PTFE Diaphragms – Introduction

Arvico Rubber’s PTFE diaphragms are some of our portfolio’s most commonly ordered components, thanks to their exceptionally resistant properties and strength.

Did you know that PTFE was discovered accidentally? It was discovered in 1938 by an American chemist called Roy J. Plunkett. This chemist registered the material as Teflon and trademarked it in 1945.

Right now, PTFE is used to make all kinds of products starting from small kitchen appliances to surgical implants, firefighter equipment, and more. Lets read everything about Polytetrafluoroethylene .

What is Polytetrafluoroethylene?

Polytetrafluoroethylene (PTFE) is a type of plastic that is used in a variety of industrial and consumer applications. PTFE is commonly referred to by the brand names Teflon, Hostaflon, and Fluon. All these are trademarked names of PTFE.

This wonderful synthetic material has a non-stick surface that makes it a great choice to make rubber components from. It has multiple other beneficial features that we will cover in the coming sections. Technically, PTFE is a fluoropolymer of tetrafluoroethylene. Tetrafluoroethylene is a fluorocarbon.

Characteristics and Properties of PTFE Diaphragms

There are a lot of properties of PTFE that make it a favorite choice of material in most industrial settings.

Here are some of the notable properties of PTFE.

1. PTFE is a solid at room temperatures and has a preferable melting point of 600 K.
2. PTFE has a density of 2200 kg/m3.
3. PTFE diaphragms and other PTFE components are FDA approved, making them a perfect choice for food and beverage industries and pharmaceutical units.
4. PTFE is hydrophobic, which means water or water-based substances cannot wet the material.
5. PTFE has one of the lowest coefficients of friction when compared to most other solids. The coefficient of friction of PTFE is measured to be about 0.05 to 0.10. This is the third-lowest value, only after aluminum magnesium boride (BAM) and diamond-like carbon. This is also the reason why PTFE diaphragms are one of the most preferred diaphragms in the industry.
6. The melting point of PTFE is 326.85 °C.
7. PTFE is very slippery, and that’s why the material is used as an outer coating to prevent insects from climbing up.
8. PTFE is non-reactive to most chemicals. The only chemicals that can affect PTFE are highly reactive alkali metals and fluorinating agents like cobalt (III) and xenon difluoride.
9. PTFE is non-toxic, odorless, and tasteless, and these are added advantages that make the material a preferred choice. Industries that produce edible products choose PTFE diaphragms, especially for these factors.
10. PTFE is steam-proof too, and can hence be used in applications where high steam processes may damage the components. PTFE can also be sterilized.

Applications of Polytetrafluoroethylene (PTFE)

Here is a list of some of the common applications of PTFE and its products.

• Rubber components

When it comes to industrial-range PTFE rubber components, the below are options to choose from.

1. O-rings
2. PTFE diaphragms
3. Valves
4. Insulated transformers
5. Wire insulators
6. Surface coatings
7. Bearings

• Insulators

It is said that 50% of all the PTFE materials produced are for insulation and wiring purposes. These are used in computer hardware applications and in aerospace industries.

• Composites

Composites are substances made using a combination of two or more materials. PTFE is combined with fiberglass or carbon fiber to make fiberglass composites and is used in aerospace industries. Using PTFE gives these composites a non-sticky nature, which is needed in specific cases.        

• Kitchenware

One of the common uses of PTFE is in the kitchenware industry. There are a lot of utensils and cookware made from this material because of its non-sticky and hydrophobic properties.

How do Fillers and Additives Enhance PTFE Properties?

PTFE, by itself, is a very productive and robust material. However, when you use additional fillers and additives, the properties enhance even more, giving the users better benefits.

Let’s consider PTFE diaphragms, for example, here. These diaphragms have two properties that you can enhance by adding the right fillers/additives to them.

1. Creep rate – Creep rate is the rate of deformation of a material when it is subjected to constant stress.
2. Wear rate – Wear rate is the rate at which the material experiences wear and tear due to everyday use.

Now, for any diaphragm, the slower the creep and wear rate, the better it is for the product.

Many industries that produce PTFE diaphragms add fillers like bronze, steel, glass fiber, carbon fiber, graphite, and carbon to improve the product’s performance.

Depending on the fillers added, the hardness of the diaphragm can be improved, the wear rate can be bettered, the flexibility can be increased, and the ability to handle extreme temperatures can be enhanced.

Popular Techniques Used to Process PTFE Diaphragms

The properties of PTFE depend majorly on the production process. PTFE is a very tough material, and molding it into shapes of choice is usually difficult. The normal production methods don’t work effectively here.

 If you want to use good quality and effective PTFE diaphragms, check the production process used in making PTFE.

Here are some of the popular techniques used.

