How Are Glass Bottles Made?

Have you ever wondered how glass bottles are 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.

Glass Liquor Bottle

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.

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.

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.

Black Liquor Glass Bottle

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.

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.

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.

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.

Shandong Jammine Package Co., Ltd. is a professional glass bottle manufacturer integrating  design(bottle, cap, logo), production, sales and service. If you are interested in our products, please contact us now!