Covid Capers

Hi Everyone

Sorry about the title. Wasn’t trying to be funny or demeaning, but couldn’t think of a better title. It’s the most serious thing most people will be able to remember, or cope with.

What will it be like afterwards?  We probably don’t want to think about that yet – - let’s get through it first.

If anyone is interested at the moment I am still around but working from home. If anyone else is in the same boat …………… difficult to keep the concentration going isn’t it. If you want to get in touch my e-mail is or if you ring the office they will be happy to give you my mobile number. Allcocks are still open and the offices are manned as normal – ish

Let’s hope it passes safely for as many of everyone as it can.

Keep smiling


ISO 9001:2015 QMS certification.

Hi Readers,

Nearly Easter …… hope you have a good break.  Easter always signals that winter is over and better weather (hopefully) is on the way.

I have some great news to pass on.  Our QMS (quality management system) certification was due for renewal, so we took the bull by the horns and went for the new, latest version viz: ISO 9001: 2015.  It took quite a lot of work, by all concerned, because the “thinking” now has a different emphasis, but we did it.  We are now fully certificated to ISO 9001:2015, as from early this month.

Copies of our new certificate, either “hard” or digital, are now available to our customers.

As Matt has now moved on to pastures new (Good Luck Matt), I will be one of the contact points.  Please feel free to contact me.

Cheers for now



Good Enough to Eat – Food Grade Silicone Oils

As we have just sold our first major consignment of Pure, Food Grade Silicone oil, I thought it would be worth posting on our blog. Food Grade Silicone oils are exactly like Industrial Grade silicone oils in that they are pure Polydimethylsiloxane (unlike or successful Allcosil 356 and 435 FG Emulsions, which are emulsified versions of this oil), but as they are food grade there production is made in a strictly controlled clean environment and the viscosities available are limited between 350cst and 1000cst viscosities. Though the material is food grade, and thus complies with all the necessary EU and FDA regulations, we wouldn’t suggest eating it!

If you’re interested in Food grade Silicone oils or Silicone products please get in touch and we will be happy to assist.

Straight to Print – DC 2418, The Post-Application Printable/Paintable Silicone Emulsion

One of the downsides of using Silicone oils or emulsions as a release agent is that the material you’ve released from the mould can’t be printed on or painted until the silicone oil has been cleaned off. The very nature of silicone oil, that it’s a non-poler, slippy polymer, means that any paint or ink wouldn’t penetrate the layer of oil, or would mix in with it. DC 2418 emulsion not only allows printing and painting of post-moulded products, thanks to Ethylated Silicone oil (and some other ingredients) but as it’s an emulsion, it’s as easy to use as traditional Silicone Emulsions.

If you’re interested in the specific properties of DC 2418, and it’s possible uses, please get in touch.

Mastering the Future of Siloxanes – Silicone Oil Masterbatches

Polydimethylsiloxane (or Silicone Oil) has been a leading mould release agent since the 1950’s. Its inert chemical nature, extreme heat resistance and total lack of harmful contents have made it the obvious choice for many. However, as plastics rose to predominance in the moulded goods sector, the use of silicone oils began to decline. Difficulty of printing on treated surfaces and the occasional slip-inducing spillage put some off using Silicone oils in favour of other mould release agents. Though the issue of printing can be solved using specialist emulsions, many manufacturers wanted to remove liquids from their production processes.

After a long development process, Dow Corning produced a method of binding Ultra-High Molecular Weight Siloxane Polymers (usually with a viscosity of millions of centistokes) into small pellets of plastic, resulting in Siloxane Master Batches (Siloxane MBs). These enabled in built Silicone Oil lubrication to be added in highly controlled doses into any plastic desired, with the use of specific solid carriers (PET, PP, polystyrene, etc). Doses as low as 1% added along with any other master batches being used (eg colour) to give the desired slip needed in a moulded product, with the added bonus of the longevity of lubrication granted by such long chain Siloxane polymers.

Siloxane MBs have the potential to be used in a huge variety of roles, in fact any that require the lubrication of plastic goods. They can be used at all stages of manufacture, be it during production, such as its use in the manufacture of plastic fibres, or to help end use such as aiding the fitting of plastic piping together.

We currently sell Dow Corning Siloxane Master Batches and are happy to help with any technical issues or trials you wish to persue. We also supply a specialist Silicone Emulsion that allows printing and painting on treated surfaces. If you have any questions or are interested in these products, please contact us through our website and we will be happy to assist.

