Elastomers
- November 13, 2020
In this brief blog, we will go over the high-level aspects regarding injection molding - what it is, the benefits, and how it generally works. Give us a shout if you think it might be a great fit for your next project or application!
What is injection molding?
Injection molding is a way to manufacture and produce parts in large quantities. It is often used in production scenarios where the exact same part is being produced over and over again in the thousands.
The main advantage of using injection molding is the ability to scale production in enormous portions, resulting in price per unit becoming much lower. While the initial investment may come with some added costs, it will eventually for itself over time and ultimately result in profit.
- August 19, 2020
Strict hygiene regulations in the food industry present major challenges for sealing technology. Freudenberg Sealing Technologies is enhancing its proven portfolio of hygienic sealing solutions with two products that are also designed for high-pressure applications. This was made possible thanks to special design solutions and the premium elastomer and PTFE materials developed in-house.
Food processing demands strict hygiene and cleanliness standards. It’s also important to ensure that no substances can migrate from the materials coming in contact with food, which could lead to contamination of the product. With its hygienic product line, Freudenberg Sealing Technologies has developed sealing solutions that fulfill food industry standards and are also resistant to CIP/SIP media. The Hygienic Forseal and Hygienic Pressure Seal are the newest members of this innovative product family.
One of the basic requirements for sealing solutions in accordance with the hygienic design standards is a dead-space-free construction. It prevents the collection and settling of product residues and micro-organisms in undercuts, for example. The selection of applied materials and their resistance to hot water, steam, acids, alkalis and high pressures are also relevant. Observing the deformation at the relevant temperature plays a particularly important role in detecting distortions and the associated formation of dead spaces at an early stage in the product development.
- May 04, 2020
EPR vs EPDM - How do they differ?
What’s the difference between EPR and EPDM? What do the different abbreviations (EPR, EPM, EPDM, EPT, etc.) mean? These questions pop up from time to time in the seal industry, and here are basic answers to these questions.
In the range of ethylene-propylene (EP) rubber there are two lightly different branches: EPR (EP copolymer) and EPDM (EP terpolymer.) The differences are subtle, and a basic knowledge of polymers and rubber compounding is necessary to grasp the differences.
First of all, polymers (derived from the Greek for “many units”) are long chemical chains that can be thought of as behaving like long pieces of cooked spaghetti. Each chain is made of one or more monomers (Greek “single unit”) linked together end-to-end.
- April 15, 2020
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Website and was written by Jarrod Cohen, marketing communications manager, Chomerics Divison.
Electrically conductive elastomers are elastomeric polymers filled with metal particles. They can be grouped by filler type and elastomer type. Then within each of these classes, there are standard materials and specialty materials.
Parker Chomerics manufacturers electrically conductive elastomers in gasket form, also known as EMI elastomer gaskets, under the CHO-SEAL brand. We won't get so much into gasket configurations and dimensions here, we'll just stick to classes of materials. So what is available? Let’s find out.
Conductive elastomers are metallic particle filled elastomeric polymers, the particles giving the shielding performance and the polymer making them “rubber." There are many materials within this generic material type, but we'll focus on the below.
Particle fillers
Setting up the grades of conductive elastomers by filler types involves six different particles:
Three types of elastomer material
- Silicone
A polymer that has a large temperature range especially on the low end down to -55F. It is a very soft material with a low compression set. - Fluorosilicone
Close to silicone, but will not swell and degrade when exposed to solvents, fuels hydraulic fluids and other organic fluids. Although slightly harder than silicone, it is still relatively soft with low compression set properties. - Ethylene propylene diene monomer (EPDM)
Does not have the temperature range nor the softness of silicone, but is resistant to highly chlorinated solvents used for compliance with NBC decontamination and is only used for applications with those needs.
All of these materials are cured or cross linked when the gasket is made. The cure either happens with heat or atmospheric moisture.
- Silicone
- April 09, 2020
EPDM is an M-Class synthetic rubber and is one of the most popular and versatile rubber compounds available. The main properties of EPDM are its outstanding heat, ozone, and weather resistance. EPDM rubber has excellent electrical insulating properties and it has good resistance to steam, ketones, ordinary diluted acids, and alkalies.
During the manufacturing process of EPDM sheet rubber, the compound can be cured with either peroxide or sulfur. The choice of curing method is determined by the end-uses and applications which the compound will service.
