A Sustainable Future

As a company that manufactures plastic products, we are only too familiar with the need for a more sustainable future.

Dudley Associates is constantly working to improve our environmental impact, increasing sustainability and creating and implementing initiatives to aid this.

Not only do we assess and improve our own contribution to a sustainable future, but we also encourage our customers to do the same. And when a customer brings an idea to us to get involved with, we jump at the chance.

One of our existing customers, within the packaging industry had an idea.

Currently, most plastic drink bottles are made from a particular recyclable material but will have a bottle screw cap and tamper proof ring that is made from a different, more sturdy material which is not recyclable. Therefore, for the bottle itself to be recycled, the ring and cap are removed by hand, which is extremely time consuming and costly.

And this is where their idea came in to play; Could we manufacture all three parts out of the same recyclable material – reducing time, manpower and costs in one move.


Industry Knowledge

Soft drinks bottles normally are easy to replicate. They are quite a standard shape and the information on manufacturing these is easy to obtain. However, the caps and threads are a different matter.

The differences between a still drink and a fizzy drink cap and thread can be the gaps or partitions, a fizzy drink will need to allow pressure to be relived before the cap is removed. Understanding this difference would be the difference between a successful design and product, and not.

The customer in question decided that they would like to create an aluminium tool for a fizzy drinks cap and thread using the same material as the bottle. This would then create a gateway into still drinks bottles. Overcome the more difficult project to then set a pathway for the easier.

Simple right?

A Completely Recyclable Soft Drinks Bottle... Could it be Possible? 2

Understanding the Uncertainties

Dudley Associates has vast industry and materials knowledge. Our experts know the different characteristics between one material and another and in this case, between the elasticity of the recyclable material and the non-recyclable.

Caps are needed to consist of a good memory so that when it expands and pops off the tool, it will remember and return to its original shape. So, using the recyclable material that does not have these attributes posed us a problem.

Next, we needed to look at the ability to get the thread to flex but also be strong enough to be able to bite the neck of the bottle using the recyclable material. A soft drinks bottle is often quite thin and weak, so we needed to find a way that this material would allow for thread engagement between bottle and cap.

Then came the time constraint uncertainties. Would we be able to create and produce a recyclable screw cap and in sufficient volume in order to support the commercial production of soft drinks?

The Next Stage

Inevitably, we needed to find a resolution to each uncertainty to be able to move on with this project.

We began with using the existing tools for the caps used with the non-recyclable material, and the same measurements. This was the only information we really had at this stage, so seemed a logical starting point.

Although this method worked to some degree, the production process was very slow, so more research and designing was needed.

A Completely Recyclable Soft Drinks Bottle... Could it be Possible? 3

The Trials Began

Using several different grades of the recyclable material, we were able to identify the grade that gave the best results. The results of this were that we managed to manufacture a screw cap, able to be recycled. But it was not suitable as per industry standards, for the drinks industry.

We then moved on to design and manufacturing a new prototype tool out of aluminium whilst using the best grade of material found during our previous trials.

Throughout many trials, we have found issues and results as we have gone along with this project. It has certainly been a learning curve but has been one of the most satisfying and interesting projects to date.

As a result, Dudley Associates has been able to quantify how inelastic the recyclable material is in relation to the threads in a cap. This is something that has not been previously known within the industry. This will help us and the customer to better design screw cap moulds, which in turn will reduce the number of prototypes and trials required.

We have also been able to identify the best grade to use for injection moulding purposes enabling us to apply this knowledge to other projects in the future.

In Conclusion, this has been a very worthwhile project to undertake. Not only in furthering the capabilities of Dudley Associates, but also to increase sustainability within this industry and help us to achieve our environmentally friendly goals.

This application can not only be applied to the drinks industry, but to many more industries looking to create a more environmentally friendly and recyclable product.


Find out how we can help you by getting in touch and speaking with one of our experts.


Written By Lucy Glover, Sales and Marketing Manager 

For any Sales or Marketing information, please contact Lucy at lucy.glover@dudleyasssociates.com