1. Sintering – This is the process of using hot stamping, compression molding, and pressing to force PTFE into required shapes.
2. Paste Extrusion – In this technique, a chosen hydrocarbon is mixed with PTFE prior to molding, and the mix is quickly fabricated into the shapes and sizes required. Later on, the hydrocarbon is vaporized before the mold can be pressed, stamped, and permanently set.

Here is a sample process of producing PTFE in industries.

• Chloroform is first produced using methane, hydrogen chloride, and chlorine.

• Chloroform is then combined with anhydrous hydrogen fluoride.

• This produces chlorodifluoromethane. By heating this chemical in the absence of air, tetrafluoroethylene (TFE) is produced.

• TFE goes through polymerization to become PTFE.

Limitations of PTFE Diaphragms

1. PTFE is not a cheap polymer. It falls under the slightly expensive category because of the difficulty in producing end components like PTFE diaphragms.
2. Mass production of PTFE is also expensive and time-consuming.
3. It is not easy to mold or weld PTFE into different shapes. The process is effortful.
4. Joining multiple PTFE materials is quite challenging.
5. If you use PTFE diaphragms in extremely toxic atmospheres, they may get eroded or damaged.

Conclusion

PTFE, when produced right, can be a very solid and trustworthy material to use in several industrial applications. By picking Arvico products like PTFE diaphragms, O-Rings, Valves, and other components for your production process, you can also improve the processes’ efficiency and safeguard expensive equipment.

When you choose PTFE, make sure you check the way it is produced and its physical properties. If there are fillers added, do look at the compositions even more carefully.

Arvico Rubber brings to you exceptional quality PTFE diaphragms and other components that are highly resistant to chemicals and temperature. Do get in touch with us to know more. We have the capacity to produce high-quality PTFE components in mass volumes and in the exact sizes you prefer.

What is EPDM Rubber?         

EPDM Rubber (Ethylene Propylene Diene Monomer rubber) is one of the most commonly used synthetic rubbers these days. The properties of EPDM rubber is any material that is produced using petroleum products. Synthetic rubbers are used for various applications and can be molded to make all kinds of products, from tiny spare parts to humongous tires!

Did you know that the global EPDM rubber market size was 1718 kilotons in 2021? It is projected to grow to 2338 kilotons in 2026! While the automotive sector is the largest user of EPDM, it is also used widely in other areas like heating and cooling industries, refineries, food and beverage industries, chemical industries, and more.

Under the A S TM International standards, EPDM is listed as an M-Class rubber. This M-class includes EPDM and all other elastomers that contain the saturated chain of a ubiquitous polymer called polyethylene.

As the name suggests, EPDM rubber is made of three major components – ethylene, propylene, and Diene Monomer.

Arvico Rubber offers its components in different types of rubbers, and EPDM is one important kind. A lot of our customers choose EPDM rubber for its various beneficial properties.

Properties of EPDM

Check out some of the critical properties of EPDM that will help you choose between this and other types like silicone, butyl, or nitrile.

Properties	Industry values
Hardness Range (Durometer ‘A’)	40-90
Tensile Strength (psi)	3000
Specific Gravity	0.86
Heat Aging	180 degrees Celsius
Elongation post-fracture	More than 300%
Service temperature (minimum to maximum)	-50 degrees Celsius to +150 degrees Celsius

Apart from these, there are other properties of EPDM rubber you should be aware of.

• The molecular structure of the rubber is made of a single bond. This means that it is extremely resistant to external conditions, and factors like UV rays cannot break this bond as easily as double bonds.
• EPDM is also blessed with low electrical conductivity. This makes it a perfect choice to adhere to other metals.
• EPDM rubber also can insulate from external noises. This is why it is being commonly used in the automotive industry.
• The density of EPDM rubber can be between 0.90 to >2.00 g/cm3.

EPDM Rubber Applications and Uses

There are so many industrial uses due to properties of EPDM rubber, and it has become a common choice for components that would be exposed outdoors to wind, rain, UV rays, and other external factors. Here are some of the uses you should know of.

Construction – In construction industries, EPDM are favorite choices as roofing membranes and come in different widths and thicknesses.

Automotive – In the automotive industry, you can see this polymer being used generously for various purposes, including as sealants, harnesses for wires and cables, seals, bumpers, and even in brake systems. Most wiper blades are also made of EPDM rubber.

Manufacturing industries – Manufacturing industries use various Arvico Rubber’s components like diaphragms, O-Rings, seals, valves, and gaskets. They choose these components in EPDM rubber because of their favorable properties. Check out our products page. You will be able to customize any of these in EPDM.

HVAC – The Heating Ventilation and Air Conditioning industry also uses EPDM rubber to make its gaskets, seals, insulation parts, PTFE, sleeves or seat rings, rubber stators, hoses  and tubing. This material is preferred for its weather-resistance properties.