Matt Darlington

Review of the Year – 2014 @ J Allcock and Sons

2014 at J Allcock and Sons Ltd.

It’s been another great year here at J Allcock and Sons. Rubber crumb and granule sales are up on last year, with an additional granulator to be installed next year and upgrading the line at our Wellington Rubber branch. FKM crumb production has increased 20% from last year and looks set to continue to increase into the New Year. In addition to our stringent particle size laboratory testing, we have recently instigated a quick pass/fail test during production, at short regular intervals. This will maintain the quality of our material that we’re known for.

Silicone sales are also up from last year, especially our Food Grade Silicone Emulsions. Of the small number of complaints to the company, most of them were due to poor housekeeping by the end user leading to silicone splitting (for tips on how to stop this, have a look at our previous blog post ‘A Splitting Headache’).

With this sustained increase in sales, we’re also looking into expanding our storage facilities, expanding our storage capacity by tens of tonnes.

Finally, we’ve welcomed 2 new members to the company. I joined just before Luke departed for a year in Australia, and Stephen has joined to learn the ropes controlling stock and purchases.

Looking to the New Year, we expect to continue our personalised service for our clients and welcome new clients from both the UK and the continent, thanks to our upcoming foreign language translations of our website. We’ll also be at DKT (Deutsche Kautschuk-Tagung) 2015 in Nuremburg in the summer to show our crumb and rubber reclaim to the European Rubber Community.

We’d like to say a big thank you to all our clients for continuing to choose us as there supplier, and the staff at J Allcock and Sons for a great year. We wish you all a merry Christmas and a happy 2015!

Matt Darlington

Silicone Emulsions – A Splitting Headache

Silicone Emulsions – A Splitting Headache

Although it was mentioned in our most recent Silicones blog (06/03/14). We here at J Allcock & Sons thought it would be a good idea to add a post about the problem of Silicone emulsions splitting.

Silicone Emulsions are basically Silicone oil, water and an emulsifier. The Silicone oil does the job (usually lubrication), the water carries the oil and allows for easy dilution of the oil and the emulsifier binds the two together.

However, problems can arise in emulsions, the large array of splitting possiblilties are shown perfectly in the diagram below:

Taken from:

Though there are many technical terms, the origin of all these kinds of splitting are the same. Like milk, Silicone emulsions can ‘go off’ if left in a hot, moist environment. Like milk, Bacteria and fungi can grow that feed on the emulsifier and cause the separation of an emulsion, leading to a ‘lumpy’ consistency.


There are a few precautionary measures that can be taken to ensure your Silicone Emulsion doesn’t split;

  • Store the container in a cool, dry area
  • Do not store diluted material for long periods of time
  • Regularly wash out dilution vessels to stop bacteria/fungi carrying over into fresh batches
  • Use Allcosil Stabiliser to increase the lifespan of your Silicone Emulsion

We hope this helps answer any questions on silicone splitting you may have. If you’d like more info please get in contact via the website or by calling myself on 0161 223 7181.

Matt Darlington

Silicone Oils, Emulsions & Antifoams

Silicone Oils, Emulsions & Antifoams

J Allcock & Sons have been selling silicones to a wide range of industries since the 1970’s. Our last silicones post on 07/11/12 missed out one of our main silicone products and as I have recently started here, I thought it would be a good first topic to write on, with the help of our technical wiz, Norman.

We’d like to go over our 3 main products in the silicone range; Silicone Oils, Silicone Emulsions and Silicone Antifoams. We’ll outline some basic information, uses and grades that J Allcock & Sons offer.

Silicone Oils

Basic Info

Silicone oils are the sensible place to start as all our silicone products are based around silicone oil. silicone oil has many names; some call it Silicone Fluid, Americans tend to call it Dimethicone, while we call it Allcosil 200.

The Scientific name is Polydimethylsiloxane, which is also the most descriptive as the chemistry minded among you can see ‘Poly’ for many, ‘Dimethyl’ for two methyl groups (CH3) and ‘Siloxane’ for Silicone and Oxygen. The resulting structure resembling this:

Taken from:


Thanks to its methyl groups and Si-O backbone, silicone oil is one of the most inert oils around. It’s a water repellent, dielectric, temperature resistant, semi-Newtonian and non-toxic lubricant, which lends itself to uses in the moulding, food packaging, automotive and cosmetics industries.

