Getting a well pressed record...

[PincheBolillo]

This is my second post on the forum. I wanted to ask those of you who have experience in running record presses what are the best ways out there to ensure you're pressing a truly top notch record. Here's what I'm working with...

1. I run 2 Viryltech Warmtone automatic presses that are connected to a Miura boiler and I always forget the chiller company. Ugh! The boiler has an average psi of 145 and our chiller is set for 67° F, so our outgoing temperatures range from 67-72 ideally.

2. I run only black PVC from NeoTech and my barrels are set to 280°/290°/300° with the die zone at 285° and the puck temperature usually around 130-140° F.

3. This is how I was taught to run the presses. The molds warm up for about 8-10 seconds, putting them somewhere between 250-275° F. Once the puck goes into the press, it sits there for 3 seconds, then the molds cool off for 10-12 seconds max (final temperature is around 100-110° F) and the record does not sit in the press any longer once the molds have cooled for that time period. The end result are records that have noise on the lead-ins and sometimes the music. Stitching on side 2. The center holes are the correct diameter, but have this small, annoying ring of material around the perimeter of the hole, under the label. And last but not least, the sound quality is good, but that short 3 second time in the heat in the closed press doesn't give the record a long enough time to really get down into the ridges of the stampers and get all the sound into the record. Our cycle times wind up being 24-26 seconds on average.

I do a lot of experimenting with different settings and found that if I want real quality, that cycle time is going to be 45 seconds or so. But I need to keep things around 30 seconds or less to keep everyone happy. Just don't want to skimp on quality because there are far too many badly pressed new records out there and I want to be able to press truly well made stuff, so I can be proud and people get their money's worth.

How do you guys run your machines? Long cycle time, short time? How can I get rid of all the flaws and defects that plague us and still have a 30 second cycle time to keep production up? Any advice will be greatly appreciated. Thanks!

[andybee]

Hello! I can share a little bit of my alpha toolex experience. heating is usually 6-8seconds (steam & condensate valve fully open),
depending on the steam trap, this should work. I prefer Spirax Sarco FT14 with ball inside or similar. after heating, the cake & labels
are loaded. after loading, the press can sit idle for a while, to spread the heat in the mould. then the press is closing,
usually fully closed in 2-3 seconds, after closing you can add a time before cooling starts, this depends mostly on the PVC.
if this time is too long, PVC can overheat, so you get white spots. cooling is 8-12 seconds, depending on the cooling water
pressure & temperature. best is 22-25degrees celsius for cooling water, 10-11bar water pressure (as stable as possible)
steam also 10-11bar, so you should get stable 175-180degrees celsius (355degrees fahrenheit), puck should have 150degrees celsius in the middle,
but also depends on the PVC. ideally, the PVC temperature comes also from the "knead" of the material inside.
a good record should be pressed in 22-26 seconds, 45 is IMHO way to long. PVC quality is always an issue. good luck

[tamachura]

Something that has helped us recently has been increasing the pre heat and trap time. increasing the preheat to blow out all of the condensed and chilling water from the molds leaving only steam. My assumption is that we lowered those times to a point where water was settling on the face of the upper mold in the channels leaving cool spots and creating some stitching. having good water pressure and gpm is also a factor as mentioned above, we have been using a pump giving us only 60psi on our water header for cooling and increasing that pressure even 5-10 psi has shaved seconds off of cooling time. currently sourcing a new pump for the ideal 120-160 psi with gpm of 20-30 per press as recommended by some pressing veterans. Also not sure if that differs with the pheonix or warmtone recommended specs but finding a hamilton manual that is what is shown on the first few pages.

cheers,

[PincheBolillo]

In the "advanced settings" section of the touchscreen for our Warmtones, we have a page that shows the breakdown of what happens when the moulds warm up and cool down. Here's what we have...

Heat:(using a 10 second warm up time)
* Heat & Cold Drain - 5.25 seconds
* Heat & Hot Drain - 3 seconds
* Heat & No Drain - 0.75 seconds

Dwell:
* Valves Closed - 3 seconds

Cool: (using a 11.5 second cool down time)
* Cool & Hot Drain - 0 seconds
* Cool & Cold Drain - 11.5 seconds

Dwell:
* Valves closed - 0 seconds

I was told that Heat & Cold Drain should not be 5+ seconds, but actually somewhere between 0.1-0.5 seconds (Viryltech recommends 0.1 seconds) and Heat & No Drain should be about 0.5 seconds as well. Changed to the new settings one night and the records looked a lot better and pressed a little better. The next night, things were still great, but I had to keep draining the water feed tank for the boiler constantly. Got in huge trouble over that and never touched it again. Still curious to know why the feed tank kept filling up and needed to be drained so much.

[PincheBolillo]

Hello! I can share a little bit of my alpha toolex experience. heating is usually 6-8seconds (steam & condensate valve fully open),
depending on the steam trap, this should work. I prefer Spirax Sarco FT14 with ball inside or similar. after heating, the cake & labels
are loaded. after loading, the press can sit idle for a while, to spread the heat in the mould. then the press is closing,
usually fully closed in 2-3 seconds, after closing you can add a time before cooling starts, this depends mostly on the PVC.
if this time is too long, PVC can overheat, so you get white spots. cooling is 8-12 seconds, depending on the cooling water
pressure & temperature. best is 22-25degrees celsius for cooling water, 10-11bar water pressure (as stable as possible)
steam also 10-11bar, so you should get stable 175-180degrees celsius (355degrees fahrenheit), puck should have 150degrees celsius in the middle,
but also depends on the PVC. ideally, the PVC temperature comes also from the "knead" of the material inside.
a good record should be pressed in 22-26 seconds, 45 is IMHO way to long. PVC quality is always an issue. good luck

PVC material is a big thing I'm trying to get answered. We use NeoTech and I've heard the melting point for black PVC is 280 fahrenheit and I heat it up to 300-325 fahrenheit before it leaves the extruder. Trying to get an answer from them if that's too hot or not hot enough for their material for a while.

[tamachura]

For anyone curious, we've seemed to have resolved our stitching issues mechanically on our smt. The cylinders that thread onto the four posts that are tightened with a side pin hole spanner must have loosened over the many cycles from vibration. I noticed when it was pressing the frame had the smallest movement. I got almost a full rotation on the 6" diameter nut and snugged them up. All stitching aside from normal over cooling has ceased! We went through EVERYTHING. Material temp, mold temp, new molds, water temp, water pressure, valves, alignments and I just had overlooked these huge honkin cylinders staring me in the face!

[therecordpress]

Hi,

your puck temperature seems very low - is 130 - 140 deg f correct? We run an Allegro II, and our puck temps are generally 100 - 110 deg C when they reach the moulds (225 deg F). If your puck is too cool when the moulds close you won't get an even flow of pvc across the stamper.

Cheers

Neil