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What is Silicone Rubber

What is Silicone Rubber and what is it used for?

 

What is silicone rubber?

Silicone Rubber is a high performance inorganic elastomer. Its characteristics mechanically and chemically are unmatched by organic elastomers.

The unique properties of silicone rubber make it a top choice for an enormous variety of applications in industrial and consumer markets From mobile phone covers to industrial powder coating ovens, silicone rubber has is used for producing huge quantities of product.

Properties of silicone rubber

Silicone rubber can withstand extremes of temperature and is extremely flexible. It can be moulded or extruded and is transparent in its natural state. It can be dyed solid colours and mixes of colour.

Types of silicone rubber

Industrial Grade

By far the most common type of silicone rubber, industrial grade silicone rubber is commonly available and suits any industrial application not involving food or laboratory environments.

Food

More commonly used for consumer applications, food grade silicone is safe for all applications where contact with the mouth, food or children may be a consideration. It’s more costly than industrial grade silicone rubber.

Medical

Medical grade silicone rubber is produced for laboratory and “cleanroom” environments. The most costly of the 3 types listed, medical grade components are supplied free of any dust or swarf produced as a bi-product of the manufacturing process. Curing is slightly different with Medical grade silicone rubber too leading to increased cost.

 

Benefits of silicone rubber

 

  • Silicone rubber lasts longer in more extreme conditions
  • Weather has little effect — Silicone rubber stands up to the environment whatever the conditions, sun, snow, rain, it maintains its properties
    • The environment can affect organic elastomers causing them to deteriorate performance
  • Withstands extremes of temperature — from -100 to 316ºC (-148 to 600ºF)
    • Deterioration is caused at lower temperatures with organic elastomers >100ºC (>212ºF); performance can also be hindered by rigidity <-25ºC (<-13ºF)
  • You have plenty of choices
    • Broad hardness range (from 10 to 80 Shore A),
    • Useful range of color choices (from transparent to brightly colored)
  • Improves performance of seals and fittings
  • High performance electrical insulation characteristics.
    • Relatively unchanged with exposure to harsher conditions (heat, cold, moisture, oil, ozone, UV rays)
  • Remains flexible and resilient across a broader temperature scale
  • Improves the way consumer goods look and feel
  • Inert (no taste or smell); many food-contact options

 

Is Silicone Rubber the material for you?  Call us on 0845 094 0993 to speak to one of our experts today or click here to find out more.

 

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Protecting and masking delicate precision metalwork during media blasting

How to protect and mask delicate precision metalwork during media blasting processes in aerospace applications

One aspect of the work we do at AFAC is to be problem solvers on behalf of our clients. Of course, more often than not a client knows exactly which product they need and our role is simply to fulfill the order. But occasionally a customer will come to us and explain a particular problem they have—and in these cases it’s down to us to configure a solution.

We recently had a situation like this that certainly required some ingenuity on our part to solve.

Our client in this case was a well-known manufacturer of aircraft engines, low-emission power systems for ships, road and rail vehicles and electrical generators. The company approached AFAC because they were facing a particular problem in the maintenance of their aircraft engines. They had discovered that when some of the engines would come in for maintenance, there would be paint peeling off them in certain areas. Given that these are still new engines that would be going out to very prestigious clients, the company decided that they needed to address the problem.

One task of the maintenance team is to strip the coatings from the affected parts and then recoat them. They use a media blast to strip away the original coating, but they were finding the powder they were using for the media blasting was distorting the metalwork. This was making it impossible to satisfactorily refit the pieces to the engines.

The company came to us and explained the issue. We came up with a solid mask to reinforce the metalwork from behind while it was being blasted. As a result the integrity of the shape was maintained and the metalwork remained in a condition suitable for recoating and refitting to the engines, representing a significant money saving for the manufacturer.

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Creating bespoke silicone rubber moulding for manufacturing case study

Bespoke Silicone Rubber Moulding

Case Study: Creating a bespoke silicone rubber moulding to speed up manufacturing

Sometimes, when a client comes to us with a unique problem that needs solving, we create a bespoke silicone rubber moulding for them. Then, having created a solution to the problem, we realise that there may be other customers facing the same problem. The result? A new product line available to all our clients.

This scenario is precisely what happened when we were approached by an international client who had a finishing problem. The company in question is a leader in secondary power distribution solutions with an outstanding pedigree. The business specialises in high-performance medium voltage switchgear for industrial, utility and commercial applications. Incredibly, they have more than 100 years’ experience in enabling the safe and reliable distribution of energy all over the world.

The problem they consulted us about was this: they were looking for a cap that would protect the threaded ends of studs during media blasting to remove oxides and scale from their steel assembly. The cap would also need to act as a mask during electro-static powder coating. However, the caps they were using couldn’t withstand the punishment of shot blasting.

