Winkworth Explains The Chewing Gum Process

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2Z blades inside a Winkworth Z850 mixer pan
With close to one million metric tonnes of chewing gum expected to be produced worldwide in 2010, it’s clear that it hasn’t lost its flavour with consumers and retailers.

A stick of chewing gum may appear to be a simple product when you take it out of its wrapper, but the process of making the finished article requires very special equipment and technical expertise.

Chewing Gum Production

Winkworth’s involvement in the manufacture of chewing gum stretches back over the decades, with the company having supplied machinery to the leading gum manufacturers around the world, including USA, Mexico, Poland, Thailand, Turkey, UK and others.

Globally, the production of chewing gum is a very competitive industry, with each manufacturer’s formula and approach being a closely guarded secret, backed by a great deal of research in the choice and design of mixing equipment, and recipe development to obtain the desired textures and flavours.

The Manufacturing ProcessGum base with primary powders added mixing inside a Winkworth Z850 mixer

In the manufacturing processes, the type and choice of mixers is crucial to success. The raw materials - often solid blocks of rubber, powders or liquids - do not lend themselves to be easily mixed together. Gum mixing will expose any weaknesses in design, material strength, construction techniques or manufacturing and will result in early machine failure or fatigue.

Mixing gum, however, typically follows two distinct “mixing” stages, both of which can both be carried out in Winkworth Z Blades Mixers.


How Chewing Gum Is Made

1st Mixing Stage – Manufacture of the Gum Base With Winkworth Double Z Blade (Sigma Blade) Mixer.

1st Gum base is the main ingredient in chewing gum and is what makes it chewable. It provides a longer-lasting flavour, improved texture and reduced tackiness and also brings all the other ingredients together.

Chewing gum products in the 19th Century used natural gum bases, such as the milky white sap, known as chicle, of the sapodilla tree, native to Central and South America. This has now been replaced with modern synthetic rubber such as Polyisobutylene.

Synthetic rubber blocks in a Winkworth Z Blade mixer during the first stage of manufacturing gum base. Synthetic rubber blocks in a Winkworth Z Blade mixer during the first stage of manufacturing gum base

The preparation of gum base requires a very robust, heavy-duty Winkworth Double Z Blade (Sigma Blade) Mixer. This is necessary because the synthetic rubber is supplied in solid bales or blocks which are very tough and need to be processed into a smooth textured mass before it can be used.

The Winkworth Z Mixer motor/gearbox drives and solid, cast stainless steel blades must be robust enough to cope with the heavy demands. They must break down these larger rubber blocks into smaller and smaller pieces and squeeze, knead and grind them through the narrow gap between the rotating blades and the pan.


Turning The Heat Up

The grinding and kneading action is assisted by the addition of tackifiers/resins and fillers. Temperature control is critical and with all the ingredients being added cold, it is essential to raise these to the desired temperature.Melted gum base inside the Winkworth Z Blade Mixer

This is achieved by heating the walls of the mixing pan, typically using steam, to approx. 100 degrees C. This helps to melt the resins, creating initially a very tough, sticky mixture and then a smooth, lump-free pumpable liquid.

Manufacturers differ in the way they then onward process the prepared gum base. This often depends on whether they will use it immediately or transport it for use elsewhere.

Certain manufacturers will discharge from the Winkworth Z Mixer either by tilting or bottom discharge into shallow trays. These trays are then left to cool down and stored.


Easy Release Of The Gum Base Mix


For continuous processes the hot liquid  gum base is discharged into a heated and agitated storage hopper, such as a Winkworth steam heated “U” Trough Mixer, with a screw discharge device to feed a heated positive displacement pump.

This may then either feed directly onto the line (via heated pipework) or through to a pelletising system, for bagging and storage.

If left to cool, the gum base will harden to a very tough and solid mass. The first stage in the production of chewing gum is now complete. 

 

2nd Mixing Stage – Combining Other Ingredients With The Gum Base To Make The Chewing Gum MassInside a Winkworth UT2000 gum  base-holding mixer with screw discharge

The gum base has to be conditioned to the right temperature. If starting from cold then heat will need to be applied through the integral double walls of the mixer during the first stages of re-mixing to soften and melt the gum base.

With the mixture heated to approx. 50-70 degrees C, some of the other powder ingredients are added to help with the melting, kneading and mixture preparation.


What Else Can Be Added To The Mix?

Further ingredients include: natural or artificial sweeteners such as powdered sugar; softeners such as glycerine (to keep the gum soft and flexible); bulking agents (to produce the right density of gum); flavourings such as spearmint, peppermint or cinnamon; colourings; preservatives and other additives.

A 650 Kg batch of chewing gum tilt-discharged from a Winkworth Z MixerArriving at the “simple” stick of high-quality chewing gum is a complex process. Each manufacturer will have tightly controlled processes governing the sequence of additions and mixing parameters at each of these phases.

Exhaustive checks are carried out to determine product qualities such as: How long the flavour will last

  •     Initial burst of the flavour
  •     Texture on the tongue
  •     Chew ability
  •     Stretchiness, softness, firmness
  •     Stickiness on the teeth and tongue

“The mixer is a vital component in the final chewing gum outcome. Winkworth’s experience in designing and manufacturing mixers for chewing gum is vast. We recognise that protecting and maintaining the integrity of a high volume, often global, brands requires quality and reliability throughout all parts of the process, and mixing is at the heart of that process,” said Winkworth’s Managing Director, Grant Jamieson. Now that’s something to chew on, isn’t it?

 Chewing Gum Fact file

  • Chewing gum is believed to be one of the world’s most common habits, dating back to ancient times.
  •  Around the world people are known to have chewed on natural materials for centuries – including thickened resin and latex from certain types of tree, sweet grasses, leaves & grains.
  •  In Ancient Greece women chewed the resin from the mastic tree to clean their teeth and sweeten their breath.
  •  The rudiments of manufacturing chewing gum have altered little, but the processes have been vastly improved by developments in machinery.
  •  It’s estimated that the British spend on average £250 million a year on gum.
  •  Annually more than 374 trillion sticks of chewing gum are manufactured – stacked on top of each other that would equate to a pile approximately 2,305,800 miles high.
  • As well as freshening the breath, additional benefits of chewing gum are believed to be improved oral hygiene, stress relief and weight management.
  • Chewing Gum can also be inspirational – Italian artist Maurizio Savini has created sculptures using thousands of pieces of chewed gum!
  • After the smoking ban was introduced in Ireland in 2004, chewing gum use was said to have increased by 30%.
  • The chewing gum industry is a profitable market with some sources indicating as many as 115 companies manufacturing in 30 countries.