Other uses – Other than the above industries, EPDM may be used for a variety of other applications, including the following.

• As insulators for electrical wires and applications
• As an elastic element in straps, hangers, tie-downs, and cords
• As solar panel elements to collect heat
• In vibrators and belts to reduce noise
• EPDM granules are mixed with flooring agents to add grip and stability while walking

Advantages of Choosing EPDM

There are so many reasons why clients prefer having their components made out of EPDM. Some of the benefits are:

• Excellent insulation properties, making it a perfect choice as sealants and insulators in electrical appliances.
• Excellent vulcanizing properties, making the rubber resilient, tough, elastic, and viscous.
• Excellent acid resistance (both concentrated and diluted), making this rubber a perfect choice for components used in chemical, pharmaceutical, and fertilizer industries.
• Excellent abrasion resistance, giving the rubber long life.
• Excellent resistance to oxidation. Oxidation is a natural process where the rubber reacts to oxygen and starts aging. Oxidation resistance improves the life of the material.
• Excellent resistance to ozone damage, making this a perfect choice to use outdoors.
• Excellent ability to manage extreme temperature changes.
• Excellent adhesion to metals and fabrics.
• Excellent tear and abrasion resistance, so you can use PDM components in rough conditions.
• EPDM rubber can also be fire resistant, adding to the safety of your unit.

Are there any disadvantages of EPDM Rubber?

 EPDM rubber may not be a good choice in petroleum-based industries as it breaksdown faster when exposed to petroleum products.

Conclusion

A mid-range manufacturing company may need thousands of rubber components to function seamlessly. Each of your processes may need components made of the right type of polymer too. EPDM rubber is definitely a popular choice out there.

EPDM rubber offers many advantages to our clients’ production lines and lasts really long. If your components are to be installed outdoors, EPDM is perfect for the reasons stated above. However, make sure you explore the other types in the market too and ensure you choose the best material of all. Arvico Rubber offers components in other materials too, including Natural, Nitrile, Neoprene, Hypalon, Silicone, Butyl, Teflon, and Polyurethane.

Our experts from Arvico Rubber will be able to help you out with the right component material choice depending on your specific requirements.

Feel free to get in touch with us to know more.

Introduction

If you work in an industrial setting or run one, there is no way you haven’t heard of a rubber diaphragm. These very humble components find usage in many applications across various industries. Some vital processes may not function without diaphragms in place, and at times, when the quality of these components is not up to the mark, the risk of contamination, hazardous blowups, and equipment damage are all very high. 

What is the Rubber Diaphragm?

A rubber diaphragm is simply a membrane added between chambers to act as a sealant. In some cases, rubber diaphragms can prevent substances in two different chambers from mixing with one another. In other cases, it can also allow flow control using its shape.

A diaphragm is often round in shape, and the rubber used to create the component is flexible. The diaphragm is anchored at the periphery and the centre part of the diaphragm can push out or pull back, depending on the pressure put on it.

You can imagine a diaphragm similar in working to that of a plunger. You have to exert mechanical force with a plunger to create a vacuum and then pull back. With diaphragms, the force exerted is usually pressure changes.

How does the Rubber Diaphragm Work?

The rubber diaphragm’s flexible material makes it respond to pressure changes. When pressure is exerted on the diaphragm’s body, it moves up to a chamber or is pushed back to the other chamber. Thanks to their ability to ensure a constant pressure differential, these components can also be used as a sealant or gasket in various pieces of equipment.

How Much Force Can Rubber Diaphragms Handle?

Tensile strength is a term that talks about the resistance of any material to break under stress. In other words, it is the maximum pressure a substance can handle before breaking down under force. Now, tensile strength is an important term for a rubber diaphragm. Components will very low tensile strength may not handle the internal pressure and break or rip open halfway through.

Arvico Rubber uses multiple materials to create our diaphragms, and you may be able to choose the right material based on the required tensile strength.

Here is a list of common materials of rubber diaphragms and their tensile strength.

Materials	Tensile strength in psi
Natural Rubber	3000
Nitrile Rubber	3500
Neoprene Rubber	3000
Hypalon Rubber	2500
Butyl Rubber	2000
EPDM Rubber	3000
Silicone Rubber	1100
Viton Rubber	1800
Polyurethane Rubber	4000

Our polyurethane rubber offers excellent tensile strength, abrasion resistance, and tear resistance. The EPDM rubber is also a great choice in components where the diaphragms need to handle high-pressure situations.

Types of Rubber Diaphragms

Depending on how these rubber diaphragms are used, there are two major categories you should know of.

1. Rubber diaphragm valves
2. Rubber diaphragm pumps

Rubber Diaphragm Valves

Diaphragm valves are components that can help control fluid flow by monitoring the direction and speed of fluid that flows through it. These valves contain a thin diaphragm-like structure that helps open and close the valve.