It was time for the AFAC team to step in. We designed a beefed-up version of the T-Cap. It has heavier walls and it doesn’t have the lip feature that the standard caps have. The reason for omitting this is that the blasting process is so fierce it tends to blast the cap completely off the stud. The resulting design for the new cap has increased wall thickness, no lip and a modified top flange to withstand the strain of being pulled off. As an extra precaution, the bore of the cap has also been reduced to give an increased friction fit—a further measure to help it remain in place during blasting.

The result was a winner! The new cap is able to withstand the rigours of blasting and the customer has requested a range of similar caps to use with different sizes and lengths of studs. These robust caps are now also available to our other customers. So one client’s problem resulted in all our clients gaining a new product!

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Manufacturing using 3D Printing – Roll on the Revolution!

How will manufacturers benefit from 3d printing?

Most of us have known about the advent of 3D printing for a while now. But what the inventors haven’t so far been able to show us is how its application is going to revolutionise certain industrial manufacturing processes. However, forward thinking businesses, such as AFAC, are starting to explore its potential—and now that it’s possible to 3D print in rubber, we can see a great future ahead!

3D printing – what is it and how does it work?

If you’ve seen a 3D printer at work, it’s an extraordinary sight to behold. A template in the form of a computer generated .cad file gives the printer its template. Press ‘PRINT’, and a stream of plasticising powder is fused with a bonding element to form a 3D plastic reproduction of the template. Furthermore, the technology has the ability to recreate complex objects, complete with moving parts—and all to an incredible degree of accuracy. But it’s not just plastic creations that can issue forth from the latest 3D printers. New printers have been unveiled that can create complicated multi-coloured sweets from sugar and chocolate. Just what the world has been waiting for!

To see an amazing 3D print out, take a look at this QI clip.

New 3D printing applications in manufacturing

However, more useful applications might not have the novelty value of spun sugar but they may revolutionise manufacturing as we know it. For AFAC, the eureka moment came when Ryan Mullins discovered that 3D printing in rubber is also available.

Rubber? What’s the big deal?

To date, most 3D printing has used plastic. For AFAC, plastic prototypes are not ideal for demonstrating a wide range of products which are generally made from rubber. The rigid nature of plastic doesn’t adequately show how the rubber and silicone plugs and covers will perform.

However, using a 3D printer to create rubber prototypes represents a game-changer for two reasons:

  • For AFAC, the properties of rubber are an integral aspect to the product design and effectiveness of proving concept for the vast majority of its products. In future, we will be able to utilise 3D rubber printing to produce rubber items with varying shore values as a way to provide the fastest and most efficient prototyping service for our clients. Lead times in bespoke product development will be slashed.
  • As 3D printing technology advances, costs will fall and its use will become widespread in all areas of mass production. 3D printing in rubber will reduce the cost of custom mouldings production. Tooling costs will exchanged for cheaper printer set-up charges and bespoke rubber prototypes will become available overnight. We’re not there yet, but with advances in the technology to increase the variety of materials and colours available, we will be soon.

3D Printing for designers and product development

For product designers and developers, this represents a massive leap forward. It’s conceivable that one could move from idea to full production in just a matter of hours. And with your own in-house 3D printing facilities, fears about product protection and pirating simply evaporate.

The UK has built its reputation on the extraordinary skill of its niche designers and product developers. 3D printing will hopefully allow more of the subsequent manufacturing to be based once again on British soil. And hopefully, AFAC will be one of the companies leading the way.

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UK Inventors of the BAKEWELL Silicone Rubber Powder Coating Plug

Inventing the BAKEWELL Silicone Rubber Powder Coating Plug

It may be a cliché that need is the mother of invention but, in the case of the Bakewell Silicone Rubber Powder Coating Plug, it’s certainly true. As powder coating took over from wet paint spraying in the early 80s, a new need was identified. AFAC, or Applied Fastenings and Components as the company was then known, devised the perfect solution – The Bakewell SIlicone Rubber Powder Coating Plug—and it’s still selling strongly to this day!

Back then, the company’s business mainstay was supplying fasteners to sheet metal workers. If a customer required a female thread, either a weld nut, rivet bush or self-clinching nut would be supplied. Once assembled, these solutions provided a far stronger captive thread than simply tapping a hole through the sheet metal.

Happy clients all round? Well, no! There was still an issue. Sheet metal components tend to need protection from oxidization. In other words, they are painted, plated or given an electro-static powder coating. The problem with this is that exposed threads can become contaminated by the coating process, leaving them unfit for purpose when it comes to the final assembly.

