Wednesday 28 March 2018

5 Most Common Products Made Out Of Rubber

Rubber is a unique material. Rubber is used in a wide variety of sectors because of its flexibility and its versatile functionality. We have decided to put a list together of common products we use in our day to life which all use rubber material.

Auto Industry

Rubber plays a vital role in the auto industry as it helps in the creation of tyres. Rubber is the perfect choice because rubber is a viscoelastic, durable and very flexible which helps protect you using your automobile and your rims by using its cushion to protect.

Footwear Products

Rubber plays an important role in our day to day life we are walking on rubber soles. The sole is located at the bottom of the sole of our shoes, most shoes in today’s world are made from natural rubber, polyurethanes, and polyvinyl chlorides.

Rubber Gloves There are two types of rubber gloves we use in our day to day life unsupported and supported. Unsupported gloves are made out of just rubber whilst unsupported gloves rubber is used on the coating of the glove. We sometimes use rubber gloves when washing the dishes as rubber gloves are a great protection from chemicals and withstands the heat of the water.

Clothing


Latex rubber is used in lots of different pieces of clothing. We generally use rubber in protective clothing for example, gas masks, wetsuits, bodysuits, stockings and many other garments. Latex clothing is made from large sheets of latex rubber which are then delivered in rolls. Latex is quite weak as a material, so when using latex clothing you need to take special care that it does not break. The original colour of latex is originally black but can be dyed any colour.

Pet Accessories

If you own a pet you know how important it is that the toys do not break as this could be dangerous for you and your pet. We use rubber in our pets chew toys and our pets play balls as well. Also for the practical reasons we use rubber materials, for example, rubber mattress, vet wraps, and collars. Which are all used daily to make sure our pets are looking healthy and feeling great.


Don't Forget About Rubber Bands!
The following video shows the process that happens when rubber bands are manufactured.

Wednesday 28 February 2018

Rubber Degradation and Antioxidants

Rubber is an elastomer type polymer, this means that once stretched or deformed, rubber can return to its natural shape.

Polymerisation

A monomer is a small molecule of an organic substance. Between each individual molecule, there is a weak double bond. A monomer can also be defined as is a molecule that binds chemically to other molecules to form a supramolecular polymer. When large numbers of monomer units combine to form polymers, this process is called polymerization. (Source: 1.)

Polymerization is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. (Source 2.)

Polymer Degradation

During the polymerization process, the formation of free radicals (R) is initiated. This is thought of as the initial stage of the degradation process.



The second stage is called 'Propagation'. During this stage, the atmospheric oxygen reacts with free radicals (R) to create 'Peroxy' (ROO) radicals.


When comparing the propagation stage to the initiation stage, the degradation process during the propagation stage is much more rapid. This reaction is called an autocatalytic oxidation reaction and will progress continually until termination takes place by forming a stable product.


Once Peroxy radicals have been formed, these react further with the labile Hydrogen atom of the polymer which in turn forms unstable hydroperoxides (ROOH).


Now that hydroperoxides have been created, they will immediately decompose via homolytic cleavage to then form alkoxy and hydroxyl radicals. These radicals then further propagate the degradation mechanism.

Polymer Oxidation

Polymer oxidation is a very complex process but can briefly be described as the effect that oxygen has during the polymerization process.

Oxidation can be the cause of chain scission and cross-linking, this, in turn, may lead to the loss of elastic properties in your product.

Polymer Oxidation can be avoided by using rubber antioxidants. To find rubber antioxidants at a reasonable price, make sure to visit Prisma Rubber Additives today!


Sources: 

  1. https://en.wikipedia.org/wiki/Monomer
  2. https://en.wikipedia.org/wiki/Polymerization
  3. http://www.nocil.com/Downloadfile/ETechnicalNote-Antioxidants-Dec2010.pdf

Wednesday 21 February 2018

Rubber Moulding

When creating your own products you'll need a plan beforehand. Once you're happy that you will know which type of rubber you need and have obtained this rubber, it's time to put it to use!

Depending on which product you plan on creating, you'll need to either create or purchase a mould. Since the release of 3d printers, you'll notice that the costs of the rubber moulding process have been greatly reduced. Choosing which method you choose to carry out when creating your product is imperative beforehand to ensure that everything runs seamlessly.

