Question about Nominal Size vs. Production Size of Ceramic Tile (EC011340), and "Calibrated" feature

Last comment 18/01/2018 10:20 by Marc
· Mark as unread
Roberto Ortega 4 years ago created
Hello,

I had a question regarding production sizes of Ceramic Tiles. When being cooked ceramic tiles can have slight variations of size so I understand that while "Nominal" Length and Width is the "official" size, the "production size" is the actual size of the tile once it has been manufactured, correct?

In addition, I have a question regarding "Calibrated" feature (EF020840). Once a manufacturer has produced the tiles, these are grouped into different groups (called calibers) depending on their size (for example, tiles that have sizes within a range of two milimeters are grouped in the same caliber, named for example "1", and the next caliber could be "2"). Each manufacturer defines their own caliber. Does the feature "Calibrated" (logic) mean that the tiles have been assigned a certain caliber, or does it mean that the production size of the tile is available?

More information about caliber here: http://etoprosto.ru/en/articles/what_is_a_tile_caliber_and_why_does_it_matter_when_buying_tiles/

Thanks,

Roberto
Marc Habets 4 years ago created
I had to do some research myself for this! 

To your first question you are not completely right: The nominal size is the expected production size of the tile plus the joint size. So for example a tile with nominal size 600 x 600 mm can have a production size of 597 x 597 mm (+3 mm joint width). Production sizes usually have an allowed deviation (normed) of around +/- 2 mm, which I am not sure is international or depends per country?

To your second question, calibrated as far as I can judge has nothing to do with caliber, as you describe. Calibrated tiles are tiles that are cut/sawn to exactly the same thickness and/or made exactly perpendicular (right-angled) in all directions. Usually relevant for natural stone tiles, but apparently sometimes also for ceramic tiles. Your 'caliber' (which I would call batches?) is more a logistical/trading feature and is not related to the technical classification of the single product.
Roberto Ortega 4 years ago created
Hello Marc, thanks for your reply!

Regarding the "tiles hat are cut/sawn to the same thickness / perpendicular", I thought that was "Rectified" (feature EF020839). More info on rectified tiles: http://www.build.com.au/rectified-tiles-vs-non-rectified-tiles-whats-difference

That's why I'm not sure about the "Calibrated" feature.

Regarding the nominal size / production size difference, can you give me your source, so I can compare? Here in Spain for example you would see the nominal size of the tile in the manufacturer's website, but then the actual production size can have a deviation. I had not heard about the joint width, I will also do further research on this.

Regards,

Roberto

Marc Habets 4 years ago created
Hi Roberto, my source in this is also just searching the truth on internet, but then also crosschecking several sources. As you can read on internet, the terms calibrated and rectified are often confused, and as I can see not all sources are 100% correct. Please note that also my estimation is not confirmed by manufacturers, would be good if we could get an expert's opinion on this. This article looks scientific, but adds to my doubt about the exact truth again: https://www.tcnatile.com/images/pdfs/Rectifying%20the%20Misconceptions%20Associated%20with%20Rectified%20Tile%20and%20Narrow%20Grout%20Joint%20Installations.pdf.

I found a screenshot where all three terms 'caliber', 'calibrated' and 'rectified' are explained in a way I can relate to, is only in Dutch unfortunately. Important to know is that rectified tiles are usually also calibrated, where as you can see from the picture the rectified tiles allow for a very narrow joint. Caliber indeed refers to sorted batches of tiles with the same exact size (depending on heat shrink during baking process) .

For the nominal size see for example https://www.villeroy-boch.co.uk/products/tiles/service/faq.html, screenshot below
Roberto Ortega 4 years ago created
Hello Marc, 

Thanks for the PDF, it is well explained there. So then I was correct, in the sense that the feature "calibrated" is if the tile has been assigned a certain caliber (Yes/No)?

Thanks for the nominal size definition from Villeroy-Boch, I will see how this is treated in Spain.

Regards,

Roberto
Marc Habets 4 years ago created
This is a tough discussion ?! No, for me caliber and calibrated is not related. Caliber means that after production they (mechanically) sort tiles with the same exact production size together, without changing anything. Calibrated tiles are machine cut after production (edges and/or thickness) to match the desired dimension specifications. But again, this is my best estimation, the information on the internet is confusing and sometimes contradictory. 
Roberto Ortega 4 years ago created
Hi again,

It's strange, because in the PDF you sent me (https://www.tcnatile.com/images/pdfs/Rectifying%20the%20Misconceptions%20Associated%20with%20Rectified%20Tile%20and%20Narrow%20Grout%20Joint%20Installations.pdf), it says the following:

Calibrated tile: Once tiles are sorted, they are commonly grouped into two to four different calibers, depending on the size with which they most correspond.
Rectified tile: A rectified tile is one that has had all sides mechanically finished to achieve a more precise facial dimension.

So the information that appears in the Dutch screenshot is contradictory to this?

Regards,

Roberto
Marc Habets 4 years ago created
As I said, the PDF adds to my doubts again. The information on the internet is not conclusive. In the discussion I gave my best estimation of what is the correct explanation. As ETIM we are responsible for the classification structure, but we can't possibly be experts in all product areas. The local member companies are the ones that make proposals for new classes and change request, we only 'shape' the proposal to ETIM guidelines. So for tile experts the classification should be unambiguous, which of course is the goal, but especially internationally can be difficult. To investigate deeper into this, you should contact the local ETIM organization, but this kind of support is usually 'members only'. One last remark: as I mentioned before, 'caliber' will NOT be a feature in ETIM, since the classification describes a single tile (the product), and caliber is information regarding a batch of tiles sold together (buy-able article), so is to be seen as trade/logistical information. This is to be communicated in the exchange format, like in BMEcat.
Join the conversation
You have to be a registered user to join the conversation.
Topic started 10 January 2018 at 09:28