AFAC had already solved this problem with regard to male threaded studs, so it was natural we should start casting around for a way of protecting the female threads. The existing solution of using PVC tapered plugs was fine for wet painting—but they couldn’t take the heat generated during powder coating. Diligent research suggested there was a material that would be just perfect for the job—silicone rubber. Able to withstand temperatures of up to 315°C while remaining flexible, it made the perfect solution for thread masking.

Careful thought went into the design of the new plug. Tapered in shape, it had a cylindrical head for easy handling. It was trialled in a range of sizes to ensure it sealed the thread, while leaving approximately one third of the plug out of the hole. This allowed electro-static attraction to draw the powder under the cylindrical head to cover the component right to the very edge of the hole. With generous help from a local powder coater, the new plug was tested and declared a success!

The Bakewell Silicone Rubber powder coating Plug has now been in production for over 30 years, in a range of colour coded sizes, and it continues to be an invaluable masking tool for all powder-coating operations. It’s the original hole-masking solution—devised and designed by AFAC!

 

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AFAC taking flight in the 1980s

As a keen engineer with a love of all things aeronautical, it was never going to be long before Lee Mullins combined his two passions to take to the sky. So, as if building up a fledgling business wasn’t enough to contend with, he found a new hobby to potter with in the shed. But his shed was a little larger than most people’s—it was a warehouse owned by his business. And his hobby? Rebuilding two written-off Auster aircraft!

Lee started his career in aviation—he was an apprentice at Westland Helicopters—but his abiding interested in planes and flying dates back even further. As well as being a Royal Marines Commando during WW2, Lee’s father, Cyril was a member of the design team at Fairey Aviation after the War. This shared interest between father and son meant that Lee spent much of his youthful spare time spotting aircraft. Living near Heathrow might be some people’s idea of hell, but for a young aviation enthusiast it was heaven—and this was in the golden years of civil aviation before the jet age.

Lee’s love of aircraft went from strength to strength and he got himself involved in aviation projects whenever he could. One such undertaking involved volunteering to help rebuild and restore the Sea Hurricane now kept by the Shuttleworth Collection at Old Warden and their Cierva autogiro, now in the hands of collector, Kermit Weeks in the USA.

Lee wanted more—so far his aviation hobby had been confined to the ground. Finally, by the time he was in his mid 30’s, he was able to fund flying lessons in a pre-computerisation 1946 aircraft called an Auster. The bug bit—he took to flying like a duck to water and he joined various groups that shared ownership of planes, until the momentous day when he was finally able to buy his own.

But there was one small snag. The plane he bought wasn’t airworthy. It was a written-off Auster and his intention was to rebuild it as quickly as he could and get it airborne. However, these sorts of projects have a habit of taking on a life of their own. He bought a second written-off Auster to harvest for parts but that, too, became a rebuild project.

Throughout the 80s, the restorations continued and his restored wreck finally left the runway in 1986. And as for Lee? He may no longer be rebuilding or flying aircraft, but his interest in aviation continues to this day!

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Turning back the AFAC clock

It’s been 34 years since Lee Mullins established a fledgling business in his spare bedroom. Now AFAC is about to celebrate its 35th anniversary. So what was life like in those dim and distant days at the start of the 80s? We’re turning back the clock to when there was just one man, a borrowed Triumph Herald (or 2) parked on the drive and a four-year-old more interested in his imminent first day at school than what than what would become an enduring family business…

On the home front

Something mysterious was happening in the spare bedroom. The door was usually shut but when four-year-old Ryan sneaked a peek, all he could see were stacks and stacks of small cardboard boxes…

For his father Lee, starting up AFAC from home was the realisation of a dream—he used his experience in the captive fasteners market to establish an off-the-shelf supply for small engineering businesses. But of course, with a young family to support, it was not a venture without risk. Happily though, the business took off and as young Ryan discovered the delights of play school, Lee was able to move the business out of the spare room and into new premises in Letchworth Garden City.

Making the news

While the establishment of a small business in Hertfordshire might not have hit the headlines, 1980 was a year with plenty going on. Vintage actor Ronald Reagan was elected President of the United States, while here in the UK Margaret Thatcher went head-to-head with striking steel workers. Taking a humorous view of politics, Yes, Minister had its first airing, while Imagine topped the charts in response to John Lennon’s murder in December. The first Ford Escort Mk3 hit the roads, MG production ended, a UFO was sighted near RAF Woodbridge and, during the Conservative Party Conference, Margaret Thatcher famously declared, “The lady’s not for turning!”

What were you doing in 1980?

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Welcome back: Ryan Mullins returns to AFAC

More than 34 years have passed since Ryan Mullins remembers his father setting up a business in the spare bedroom of the family home when he was four years old. Fast forward three and a half decades and that tiny start-up is now the UK’s leading supplier of silicone rubber masking products for powder coating and metal finishing. And now Ryan is delighted to be returning to the family firm in a new Sales and Marketing role.
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