Jehbco’s QUICKJOINT by JEHBSIL is our line of products specifically tailored to meeting Australia’s demand for façade seal and expansion joint seals in the building and construction industry. Solid silicone extrusions offer a substantially more convenient and cost effective replace ‘wet silicone’ that is traditionally used to seal between composite façade panels. Wet sealants are chemically hazardous, have a notorious reputation for being tedious and difficult to install, and frequently have rough and inconsistent finishes. Quickjoint offers many benefits over wet silicone from its temperature and weather resistance, ease of installation, and its ability to be customised to strict specifications. Jehbco is able to customise Quickjoint to any width, any depth, and any colour.
Articles posted by Jehbco Silicones
Dry Gap Sealing Compared With Wet Silicone Sealing
Wet silicone can be difficult to apply, can be messy with high wastage, and if it is not used correctly, it can contribute to poor sealing quality and performance issues in the medium and longer terms. In this video, we have compared Jehbco Dry gap sealing with wet silicone sealing.
Jehbco Silicone Extrusion Adhesion Procedure
This instructional video is provided to you by Jehbco Silicone experts to help with the application of silicone adhesives. In this video Jehbco Silicone extrusion adhesion procedure are compared with easy to use self-adhesive backing.
Fluorosilicone
Silicone is a very versatile elastomer that is used in numerous industries due to its superior physical and chemical properties, such as: excellent thermal resistance, higher longevity in hostile environment and flame retardancy [1]. These properties make silicone a desirable material for fuel systems, which unfortunately is not possible due to silicone’s limited fuel and oil resistance. However, this problem can be solved by substituting a small number of methyl groups in silicone (VMQ) with trifluorpropyl substituents, which results in fluorosilicone (FVMQ)[1].
The trifluoropropyl substituents enhance silicone’s chemical resistance to non-polar solvents, hydrocarbon fuels, oil, acids, and alkaline chemicals, making it a more ideal material for sealing in applications requiring resistance to hot fuels, oils and diesel based lubricants[2],[3]. This makes fluorosilicone a preferred material for static sealing and cushioning applications in aerospace, automotive and aviation industries [2].
Figure 1: Fluorosilicone is a Problem-Solving Material for Aviation Industry
Whilst it offers similar properties to silicone, there are several differences as shown in table below:
| Unit | Silicone[1] | Fluorosilicone[4] | |
| Hardness Range | Shore A | 3-90 | 30-85 |
| Operating Temperature | ℃ | -50 to +250 | -55 to +180 |
| Tensile Strength | N/mm2 | 5-12 | 8 |
| Elongation at Break | % | 100-1,100 | 200% |
As seen above, standard compound fluorosilicone has an operating temperature of up to 180℃. Due to this limitation, fluorosilicone is primarily used in fuel systems at temperatures up to 177℃[5]. However, there exists high-performance fluorosilicone that has a temperature range of -55℃ to 230℃[2]. It also has been reported that fluorosilicone could remain serviceable from -68℃ to 232℃, making it a fuel-resistant elastomer that is superior compared to fluorocarbon (FKM, such as Viton and Tecnoflon, poor low-temperature flexibility) and nitrile (NBR, heat resistance only up to 120℃)[2].
It is important to note that fluorosilicone is generally recommended for static applications only due to its relatively low tear strength, limited abrasion resistance and fair flex-cracking resistance [3],[5].
Fluorosilicone is usually used in the form of O-rings, gaskets, washers, diaphragms, and seals in fuel line connections, fuel control devices, electrical connectors, hydraulic line connectors, and fuel system access panels[6].
For more information and to keep updated with our research and development of fluorosilicone products, please do not hesitate to contact us.
References
- Wacker Chemie AG, ‘Solid and Liquid Silicone Rubber: Material and Processing Guidelines’. Wacker Chemie AG, n.d.
