''flexible'' azura plates...

[motormount]

Hi all!

I don't know if it's just me,but i think that the last azura TS plates we purchased are kind of more ''flexible'',like they changed the aluminium.
I didn't notice anything on terms of press behavior-and how could i,plate checks are performed by our pressmen eyes ,but still i think that plates delivered from September and on are not exactly the same with those we got until then...

Anyone else noticed something similar or is it just me?

 

[BillJ]

Agfa makes these plates in a least 2 different factories that I know of. It might be possible that that batch came from the "other" factory. They likely source their aluminum from different suppliers.

 

[chevalier]

It could also be the grain direction is different. I had a vociferous debate with a pressroom manager once about whether the grain direction in the aluminum plate actually made a difference. A number of experts were sourced from both press side and prepress side who basically said it shouldn't make any difference on our equipment and with our plate thickness. He would not concede. Thus we bought plates with each grain direction and tested. No discernible differences were observed. He still would not concede and we now order plates that are only a specific grain direction.

 

[motormount]

We are a small market here so i thought that all TS plates would come from the same manufacturer.


I thought that grain direction would apply to papers only-if that's the proper term in english,but you know what i mean-.

I couldn't possibly think that you could order plates with specific direction!!!

Though i can't think how grain direction would affect -in a noticeable way- printing,i thought that companies like agfa would be very strict on expencive products like TS plates!

Thanks all for answering!

 

[BillJ]

Grain might make some difference in the flexability. Unless the grain direction is specified on the package, you may get long, short or a mix in the same box.

 

[motormount]

Thanks again Bill!

 

[chevalier]

I should have elaborated...
The grain direction is almost certainly printed on the label of the plate box along with the lot code, size, type, safe-light etc. If my memory serves for AGFA it is typically something like this: GS (grain short), GL (grain long), GI (grain irrelevant? indifferent?). If you don't find it upload a picture of your label and I'll see if I can sort it out for you.

As with paper bending against the grain can cause fracturing and resistance. Thick plates can fracture or resist if bent against the grain. If mounting a very thick plate perpendicular to the grain it may resist and not want to load on the press easily (especially with autoloaders). I think this covers the idea but I am sure there are some other scenarios where it does matter.

 

[Santa]

On the back of each plate there is an alphanumeric code. After the first letter there is a "<" symbol. I was told (2005/2006?)that this is the grain direction and we should always load our plates consistently in the same direction. For the last 9-10 years we make sure that arrow always points to right.

 

[motormount]

I hesitated to ask a question about plate ''flexibility'' - it seemed silly to me - but here i am with so much unexpected information!

Anyway here's a plate label,and i'll check Santa's hint tommorow!

Thanks again!

 

[Alois Senefelder]

mmmm !

mmmm !

Hello fellow Lithographers,


The Fundamental Influence Properties are - "Inter-anneal and the Cold Rolling Processes" are key

properties of Aluminium Litho Plates, not the grain.


Regards, Alois

 

[motormount]

There it was,on the back of the plate!

-I had to google your post Alois,thanks for your input as well!-