Arvico Rubber offers two types of diaphragm valves, including:

• Weir or saddle diaphragm valve
• Straight-through or full-bore diaphragm valve
• Reverse diaphragm valve

We also have a dedicated exclusively to the working of diaphragm valves. So do check that out when you have the time.

Rubber Diaphragm Pumps

Diaphragm pumps are also called membrane pumps, and these help draw fluids from one chamber to another chamber, using pressure as a force. These diaphragm pumps act as seals, helping pumps to push fluids without the need for lubricants.

There are different types of pumps that may use Arvico’s diaphragms.

• Air Operated Double Diaphragm Pumps (AODD)
• Metering pumps
• Membrane pumps
• Dosing pumps
• Vacuum pumps
• Impellers

Advantages of Rubber Diaphragms

Here are some of the advantages a rubber diaphragm offers.

1. Offers excellent sealing features.
2. Good quality diaphragms offer airtight seals.
3. Diaphragms are relatively very affordable than other sealant methods.
4. Very low assembly cost and effort.
5. Choosing the right material can ensure your diaphragm handles high temperature and pressure changes effectively.
6. Certain materials of rubber diaphragms handle harsh environments amazingly well.
7. Can be replaced easily without fuss.
8. Diaphragms can be designed in literally any size and other specification required.

Disadvantages of Rubber Diaphragms

There may be certain disadvantages of rubber diaphragms that need to be addressed to use these components effectively.

1. Using diaphragms in high-sludge applications may cause blockage.
2. Diaphragms need to be changed regularly based on manufacturer recommendations. Otherwise, their effectiveness reduces.
3. Picking up the wrong material can lead to breakage or damage to the diaphragm, causing contamination, leakage, and even worse, escape of hazardous materials.             

Rubber Diaphragm Selection Guide

Now, a rubber diaphragm may be a very small part of your expansive industrial setup. However, when this is not chosen right, you may have to end up with inefficient processes and damage to expensive equipment. So, before you decide on the type of diaphragm needed, try to answer the below questions.

• What is the maximum temperature/pressure change the diaphragm has to handle?
• Will your process include abrasive or chemical media that can damage the diaphragms?
• How much force will the diaphragm be exposed to?
• Are there any sanitary standards to be kept in mind?
• Would you require higher flex lives?

Discuss these questions with your diaphragm manufacturer to pick the suitable material of rubber diaphragm for your needs.

We, at Arvico, do not proceed with the manufacturing process until we clearly understand the kind of diaphragm that will work the best for our client’s processes.

Where are Rubber Diaphragms Typically Used?

Rubber diaphragms are used in a variety of equipment and gadgets. Some of the common ones are mentioned below.

• Pumps
• Valves
• Control devices
• Meters
• Modulating devices like regulators
• As shock absorbers in pulsating systems and dashpots

It is also used in most industries like the ones below.

• Chemical
• Food and beverage
• Textile
• Pharmaceutical
• Oil refineries
• Medical and Life sciences

How to Install a Rubber Diaphragm?

Diaphragms are generally very easy to install and fit into the appropriate housing easily. You may need to contact your diaphragm manufacturer to understand how exactly their product is designed to be fixed. Most times, it does not take external help to install a rubber diaphragm.

Maintenance of Rubber Diaphragm

 The first step to maintaining your rubber diaphragm is to install it right. This, by itself, will give the component longevity. Most experts talk about ‘preventive maintenance,’ and we encourage our clients to do this too.

Preventive maintenance includes regularly checking for performance issues and physical damages without waiting for a problem to actually show up. Preventive maintenance is even more vital if your processes use abrasive or harmful media or extreme temperatures and pressures.

As a thumb rule, diaphragms need to be changed every couple of, despite whether or not they look damaged. So make sure changing diaphragms is in your staff’s to-do list at the right intervals.

What Media do Diaphragms Come in Contact With?

Depending on what application the diaphragms are used in, they may come in contact with so many different kinds of media, including water, oil, gases, chemicals, and other abrasive fluids. The type of rubber diaphragm and its material needs to be chosen depending on the media.

Where to Buy Rubber Diaphragms in India?

Arvico Rubber is one of the country’s leading polymer product manufacturers. We have 55+ years of experience in this industry, and our catalog includes 2500+ products that can be customized in endless ways, thanks to our 20,000+ molds.

All you need to do is reach out to us with your specifications, and our expert team will be able to recommend the right diaphragm for your needs.

Conclusion

If one tiny component plays a vital role in improving process efficiencies and safety in an industrial setup, it is a rubber diaphragm. If you think your manufacturing unit needs a positive revamp, then get in touch with us right now. If you are an original equipment manufacturer or seller, offer your customers the best possible products by choosing our quality diaphragms.

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