- Stockwell Elastomerics, ‘Fluorosilicone / Fluorosilicone Rubber’, Stockwell Elastomerics, Inc., n.d. https://www.stockwell.com/fluorosilicone/ accessed 11th September 2019
- Polymerdatabase, ‘ FVMQ – Fluorosilicone Rubber(Fluorovinylmethulsiloxane Rubber’. Polymer Properties Database, 2015. http://polymerdatabase.com/Elastomers/FVMQ.html, accessed 10th September 2019
- Infinity Seal, ‘Fluorsilicone [FVQM]’ Infinity Seal, 2015. https://infinityseal.com/wp-content/uploads/2015/05/fsilicone.pdf accessed 10th September 2019
- Eriks, ‘FVMQ’ https://o-ring.info/en/materials/fluorsilicone-fvmq/ accessed 10th September 2019.
- Bhuvaneswari, et. al., ‘Evaluation of Fluorosilicone – Silicone Elastomer Blend for Aeronautical Fuel System’. 2014 http://www.polymerjournals.com/pdfdownload/1204301.pdf accessed 11th September 2019
Jehbco’s Silicone Products for the Rail Industry
Rail is one of the most important modes of transportation in Australia. For passenger rail, in 2013 alone, about 2.3 million people travelled by train on a daily basis, totalling 850.3 million passenger trips [1]. On top of passenger rail, rail accounts for almost 50% of freight activity in Australia [1]. Additionally, Australia’s freight task is expected to grow by over 35% in the next 20 years, bringing the total volume to just over 1,000 billion tonne-kilometres[2]. Of this, rail is projected to grow to about 550 billion tonne-kilometres, about one-half of the total volume, maintaining its number 1 position in terms of volume [2].
Due to its sheer volume, it is pivotal for the rail industry to put performance and passenger welfare as their utmost priority. Hence, the rail industry has stringent aesthetic, technical and safety requirements for the materials and products that they use. Silicone meets these criteria due to its material advantages, such as [3]:
- Cosmetically appealing (for more information please click here).
- Non-toxic combustion products in the case of fire.
- Compliance with fire safety standards such as UL 94, NFF 16101, BS 6853 and DIN 5510.
- Can be exposed to wind, rain and UV rays for extended periods of time with almost no change in its physical properties.
- Low compression set, resulting in increased long term reliability for anti-vibration, cushioning and sealing applications.
Figure 1: Sydney Metro Trains
As an ISO 9001 accredited company with almost 50 years of experience manufacturing silicone products, Jehbco Silicones prides ourselves on our OEM capabilities that makes us the preferred supplier of some of the largest rail manufacturers, such as:
Security of supply
We are able to produce the required quantity within the specified timeframe.
Strict safety standard
Particularly in terms of fire safety standards, Jehbco’s silicone products are known for their non-toxic bromine-free components, which meet the most stringent industry requirements for fire, smoke and toxic fumes, such as BS 6853.B2.
R&D capabilities to produce highly engineered materials for rail industry
Jehbco offers flame retardant silicone products that have been proven to have superior flame retardant properties to that of standard silicone rubber. As can be seen from this article, our flame retardant silicones have much lower fire damage compared to standard silicone rubber.
Jehbco is also able to supply flame retardant products in jet black colour as seen in the figure below.
Figure 2: Sample of Jehbco’s Jet Black Flame Retardant Extrusions
For further information about Jehbco’s silicone products for the rail industry, please see our transport applications page and do not hesitate to contact us.
References
- Australasian Railway Association, ‘Australia’s Rail Industry’. Australasian Railway Association, n.d. https://ara.net.au/sites/default/files/Australian%20Rail%20Industry%202014%20web.pdf (accessed 21st August 2019)
- Transport and Infrastructure Council, ‘National Freight and Supply Chain Strategy – August 2019’, Department of Infrastructure, Transport, Cities and Regional Development, 2019.
