Powder Printer Recipes

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Recipes for Powder Printers


Many of the following recipes come from the Open3d blog maintained by the Solheim Rapid Manufacturing Laboratory (located in the Mechanical Engineering Building at the University of Washington in Seattle. They have been experimenting with various formulations in their powder printers and have several that work and are much cheaper than commercial powders.


I have shamelessly stolen most of the text and pictures from that site. My intent is simply to provide all the recipes in a single document that can be downloaded and printed off for experimenters to keep handy. At the moment most of the recipes are from Open3d but I will add any that I find from other sources as time goes on to allow this document to have maximum usefulness.


Important Note - All of the measurements in these recipes are expressed by weight, not by volume.


Important Note – For those of you with commercially built powder printers. I believe that you may void the warranty on your printer if you use anything but the powders provided by your vendor. Read your warranty and be sure you know what you are up to.

Important Note - If you look at the formulas and their strategy, you will see that they put the adhesive in the powder and the “binder” is, in fact, just a solvent. While each new powder that is attempted in the lab goes through a set of tests for adhesive/binder compatibility, they have had great success with the sugar/malto-dextrin/wheat-dextrin combination. Also, they are VERY low cost -> Bonus! Malto-dextrin/wheat-dextrin really dissolve well and really like water (they are considered hygroscopic). Therefore be warned: the powder/binder combination produces parts which are water soluble. In fact, a very small amount of water will cause the part to melt!


Materials

Isopropyl alcohol
Available as Drugstore Brand 91% Isopropyl.
DO NOT SUBSTITUTE DENATURED ETHANOL as it contains various chemicals that end up plugging the print head
Maltodextrin
is a polysaccharide that is used as a food additive. It is produced from starch by partial hydrolysis and is usually found as a creamy-white hygroscopic powder. Maltodextrin is easily digestible, being absorbed as rapidly as glucose, and might be either moderately sweet or almost flavorless. It can be purchased in bulk at health food stores where it is sold as a supplement. If you can’t find Maltodextrin, then use Benefiber, which is a wheat dextrin.
Methyl cellulose
is actually only one of a huge family of materials called cellulose ethers, all of which are based on molecules made from chemically-altered cellulose. There are many different cellulose ethers available, with a dizzying array of molecular weights, solubilities and characteristics. One of our favorites is sodium carboxymethylcellulose, or sodium cmc – it has greater adhesive properties than methyl cellulose and is almost as stable.
Plaster of Paris
There are a fair number of different kinds of plaster of paris – common plaster of paris, #1 Pottery Plaster, Drystone Plaster, Duramold Plaster, GardenCast Plaster, Hydrocal Plaster, Ultracal Plaster, and various Dental Plasters. Each plaster has different properties and each requires experimentation.
Polyox™
is a group of water-soluble resins. They are white, free-flowing hydrophilic powders supplied in a wide variety of molecular weight grades, ranging from one hundred thousand to eight million. Polyox has a long history of successful applications in pharmaceutical products, in uses such as controlled release solid dose matrix systems, tablet binding, tablet coatings, transdermal drug delivery systems, and mucosal bioadhesives. PolyOx may serve as a cross-linking agent for SCMC and/or PVA.
PVA
is a really vast array of products and modifications of base product. Contact a technical rep for a vendor near you to discuss your application.
Urea Formaldehyde (UF) glue
is a urea formaldehyde resin or glue (also commonly called a urea glue or a UF). It is also called “plastic resin glue”. This product is sold as a water soluble wood glue.
Versa Cement
add definition


Wetting Agent Formulas

Sake Binder

M.A. Ganter, University of Washington, Seattle

Sake Rice Wine, unflavored, uncolored, 15%-20% alcohol.

Use directly from the bottle.

XB1 Experimental Binder

M.A. Ganter, University of Washington, Seattle

This is one of the working binders for the lab. It really is a solvent system. The real binder is in the powder and this liquid is just the solvent to activate the binder (the concept was partially developed by B. Utela).

105 Proof Vodka – 750 ml

Distilled Water — 1500 ml

Food Coloring — 60-120 ml (depending on color saturation)

They found that this binder seems to work with 400 class machines since it employs Cannon bubblejet technology. Bubblejet technology likes very low viscosity inks with low surface tension.

{This recipe has caused difficulties in the educational sector as administration may have issues with lab purchasing this type of liquid.}

DO NOT SUBSTITUTE DENATURED ETHANOL as it contains various chemicals that end up plugging the print head

XF1 Experimental Fluid

M.A. Ganter, University of Washington, Seattle Original Article

One of the new working binders for the lab. It really is a solvent system. The real binder is in the powder and this liquid is just the solvent to activate the binder (the concept was partially developed by B. Utela). It was developed to aid the educational users that have difficulty with the Vodka based binder.

