To paraphrase the late Carl Sagan, To make a minifigure from scratch, you must first create the Universe. 

Let’s move a few steps down that path. Recently we took a look at some of the prototypes that were passed over on the path to minifigure development. Once you have a design, you need a way to put it together. Today, let’s take a look at the moulds that are in use.

Mold or Mould?

Over the last few years, I have been struggling with the word used to describe the thing that molten plastic is injected into, where it gains its special shape.  Is it a mould or a mold? And which is the spelling that has spores, and was the bane of my bathroom back in my bachelor days?

A quick call out to to the Wikipedia suggested that both spellings would apply to those fungi, depending on where in the world you are standing. (Molds in USA, moulds in the rest of the English speaking world).

But what about the verb meaning to shape/form or the noun referring to the thing used to do the same? It turns out that that is also spelt mold in the USA and mould everywhere else!  I am not about to revise every spelling of the world ‘mold’ over the last two and a half years.  going forward, however, I will endeavour to use the form of spelling that my computer attempts to direct me towards every time. This dialogue from the Australian Writer’s Centre might shed a little light on the subject.

So, now that we have that clarified:

Injection moulding was introduced as a process in the workshops of Ole Kirk Kristiansen all the way back in 1947.  The first manufacturer to introduce such technology in Denmark. Over the next 15 years, the toy factory produced a combination of wooden and plastic toys – the patent for LEGO Brick, as we know it, was submitted in January 1958.  In 1960, a fire destroyed the carpentry workshops: they were not rebuilt, as the ‘plastic toy’ side of the business was taking off.  (ref: 50 years of the LEGO Brick, C Humberg, 2008).

With injection moulding of LEGO bricks today, Acrylonitrile Butadiene Styrene (ABS) polymer granules are heated to 232ºC, and injected into the moulds.  Once the plastic has cooled sufficiently, it is ejected and the process repeated. Over the years the design of moulds and subsequent contruction of elements have been adapted to allow greater efficiency in productions.  For example, over the years, the minifigure head mould has been updated several times.  Over the last forty years, these changes have seen the number of elements produced increase from eight heads per 9.8 seconds in 1978 to 128 elements per 14.7 seconds today.   This information fills a gap for me with regard to the repeated upgrades to minifigure moulds we have seen over the years – for details of these updates, you may wish to refer to my previous article on the structural changes in minifigure elements over the years.

In an interview appearing in HispaBrick Magazine #26, archivist Tine Froberg Mortensen spoke about the life of a mould: Typically a mould will undergo eight to ten million injections, and undergo cleaning/maintenence every 500 000 injections or so (depending on the complexity of the element, and the material used.)

In the past, discarded moulds were buried in the foundations of the Hoejmarksvej, Koewvermarken andKornmarken factories, all located in Billund. Although occasionally cast in concrete, the moulds discarded at Hoejmarksvej were buried in sand.  Some were recovered when that factory was demolished.

After the moulds were no longer being cast in concrete, they were melted down by a steel rolling mill until 2002.  Since then, all obsolete moulds from Billund, and around the world, are sent to the Kornmarken factory for destruction.

Further information about the factories involved in constructing LEGO Moulds as well as their service and destruction can be found on the Official LEGO History site.

What about the minifigure?

The typical minifigure involves the use of eight moulds: Head, torso, hips and hands, and also left and right moulds for the arms and legs. (Thanks to the LEGO Group for these great images)

Let us start at the top: here you can see a mould for eight minifigure heads, with the ejector pin pushing out a recently moulded element.

This torso mould with internal ribbing was introduced in the late1990s, and continues to this day.

The left and right arms each get their own mould (but I only have pictures of the left).

The hands also have their own mould.

The hips come next:

And then the legs follow. Again, there have been some subtle variations in leg moulds over the years, and some of the newer moulds allow for injecting multiple colours into a leg

From here, they all get put together: Join us soon when we visit the LEGO Factory in Kladno, to see how minifigures get put together. Tag your Fortieth Birthday images with #minifigure40 on social media, and follow the Rambling Brick for further articles, reviews and curiosities.

Until Next Time, Play Well.