Sponge Extrusion Department Continues its Improvements

It is a common saying that business never stands still and that can certainly be linked to continuous improvement to keep up with the constant changes in the market place. We have recently been looking into our sponge extrusion lines to assess where we can add further value to our finished product to allow it to continue to be the high quality range of expanSil™ silicone sponge products many of you are familiar with.

Our innovation team have been looking into the emission levels and extraction systems along the sponge extrusion lines to further improve the speed at which the volatiles are driven off when the sponge is being cured. Over the last month the team have worked to improve the extraction systems on each line to allow the emissions to be extracted at a faster rate, therefore improving the finished sponge appearance and performance.

Phil Martin, Sponge Extrusion Team Leader said of the improvements “It has most certainly improved the quality of the silicone sponge and the skin finish. The improvements have given a much whiter, brighter sponge.”

These improvements have been noticed out in the market place with customers commenting on the sponge’s whiter appearance.

As well as the extraction improvements, further development was seen a few months ago to raise sponge extrusion capacity by an amazing 50%. This extra capacity has allowed for quicker turnaround for our customers and the upstream supply chain.

Improvements being made in the sponge extrusion department are just some of many being implemented across the business at Silicone Engineering to improve the quality of our materials as well as improving customer service.

Find out more about expanSil™ sponge extrusions.

Silicone, a key ingredient in renewable energy

Indeed, some forms of silicone have been designed with the express purpose of aiding in the responsible construction of renewable energy providing devices and installations. kSil™VAC, a proprietary silicone material produced by Silicone Engineering is a prime example of this, with its high tear resistance and high elongation properties making it an ideal material for the use in vacuum membrane machines for the construction of solar panels and composites such as wind turbine rotor blades. The superior attributes of a custom silicone material like Silicone Engineering’s kSil™VAC greatly increase the speed and environmental efficiency of the production of renewable energy sources; helping both the renewable energy industry and the planet.

With silicone’s impressive material credentials established, we’ll take a look through some of the ways in which the many positive attributes of silicone materials are of particular benefit to the renewable energy industry, through the use of some specific, practical examples.

Solar panel design and production

solar panels - renewable energy

Solar panels are simply a collection of solar cells, which themselves generally consist of multiple layers of silicon, placed over a substrate such as glass or plastic. The specific variety of silicon that is utilised in the construction of solar cells can vary to a fairly large degree; from monocrystalline silicon to ribbon silicon. The differences between these forms of silicon is down to the way in which they are formed, and resulting in an array of different chemical structures, all of which best suit a number of individual uses. Therefore some of these varieties of silicon are better suited to the efficient operation of solar panels than others; some are used for their aforementioned efficiency, while some are instead cheaper to produce than others.

But this is where it becomes important to differentiate between silicon and silicone; the silicon from which solar cells are primarily constructed is a naturally occurring element, while the silicone that this article primarily concerns is a compound made up of silicon mixed with other elements; such as carbon and hydrogen making it an elastomer. This addition of elements makes the silicone compounds in question that much better adapted for their specific roles, adding new attributes to an already robust selection.

The primary use of silicone in regards to solar panel design is in the actual vacuum membrane presses that construct the solar panels rather than kSil™VAC silicone rubber being in the solar panels themselves.

kSil™VAC, by Silicone Engineering, is used to maintain a vacuum around the components of a solar panel, which in turn assists the bonding, by forming a membrane. This process is essential for ensuring the long life and structural integrity of solar panels, and the superior elasticity, tensile strength and overall durability of kSil™VAC ensures that fast and efficient production of solar panels is consistently possible as well as providing longer production life of the membranes meaning a more cost efficient material than that of latex or other rubber materials. This in turn means that manufacturers are better able to cope with the increase in demand that is forecast for solar panel construction in the near future.

Wind turbine construction

wind turbines

Protection from the elements is not the only manner in which silicone assists in the promotion of environmentally friendly energy production, though. While the safeguarding of the internal workings of a wind turbine is obviously of extreme importance to the efficient production of energy within such installations, silicone is also able to assist with the efficiency of energy production in more immediate ways. Despite the protection offered by silicone externally, wear and tear are sadly still an inescapable reality of machinery such as wind turbines; even if adverse weather wasn’t an issue, the frequent action of the moving parts within a wind turbine ensures that mechanical failure is an inescapable eventuality. Therefore, silicone based lubricants can form a key role in the maintenance and continued function of wind turbines, allowing them to keep operating long after their mechanisms would have otherwise ceased to function. This range of long lasting lubricants keep the many moving parts of a wind turbine working as effectively as possible; allowing the effects of age and wear to be mitigated for as long as possible.

