A helmet is born: Kask's Protone from start to finish

We learn exactly how a helmet is made

BikeRadar recently visited Kask’s production facility in Italy where we learned how a modern in-mould helmet is produced.

The exact model, whose production we shadowed, was Kask’s long running and successful Protone road lid. It’s this process, and slight variations of it, that sees Kask produce around 800,000 helmets a year in Italy.

You can think of a modern in-mould helmet as being made of two key parts: the shell and the liner. We kick off with the production of the shell below.

Thermoforming

KASK's Protone starts out life as a single polycarbonate sheet
KASK's Protone starts out life as a single polycarbonate sheet

The shell of our helmet starts off life as a single polycarbonate sheet. One that is then loaded into a large printing machine.

Paint is then added by hand into the machine using pre-mixed colours.

Paint is then applied using a large printing machine
Paint is then applied using a large printing machine

Multiple layers of paint are often used to achieve the correct finish, with certain fluoro colours requiring this process to be completed seven times!

Each layer of paint takes approximately 40 minutes to dry.

Once the correct finish is achieved the polycarbonate is then ready for vacuum forming
Once the correct finish is achieved the polycarbonate is then ready for vacuum forming

The sheets can then be loaded into the manufacturer’s vacuum forming machine where the polycarbonate is heated to around 90 degrees before it is drawn over a helmet-shaped mould as air is quickly removed.

The sheets are loaded in place at the vacuum forming machine, beneath them are two helmet-shaped moulds
The sheets are loaded in place at the vacuum forming machine, beneath them are two helmet-shaped moulds

Heat is applied and then…
Heat is applied and then…

The heated polycarbonate is drawn over a helmet-shaped mould
The heated polycarbonate is drawn over a helmet-shaped mould

A significant part of the helmet's shell is now visible
A significant part of the helmet's shell is now visible

The raised section of polycarbonate sheet — part of the shell — must then be cut from the excess material that surrounds it.

The vacuum-formed shell sections must then be lifted from the moulds and trimmed from the sheet
The vacuum-formed shell sections must then be lifted from the moulds and trimmed from the sheet

Other sections of the shell are produced in the same way but require additional finishing.

These parts are placed onto a wooden mould while a pre-programmed CNC machine makes precision cuts to the plastic for any vents or edges.

Please don't be confused by the altering colours here, the factory handles many different colour options!

More intricate parts are finished by a CNC cutter
More intricate parts are finished by a CNC cutter

Suddenly things start to look a whole lot more helmet-like.

Shell components are then quality inspected before being packaged in preparation for the next manufacturing process
Shell components are then quality inspected before being packaged in preparation for the next manufacturing process

In-moulding

The helmet’s liner is made by expanding granules of EPS foam within a mould. The powdered foam expands when it is subjected to a combination of steam and pressure.

The EPS foam arrives in powdered form before it expands into small spheres with the application of steam and heat
The EPS foam arrives in powdered form before it expands into small spheres with the application of steam and heat

The expanded polystyrene (EPS) beads arrive in powdered form and are stored in vast vats at one side of the factory, and are divided into different types and densities.

A vast network of vats contain foam of various types and densities
A vast network of vats contain foam of various types and densities

Steam is applied to the sherbet-like polystyrene, which then causes each one to expand significantly. After a few hours of rest these beads adopt the correct shape and are ready for the next step of the process.

The components we saw earlier are then loaded into a machine alongside these additional plastic parts
The components we saw earlier are then loaded into a machine alongside these additional plastic parts

The shell we made earlier is then placed into a mould along with various pre-made plastic components. These plastic inserts form part of a structurally significant skeleton-like form within the helmet’s liner and are often necessary to keep helmets with large vents from separating in case of an impact.

Unfortunately, what takes place next I wasn’t allowed to photograph, but it’s best described as making a big helmet sandwich.

Two opposing sides of a large and scary machine are loaded with what will effectively become the top and bottom of the helmet. Then, once all human limbs are out of the way, the machine comes together in a way that’s reminiscent of the trash compactor scene in the first Star Wars film.

A few gentle taps with a mallet is all that is required to separate the helmet from its mould
A few gentle taps with a mallet is all that is required to separate the helmet from its mould

Lots of hissing and flicking dials confirm that the polystyrene beads are making their way into the now closed mould.

Approximately six minutes later and the halves separate once more, leaving a combined shell and liner in the form of a helmet that is very nearly complete.

Two halves and many components are combined as heated EPS beads fuse together to form the helmet's shape
Two halves and many components are combined as heated EPS beads fuse together to form the helmet's shape

No straps or stickers yet but the Protone is nearly complete
No straps or stickers yet but the Protone is nearly complete

The helmet can now be gently prised from its inner mould, and is then kept in a dehumidified environment to remove any moisture.

Finishing details and final quality inspections are then all that is required before the helmets become company stock
Finishing details and final quality inspections are then all that is required before the helmets become company stock

The lids are then shipped to another facility where the chin strap, retention system, padding and stickers are applied.

Finally, quality control checks are completed before the helmet makes its way onwards through Kask’s distributor networks and eventually onto the heads of riders.

Kask produces around 800,000 helmets a year
Kask produces around 800,000 helmets a year

Oli Woodman

Section Editor, UK
With more than 10 years of experience riding mountain bikes, Oli knows the good from the bad when it comes to gear. He's a total bike nerd and loves few things more than fettling with spangly riding bits. Also, he seems to have a talent for crashing hard but emerging unscathed.
  • Discipline: Mountain
  • Preferred Terrain: Loamy singletrack
  • Current Bikes: Marin Pine Mountain, Pinnacle Dolomite
  • Dream Bike: Honda RN01
  • Beer of Choice: Corona
  • Location: Bristol, UK

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