DUPLO PUR Binding Issues, help me! Before i lose all my hair

[UK Printer]

We have a DUPLO PUR Binder (DPB 500 PUR).

We use the binder to perfect bind inners for hardcover photo books, here is the problem we have, i'm hoping someone has had the same issues and found a workaround: I can't seem to get any kind of reliability out of the machine.

We purge the PUR glue, ready for its first book, we're binding 13 sheets of 200gsm with the end papers, so its not the thickest book in the world.

We first put a few thick blocks of waste thought to get the glue going.

When we put our job into be bound (the thinner block) then no glue gets onto the spine to bind, we get a small lump at the start of the spine, but then nothing else.

Now i'm thinking when the nozzle closes up to bind the smaller block we may have some dried glue and thats stopping the glue from getting out, but...

If i manually purge the glue, same width of slot closure then the glue pumps out fine.

If i got to bind my smaller book block then nothing comes out :-(

If we put a thick book block on, then the glue comes out no problem.

We have the glue pressure set to maximum (pressure thats forcing the glue out)

At the moment, we're having to bind together multiple book blocks with their endpapers, separated by sheets, which when the glue hardens we then have to separate out, this separation process is proving tricky and we're losing quite a few book blocks, which cost a fortune!

So before all my hair falls out, i'd really appreciate some advice.

Regards

Tim

 

[stu]

Hi Tim
You may be on to something there, when the nozzle is closed for the thinner book, the hole is smaller, which will require more pressure to force the glue out. The fact you are having to run the air pressure at maximum shows something isn't right.
Has it always been like this? We find that if there is cured PUR adhesive in the system that people up and up the air pressure. You can get a cleaning candle to run through the system to remove any cured PUR. Failing that i'd check the source of the compressed air and all the subsequent connections.

Hope this helps