Depending upon which curing method is chosen, there will be differences in the final properties and characteristics of the cured compound. Knowing these differences can be an important factor in selecting the right EPDM gasket material for servicing your specific application.
EPDM Sheet and Gaskets: Peroxide Curing
EPDM compounds cured with peroxide possess a superior chemical and thermal resistance compared to
- February 07, 2020
The term “plastics” is generic way of describing a synthetic material made from a wide range of organic polymers. Organic polymers describes a man-made substance that is formulated using polymer chains to create what we commonly refer to as…(you guessed it), plastics.
Before plastic, leather had been used to create Backup ring devices behind O-rings. Leather allows fluids to be retained, providing lubrication for the O-ring when the system was running dry.
The problem with leather was that it could become dry and shrink away from the sealing service, exposing the elastomer to same pressure it was intended to protect against.
With the advent of polymers, a piece of plastic could be cut or formed into the exact shape to allow for zero extrusion gap, and for continued protection for the O-ring.
Some polymers were very brittle. Since they needed to be deformed to allow for installation into solid glands, the cut of the plastic could nibble at the O-ring, causing premature failure of the element it was supposed to be protecting.
The Revolution of PTFE
When PTFE moved out of the lab and into industrial use, it quickly found itself adjacent to the O-ring. PTFE offers extrusion resistance and, at the same time, doesn’t erode or nibble at the O-ring due to the “softness” of the polymer.(Hardness between 55 and 65 Shore D)
Given the composition of PTFE, or Teflon, it could be utilized as a sealing element to protect Backup rings and conform to the shaft. The bonus was it was generally easy on shafts (depending on the filler added to the PTFE).
There are some negative aspects to Teflon that needed to be overcome by early engineers. First, it has a fairly high rate of Thermal expansion which, by its own nature, could often times lose contact with the sealing surface. This meant some kind of loading was necessary to ensure contact.
PTFE is as tough as other polymers, so the fact that it could seal on a shaft made it vulnerable during installation for tears or nicks on sealing surface.
Second, if it were stretched during installation, the material had to be sized back to its original shape due to its poor elastic properties.
- January 31, 2020
Food, Beverage, and Pharmaceutical Regulations
Stringent government regulations mandate that food, beverage, and pharmaceutical manufacturers keep foreign material out of ingredients to ensure food and drug safety for consumers. Preventing foreign material from entering the processing stream is of the utmost concern but there must also be measures in place to detect contaminated product and quarantine it before distribution.
Component parts that are used in food and drug processing equipment can become damaged by improper installation and/or excessive shear experienced during operation that causes fragments of rubber, plastic, and metal to contaminate ingredients. Chemicals used for cleaning and sterilization of equipment can cause rubber seals to degrade, increasing
- November 20, 2019
Wettablility of the Sealing Lip
The optimum function of rotary shaft seals depends on many factors. One of them is the "wettability" of the sealing lip. This parameter plays a particularly important role with synthetic lubricants such as polyglycol. If wetting is too low, not only does wear on the sealing lip increase, but the contact with the rotating shaft can also damage the shaft itself. The engineers at Freudenberg Sealing Technologies (FST) and Freudenberg Technology Innovation (FTI) have developed a new coating that forms a flexible bond with the elastomer of the seal and significantly improves wetting with synthetic lubricants.
Thanks to different materials and shapes, radial shaft seals for sealing rotating shafts can be used in a wide variety of industrial applications. What they all have in common is the demand for the lowest possible friction, low wear,
- November 14, 2019
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Website and was written by Fred Fisher, Technical Sales Manager for Parker O-Ring & Engineered Seals Division.
ASTM Elastomer Compounds
When looking at drawings to define a specific application or elastomer requirement: Is there value in using an ASTM elastomer
- October 29, 2019
Better and faster access to the seals you need to keep your production running.
King of Prussia, PA. October 29, 2019 /News and Updates/ -- Gallagher Fluid Seals (GFS) is excited to announce the launch of its e-commerce store, providing a brand new experience to shop for seals.
“It’s been a complete team effort,” says Chris Gallagher, CEO. “Our team has worked diligently over the past several months to prepare and deliver a state-of-the art e-commerce store for both new and returning customers.”
As the world’s economy has evolved to an online platform, GFS felt seal buying should be easier. Gone are the days of calling in and ordering a replacement seal - or sending an RFQ. This new online experience allows greater and faster access to the seals you need to keep your facility up-and-running.
“Maximizing the ease-of-purchase and visibility of fluid sealing products is imperative to the future of seal buying, and