- Wacker Chemie AG, ‘Solid and Liquid Silicone Rubber: Material and Processing Guidelines’. Wacker Chemie AG, n.d.
Jehbco is Defence Ready
As a trusted supplier to the defence industry with over 45 years of experience as an industry leader, Jehbco Silicones has both the experience and the capability to supply to complex defence projects with delivery in full and on time. With R&D expertise in mechanical, polymer and elastomer engineer Jehbco is able to create in-house custom products for our customers with the capability to manufacture both build to print and build to spec.
ISO 14001:2015 Environmental Management System
Jehbco considers all the environmental issues related to its operations such as energy consumption, waste management, resource use and efficiency as important. Jehbco has a team which is currently working on implementing an Environmental Management System (EMS). Jehbco aims to get its EMS certified ISO 14001:2015 by the end of 2020.
ISO 14001 is a standard providing specific requirements for an effective environmental management system. The standard does not establish environmental performance requirements or telling organisations how to manage the environment. The standard provides a framework for an organisation to manage its activities, products and services in balance with its socio-economic needs1.
The standard is suitable for all types and sizes of organisation. The standard uses a high-level structure (see Figure 1) which is similar to the quality management system (ISO 9001:2015) that Jehbco has been holding for the last 20 years2. This means that ISO 14001 can be easily integrated into our existing quality management system.
Figure 1: High Level Structure
The implementation of an environmental management system is going to bring many benefits to the organisation. For example, the standard will help Jehbco to improve its resources efficiency by setting for example some environmental objectives. This implies that Jehbco will constantly look at reducing its general waste, raw material, water and energy use. This will have the key benefit to lower the business cost.
At Jehbco, we are always concerned with satisfying the expectations of our customers. Being ISO 14001 certified will ensure that our customers that we are meeting statutory and regulatory requirements. We will also encourage our suppliers to have a better environmental performance by integrating them into Jehbco quality and environmental management system.
ISO standards promote the application concept of the process approach. This means that the organisation manages the business as a system of processes linked together (i.e. network) and not by departments, people or products3. This helps the organisation to ensure that each process delivers its expected outputs as this could impact the inputs of what the other next processes need.
Additionally, the new revision of the standard introduced an emphasis on addressing the risks and opportunities of the organisation in order to achieve the intended outcomes of the environmental management system and prevent its undesired effects i.
Finally, like any ISO, the standard specifies the need for continuous improvement of the organisation system and approach to environmental concerns ii. The Plan Do Check Act model (see Figure 2) is an iterative four-stage approach process. The standard can itself be integrated into a PDCA model i. The four stages are4:
- Plan: identity, analyse, develop hypothesis and decide on one hypothesis to try first
- Do: execute the plan
- Check: see how it works
- Act: review the results and make decisions to improve the process
Figure 2: Plan Do Check Act Model (PDCA)
While working towards implementing an environmental management system, people at Jehbco are also putting in place an occupational health and safety management system to obtain ISO 45001:2018 certification.
References
- ISO 14001:2015 standard, September 2019
- International Organization for standardization, ‘ISO 14001 Key Benefits’, viewed on 12th August 2019, https://www.iso.org/files/live/sites/isoorg/files/standards/docs/en/iso_14001_key_benefits.pdf
- 9000 Store, ‘What is a process approach’, viewed on 12th August 2019, https://the9000store.com/iso-9001-2015-requirements/iso-9001-2015-context-of-the-organization/what-is-a-process-approach/
- ISO 14001:2015 Requirements, Environmental Management system, Training Course Manual, BSI, May 2016, version 3.3
Silicone vs HNBR
Whether it be designing a new product, or improving an existing piece of equipment, the choice of material is extremely important to ensure a low cost and smooth operation.
