Why Plastic Parts Are Rapidly Overtaking Metal

Plastic vs metal – it’s a long-debated topic in agricultural, mechanical, automotive and several other industries. While metal parts and assets have been king since the first machines were created, new science has made a new (better suited) successor. Enter plastic. 

Traditionally plastics struggled to compete with the strength and durability of metals. However, current plastic technologies have allowed this substance to perform as well as, and, in some cases better than, metal. 

So when both substances can perform the same job at the same level, it boils down to cost, weight and efficiency – to which plastic is the clear victor. 

If you haven’t already, it’s time to start rethinking where you’re using metal parts and consider if you could benefit from a cheaper and better tool. 

Plastic – Stronger Than You’d Think

Plastics excel at having a high strength-to-weight ratio. It can withstand more stress before failure while weighing less than a metal part. Combine this with better tensile strength and a higher ability to resist being deformed under mass density and plastic makes a good argument against metal enthusiasts. 

The below diagram shows a broad performance range of several plastics (categorised in Polymer and Composite categories) and how they compare to metal options. While the strongest metals rank higher than plastics, the plastic options aren’t far behind and have a lower density. 

Better Chemical Resistances 

Plastics are generally less susceptible to damage from chemicals or chemical reactions. Metal water storage tanks can cause zinc to leak through your water supply, leaving an unpleasant metallic taste. 

Worse, a study by the Public and Environmental Health Service in Tasmania found harmful lead levels in some stainless steel tanks. Steel tanks are used commonly in the mining industry to store sulfuric acid. At a high concentration (98% or above) steel can handle the acidic qualities of the acid for years. However, once the solution is diluted (Lower than 93%) the formula becomes highly corrosive. Poly liquid storage tanks, which we specialise in, can dependably store this acid at most concentrations. 

Poly Plastics, The Lightweight Champion 

More weight means more power is needed to move it. One of the best reasons to replace your heavy steel products with lightweight plastic products is you significantly lower your load. 

Our poly agricultural equipment is easy to roll, lift and reposition. Very rarely do we rely on heavy machinery when it comes to installing even our largest products. If you’re looking to replace a vehicle-mounted item with a plastic one, you’ll have improved fuel efficiency and no problem lifting them on or off your ute.

Faster Fabrication Times To Meet Strict Deadlines

Time equals money! When you’re in a pinch and need a replacement part fast, utilising plastic manufacturing will have you back on your feet long before a metal replacement can be created. 

Plastic’s design flexibility allows for designs to be created in one part, whereas metal parts often require assembly or welding to create one piece. Because of a more simplistic design process, you save time, labour and cost compared to what metal manufacturing would take. 

Heat Resistance

The biggest argument against plastics is it’s lower melting point than popular metals like steel or iron. However new high-performance thermoplastics technology has a melting point of 3593.333°C where carbon steel melts between 1425 – 1540°C. Still, most common plastics will melt somewhere in the 200°C range.

Know When It’s Right To Use 

Your safety and wellbeing is our priority at Global. While we love the benefits plastics offer, sometimes metal is the right material for the job. Consider these cons when planning your replacements.

Limited Wear Resistance

Plastic’s low resistance threshold means it may be affected by high temperatures, acidity and other corrosive elements. However, there are higher-resistance plastic options better suited for handling chemicals. For example, our rotomoulded cartage tanks are suitable for transporting diesel and a range of other substances. 

Lower Structural Strength

Plastics are unsuited for supporting structures and replacing high-weight bearing parts of heavy machinery.  

If you feel that lightweight plastic will benefit you, the team at Global Rotomoulding can help out. We create a range of tanks, parts and other agricultural equipment. If you want a custom plastic piece to help you out, call us today to see how we can help. 

Why Your Poly Tank Colour Is More Important Than You Might Think

So, you’ve decided to buy a water storage tank. Once you have chosen your tank size, type and location on your property, it’s time to choose the tank colour. It turns out, there is so much more to poly tank colours than just the aesthetics; although these are important. 

In fact, there’s plenty of science involved in poly tank colours. Tank owners can leverage this science to their advantage when it comes to their water storage. 

We want to help you make an informed, well-rounded decision when choosing your poly tank colour. So, we’ve put together this comprehensive list of considerations to help you choose the best poly tank colour for your property. We’ve broken it down – first diving into how poly tank colours work, then functional considerations and lastly the aesthetic considerations of poly tank colours. 

Read on if you want to make an informed decision when choosing your poly tank colour. 

How Do Poly Tank Colours Work?

Let’s first dive into how poly tank colours are made. 

What Poly Tank Colours Are Made Of

The colours that are used in poly water tanks come from either one pigment or a mixture of pigments. There are two main sources of colour pigments: chemicals created in a lab, or mined minerals. Each production method yields different pigments. The pigment can then be combined with uncoloured polyethylene which is then eventually utilised in rotational moulding.  

