 °C. They are also able to maintain their flexibility at temperatures as low as - 60 °C compared with other adhesives that have Tg above 0 °C. Silicones can have excellent optical stability after heat and UV exposure.
Jan 13, 2009
Lubricious Silicone Coatings and Lubricants
Cutting edges, hypodermic or suture needles, and other medical instruments that are inserted into the human body often require lubrication or lubricious coatings that are durable and long lasting for repeated use. Known for their feel-enhancing effects and lubricity, silicones provide effective lubrication solutions for many medical device applications, such as catheters and feeding tubes.
Oct 16, 2008
Troubleshooting Silicone Materials Series
Curable silicone systems can be challenging to use because they are formulated with specific amounts of reactive species, catalysts, crosslinkers, polymers and inhibitors that can create variability. The keys to understanding and resolving problems using silicone materials require an understanding and appreciation for each component and how it functions.
Sep 2, 2008
Avoiding Inhibition When Working with Platinum Catalyzed Silicones
Silicones are formulated to cure with a number of catalysts. Each catalyst requires a certain set of conditions to cure and these conditions are typically included on the Product Profile or data sheet. Silicones can contain chemical entities known as cure inhibitors that are added by the manufacturer to adjust pot life (working time) and curing time.
Jul 31, 2008
Methods Used to Sterilize Silicone Based Medical Devices
There are several sterilization methods commonly used for medical devices including: dry heat, steam autoclaving, ethylene oxide, gamma radiation and electron beam sterilization. Several concerns arise about the effects sterilization has on material properties including silicones. Device design, raw material selection, and processing are fundamental considerations that should be addressed before the product is sterilized and shipped to the device manufacurer.
Feb 14, 2008
Silicone Removal For Electronic Rework Applications
Reworking electronic packaging is essential for failure analysis and recovering valuable materials. It involves using chemicals and processes that will cause minimal damage to substrates when removing adhesives in the most cost effective manner. Removing silicone adhesives can be difficult if using removal methods designed for adhesives other than silicone. The purpose of this study is to evaluate the removal rate of various silicone adhesives bonded to various substrates by silicone digesters typically used in microelectronic packages.
Jul 11, 2007
Designing With Silicone Materials
This 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.
Apr 21, 2007
Low Volatility Silicones for Advanced Electronic Packaging
NuSil Technology's Electronic Packaging Materials (EPMs) are comprised of encapsulants and adhesives. Our EPM Product Line is designed to have very low levels of contaminants commonly linked to device reliability.
Aug 8, 2006
This document provides a list of published documents referencing NuSil Technology products.
Jun 24, 2004
Silicone Terms and Definitions
This document provides definitions and explanations of terms related to various material types, characteristics and preparation techniques related to silicone technology.
Jan 8, 2003
Avoiding Cure Inhibition
Lightspan™ Optical Thermosets and Gels provide excellent optical, thermal, and mechanical properties. However, because of the cure chemistry, addition cure, some ingredients commonly found in certain adhesives, plastics, and elastomers adversely affect these products’ cure. This is true for all addition cure systems not just Lightspan Optical Thermosets and Gels. This Application Note offers guidance on avoiding cure inhibition and bubbles when using Lightspan Optical Materials.