Silicone and Hydrogenated Nitrile (HNBR) have distinct physical and chemical properties, which determines what application each material is best suited for. Silicone and HNBR are both commonly used materials for o-rings, gaskets, seals, tubing and membranes. While both elastomers may be used to create similar products, the specific application and environment will ultimately determine whether HNBR or silicone will be the better choice for you. The table below summarises some of the key differences between the two materials.
| HNBR | Silicone |
| -30°C to 150°C | -50°C to 230°C |
| Good compression set | Excellent compression set |
| Good weather resistance | Excellent weather resistance |
| Approx. tensile strength 20 MPa | Approx. tensile strength 5 MPa |
| Great abrasion resistance | Poor abrasion resistance |
| Not compatible with: esters, ethers, halogenated solvents, brake fluids, ketones | Not compatible with: hydrocarbon fuels, alkalis and acids, steam over 121°C, trichloroethylene, aromatic hydrocarbons. |
| Compatible with: most oils and fuels, alkalis and acids, hot and cold water, alcohols. | Compatible with: oils, brake fluids, hot and cold water, saltwater, high molecular weight chlorinated hydrocarbons, fire-resistant hydraulic fluid, ozone. |
Both HNBR and silicone can operate at extremely low temperatures, although silicone is the far better option in high-temperature environments. Silicone can resist intermittent temperatures of up to 230°C, or up to 280°C if a heat stabiliser is added into the raw material.
HNBR has excellent tensile strength and good abrasion resistance, whereas silicone has good tensile strength, but poor abrasion resistance. For dynamic applications with friction, HNBR would most likely be a better option. Granting this, silicone can be formulated to have improved tear strength, making it an ideal choice for applications such as vacuum sheeting and peristaltic pumps. Silicone also has the superior compression set, which makes it a better choice for applications requiring a long-lasting, reusable seal, especially in high-temperature environments.
While silicone has excellent resistance to ozone and UV, HNBR does not have the best resistance to ozone and UV, making silicone the more viable for most outdoor applications. However, HNBR is resistant to most forms of fuels and oils, whereas silicone is not compatible with a lot of hydrocarbon fuels. With this in mind, HNBR would be the superior choice for the automotive industry, although fluorosilicone compounds can be a good fuel-resistant alternative if a silicone-based material is required.
It is clear to see that there is merit in using either HNBR and silicone, depending on what physical properties you require and the operational environment. For help selecting a material for your application, consult our applications page and contact us with any questions.
Advantages of Silicone Products
Jehbco Silicones manufactures extrusions which are made from 100% pure silicone elastomer and exhibits the characteristics of both inorganic and organic materials, which offers a number of advantages not found in other organic rubbers, such as [1][2];
a) Excellent resistance to heat and cold
Silicone rubbers have a broad operating temperature of -50°C to around +250°C for addition (e.g. platinum) cured and around +300°C for peroxide cured. Furthermore, it exhibits only slight changes in physical properties between -50°C to +180°C.
In terms of heat resistance, silicone rubbers can be used indefinitely at 150°C with virtually no change in its properties and can be used for 10,000 hours of more at 200°C.
Table 1 Operating life and temperature of silicone rubbers before any changes in properties.
| Operating Temperature (°C) | Operating life (hours) |
| 150 | Indefinite |
| 200 | 10,000 |
Whereas in terms of cold resistance, the embrittlement point of silicone rubbers is -60° to -70°C, as opposed to typical organic rubbers which is between -20° and -30°C.
Table 2 Cold resistance comparison between organic rubbers and silicone rubbers.
| Product | Embrittlement Point (°C) |
| Organic rubbers | -20 to -30 |
| Silicone rubbers | -60 to -70 |
b) Higher longevity in hostile environment.
