Decisions, decisions: Sintering oven '?'

[loadmaster]

Help! Any & everyone, I'm getting information overload. We are just getting our first new milling system & we can't afford to swing and miss on a sintering oven. The one thing I DO know I want in the oven are the 'MoSi2' elements. Looked at the Programat S1, the Mihm Vogt HT Speed, Origin's DuoTron Pro (too pricey) and the list goes on. I want something very consistent and reliable when it comes to firing, shades and fits. Any and all input will be extremely helpful because I value everyones 'first-hand' experience

 

[ParkwayDental]

We have two of the Origin DuoTron great furnaces haven't had any issues with them. I can fit roughly 80 unis give or take in it.

The S1 I wouldn't waist your time or money on. Not enough tray room and nwhen you get in a bind and need the quick fire sintering it's worthless on this unit just from experience, and not worth the money!

The Mihm Vogt HT are nice if I had to do it over again I would go with these!!!!

Main thing is to do a cleaning cycle in your furnace and change the beads. I run a cleaning cycle once a week and when I do I put just some scrap green state zirconia to help absorb the contamination. I also change the beads once a week!

Sent from my IPad

 

[loadmaster]

Tyler, I greatly appreciate your input. It helped solidify my decision. The Mihm-Vogt was the unit I was leaning toward but didn't have enough info on to confirm a 'wise' choice.

Go Tigers!

 

[charles007]

Mihm .. large or small ... HT SPEED 6 elements or HTs Speed 4 elements
The smaller HTs Speed I just bought holds aprox 25 units...

 

[macminn]

Parkway,
What is the "cleaning cycle" you use?

 

[DMC]

What do you think you are cleaning?

You are actually just re-growing the Silica crystals on the Molybdenum.

Your Silica insulation of chamber is not affected by any acids.

Acids are commonly stored in Glass (Silica) jars. It does not absorb any "Acids".

Total urban legend. IMO

Exposed, raw Molybdenum in an Oxygen containing atmosphere at 1500C will combust and create the gnarly gas that is the root cause of discolored Zirconia.

Has absolutly nothing to do wih any acids.

Scotty

 

[ParkwayDental]

All we do is place scrap zirconia in the furnace and run a cycle at 1600c degrees for 4 hours. I know with our furnaces you will see the scrap zirconia absorb some color. Basically just burning out all the residues in the furnace to gt it clean and grow silica back on to the heating elements as Scott stated.

 

[BobCDT]

Hi, We are selling the Sintra. It has the MoSi2 heating elements. We have 3 of them we use daily (or twice a day) The oldest one will be in operation two year this coming Feb. Never changed a heating element in any of them. Bottom entry for even heat distribution, capable of fast firing. 2 stage cycle programs hold many more programs than you'll ever need. Consistent firing.
We also have a Takema that is running well as well as a few others that I really would not recommend.

 

[NicelyMKV]

I'm using a Mihm Vogt with zero issues. Excellent firing. Just plug it in and forget it


Sent from my iPad using Tapatalk HD

 

[PCDL]

I have been using a Nabertherm for the past two years... Works fine, very programmable, big capacity. Overall very happy. Lincoln dental had them for a shade under 10k when I bought.

 

[STJDENT]

Dekema anyone?

 

[k2 Ceramic Studio]

Dekema anyone?

A good friend of mine had one of these, he was Vita's head of R&D ,then helped develop the Everest system and leactured all over the world about Zirconium and milling, also one of Ivoclars main material testers. Dekema is the way to go if you have the cash. If I needed to get a new one thats what I would go for. All the best Pete

 

[macminn]

You change the beads once a week? That's got to be pricey! I didn't think the beads can soak up contaminants. This is very interesting. If you run a cleaning cycle, doesn't that clean the beads as well? What parameters is your cleaning cycle?

We have two of the Origin DuoTron great furnaces haven't had any issues with them. I can fit roughly 80 unis give or take in it.

The S1 I wouldn't waist your time or money on. Not enough tray room and nwhen you get in a bind and need the quick fire sintering it's worthless on this unit just from experience, and not worth the money!

The Mihm Vogt HT are nice if I had to do it over again I would go with these!!!!

Main thing is to do a cleaning cycle in your furnace and change the beads. I run a cleaning cycle once a week and when I do I put just some scrap green state zirconia to help absorb the contamination. I also change the beads once a week!

Sent from my IPad

 

[technician]

I bought this one. I am no specialist but this oven has everything extra and it seems to be ready for the future. And not so expensive compared to other brands.
And it looks really nice

Mikrowellenofen 1800 Vakuum

(no I have a Roland mill)

 

[Drizzt]

I bought this one. I am no specialist but this oven has everything extra and it seems to be ready for the future. And not so expensive compared to other brands.
And it looks really nice

Mikrowellenofen 1800 Vakuum

(no I have a Roland mill)

Hey technician ,

How much did you pay for it ? What made you choose a microwave oven instead of an oven with MoSi2 elements ?