As with the manufacture of solar panels, the manufacture of wind turbines requires the use of silicone rubber to act as an effective vacuum membrane when dealing with intricate composites. And in the same way as with the manufacture of solar panels, this area of manufacture once again allows kSil™VAC, the specialist silicone vacuum sheeting manufactured by Silicone Engineering, to shine; providing a high level of performance that support the increasing demand for renewable energy in both civil and private spheres. Indeed, the continued development of specialist materials such as kSil™VAC demonstrates the ongoing popularity, and growing demand, for renewable energy sources as a whole.

Power line protection and insulation

Of course, all of the extra efficiency and protection provided to renewable power sources by silicone based products would be moot if the delivery method of this hard won energy was itself inefficient. It doesn’t matter how effectively a well can draw water, if the bucket used to transport the water has a hole in the bottom! In order to ensure that the energy efficiency and environmental sustainability bought by innovations in silicone technology and treatments at the energy production stage isn’t wasted, it’s necessary to also protect the efficiency and function of energy delivery.

Silicone is also able to step into this particular gap in functionality, further protecting the production of environmentally friendly energy from inefficiency and untenable wastage. As with the previously mentioned issues in solar and wind energy production, the principle issues facing the efficient and environmentally friendly carriage of responsibly generated electricity are caused by weather.

Silicone materials are already widely utilised for the insulation of electrical wires, providing a layer of protection for people within close proximity to them, while also ensuring that energy isn’t leached out or diverted by any other means. In the case of power lines, there is often also a coating of silicone insulation material coating the wire. However the nature of power lines also ensures that the presence of specific insulation apparatus at intervals along the line, to protect against surges, and lightning strikes, is necessary. In this way silicone provides an essential role in safeguarding the efficiency of energy production, and minimising environmental damage in the process.

Environmentally friendly

While the functionality of silicone materials in maintaining the efficiency, and protecting the operation of renewable energy, is clearly demonstrated above, another important aspect of silicone usage in the manufacture and transport of environmentally friendly energy is in its own environmentally friendly nature.

Due to its non-biodegradable chemical structure, silicone produces no harmful by-products, and refuses to degrade, regardless of the environmental conditions that it’s exposed to. Not only does this make the environmental impact of silicone minimal, it also ensures that the environmental impact of the devices protected by silicone based materials are extremely low, and considerably better than they would have otherwise been.

Benefits of Solid Silicone Rubber in Application

What is solid silicone rubber and what are the benefits of using solid silicone in a range of industries and environments?

The key factor when choosing a material is the application the silicone will be placed in. These key questions can be asked:

  • Where will the material be used?
  • What is the purpose?
  • What is the function?
  • Why is a silicone component needed for that application?

What do we mean by solid silicone? 

  • Solid silicone is a flexible rubber or elastomer
  • Its hardness is measured in Shore A
  • Silicone Engineering can produce solid silicone from 30 shore A (very soft) to 80 shore A (hard)
  • Perfect for use as a seal or gasket in precision machined applications
  • Solid is much stronger than sponge, there are no air bubbles present, which helps it to withstand high torque and pressure forces

Elastomers are used where a degree of flexibility is needed; or a certain amount of ‘give’ is required. Solid silicone rubber, like other rubber, will always feel soft and bendy in contrast to inflexible plastics. Most plastics are rigid in nature and design, but at the same time will work great in certain applications where rubber would not be suitable.

If a sealing gasket is required for a large effluent tank lid, we would not choose a hard rigid plastic as there is no give and it would not conform to the mating surfaces. Silicone (or other rubber) would be the choice for this application. We choose one material in preference to another by comparing the different properties in reaction to the application. The following list highlights different reasons people turn to solid silicone rubber when choosing a material for their project.

Benefits of using solid silicone

Excellent Flexibility

  • Solid Silicone rubber has excellent flexibility, it can be modified easily and responds well to a variety of circumstances.

Noise Reduction

  • Solid silicone reduces high volume noises passing through.

Vibration Dampening

  • The rubber reduces vibration, suitable for mass transit applications.


  • Solid profiles are mainly used for precision sealing, this format of silicone responds well to sealing tight spaces due to its flexible nature.


  • Solid silicone rubber is designed to stop the process of heat and electricity from spreading.

Thermal Insulation

  • The material stops unwanted heat from entering through to the other side.

Thermal Shielding

  • The material acts as a shield from absorbing excessive heat from travelling to it’s centre.


  • Solid silicone gaskets sit between two surfaces, generally to prevent leakage into the joined objects while under compression.


To find out more about kSil™ solid silicone sheeting all manufactured by Silicone Engineering click here


Silicone Elastomers World Summit 2015

The annual Silicone Elastomers World Summit is back once again for 2015 and we are honoured and excited to announce that once again Silicone Engineering will be proud sponsors of the of the event held this year in the historic Catalan city of Barcelona.