Our Range

Silicone oils come in a wide array of viscosities, which are dependent on the length of the polymer (the longer the polymer, the more viscose the oil). The different viscosities enable silicone oil to perfectly meet desired needs; Allcosil 200/20 has been used for laboratory heat baths, while Allcosil 200/12,500 can be used as a hydraulic fluid. Silicone oil can come in industrial grade, food grade and cosmetic grade. The common viscosities of Allcosil 200 are 20, 100, 200, 350, 1000, 12,500, and 60,000 (the full range and further information can be seen in our previous blog)

Silicone Emulsions

Basic Info

Silicone emulsions contain 3 components silicone oil, emulsifier and water. The silicone oil provides the desired characteristic, most often lubrication. The emulsifier binds the silicone oil with the third component, water, so that the oil is suspended in solution and can be diluted down easily. The emulsifier-bound oil forms microscopic droplets of a uniform size in the water, which thanks to Brownian motion are kept at roughly an even distance apart.

As long as the droplets remain in this suspension the emulsion will be in good working order, however if the droplets are allowed to rise to the top of the solution (‘Creaming’) form into small clusters (‘Flocculation’) combine into large droplets (‘Coalescence’) or form a continuous layer on the solution’s surface (‘Breaking’) the emulsion will cease to work (see below for a good schematic).

If any of these problems occur, we at J. Allcock & Sons will be able to help solve the problem. We have our own stabilizing agent (Allcosil Stabilizer) that can resolve most emulsion separation issues.

Taken from:


Silicone emulsions are mainly used as a lubricant. One such use is as an anti-nesting agent for the thermoplastic container industry, another as a mould release agent in the rubber industry. Wherever a small amount of silicone oil is needed (usually in ppm) silicone emulsion is the best product.

Our Range

We have a wide range of silicone emulsions available. Allcosil 35 is a 35% silicone oil emulsion suitable for industrial use, while Allcosil 356 and Allcosil 435FG are food grade 35% emulsions. A 60% Silicone oil emulsion suitable for industrial use (Allcosil 60B) may be useful if a smaller dilution is required. We also supply high viscosity oil emulsions, if you wish to use higher centistoke oil in your emulsion (Other emulsions are available) Again our previous blog post has more information on emulsions.

Silicone Antifoam

Basic Info

Antifoams use the intrinsic property of silicone oil to lower water surface tension to pop bubbles and eliminate foam (see below) Silica particles are also present to help pop bubbles through physical piercing.

Taken From:


Silicone antifoams can be used wherever foams form and need to be removed. When solutions are pumped through a high pressure system, soaps are used, or froth is generated by chemical or biological action e.g. in sewage treatment, antifoam can be used to totally remove foam from the solution.

Our Range

As only tiny amounts of silicone are needed for the antifoam effect, J. Allcock & Sons provide two main products, A.011 and Allcosil 30G Antifoam, 10% and 30% silicone based antifoams respectively. We also provide food grade antifoams for the food industry, both 10% and 30% available.

I hope this helps in any Silicone-based queries you may have. If you’d like more information or are interested in any of our products please call myself on +44 (0)161 223 7181

Matt Darlington

ISO 9001:2008

J. Allcock & Sons have been certified ISO 9001:2008 since 14th of January 1997. This month we had our re certification audit and have now gained certification up until 9th March 2016.

We are proud to be certified ISO 9001:2008 and believe this shows our commitment to keeping high standards and customer satisfaction throughout our organisation. We also believe we are probably the only rubber recycler in the UK to attain this certification.

ISO 9001:2008 Certificate



Masterbatch – New Range

In the past year, we have found an increasing number of customers asking for anti mist / anti fog masterbatch for use in PET and PP plastic. Primarily in the food packaging market.

Anti mist / anti fog  PET/PP masterbatches will prevent condensation forming on the inside of food packaging.

We have therefore been in discussions with suppliers to offer a new range of additive masterbatches. This range will also include anti block masterbatches for PET & PP, we have also found there to be a small market for this type of masterbatch. Anti block masterbatches are an alternative to our Allcosil 435 FG food grade silicone emulsion.

As of 01/01/2013 we can offer the following masterbatch:

  • Non-crystallised PET AB(Anti block)
  • Crystallised PET AB(Anti block)
  • PP AB(Anti block)AF(Antifog)
  • * We are in the process of researching with our new partner a suitable PET Antifog/Antimist – Please still enquire *

If any of our new masterbatch range interests you, we would be happy to arrange 20-kg samples. Our masterbatches could be added at approximately 2%, therefore a 20-kg sample will give you a 1 tonne trial.

Data sheets for our range will be in the Data sheet library and masterbatch products section (found under silicones) in the new year.

J. Allcock & Sons always tries to adapt to customers needs.