Olympic Stadium Wrap: Innovation, Part III

Producing the fabric with The Cooley Group

Perhaps the most challenging part of making the Olympic Stadium Wrap was getting the fabric right.

To pass the British Standards for fire testing, the fabric was made using a chemical composition similar to that of roofing membranes.

The extruders – the machines that press pellets into sheets of fabric – didn’t like this very much. Neither did our printer.

We went through about 6 months of testing before we found fabric that we could even try on our printers. Here’s a quick glance at what that process looked like.

To make fabric, you have to run a minimum of 1,000 yards.

The process takes 8 hours – if there are no problems. And you don’t know anything about the quality of the material until you’re done.

Plus, the fabric passes through the extruder three times, multiplying the potential for failure.

  • Pass 1: Apply the black-out layer.
  • Pass 2: First coating of white.
  • Pass 3: Flip it, apply the 2nd coating of white.

To OK the final version of the fabric, Rainier’s Display Division Manager Charlie Rueb flew down to Cooley’s plant in South Carolina.

As the fabric rolled off the extruder, using finely calibrated instruments (his eyes and fingers), Charlie deemed it fit for printing!

A great ending to a long and tedious process… Thanks to the tenacity and dedication of the teams at Dow, Cooley and Rainier, we turned vision into reality with a winning product.

Here’s a visual rundown of the process:

1. This is what the raw material of polyethylene looks like before it’s melted & run through the extruder – it comes in pellets.

2. Raw material coming through the extruder. As you can see, it’s not coming through smoothly, as one sheet.

3. A different try—this is better, but not good enough.

4. Once we got a smooth sheet, we put the material through the extruder for pass #1 – applying the black-out layer. As you can see in this video, the black is shredding off the scrim.
5. We re-formulate the pellets and try again. It appears to work…

6. …but during pass #2, the material goes in front of the light-box and it’s clear the black has not evenly applied. Try again.

7. This time we get all the way to pass #2 – the black-out has been applied, the extruder is layering white on, and now we can see holes in the white. (Those aren’t black dots – they’re holes showing the black layer beneath.) Fabric is extremely heat sensitive, and because this is so thick, the heat from the extruder isn’t applying evenly, and the white can’t spread properly across the entire surface.


8. We get a full, clean sheet of fabric through all 3 passes of the extruder (black-out, white, & white again). But the fabric puckers & bunches in the middle. Back to the beginning.

9. Finally! A smooth clean white stretch of fabric.

10. We color test…

11. And get down to the business of making panels (see Monday’s post for a walk-through of what that process looks like).


Tomorrow: Installation of the panels at the Olympic Stadium.