Wikipedia:Featured picture candidates/Tablet press animation

Tablet press animation

Original - A tablet press compresses powdered pharmaceutical formulations into hard tablets of uniform shape and weight. The lower punch retracts to form a cavity which is filled with powder by the feeder. The excess is scraped off and the punch is drawn down and covered. The upper and lower punches compress the tablet in two steps as they travel across heavy compression rolls. The tablet is then ejected from the cavity and the process repeats. At full speed, a typical press can make over 250,000 tablets per hour.

Reason: Animation shows the complex, multi-step process of tablet pressing in a convenient view.
Articles this image appears in: Tablet
Creator: Jeff Dahl (Talk • contribs)

Support as nominator Jeff Dahl (Talk • contribs) 01:36, 24 February 2008 (UTC)[reply]
Support I spent a few minutes staring in wonder. Well done. Cacophony (talk) 02:01, 24 February 2008 (UTC)[reply]
Question. What's the deal with the rollers? Do they actually roll? It looks like the tracks just sort of get closer together there and are supported by the rollers- why couldn't they just narrow the track and bolt it down real tight there instead of having "heavy compression rolls" in the way to support it? :D\=< (talk) 04:04, 24 February 2008 (UTC)[reply]

The compression rolls do the heavy pressing (yes, they actually rotate) and the punches actually travel directly on the rolls during this compression step. A typical force might be 10 kNewtons on the first set and 30kN (equivalent to about 3000kg force) on the second set. The photo on tablet is a good comparison. Jeff Dahl (Talk • contribs) 04:19, 24 February 2008 (UTC)[reply]

I hate to say it but it looks like you should fix the image.. it looks like the punches are hanging from the track and when the tracks get closer, the punches get closer.. the picture of the old press has no track at all- the punches are all mounted to the assembly (no track) and pushed downward by the rollers. :D\=< (talk) 05:15, 24 February 2008 (UTC)[reply]

The edges of the punches rest on cams. If you look carefully in the photo you can see them. It is really only the lip of the punch that touches the cam. The animation is based on a blueprint of a more modern press which is constructed in a slightly different way, the photo is of a much older machine. Either way, the basic process is the same. Jeff Dahl (Talk • contribs) 05:22, 24 February 2008 (UTC)[reply]

Hold on, I still don't get why they spin. They're smooth- how does spinning do anything? :D\=< (talk) 09:59, 25 February 2008 (UTC)[reply]

All of the punches are inserted into a large rotating turret (not shown in the animation for clarity), similar to the photo. When the turret turns, the punches do too, just like a merry-go-round. The punches are analogous to a horse, they ride up and down as the ride spins and moves over the cam. Jeff Dahl (Talk • contribs) 15:44, 25 February 2008 (UTC)[reply]

Abstain until there is animation in the rollers. Is this 6 frames or so? Then a simple set of dots or other marks on the rollers moving in a cycle of 6 frames would indicate roller movement. --Janke | Talk 09:17, 24 February 2008 (UTC)[reply]

Done. Jeff Dahl (Talk • contribs) 18:26, 24 February 2008 (UTC)[reply]

Thanks, but - the small rollers are slipping badly, and there's some slip on the large ones, too... --Janke | Talk 08:33, 25 February 2008 (UTC)[reply]

New version uploaded over old one. Jeff Dahl (Talk • contribs) 18:54, 25 February 2008 (UTC)[reply]

Support now that my petty gripes have been addressed... ;-) --Janke | Talk 19:37, 25 February 2008 (UTC)[reply]
Support looks good. — BRIAN0918 • 2008-02-26 19:05Z
Support Thanks for the careful hard work on this one. Durova^Charge! 19:14, 27 February 2008 (UTC)[reply]
Support. Very informative animation. Kaldari (talk) 00:15, 28 February 2008 (UTC)[reply]
Support I always wondered how they made those little guys. Dr. Extreme (talk) 21:07, 28 February 2008 (UTC)[reply]
Support EgraS (talk) 08:42, 1 March 2008 (UTC)[reply]
Support Very nice, definitely encyclopedic. --ErgoSum88 (talk) 11:35, 1 March 2008 (UTC)[reply]

Promoted Image:Tablet press animation.gif MER-C 11:23, 2 March 2008 (UTC)[reply]