Drugstore Brand 91% Isopropyl – 280 ml

Distilled Water — 920 ml

Food Coloring — 45 ml (depending on color saturation)

They found that this binder seemed to work with 400 class machines since it employs Cannon bubblejet technology. Bubblejet technology likes very low viscosity inks with low surface tension.

XS1 Possible 300 Class Binder

Posted by Threedeelabs in the DIY 3DP Group Original Article


Here are details of a new eXperimental Solution which seems to work for 300 class hardware (basically any of the HP head models).


Binder: Percentage (amount needed for 1 gallon)

Distilled Water: 93.45% volume (3537 ml)'
'
Surfynol 465: 0.5% volume (18.92 ml)'
'
Glycerol: 6% volume (227.12 ml)'
'
Potassium Sulfate: 0.2% weight (7.5 mg)'
'
Proxel GXL: 0.05% volume (1.89 ml)


From information obtained through patents, an HP10 or 11 cartridge needs:

Surface tension: 45 dynes/cm'
'
Viscosity: 1.35 cps


Z-Corp™ binder fluid

This information comes from the publicly available Material Safety Data Sheet for Z-Corp binder fluid which was posted on the RepRap forum by Gene Hacker. The full document can be located at: www.tech.plymouth.ac.uk . It is provided as-is and would require some experimentation to be usable but it appears to be mostly water and coloring.



Components

Approximate

% by weight


C.A.S. No. &

EINECS No.


UK/EU

Classification


1. Glycerol

1-10%

56-81-5

200-289-5


Irritant Xi

S 23 24/25


2. Preservative (Sorbic acid salt)

0-2%

Trade Secret

Irritant Xi

R 36/37/38, S 26,

S 36


3. Surfactant

<1%

Trade Secret

Irritant Xi

R 36, S 24, S 26


4. Pigment

<20%

Trade Secret

R 42/43


5. Water

85-95%

7732-18-5

NA



Powder Formulas

Porcelain Powder

M.A. Ganter, University of Washington, Seattle Original Article

It has weak damp strength, OK green strength, and behaves poorly in the kiln cycle.

SPS Swan White Porcelain – 1000 units

Powdered Sugar ———– 250 units

Maltodextrin ————- 250 units

They are looking at testing better porcelains.

File:Recipes for Powder Printers March 2011 html m7664acb4.jpg©M.A. Ganter

Clear glazed porcelain test piece.

RedArt Terra Cotta Slip V1

M.A. Ganter, University of Washington, Seattle Original Article

Terra Cotta slip powder was the second ceramic powder tested. It has OK damp strength, good green strength, and has interesting behavior in the kiln cycle.

SPS Redart Terracotta Slip – 1000 units

Powdered Sugar ———– 250 units

Maltodextrin ————- 250 units

We like the nature of Terra Cotta as it changes color and strength depending on how high you fire it.

File:Recipes for Powder Printers March 2011 html 47edf2b1.jpg©M.A.Ganter

Terra Cotta test firings. Notice that there is more shrinkage and the color gets darker as temperature goes up.

RedArt Terra Cotta Slip V2

From an article in Ceramics Monthly, 'The Printed Pot' by Mark Ganter, Duane Storti and Ben Utela, University of Washington, Department of Mechanical Engineering in Seattle, Washington.

Xtra-White, Redart TerraCotta or Stoneware Buff Slip . . . 62.50 % (1000 units)
Sugar (extra fine) . . . . . . . 31.25 % (500 units)
PVA (PolyVinyl Alcohol). . . .6.25 % (100 units)

3DP Glass Recipe V1

M.A. Ganter, University of Washington, Seattle Original Article

This is a workable glass powder that is very inexpensive and is environmentally friendly because it uses recycled glass. It was the first glass powder tested in the lab. It has weak damp strength, OK green strength, and OK behavior in the kiln cycle.

SPS Powdered Recycled Glass – 1000 units

Powdered Sugar ———– 250 units

Maltodextrin ————- 250 units

If you can’t find Maltodextrin, then use Benefiber (it is no longer maltodextrin but rather a wheat dextrin).

Use either binder. Let the part dry (in the bed) overnight and bake at 175 F for one hour. Then kiln fire to the desired crispyness.

File:Recipes for Powder Printers March 2011 html m3520b544.jpg©M.A.Ganter

3DP glass test bars

This glass works very well for the 3DP process. The only issue that I have with it is the resulting color. The strength is fine.


