Engineering Design
Category: Innovation, Insight, Latest, Slider Tagged

With a new contract to manufacture and deliver, the hot topic around our office this week has been optimising the production process.

Engineering and manufacturing experience coupled with good judgement tells us our product is feasible within budget limitations.

Our designers are using our schematics, drawings and solid modelling to produce our CAM programmes.

Our  CAD programs have made our detailed design phase more efficient. This is because it provides optimization, where it can speed manufacturing time without hindering our part’s quality. It also helps us work out how to make our product safe by calculating stress and displacement  throughout the part which we use as a check, determining whether these stresses and displacements are allowable.

Our team are thick in the planning process – selecting the best material and production processes.  Our production manager enjoys nothing more than calculating the optimal sequence of operations and tools, such as jigs, fixtures, and laser welder.   His eyes are sparkling at the thought of the prototype which will be in his hands next week…

What’s so clever about plastics engineering? – Part 2
Category: Innovation, Insight, Latest, Materials

Part 2 – Mass Transfer

Once again we find ourselves in a situation where an intellectual partnership between us and our clients teaches both parties learning something.

Our client is a specialist in the field of mass transfer. In layman’s terms this could be referred to as bulk filtration of fluids.

This can be a relatively simple situation such as the supply of seawater to coastal power stations for cooling purposes.

Whilst seawater itself is fairly innocuous stuff it can’t simply be pumped straight from the sea and used for cooling duties. It’s full of organic material, from simple cellular organisms to such complex life as fish, crabs, etc.

So the seawater’s filtered, under force of gravity, through the tall towers you’ll commonly see at process engineering plants. It’s a fairly simple matter of allowing water to fall through a series of filter mechanisms of progressively smaller mesh.

The supports for the filter media can be relatively inexpensive metals.

But what if the liquid being filtered is an aggressive acid?

This is commonly the case where acid has been used in the production of electrical components, where silver and other precious metals are held in suspension in the acid media as part of the component cleaning operation.

Separating the precious metals from the acid solution is once again a fairly simple operation, providing the filter materials are proof against the acids involved.

Cue the use of exotic, expensive alloys in the filter equipment.

A more cost effective solution could be applied if only a material could be sourced that was acid resistant without the expense of exotic alloys.

Like, for example, polypropylene, polyethylene and cpvc.

Simple plastic materials with marvellous chemical properties and materials we work in every day.

We’d like to work with you to solve your materials problems. Give us a call at 0800 138 6688

What’s so clever about plastics engineering? – Part 1
Category: Innovation, Insight

Part 1 – Deep Sea installations.

The answer is, of course, that plastics engineering is no cleverer than conventional engineering.

We’re lucky, though, that the wide variety of enquiries from our varied clients give us the opportunity every day to spread the word – that plastic is the answer.

For example, we learned an interesting fact the other day.

It’s well known that sea water will corrode steels. So it’s no surprise that the use of stainless steel is widespead within marine engineering.

Something we didn’t know, however, is that the corrosive effects of sea water are massively multiplied by the effects of pressure.

And where do we find sea water at high pressurers?

In the deepest ocean trenches.

It’s a fact that components made of the highest quality stainless steel still corrode at extreme ocean depths.

Polypropylene, however, is entirely resistant to the corrosive effects of salt water.

No-one would pretend that polypropylene has a fraction of the strength of stainless steel.

But by careful design, processing and manufacturing techniques we have developed a range of replacement parts, some of them quite complex plastic fabrications, for our clients within the ocean surveying/oil production industries.

Components which were replaced regularly through corrosion can now be considered to have an infinite lifespan

Not to mention the fact that Polypropylene, (the stuff that washing up bowls are made of) is a fraction of the price of stainless steel.

We’d like to help you look at plastics as a solution to your design problems – get in touch!

Hydrogen Fuel Cells
Category: Innovation, Latest, Precision Engineering, Slider

A fuel cell is an electrochemical cell that converts fuel into an electric current. A fuel and an oxidant flow into the cell and reactions are triggered in the presence of an electrolyte (the electrolyte remains in the cell). These reactions generate electricity, which then flows out of the cell so it can be used. For hydrogen fuel cells the fuel is hydrogen and the oxidant is normally oxygen from the air.

People’s growing concern for the environment means that companies are now focussing more and more on reducing their carbon footprint. There is huge pressure at the moment on vehicle manufacturers to lower petrol consumption and CO2 emissions. Hydrogen fuel cells could offer a solution to this problem, enabling companies to make “greener” cars.

The manufacture of plastic hydrogen fuel tanks demands close-tolerance welding with an absolute guarantee of weld integrity. This can be achieved by conventional welding methods but is of necessity time consuming and hence expensive.

Enter Barkston’s CNC controlled laser welding robot…

Capable of producing welds of the utmost strength with a very high degree of repeatability, the robot welder could have been purpose designed for this task. For more information on laser welding you can follow this link.

We have laser welded fuel tanks for new hybrid London taxis to assist with a government directive for cleaner and greener transport. These taxis use an Intelligent Energy hydrogen fuel cell system hybridised with lithium polymer batteries. This is much better for the environment than using a petrol car because they are not using up valuable, non-renewable petrol, and also because this type of fuel does not release any emissions (except water vapour), giving the taxis a great carbon footprint.

Abrasive Blasting
Category: Latest, Materials, Precision Engineering, Slider

If you have heard of abrasive blasting (sometimes referred to as grit blasting, shot blasting or sand blasting depending on the blast media used) then I guess you would probably associate it with metals, in particular the sand blasting of metals to remove paint. However, it is also possible to modify the surface finish of plastics using abrasive blasting. After contacting many companies regarding the abrasive blasting of plastics we carried out some in-house testing. I also had a day out and visited Hodge Clemco in Sheffield for a demo, who specialize in abrasives and blast equipment.

Overall we have tested around 15 different blast media, including glass bead, sand, plastic media and various grades of aluminium oxide. We have found that aluminium oxide 180/220 gives the best results. It can be used to remove the lines caused by machining and give the plastic a smoother, more even surface finish.

Abrasive blasting can also be used to give acrylic a frosted appearance. Frosted acrylic can be purchased but not always in the exact dimensions required, and cutting or machining will remove the frosted effect. It could also be possible to spray the acrylic after machining to give it a frosted effect but this coating could chip. Shot blasting has therefore offered a solution to this problem. The image below shows some acrylic that has been shot blasted to create stripes with a frosted appearance.

We have managed to show through our abrasive blasting trials, that a process that many people would think is not suitable for plastics, can actually work quite well and give some good effects. Can you think of any processes that are traditionally used for metals that might work for plastics?