How The Colours Are Added 

The polyethylene, colours and additives are initially processed through an extruder. This creates a masterbatch or encapsulated colour. This colour is then added to a carrier resin. 

To create a colour compound, the masterbatch is again combined with the natural coloured polyethylene in an extruder. After, the mix is processed through a mill. This results in a coloured polyethylene powder, which is utilised in the roto-moulding process. 

When adding colours to polyethylene, they must be durable enough so they will not fade when exposed to the high temperatures that occur during the roto-moulding process.

The colours must adhere to the following requirements:  

  • Maintain colour at high roto-moulding temperatures.
  • Resistant to fade in harsh outdoor environments.
  • Must not bleed out onto the mould.
  • Food and water grade plastic where necessary. 
  • Contain no heavy metals.
  • Economical price.
  • Sustainable impact on the environment.

What Poly Tank Colours Are Available

Tanks made from polyethylene generally accommodate the widest range of colours. At Global Rotomoulding, we offer tanks in plenty of colours across the COLORBOND colour range. 

Regulations

Many paints may contain solvents and other materials that could leak into the water supply. Therefore colours used in tanks need to comply with government standards for the safe storage of water.  

Functional Considerations

Now we’ll dive into why you should care about your poly tank colour from a practical perspective.  

Algae Contamination

Algae thrive in sunlight. If a tank was painted with an inadequate amount of pigments, this can let in enough sunlight that facilitates algae growth. This can have troubling health concerns. Some forms of algae, like the toxic blue-green algae, are highly dangerous to humans and animals. 

This does not mean that light coloured tanks are a breeding ground for algae. When they are manufactured with an adequate wall thickness by an established manufacturer, algae is effectively prevented.   

It is important to note that algae could be present in a tank with adequate wall thickness if the water is sourced from areas already contaminated with algae. Or, it may occur if the lid of the tank has been left open, letting sunlight in. 

Water Temperature

The colour of the tank can affect the temperature of the stored water too. Pigments will absorb light from the sun and convert the energy into heat. Darker colours will lead to a hotter tank as the day progresses. The tank will also climb to higher temperatures when it is empty.  

Carbon black, which is a pigment used for black or grey tanks, will reach the highest temperature among all of the tank colours (unsurprisingly), reaching up to 63 degrees celsius. 

Other darker colours like phthalocyanine blue and phthalocyanine green can reach between 60-62 degrees celsius. 

Hence, a lighter water tank will store water at cooler temperatures. Generally, this is better for tank owners – especially those caring for livestock. Livestock are more likely to drink cooler water. When our livestock drinks more, they will consume more food, hence increasing their productivity.   

Cooler water may also be necessary across other industries, such as industrial sectors. Here, cooler water is especially pertinent for concrete mixing. It is also required when washing and processing food products. 

UV Protection

UV protection may be a requirement for some tank owners. A process known as photo-oxidation is the primary cause for faded water tanks. Therefore, opting for UV stabilised water tanks that utilise high quality, durable poly resins will help to prevent any damage caused by UV light. 

Choosing an established manufacturer that sells UV stabilised poly tanks is critical to ensure protection from sun exposure.   

Aesthetic Considerations

Once you have considered the functional requirements of your tank, it’s time to consider your aesthetic preferences.

Make It All Flow

If you don’t want your tank to stick out like a sore thumb, opt for a colour that will blend seamlessly with the environment it is placed in. For example, when placing a tank outside a neutral cream or beige coloured home, why not try Classic Cream or Paperbark for the rainwater tank? 

Make A Statement

Perhaps you want to make a statement with your colour choice? You could opt for complementary colours for your house and tank. Complementary colours sit opposite each other on the colour wheel. When together, they pop in a fun and bright way. Common combinations are red and green or orange and blue. We particularly love Mountain Blue, which compliments earthy reds and oranges.  

Pick Up On Accents

If you have accent colours on the eaves, doors or window sills of your home, perhaps choose the same colour for your tank. This gives a seamless finish, without looking too uniform. Rivergum is a common accent without being too bright.

An Aerial View

Alternatively, you may choose to match your tank to your roof. An exact match is easy with Global Tanks COLORBOND colour matched tank colours. 

This makes for a stunning aerial view for those living on a farm where helicopters and planes tend to pass. A common colour choice is coupling a Heritage Red COLORBOND roof with the matching tank.  

When it comes to choosing your poly tank colour, there are perhaps more considerations to make than you’d initially think. This can be overwhelming. But, as long as you’re addressing the functional and aesthetic requirements for your poly tank, you can rest assured you have made the right decision. At Global Tanks, we stock tanks for a diverse range of applications, including Domestic tanks (Slimline, Underground tanks), Rural tanks and tanks for commercial systems (fire services, chemical storage). Our tanks come in up to 30 beautiful, rich colours. Find out more about our range of tanks here, and be sure to contact us if you have any questions.