Force required for 12" press

[filtersweeper]

I'm getting stuff together to make a significant press over the winter including hydraulics and structure that will include die shoes retrofitted with the stampers etc. How big of a cylinder will I need or rather how much force is required to achieve this? I will be stamping hot PVC pucks instead of the granlulated/powdered method.
Thanks society members.

[markrob]

Hi,

I'm sure Mossy will chime in here, but according to the Cook patent, something on the order of 2000 PSI. So with a ram of 12 inches, you would need about 100 tons of force. I can't imagine doing that on DIY basis, but good luck with it. How are you planning to do the heating/cooling?

If you want a copy of the Cook patent, PM me and I'll be glad to send it your way.

Mark

[mossboss]

Not sure why one would bother doing this
But if it s to be let it be
Hey Fliter man if you are so keen find a 4 post press from a junk yard first, start with that
Make sure it has all the hydraulics on it as well as a pressure multiplier for the final push
If not so make sure it gets to about 120 Tonne with the space between the posts at least 18" x 18" so you can get a 12" mould and holder in there
As an example look here http://www.kempler.com/product_detail.cfm/seqnumber_content/728.htm
They have about 40 odd in stock Not That I get a commission either He He
Than you can at least have half a change of getting a result
The rest is fairly easy if you know what you are doing, like you dont have to use an extruder or a puck
You can use PVC sheets that you can preaheat in any domestic oven with steam boiler ex laundry 15 KW Than some cooling water from any source Straight from the tap and out to waste if it is plentyful in your area
Moulds book style you can buy from RPA and you would need a trimmer Well there is ways of skinning cats
You can press away and than punch the flash out on your press by removing the moulds, replace them with a simple round punching tool ala Lened than you can trim your output for the run
Any way If you are prepared to spend that kind of money you may as well buy a proper press to start off with save yourself a lot of heart ache you would still need all the peripherals at least you would have a good basis to start off with
Here is an email trail that I got from another guy that I have been baby sitting since February He started with a proper press as well
Here is one

you help me sending the plants from a toolex

now i am ready to run the machine was much more work i thought

many many thanks for that help

and another

i have only one machine and never want one more it is to much work for that what looks so easy

and another

hi i saw a calculation for a pressing plant from you yes that happend with me
always more money going away for some extras

and the end result??? here is another

anybody there ?? mossboss HELP

press is running non stop but all is waste

I still have to figure out why people think this is an easy task and want to do it
Who wants to go down that path?
Cheers

[filtersweeper]

thanks mossboss for the response. I won't be buying a big press like that although it would make sense seeing as it's ready to go. ( too much $) I will be welding up a structure that will be equipped with a big cylinder and two die shoes that will keep the stampers concentric. I'm looking at cylinders from a catalogue: might these be up to the job? I just need to know if they will be capable of press the PVC flat.

6.00” Bore @ 3000 PSI = 84,800 lbs force

or

8.00” Bore @ 2000 PSI = 100,500 lbs force

If 200g + is easier to achieve in terms of squashing the puck flat to a diameter of 12" then this is viable as I won't be worried about cost per unit, and materials.

[mossboss]

Mate You are barking up the wrong tree
If you where to use a 6",8"or 10" cylinder you never push a puck flat so as to make a record of 12" diameter
Take a look at "projected area" when pressing something under hydraulic pressure
Or better still look under piston pressure multipliers than look at it in reverse
and that is exactly what you would be doing
Learn a bit and than decide
You want to do a lot more home work
These people who made 1000's of presses certainly knew enough how not to go down the path you are choosing
Any way, one can take a horse to water but cannot make him drink
May be you can horse shoe him with whatever you are going to use to hold your stampers He He
Looks like you want to do it so go for it man have fun but choose your cylinders well if that is what you want to do
Ill give you another tip
Find a junked Injection moulding machine not the toggle type the straight cylinder type and you would have a very good basis at less cost to start off with including an extruder hydraulics and all the controls you would need
They go for around the $1-3 K mark
Cheers

[Serif]

It's reassuring to see grass roots interest in pressing. Keeping vinyl alive and headed for the global re-revolution (program pass?) is a pressing concern... );


Might be some decent info, here:

http://www.moldmakingtechnology.com/articles/quick-math-for-cylinder-calculations



Glad to see pi (3.14) getting plenty of quality time with these "boring" questions... [-;

Seriously, though, I love that analog uses so much the irrational numbers - pi, tau, root2, etc...

Good luck, bro, and listen to MossBoss for the pointers...





- Rod D. Yammeter

[andybee]

yo,
toolex wrote on their advertistment from 19??:
12": 2850psi = 200bar hydraulic pressure,
main piston diameter: 270mm, closing force 114tons,
opening force 6tons, actual pressing force 108tons,
lenght of stroke 55mm, daylight 167mm, distance between columns 562mm (3 column design), column diameter 90mm, closing and opening speed 120mm/sec, 3.15liter hydraulic liquid consumption per cycle, steam 1.2kg per record (220kg/hour @ full speed) 15liter cooling water per cycle, water and steam @ 12bar stable (thats what andybee advises)...

hope that helps...

[mossboss]

Yo
Its really a bit of a bummer sometimes attempting to steer people on to the right path
Its the nature of forums I suppose Someone gets on asks questions gets some answers most likely right if it is coming from the right source than they go all quite
It seems that you more or less have blown away their dream
Its only recently that this 17 yo old kid was asking here the ins and outs of record pressing
Good to see on the one hand on the other hand it is somewhat of a time wasting exercise
Well we just don't know who is asking so we just give them what we know
May be we just save them a lot of heartache as well as money
Cheers