Since the success of last year’s event held in Vienna, the company have made the decision to return again as a show sponsor and also exhibit at the event.

Last year’s event offered the company attendees a chance to network with industry leaders and like-minded individuals within the silicone industry. The conferences allowed us to facilitate best practices, gain new innovative ideas whilst also voicing opportunities and concerns with a broader audience all focused on silicone as a material.

Smithers Rapra, hosts of the event, have been providing expert information to the plastics, rubber and composite industries for over 90 years.

Mirroring last year’s summit, Smithers Rapra will be coupling the Silicone Elastomers World Summit with Thermoplastic Elastomers World Summit. The two events will co-locate for the second time, with the union expected to draw over 250 industry experts to attend the summits at the Pullman Barcelona Skipper Hotel.

Silicone Engineering are already looking forward to engaging with industry advisers, exhibitors and delegates, strengthening existing industry contacts and building new ones to ensure we keep delivering silicone solutions for years to come.

To find out more about the Silicone Elastomers World Summit click here



Growth and Diversity of a Silicone Manufacturer

It is both interesting and notable to think where UK manufacturer Silicone Engineering have come from and where the company are now in terms of manufacturing machinery and the possibilities for the future.  Twenty years ago the company comprised many “small scale” machines churning out short runs, we prided ourselves in being able to squash or pull raw silicone compound into any shape or size the customer wanted, 10 meters here, 20 meters there. Here is a stand out thing;

“Silicone Engineering could not be set aside from any other silicone manufacturers at that time as we were all manufacturing the same products because we all had the same conversion machinery”.

It was easy (and still is) to set up in small industrial premises and start producing extrusions. So with that in mind and in order to get ahead of the competition there were two things that were needed

1. A desire to grow and differentiate ourselves to break away from small time extrusions

2.The money to do so

During May 2002, Silicone Engineering became an independent company, breaking away from Aerospace company Meggitt.  Since then the company have advanced ahead of many competitors as investment has taken us from 35mm extruders making 10mm strips to 250mm extruders and calenders making 1.8 meter wide sheet in roll form.

Silicone Engineering’s Manufacturing Capabilities:

The manufacturing facility at Silicone Engineering is split into three distinct sections:

1.Compound preparation and mixing – consisting of various mixers and mills, where many combinations of different additives are blended with raw base rubber to produce the compounds we know under our brands – kSil™, suraSil™, expanSil™, metectSil™ and neutraSil™

2.Vulcanisation machinery – these are the machines that convert the compound into cured strips, tubes and sheeting products that we sell to our customers

3.Secondary Operations – these are additional, added value processes like self adhesive backing (PSA).

Compound Preparation and Mixing – Mill Room:

Silicone Engineering has a significant benefit and advantage over most of our competition, The Mill Room. We have built up, and continue to do so, a substantial unit for mixing and blending of our own bespoke compounds.  Approximately 2 million kilograms (4.4m lbs) of compound is produced per annum through our mill room and with capacity to increase this figure it is an enviable amount, a capability that our competitors wish for. The set up gives Silicone Engineering great flexibility and can react rapidly to customer’s needs especially in the compound business, on many occasions we have turned around orders within 24 hours.

Here is a table broadly outlining the capabilities in terms of Mill Room manufacturing machinery.


1997Producing ~ 300 Tonnes per year 2015 Producing ~ 2,000 Tonnes per year
2 x manual Winkworth mixers with 80kg capacitymix time 20 to 30 minutes – sponge silicone 2 x Banbury (intensive) mixers with 50kg capacitymix time 3 to 5 minutes – solid silicone
3 x small capacity (20kg) mills – sponge & solids 1 x automatic Winkworth mixer with 350kg capacitymix time 30 to 45 minutes – sponge & solids
2 x Barwells 1 x automatic Morton mixer with 200kg capacitymix time 20 to 30 minutes – sponge & solids
1 x manual Winkworth mixer with 80kg capacitymix time 20 to 30 minutes –  sponge
1 x manual winkworth mixer 10kg capacitymix time 20 to 30 minutes – sponge & solids
2 x large capacity (150kg-200kg) mills – solids
1 x very large capacity (330kg) mill – sponge & solids
2 x small capacity (20kg) mills – use sponge & solids
1 Barwell

Even a cursory glance will show you the difference in silicone output since 1997, approximately 6 times.  All machinery in the right column are new installations within the past twenty years with most being added as recently as the past 5 to 8 years with more to come in the next two years as the growth continues.

In part II of this blog we will discuss our conversion machinery which transforms compound into our silicone products that many of you will be familiar with.

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