3DP Glass Recipe V2

M.A. Ganter, University of Washington, Seattle Original Article

An improved glass powder is composed of better quality glass (i.e. Spectrum Glass). This is the second major glass powder tested in the lab. It has ok damp strength, good green strength, and OK behavior in the kiln cycle.


Spectrum Powdered Glass – 1000 units
Powdered Sugar ———– 90-100 units
Maltodextrin ————- 90-100 units


The Spectrum Glass is available in cullet form (pieces of broken glass) which then must be crushed/powdered to better than 400 mesh. We had Olympic Color Rod perform this task.

Use either binder. You need to run as low of binder settings as you can for this glass recipe. Let the part dry (in the bed) overnight and bake at 175 F for one hour. Then kiln fire to the desired crispyness.

The resulting parts are opaque white.

File:Recipes for Powder Printers March 2011 html m555ea00d.jpg

©M.A.Ganter - Three white 3DP glass SW pots



Plaster Based Powder

M.A. Ganter, University of Washington, Seattle Original Article

This recipe has been in user for years. The recipe is rather complicated. It was developed over a period of two years. It has ok damp strength, good green strength, and is quite strong after baking in the convection oven. When finished, one might infiltrate with CA glue, or thin epoxy, or wax/parafin.

Plaster of Paris – 1000 units

4X Sugar (ultra-fine) – 500 units

Powdered Sugar – 500 units

Polyvinyl Alcohol (PVA/PVoH) – 100 units

Sodium CarboxyMethylCellulose (SCMC) – 100 units

Polyox – 50 units

Sugar-Sugar Powder

M.A. Ganter, University of Washington, Seattle Original Article

It seems that everyone wants to print in THE cheapest material possible. If this powder is not the cheapest, it is clearly in the running. They ran this powder for 6 solid months to support their educational activities.

White Satin Baker’s Special Sugar – 200 units

Powdered Sugar (10x or 12x) – 100 units

These sugar products are produced by The Amalgamated Sugar Co./Snake River Sugar Co. out of beet sugars. The White Satin is a tri-modal sugar with screenings in 50, 100, and 140 mesh. 10x or 12x powdered sugar always has some corn starch added to stop clumping. If you can get 12x, it is the better choice. All of these products are available in 50 lbs plastic bags. The cost of this mix is $0.15 – $0.30 per pound!

The nice thing about parts produced using this powder is that you can use them for investment casting/lost wax casting by infusing them with wax.

Helpful Tip: keep your machine clean using this mix as things could get sticky!

Variant: Sugar-Meringue Powder

  • Granulated sugar: 50 units
  • Wilton's Meringue Powder: 1 units
  • 10-X Powdered Sugar: 8 units

In this recipe, meringue powder (basically dehydrated egg whites) is used as the bonding agent for the sugar crystals.

Although this recipe works with granulated sugar, you can get better resolution with finer sugar grinds. With granulated sugar, a layer height of 0.3mm is recommended. Running the mix through a household food processor for 60 seconds gets a grain size that permits 0.2mm layer height.

Requires a 'in bed' curing time of approximately 8 hours.

Originally from EvilLabs ZCorp Z310+ Hacks

Plaster Powder V2

M.A. Ganter, University of Washington, Seattle Original Article

We’ve have been using this plaster based replacement powder over the last two years. The recipe is simpler and more available than our previous plaster recipe. It was developed over a period of about one year. It has ok damp strength, good green strength, and is quite strong after baking in the convection oven (with a temperature between warm and defrost). When finished, one might infiltrate with CA glue, or thin epoxy, or wax/paraffin.

DAP Plaster of Paris 1000 units

Powdered Sugar 250 units

Maltodextrin 250 units

If you can’t find Maltodextrin, then use Benefiber (it is no longer maltodextrin but rather a wheat dextrin). Also, you might try experimenting with replacing the sugar 1:1 with Polyvinyl Alcohol (PVA/PVoH). PVA is much more expensive than powdered sugar but there are some advantages.

PVA is a really vast array of products and modifications of base product. Contact a technical rep for a vendor near you to discuss your application.

There are a fair number of different kinds of plaster of paris – common plaster of paris, #1 Pottery Plaster, Drystone Plaster, Duramold Plaster, GardenCast Plaster, Hydrocal Plaster, Ultracal Plaster, and various Dental Plasters. Each plaster has different properties and each requires experimentation. We have been using DAP Plaster of Paris (especially because it is readily available for a reasonable cost).


