Have you been exploring ideas to manufacture your bottles?
Done some initial research but still aren’t sure which material could be suitable for your bottles?
When choosing a material for bottles, there are three main types on the market; each will have its limitations, advantages and associated costs.
It is essential to make the right choice in the early stages as it will affect the contents of your bottle and the happiness of the end customer.
When the contents are as expected or better, they will be delighted, yet when they’ve become tainted or infused with unwanted flavours, it is not so lovely.
Bottle breakages and material failures will impact each stage of the bottles logistics journey.
Aside from human errors or accidents, these problems can largely be avoided through the correct choice of bottle and packaging.
Brands are built or destroyed on reputation, so if there is dissatisfaction from the end-users and supply chain partners, you will have a tough job in your hands trying to rectify this. It is far easier to get it right, to begin with.
This article will assist you in gaining more insight into the options you can use to make an informed decision on which type may be right for you.
What Are The Main Materials Used For Liquid Containment?
A long-standing favourite globally, this material comes with many beneficial properties.
You can use it to produce complex, robust, and transparent bottles.
Also, by adding colourants, you’re able to produce a range of tinted or translucent finishes.
The nature of glass means it does a fantastic job at protecting its contents, including carbonated beverages or those which may be impacted by degradation from light or temperature ordinarily.
As appealing as glass might be, we should also consider that it is brittle, can crack or shatter when subjected to impact and is generally quite heavy.
You could choose from several polymers here to create bottles. However, the main types tend to be Polyethylene Tetraphalate (PET), High-Density Poly Ethylene (HDPE) or Low-Density Poly Ethylene (LDPE).
All are excellent choices in their respect, but we will focus more specifically on PET for this article.
If you’d like to read more about HDPE, you can do so here.
PET is an appealing polymer to use due to its cost, mechanical properties and ease of manufacturing.
You can create distinctive bottle shapes that will help your brand stand out, and the factories production can be scaled easily to keep up with your demands.
This bottling or liquid containment option is neither glass nor metal, technically not plastic either, so it gets a separate mention here.
A patented technology created for containment of milk, its slogan is ‘protect whats good’, so it has been designed to do just that.
Using their aseptic system, you can see the contents being kept viable for up to 12 months. Keeping the food and drink based contents fresh is a key component they are used for, especially in the refrigerated range, such as dairy-based items.
It’s a layered cardboard carton that undergoes other processing to make it more mechanically appealing. The result is resistance to moisture, improved strength properties, and a cost-effective solution for some producers.
The exteriors can be printed on quickly enough and therefore is excellent from a branding perspective and omit the need for separate machinery to label the products once bottled.
Ancient drinking vessels were formed from copper, which is a good choice due to its workability and anti-bacterial properties.
Nowadays, it is quite a costly material, so it isn’t used extensively on its own but still can be incorporated as a liner or insert along with another metal shell or casing.
Stainless steel food grade is the preferred choice and has good thermal and mechanical properties.
Due to the expense of manufacturing, these bottles are not classed as one-time use options but relatively long-lasting products.
What Type Of Liquid Are You Planning To Bottle?
You should know all about the contents you wish to bottle before establishing which type of bottle is best for your needs.
The scope of this article is not to deep dive into this area but is worth mentioning.
Acidic contents can interfere with the properties and structural integrity of some materials.
Use a porous material, and it can leak gas or allow external influences to impact the liquid contained within.
Luckily PET is resistant to a wide range of these.
Exposure to daylight can also break down and affect the bottle’s contents, so this must be a consideration.
When bottling self-care products, cleaning chemicals and such, we must consider how the contents will interact with bottle material, now and over time, as some may be used infrequently.
Are You Looking To Handle Each Step Of The Bottling Operation? Manufacturing Of The Bottle Types
You’ll need to consider the specific processes required to produce each type of bottle here.
To take care of manufacturing a PET bottle from start to finish will require a few critical pieces of equipment, with the main stages being:
- Formation of preform plastic mold can be done in your factory or sourced elsewhere.
- Injection stretch blow molding will create the final shape from the preform, blowing it to size then stretching it mechanically.
Once formed, it will need to cool sufficiently before being ejected.
An efficient operation can see one piece of machinery take care of this process in one or two pieces of equipment. To get an idea of how that could look, check this link.
To set up a soda-lime glass bottle manufacturing operation, you’ll need first to have the raw materials, which are:
Soda Ash, Limestone, Silica and Cullet.
These will need to be stored on-site and accessible when required to run an efficient operation.
Typically a blow molding technique similar to plastic bottles is used, with machinery available to take care of the processes within one unit, referred to as an individual stage machine.
Your raw materials are fed in, following the recipe for the desired properties of glass in exact proportions where they’ll be heated to glass state.
Next up, the molten glass is cut into equal pieces, known as gobs, dropped into a forming machine.
Creation of the parison is next, ensuring the correct neck and thread are formed align with the adequate size and initial shape.
This parison is then transferred to a blow molding stage where it is reheated to temperature and then injected with pressurised air to inflate the glass within a mold.
