Film-Tech Forum ARCHIVE: Dolby-recommended washing machine

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Posted by Pietro Clarici (Member # 4937) on 01-28-2009, 09:17 AM:

Hi everyone,

My theatre in Italy is most likely going to choose XpanD as a 3D provider, and we are trying to understand how to wash the glasses after each use. XpanD Europe recommends manual wiping, which sounds overly complicated.
Can someone give me more information (washing machine maker and model, chemicals used) about Dolby 3D's washing process? I'm particularly interested in the 3-minutes cycle, and I'd like to check if the operating temperatures can accomodate XpanD's new glasses too.
Thanks a lot,

Pietro

Posted by Matt Fields (Member # 3211) on 01-28-2009, 09:35 AM:

Dolby recommends:

Knight Equipment (A Unit of IDEX Corporation)
KLE-175 GT Upright Dishmachine
Left and Right Tray Tables
Hatco C-9 Booster Heater

and Ecolab brand chemicals.

Recommended water temp is minimum 120 and maximum 140 degrees.

Any low temp commercial dishwasher will wash the glasses, but Dolby recommends this set up because it is high volume. They also recommend special metal trays to put the glasses in. If you look at some of the other Dolby 3D related treads on here, you can get the part number and supplier for the trays.

Posted by Pietro Clarici (Member # 4937) on 01-28-2009, 10:23 AM:

That was very helpful.
Thanks,

Pietro

Posted by Mark Gulbrandsen (Member # 72) on 01-28-2009, 11:54 AM:

Do a search here on F-T and you'll find more info on dishwashers. If you take the time to shop around you can find machines very similar to Dolby's reccomended machine for as little as 50% of the price of the Dolby reccomended unit. These machines are very common... there are even units that are much more compact.

Mark

Posted by Sam D. Chavez (Member # 1841) on 01-28-2009, 08:41 PM:

I would sure want to make sure the XpanD glasses are tough enough to stand up to the wash cycle. There may be a reason they recommend wiping them.

Posted by Poon Limpapun (Member # 4551) on 02-10-2009, 03:35 PM:

Does anyone have any problems with the 3D Glass Anti-theft tag sensors not working after being washed? We have to test each of them one by one after being washed and dried through the Sensormatic gate and we found that 10% of the inventory we have doesn't work. We have two Dolby screens and 10% is a lot.

Posted by Julio Roberto (Member # 4976) on 02-10-2009, 04:00 PM:

I have no direct experience with Dolby 3D, only with Dolby's traditional 35mm digital/analog sound equipment, so I can't really help.

But talk to your distributor. If the glasses are under 1 year old and used as directed, they should be covered by warranty by law (at least in the European Union), as they can be considered a manufacturing defect and should be replaced at no cost to you with ones that meet all original specifications.

Posted by Poon Limpapun (Member # 4551) on 02-10-2009, 04:03 PM:

We already talked to our manufacturer rep and yes they will replace the glasses but the main issues we are having is that we are running out of spare glasses during a changeover as the glasses do not dry in 15 minutes so we stock 200% assuming that we don't have a full house. However, we are now running close to full house for every show and thats when the problems comes in! Not enough glasses as they kept breaking! We are now stocking 220% and it still keeps breaking. I've already checked the water pressure and removed the washing chemicals! Still the same problem. I am starting wonder whether is it to do with the fact that there is some strange thing with the water we get?

Posted by Julio Roberto (Member # 4976) on 02-10-2009, 05:43 PM:

Well, sorry I can't be of any more help. You could try figuring out if your washing machine is affecting the security tags by, i.e., the motor degaussing them.

I.e. check if the glasses failing are those in the bottom shelf, the top shelf, or those close to the rotating metal water injectors or motors in the middle of the bins.

A strong A/C current motor that is slowing moving in-out of ferromagnetic material can degausse it. Since the security tag is probably an acoustic-magnetic type made of magnetoresistive alloy, it may be affected and rendered unuseable from too much magnetic shriking/expansion, like when a security tag is permanently de-activated (i.e. magnetized or demagnetized) by a store clerk.

I realize that Dolby's tags are not meant to be "deactivated" like in a store, but meant to be permanent. That doesn't mean, though, that they are inmune or inert to magnetic fields (they can't be, of course, or they wouldn't work) which, if strong enough even in the wrong frequency, can render them unuseable.

Just a theory. Probably wrong as it would be very weird to get a dishwasher become an effective degausser by chance.

If you still suspect the water or something you could do an experiment. Put 20 or 30 working glasses in plenty of warm water for plenty of time and wash them manually. If after that they all work fine instead of getting 2 or 3 failures (10%), then the water is fine and the problem may be with the dishwasher itself rather than the water or the chemicals.

I'm assuming the dishwasher is not heating up the water/glasses too much, but physical heat-cold expansion of the tags alloys could also throw them out of tune with the security antenna "detector", rendering them once again permanently inoperative.

It would be of help if someone else with a Dolby 3D theater operating for a while with a sensormatic alarm system could check their stock of 3D glasses and see if they are all working or indeed quite a few are no longer being "detected".

If the problem is magnetic, you could try shielding your dishwasher motors with metal or something. If it is thermal, make sure the temperature is set to lower and try to get them to not cool-heat-cool too fast or too much. I doubt it will be chemical, as small amounts of metal or water deposits outside shouldn't stop these types of labels from working, and I doubt the liquids are getting inside the glasses.

But who knows. Perhaps someone can ask Dolby to ask Infitec to ask the tag chip manufacturer what could be going on here. Just out of curiosity, do you use any salts in your dishwasher? Is your water soft or hard?

I'm perplexed by this issue, though. Just to be sure you are saying that you tested glasses and they were all working, and that after washing them (a couple of times?) about 10% of them stop permanently to be be detected by the anti-theft security system, right? Are more and more failing as you keep washing them or it's just that fixed "10%" that initially failed? [Confused]

[ 02-10-2009, 07:18 PM: Message edited by: Julio Roberto ]

Posted by Poon Limpapun (Member # 4551) on 02-11-2009, 02:08 AM:

Hi!

It seems that there is nothing wrong with the water. So I guess it's the issue with the anti-theft tags. Out of question, does anyone seem to be having problems with customers stealing the lenses of the glasses?

[ 02-12-2009, 02:48 AM: Message edited by: Poon Limpapun ]

Posted by Pete Naples (Member # 761) on 02-11-2009, 05:04 PM:

To paraphrase Crocodile Dundee, that's not a 3D glasses washer.

THIS is a 3D Glasses Washer.

I've no idea what the make or model of this machine is but it washes and dries several hundred iWerks 3D glasses in each cyel, in very short time. Made a hell of a noise in the process.