I thought it was not released yet .

 

[Broadway your way]

I would run with the Mihm Vogt HT speed! easy to program. only 10Amps and very reliable!
Like Scott mentioned
-Yellow discoloration is a common problem for processing Zirconia in furnaces with MoSi2 heating elements.
It is unlikely that iron is the contaminant, it has too high of a melting and boiling point.
The most likely cause for yellowing is Molybdenum Trioxide (MoO3) contamination from the heating element. He has done tests using Mo to confirm the yellowing effects on Zirconia.
MoO3 is the “pest” that forms at low temperatures (400-600C) on MD elements that are not glazed (i.e when elements are new or after a spall event). The MoO3 sublimes (solid to vapor – no liquid) as the elements are taken up in temperature above 1155C. The vaporous MoO3 deposits on the furnace insulation and on the Zirconia product in the furnace.A key to reducing the number of spalls in an MD element is to limit the growth of crystalline silica in the glaze.

There are two factors that promote the growth of crystalline silica:

1- using the elements at low temperatures (below 1600C element temperature) and
2- impurities either in the atmosphere or in the element itself

Many dental furnaces are run in the 1500ºC to 1600ºC temperature range that promotes crystal growth in the glaze layer.

It is impossible to eliminate spalling completely with our MolyD elements in a periodic furnace that operates at 1500-1600C.

 

[Broadway your way]

Dental Zirconia Sintering Furnaces & Ovens - ISINT - BroadwayDentalLab.com

 

[technician]

Hey technician ,

How much did you pay for it ? What made you choose a microwave oven instead of an oven with MoSi2 elements ?

I thought it was not released yet .

Hello its about 8K Euros it has MoSi2 elements AND has the microwave function.

No its coming soon I´ll get the 700 untill it´s released.

Why I bougt it? Because it´s the most stylish out there and it has all these nice features:

To be charged with 3 different protection gases for oxygen-free sintering
Prettau® Zirconia will become even more translucent
l for the material technologies of the future
High speed sintering possible
The zirconia’s crystal structure remains compact, resulting in higher stability
Susceptors exchangeable
Variable combustion chamber up to max. 12 x 8 x 11 cm
Modern, high quality all-glass
4,3” colour touchscreen control panel
14 preset programmes
Updatable via USB port
Memory for up to 2000 programmes
Special sintering programmes upon request of the customer
With high vacuum for sintering of sintered metals
Capacity approx. 100 elements



No I´m not working for ZZ ;-)

 

[macminn]

So how do you eliminate, or reduce yellowing?

I would run with the Mihm Vogt HT speed! easy to program. only 10Amps and very reliable!
Like Scott mentioned
-Yellow discoloration is a common problem for processing Zirconia in furnaces with MoSi2 heating elements.
It is unlikely that iron is the contaminant, it has too high of a melting and boiling point.
The most likely cause for yellowing is Molybdenum Trioxide (MoO3) contamination from the heating element. He has done tests using Mo to confirm the yellowing effects on Zirconia.
MoO3 is the “pest” that forms at low temperatures (400-600C) on MD elements that are not glazed (i.e when elements are new or after a spall event). The MoO3 sublimes (solid to vapor – no liquid) as the elements are taken up in temperature above 1155C. The vaporous MoO3 deposits on the furnace insulation and on the Zirconia product in the furnace.A key to reducing the number of spalls in an MD element is to limit the growth of crystalline silica in the glaze.

There are two factors that promote the growth of crystalline silica:

1- using the elements at low temperatures (below 1600C element temperature) and
2- impurities either in the atmosphere or in the element itself

Many dental furnaces are run in the 1500ºC to 1600ºC temperature range that promotes crystal growth in the glaze layer.

It is impossible to eliminate spalling completely with our MolyD elements in a periodic furnace that operates at 1500-1600C.

 

[DCH]

If you want a durable and reliable sintering furnace that has MOSI2 elements and is made in the USA, try the HotSpot from Zircar Zirconia Inc.

http://dentallabnetwork.com/forums/f32/doutronpro-not-firing-properly-anyone-else-12988/ a recent post referencing that the Zircar Oven keeps on working

There are HotSpots with 7-8 years of service still running with original heating elements and original insulation. Priced less than all but the Chinese made furnaces

3M, Glidewell, CAP, Dale Dental, etc all use a Zircar sintering oven in their production or R&D labs