On top of its excellent thermal resistance, silicone rubbers also have exceptional weatherability. It can be exposed to wind, rain and UV rays for extended periods of time with almost no change in its physical properties. Hence, it has higher longevity in hostile environment compared to organic rubbers. Furthermore, when phenyl groups are added to the polymer molecules, silicone rubbers are able to resist radiation and can be used in the manufacturing of cables and connectors used in nuclear power plants.
c) Good flame retardancy
Flame retardancy and/or self-extinguishing properties can be added to silicone rubbers by adding a small amount of flame retardant. When they do burn, unlike organic polymer rubbers, silicone rubbers do not produce black smoke or noxious gas. Hence, silicone rubbers are suitable to be used in consumer electronics and business equipment that are used in closed spaces such as aircraft and subways.
d) High purity
Silicone rubber is exceptionally pure compared to other elastomers. Furthermore, it is physiologically inert, which consequently affects living tissues to a lesser degree than by exposure to other organic polymers. Hence, it is suitable for use in the food and medical industry. Additionally, to ensure that our products are safe for sensitive applications, some of Jehbco’s products have certifications such as FDA CFR 21 177.2600 for food contact, AS/NZS 4020 for drinking water and USP Class VI for biological tests.
Due to its many advantages, silicone rubber is used in nearly every industry to improve the quality and function of various products and manufacturing processes.
For further information about the benefits of Jehbco’s silicone products and how it could suit your specific application, please contact us.
References
- Shin-Etsu Chemical Co. Ltd., ‘Characteristic Properties of Silicone Rubber Compounds’. Shin-Etsu Chemical Co. Ltd., August 2016.
- Wacker Chemie AG, ‘Solid and Liquid Silicone Rubber: Material and Processing Guidelines’. Wacker Chemie AG, n.d.
Silicone vs Fluorocarbon
When it comes to providing expert silicone solutions and rubber products, Jehbco Silicone is leading the way, growing its supply chain at a global scale. This article explores the properties of silicone rubber and how it compares to Fluorocarbon, an elastomer based on fluoro-rubber (FKM), also known as Viton (Fluoro Elastomer brand).
Although Silicone and Fluorocarbon are quiet similar in their properties, the fluorene (trifluoropropyl) groups do provide significant variances in chemical resistance and compatibility which develops a wider range of possible applications. The following table compares the key chemical and mechanical properties of Silicone and Fluorocarbon.
| Fluorocarbon | Silicone |
| -20° to 250° C | -50° to 230° C |
| Excellent compression set | Excellent compression set |
| Excellent weather resistance | Excellent weather resistance |
| Approx. tensile strength 10 MPa | Approx. tensile strength 5 MPa |
| Fair abrasion resistance | Poor abrasion resistance |
| Not compatible with: amines, oxygenated solvents, lacquer solvents | Not compatible with: hydrocarbon fuels, alkalis and acids, steam over 121 °C, trichloroethylene, aromatic hydrocarbons. |
| Compatible with: acids, alcohols, oxygenated solvents, alkali, fuels and hydrocarbons, mineral oils, | Compatible with: oils, brake fluids, hot and cold water, salt water, high molecular weight chlorinated hydrocarbons, fire resistant hydraulic fluid, ozone. |
Silicone and Fluorocarbon have very similar temperature ratings ranges, however Silicone is generally superior for low temperature applications at -20° C. Fluorocarbon is able to withstand higher temperatures at 250° C, although Silicone with the addition of heat stabiles and fame retardants, can exceed this and provide temperature ratings of up to 300° C making it an idea for high temperature applications.
They both share very similar abrasion resistance (fair- poor) which reduces their ability to perform well in dynamic applications and have similar ability to perform well in applications which demand durability due to their excellent compression and weather resistance. The tensile strength of Fluorocarbon is higher than Silicone at 10 MPa making it an ideal possible selection for high force and pressure applications.
In general, Fluorocarbon due to its chemical structure is an ideal material for applications that require strong chemical compatibly with hydrocarbons, oils and fuel/petroleum. As silicone is ideal for static high-temperature sealing applications, they have poor compatibility with oils and hydrocarbons which allow fluoro-elastomers such as fluorocarbon to be the best material choice.
To discuss the ideal material for your application, please contact us.