Tool and die cost

I don’t know if there are other mechanical engineers or tool/die makers here. I tried asking the engineer I did work for, but he never responded to me (I suspect he snoozed me for whatever reason).

A friend is talking to me about making some foam/concrete building bricks for construction. Basically this is foam blocks that are put together like lego pieces with space in between where reinforcement goes. Then that space is filled with concrete. The plus is this allows you to build a strong building that has excellent insulation properties, since as you know concrete has no insulation properties at all. Given cost of AC is an issue in Taiwan and there are always issues with not having enough power to go around, this is something my friend wants to start making in Taiwan.

So the idea is to have injection molds made so we could manufacture the stuff here in Taiwan as shipping foam is not cost effective at all.

However I have no idea how much it costs to make a mold, not even a ballpark figure. I know it’s not cheap but I want to at least know what’s involved. Like the cost, how are tool/die made, etc?

1 Like

Interesting idea. How big would each piece be, what material (what Foam), and what kind of production volume (a few, or hundreds per day)? No idea if “my” mechanical engineers can give a ballpark number though, since they only work with metal and hard plastics…

I would imagine it would be polystyrene foams, as for production I need to ask him, but there are many different kinds of bricks for corners, windows, etc. but I imagine there is one type of brick that is used in 95% of the construction of a building, so that would need high volume process whereas others would be done with lower volume process.

I am also kicking around the idea of turning trash PET bottles into urethane foams then using that to cast the bricks. It would also play into environmentally friendly as you know PET bottles are just thrown away anyways. There has to be a way to turn it into a foam of some kind.

The pieces should be about the size of a cinder block, so probably about 18" x 8" x 10" or so (I don’t know the size of a cinder block off hand).

I told him for the pieces that are low volume (a few per day) I can make a fiberglass mold shell for him for about 10,000 or so depending on the complexity of the shell. I am fairly familiar with fiberglass. The idea would be to make the mold, then pour urethane foam into it to make the brick.

You need to take into account the flammability of the foam or you will end up building a massive bonfire. Cinder blocks, concrete and bricks are non-combustible.
Many high rise building have been covered in foam insulation panels and burn very well.
Grenfell Tower London June 2017 -72 deaths, 70 injured an example.

1 Like

These bricks, at least ones manufactured by companies in the US and Canada are said to be non combustible. So I imagine they used foams with fire retardant added to it and used inert gases to fill the foam (like nitrogen).

That’s something we’ll have to test and find out because I imagine the bricks would need to pass fire resistance test.

Yes agree with you, each country has a certification board to test the fire resistance of a material. Pretty sure its NFPA in US and Canada , in UK and Europe, European Standards board.
Interestingly in the public enquiry into the Grenfell Tower Fire the manufacturer of the foam blocks has just admitted to rigging the materials for test so they passed certification!

There is the ytong system, insulating, fire resistant. Numerous sizes of building blocks. Glued together, probably easy to adapt to be filled with additional concrete.

1 Like