Salt Powder

Mark Ganter, Adele Klee, Zack Chan


The salt was first ground in a coffee grinder and sifted through 60, 100 and 120 mesh screens. Once they got the salt to something that looked like white dust. They screened the batch through 150 mesh screen. The salt powder mix spread extremely well, and produced the best surface finish on the printing-bed surface that we have ever seen. Several adjustments to layer thickness and saturation settings, and amazing parts appeared. They used one of their existing binder solutions.

Finely Powdered Salt — 8 parts by weight

Maltodextrin — 1 part by weight


Bone Powder

M.A. Ganter, Juliana Meira do Valle, Michael Storey

University of Washington, Seattle Original Article


This formula was created by two of Mark Ganter’s students who wanted to be able to print bones for fictional animals.

Powdered Bone Meal 4-5 parts by weight.


UF plastic resin glue 1 part by weight.



File:Recipes for Powder Printers March 2011 html m2c360a58.jpg

2010 J. Meira Do Valle - Bones in Bone (photo Laura West @ 2010)

Z-Corp™ Powder

This information comes from the publicly available Material Safety Data Sheet for Z-Corp printing powder which was posted on the RepRap forum by Gene Hacker. The full document can be located at: www.tech.plymouth.ac.uk. It is provided as-is and would require experimentation with the mixture to be usable.


Component Classified As

Dangerous (CHIP3)

Approximate % by

weight

C.A.S. No. &

EINECS No.

UK/EU

Classification

1. Plaster which contains

Crystalline Silica1 at <1%

50-95%

Trade Secret

None


2. Vinyl Polymer

2-20%

Trade Secret

Irritant Xi

R 36/37/38

3. Sulfate Salt

0-5%

Trade Secret

S22

S24/25


Gene’s comment: “Sulfate salt is probably Calcium Sulfate. Vinyl polymer is probably polyvinyl alcohol or polyvinyl acetate, which are substances used in glues.”

Infiltrants


Cyano-acrylate Glues

M.A. Ganter, University of Washington, Seattle Original Article


CA or cyano-acrylate glues can be purchased in bulk. The resulting part is very strong and can be sanded and finished using any other common finish. Several big issues with CA are the smell (and chemical out-gassing), and the fact that it glues flesh to flesh very well. Therefore: Always use CA glues in properly ventilated areas and always wear gloves and eye protection.


Epoxies

M.A. Ganter, University of Washington, Seattle Original Article


Water-thin or penetrating epoxies are also a very good choice for high strength. Sometimes these epoxies are known as epoxy sealers. There are multiple vendors for this line of products. One web site had done testing and includes general recipes to make your own (a very Open idea which we like!). Note: there are chemical hazard issues with these products. Therefore: always use epoxies in properly ventilated areas and always wear gloves and eye protection.


Shellac

M.A. Ganter, University of Washington, Seattle Original Article


Shellacs are generally an organic resin dissolved in an alcohol solution. They are a very old wood finish. Please check out the Wikipedia listing for Shellac. We like this product because it is very thin and it contains the same solvents as our binders ->alcohols. A variety of colors and concentrations exist for Shellac (as well as additional colorants). We transferred shellac out of the can into a glue/squirt bottle and applied by the drizzle technique. We found that a thin first coat which may or may not be followed by a second coat. A low temperature bake is suggested (150F). Cool after baking. Sand and finish as desired.


Plastic Formulas

Powder Coat


Several people are looking at building powder printers that would use a laser to selectively sinter plastic powder to build objects and there has been a bit of discussion around what to use as a medium. One source suggested that the fine plastic powders used in powder coating metal parts might work. It is a very fine powder, comes in many colors and is heat cured. Note – I am aware of some people working on this but I don’t have any published information yet. I just wanted to get it documented as a place-saver so it wasn’t forgotten. Update – I have been informed sintering that this powder results in very brittle parts. Might need to add some other material to the mix in order to use it as described above.


Casting Formulas


Metal Casting Powder


M.A. Ganter and Laura West, University of Washington, Seattle Original Article

1000 parts Versa Cement
250 parts Maltodextrin
250 parts PVA powder

This formula also works well for sculptural forms and has the advantage of not needing any infiltration for strength.

These molds should be approached much like sand molds. They will have similar surfaces and strengths, you will also need to think of venting them in a similar way. For smaller molds, you should not let the thickness get less than 1/2″ and for larger molds you should increase it to 1″ or more. You will either need to build them as open face molds or as 2 part molds to get the powder out of the center. As time goes I will post more mold making tips on either on the open3dp blog or on rpsculpt . (this site is dedicated to the sculpture side of additive manufacturing as well as its use in metal casting, it is relatively new).