Custom Rubber Moulds

Typically manufacturers would use one of the following rubber moulding techniques:

Compression Moulding: 

When looking to manufacture large and intricate parts you will most likely be using a compression moulding technique to craft these.

Compression moulding is a method of rubber moulding whereby the material is preheated and placed in an open, heated mould cavity.

This method is best used for large parts where flawless finishes aren't necessary.

Transfer Moulding: 

When carrying out the Transfer moulding (BrE moulding) process, the casting material (in this case, rubber) is forced into the mould.

Transfer moulding contrasts compression moulding due to the fact that the mould is enclosed, opposed to the compression moulding technique whereby the mould is open.

As the mould is closed, you will be less susceptible to environmental impact and the end product will maintain a higher dimensional tolerance.


Injection Moulding

Injection moulding BrE or Injection moulding AmE is exactly as it sounds. This manufacturing process is used for producing parts and can be carried out using a whole range of casting materials.

The injection moulding process is carried out by injecting molten material into a mould and is most widely used for when you need to create a variety of parts, from small to large.

When using the injection moulding manufacturing process you must ensure that you take in to account the material used, the desired shape and any particular features that you would like to include before going head with it. Injection moulding is one of the most versatile moulding techniques.


Wednesday 7 February 2018

Rubber Additives

Rubber is one of the most interesting commercial materials on the market. Its uses are as varied as the composition of the rubber itself. In order to attain particular properties, manufacturers may use a whole host of rubber additives during the process.

Depending on which type of rubber you desire, both natural and synthetic rubbers may have their formulations modified to create the perfect end product.

Mix formulations often begin with a defined amount of elastomer. This can be butadiene rubber, natural rubber or styrene-butadiene rubber. This quantity is measured as 100 parts/weight.

Once the manufacturer is happy with this, they will then begin to add another ingredient which is expressed in parts by weight added per 100 parts by weight of the elastomer. Staying with me?

If you should decide to use two or more elastomers in order to achieve particular properties, these will be shown as fractions of 100 parts within the recipe formula.

"The Cure Package"

When formulating the perfect rubber mix, you will need to take in to account which products you will be purchasing for your "cure package". The cure package is the ingredients which are used to cause interlinking reactions within the mix when it is cured. To ensure that you are not left with a premature cure, it's important to add these ingredients after the mix is cured.

The cure package tends to be comprised of rubber accelerators such as sulfur, thiurams, or thiazoles. Once these are added the sulphur interlinking reaction will happen at a speedier pace and in a more efficient manner; hence the name "rubber accelerators". Rubber accelerators and rubber additives can be purchased from Prisma Rubber Additives, visit their website for more info.

Efficient Vulcanization (EV)

To create EV products which are known for having an enhanced resilience/lower strength (due to shorter-lengthed sulphur interlinks); you must ensure that the proportions of your rubber mix are correct. In order to achieve this type of rubber you must ensure that the ratio of sulfur to the accelerator is less than one, once created you will be left with an efficient vulcanization system.


Vulcanization Activators

Activators such as stearic acid and zinc oxide can be used in order to create a reaction between each other and the accelerators in the mix. Once this reaction takes place, you will notice that a zinc sulfurating compound has been formed. This compound is the perfect properties to work as the intermediary in adding sulfur to a diene elastomer, this, in turn, will result in the creation of sulphur interlinks.

Sulfur Donors

Sulfur compounds such as tetramethylthiuram disulfide may be used to introduce monosulfide interlinks between polymer molecules and peroxides (in particular, dicumyl peroxide).

Peroxides are special because when heated, they decompose, causing radicals to arise. These radicals will then abstract hydrogen from groups on the polymer molecules. Carbon radicals which are formed in this way on different molecules then combine to create carbon-carbon interlinks, once again, changing the composition of your rubber mix.

C-C interlinks are special as they are more resistant to heat and oxidative attack, however, their strength is lower than products with sulphur interlinks. Monosulfide links create weaker products than polysulfide links.

This paradoxical result—that inherently strong C−C interlinks give the weakest products, whereas inherently weak polysulfide links give the strongest products—is attributed to the fact that weak interlinks will break under stress before the main chain does, so failure of the elastomer molecule itself is delayed. - (source: https://www.britannica.com/science/rubber-chemical-compound/Additives)