How Are Glass Bottles and Jars Made

Updated: Sep 16, 2021

Have you ever wondered how glass bottles and glass jars are made?


At Sen5es we work with fantastic glass manufacturers to bring you the perfect product. But how exactly are those products made?


In this weeks blog we go through the step by step process to explain exactly how glass is made. And the process of it getting from raw materials to your doorstep.


Glass is the only packaging material that is 100 recyclable with no loss of quality. The purest and most sustainable packaging material.


The Raw Materials


The ingredients for making glass are very simple. All that is required is Silica Sand, Soda Ash, Limestone and recycled glass (or cullet). All the ingredients are added together in precise quantities, which are worked out by weight. You can also add extra ingredients at this stage to create different coloured glass.


glass cullet
Glass cullet is one of the main ingredients in glass manufacturing.

Heating and Melting


The raw materials are put in to a furnace which heats them to a temperature of 1565°C or 2850°F. Once the materials are melted together they are ready for forming.


At glass manufacturers they have their furnaces running 24 hours a day. To ensure they are constantly creating new glass. This process requires a lot of energy and is one problem with the glass making process.


We work with manufacturers who are trying to reduce their need for fossil fuels during this process. We think it's important to work with manufacturers who share our beliefs. That we need to work towards a better more sustainable future.

how glass bottles are made
Millions of bottles are produced everyday at our suppliers factories.

Forming


Once the glass is melted, the molten glass is passed though a refiner. Here the glass is conditioned and cooled to a uniform temperature.


It is then fed in to a feeder which pushes the liquid glass down a narrow tube, called an orifice ring. As the streams of glass emerge they are cut by mechanical shearers in to exact pieces called gobs.


The gobs are then distributed in to blank moulds which turn them in to partially shaped masses called parasins.


The parasins are then loaded in to a blow mould to form the final shape of the container.


There are two methods for this step and it depends on the style of container being made.


The first method is the press and blow method, usually for wide mouthed containers such as jars.


And the second is the blow and blow method used mainly for larger spirit and wine bottles.

how glass jars are made
There is a different mould for every bottle!

Inspection


Once formed, the containers are ready for their first inspection. Depending on which manufacturer is making them there are several methods.


Most glass bottles and jars will go through several forms of inspection all along the process to ensure that they are of the highest standard possible.


The bottles or jars that don't pass the first round of inspection are sent back to be turned in to cullet and the process starts again.


glass bottle production
Most processes in the factories are automated.

Finishing off


The bottles are loaded in to a special cooling oven called the annealing lehr. This is a special oven which heats the glass again and allows it to cool gently to room temperature.


This process relieves internal stress and makes the containers much more durable. Once cooled a protective layer of Polyethylene wax is sprayed on to the bottles to protect them from scratches.


bulk beer bottles
How many beer bottles can you count?

Packing and Delivery


Before packing the bottles or jars, they are inspected again. Both by automated machines and quality control technicians. If any bottles don't meet the high standards they are returned to the start of the process and are recycled in to cullet to start the process again.


The bottles are then packed on to wooden pallets, then strapped and wrapped for security and safety. This is the most cost effective way of shipping large quantities of both glass jars and glass bottles.


They are then loaded on to lorries (or our very own van!) and delivered to our warehouse in Saint Helens.


empty glass bottles for sale
Pallets of empty glass bottles ready for ordering

Repacking and Delivery to You


Having pallets of glass delivered direct to your house isn't always convenient for everyone. You need a lot of space and usually a forklift to take delivery! Luckily that's where Sen5es steps in.


We are able to repack the bottles and jars and sell them in either wholesale or small quantities.


We open the pallets and pack the glass bottles and glass jars in to boxes. We use a variety of packaging materials including cardboard dividers and bubble wrap.


We visually inspect every bottle and jar that we pack to send to you. So you can guarantee only the best products arrive with you when ordered with Sen5es.


Once your order is packed and ready to go, it is collect by our courier. From our warehouse it heads to a distribution hub. Then on to your local hub. And finally it is delivered to you!


Sen5es glass bottle shop
All of our orders ready to be delivered to you!

As you can see all our glass jars and glass bottles have a long life before they finally reach your kitchen, brewery, distillery or jam factory!


So next time you pick up a jar or bottle think about it's journey before it reaches your hand.


But