Once cooled sufficiently, it’s then ejected and moves into the next stage of your production line.
The glass needs to be annealed, which gives it more desirable properties and prevents shattering or cracking, essentially it is reheated the allowed to cool gradually, removing internal stresses.
After the bottles have been quality checked, they can be cleaned, filled and labelled before being packaged for distribution.
This manufacturing method for bottles is costly and
This website can be a helpful reference if you like to learn more about glass bottle production.
And for metal, let’s pick the stainless steel option mentioned earlier, which will require several processes to create a useable bottle. However, much of this is also true for aluminium, the other common metal used.
The main methods are:
- Stretching and formation through mechanical means, which relies on machinery. This will sculpt and shape the stainless steel sheets into a bottle shape, using high pressure and a punch press.
- Water expansion
To create a bottle using this technique, you first start with a pipe of metal which then has a jet of water delivered into it at high pressure.
Due to the pressure internally being higher than the metal’s strength, it deforms to your required shape.
The machinery controls the output size and shapes it produces within a much thicker and stronger metal mold.
If your bottle is being created using the water expansion method, you will need to add a bottom, which is welded in as a separate process.
After the bottle shape is formed, it will require cleaning before a coating is applied internally to help with durability and safe containment of the liquid contents.
It may be needed to perform additional reheating and solidification of the metal and then painted, printing logos onto it and final checks before approval.
This operation will require many pieces of equipment and operators to produce, along with the higher cost of materials, which means overall more expensive to manufacture a metal bottle than PET.
Life Cycle Of Materials
Whilst you can and should recycle the bottles you use, it is not always possible or easy.
Each area will have a differing level of enthusiasm for these facilities, with some governments being very good at the uptake and encouragement to recycle.
When it is available, the commonly accepted materials will include PET plastic.
Since it is widely used and one of the most common materials for recycling, it also makes this material choice a good one.
PET plastic is easy to recycle due to its low melt point and the fact it doesn’t degrade when recycled.
Glass is also a widely accepted recyclable material. However, the metal ones can be trickier to deal with.
Aluminium is more widely accepted as a recycled material worldwide than stainless steel and is easier to reuse within bottles and cans.
Structural Properties of Bottles
PET Plastic has some very desirable properties specific to this type and makes it a particularly appealing choice for beverage bottles.
The reasoning for this from a structural standpoint is:
- High tensile strength- due to the blow moulding and injection stretch blow moulding even more so, when the PET is stretched, it creates a more tightly packed molecular structure.
- Therefore, less porous material and gases cannot easily escape from the bottle over time, perfect for soft drinks but not for beer.
- Maximum load capability is generally reasonable.
Glass is good for keeping contents intact, but its weight and fragility can see it reserved for more valuable contents.
Examples are carbonated alcohols and liquors, which command higher prices and are shipped in lower quantities per package.
Plastic can be more versatile and adapted to suit the various industries and products used with relative ease.
Storage Of Bottles And Materials
If you’re currently purchasing bottles for your operation or plan to manufacture your own, then storage should always be a consideration that you need to address.
The items can be pretty bulky and heavy with metal or glass, so stacking them up will be dictated by this to a degree.
Most products can only be stacked so high until they become dangerous axial loads can soon mount up, as overall weight limits.
The shelving and racking system needs to cope with heavier weight, whether the bottles are empty or full.
With PET plastic, you can store the preforms until ready to use, taking up less space.
When completed, the plastic option is lighter overall.
The temperature of the stores and exposure to heat. It should be a factor here as if too warm, and the plastic could deform over time and warp.
The raw material will need to be stored somewhere. In the case of PET, only a few ingredients are required, which is also similar to metal.
However, you require a few different aspects to create the perfect blend with glass.
Transportation Of Bottles
With PET being a lightweight and strong plastic, the freight costs are generally lower than other material choices.
It is also due to fewer breakages, therefore a lower likelihood of cleaning up an exploded pallet of drinks or leaking bottles.
Less fuel will be needed, which also helps reduce the carbon footprint of manufacturing and distribution.
Since PET plastics are more resilient to impact, you’ll need less protective packaging over the glass or metal counterparts if they are dropped or need to be stacked. The reduction here will translate to saving in costs.
When transporting the base ingredients, we also find that the main ingredients are pellets and colourants if used with PET bottles.
Whereas raw materials for glass or metal bottles can be more costly to transport, often requiring multiple suppliers and deliveries to arrive at your factory.
Should one of these fail to arrive in good time, it can disrupt your output.
Overall, plastic PET bottle manufacturing is more advantageous than its counterparts; it is especially true for the beverage industry. These bottles are generally cheaper to produce, lighter and more durable. They are primarily single-use items; therefore, price is a primary driving factor and the ability to mass-produce.
It doesn’t leach any chemicals into the bottle’s contents even when using recycled PET, the most widely recycled plastic in the world.
It will still be more beneficial to produce and use glass bottles as a consumable product and metals certainty; it presents an excellent choice for insulated bottles and reusable options.
To discuss your particular plastic requirements or seek advice for the best solution, send an email to [email protected]. or Submit below form for a quick quote.