You will find that you need to print adjust your powder setting to be fairly wet, but not so wet that the part pulls away from its surroundings. The first few layers may tend to slide, so you should orient your part to account for that (put the bottom of your mold on the bottom of the build) and put it at least 1/4″ up into the build. Placing a few test bars below your build is also a good idea. Creating your patterns on a textured build plate also seems to help. You may find that you need to adjust the anisotropic scaling on x-plane in your print program, which is easy enough to do. Baking the mold on warm (do not go above 125 degrees F or the sugars will start melting) will help with de-powdering. If you spray your mold with a light misting of alcohol, the form will strengthen significantly. This will make the surface of the print hard enough to file your nails – seriously I have filed several broken nails in the lab with this material!

For a finer surface on your cast you may want to paint or spray a thin layer of mold wash on the surface. You can buy a commercially available recipe (Porter Warner) or you can create a mixture 50/50% zircon flour and graphite stirred into either alc0hol or naptha. Fused silica flour can also work as part of the recipe. A mold wash, depending on the pattern, can allow for a second pour if it is an open face mold. If you have a two part mold, you will need to join the two sides. Any 5 minute epoxy will work for small molds. For larger molds you should use a professional grade core paste and/or mold weights/metal clamps to hold the mold together.


Investment formula 2


NOTE – this is not really a formula yet. This is an article that contains enough information that someone should be able to create a formula from it. Hopefully, after some experimentation this can become the first free investment casting formula for DIY powder printers. The original article is by Richard Beckman at the Chicago Artists Resource.


When casting bronze using the lost-wax process, the hazards of silicosis can greatly be reduced by using a standard investment recipe of plaster and 30 mesh sand. Commercial investments use a mixture of plaster and cristobalite, which is even more toxic than normal quartz silica. The particles in the 30 mesh sand used in the following recipe are too large to be airborne, and thus have a much lower chance of being inhaled.


Though there are many variations of the ratio between the sand and the plaster, the formula that I have successfully used combines one part plaster with one part sand by weight. Since plaster and sand are commonly packaged in 100 pound bags, it is easiest to premix one bag of each in a large tin washtub and then add this mixture to your water.


To arrive roughly at a 5-gallon bucket of investment, fill the bucket with 1.5 to 2 gallons of water, and add the premixed investment until an island forms whose surface area is two-thirds the diameter of the bucket. Let this slake for a few minutes, and then mix by hand from the bottom of the bucket, carefully avoiding stirring air into the mix. Work out all the lumps with your fingers and then pour the investment into your flask. The investment consistency should be creamy and thick enough to coat your skin when you pull your hands out of the bucket of mixed investment, but not allow your flesh tone to show through. It should be thin enough that, when pouring the investment, it easily flows into all the crevices of your wax.


The use of 30 mesh sand will in no way bring down the quality of surface reproduction as the plaster will flow around the grain size and give you the exact detail that was in your original wax. As with all investments, whether commercial or described here, some extra precautions should be taken to assure that no air bubbles are trapped against the surface of the wax, which will translate into surface imperfections once cast in bronze.


To begin, you should spray a debubbler, such as alcohol, on the surface of your wax to relieve surface tension. If your wax was pulled from a rubber mold and you used a silicone release agent, be sure to wash the wax with liquid soap and water to assure that the silicone does not resist your debubbling agent.


Next, you should mix a small batch of investment and brush it on the wax. Using a brush assures that you can force it into all of the details of your wax and therefore avoid any air bubbles. If you have super fine detail, you might consider using 80 or 100 mesh sand for this first coat. In my experience, however, the 30 mesh sand is sufficient to reproduce fingerprints, so I see no need to risk breathing the finer sand particles. Build this brushed coat 1/2" inch thick and leave it rough so that the poured investment will grab onto it. Mix your investment and float your brushed wax piece in your flask. Pour your investment around it, bringing it level to the pouring cup.


A few final notes are worth mentioning to assure your casting will come out with minimal or no flashing. Use chicken wire to line the inside of your flask to keep your mold from radically shifting if cracks do develop. I use sheet tin for making my flasks since it is both strong and reusable, naturally assumes a round or oval shape, and thus has no sharp edges or lap marks, which are natural places for cracks to occur. During the burn-out, bring the temperature up 50-75 degrees an hour to 1100°F, and hold for 24-36 hours. It is critical that this process is slow to avoid shocking the molds. Finally, when taking the molds out of the kiln, open the doors slowly over an extended period of time so there is no thermal shock.


Using this standard investment recipe and the other steps I have noted will greatly reduce your risk of silicosis and will result in excellent surface reproduction in the casting. Though I have never cast jewelry, the process is essentially the same and I imagine this investment recipe would be more than adequate.