Getting to Know PADT: Support Cleaning Apparatus (SCA) Manufacturing and Support

This is the third installment in our review of all the different products and services PADT offers our customers. As we add more, they will be available here.  As always, if you have any questions don’t hesitate to reach out to info@padtinc.com or give us a call at 1-800-293-PADT.

PADT is in the business of helping people who make products.  So most people think of us as a provider of tools and services.  What they do not know is that PADT actually has a few of its own products.  The most successful of these is our line of Support Cleaning Apparatus systems, abbreviated as SCA.  These devices are used to remove soluble support material from parts 3D printed in Stratasys Fused Deposition Modeling Systems. They are robust machines manufactured and serviced by PADT, but sold through the Stratasys worldwide sales channel. As of July of 2017, over 10,800 units have been delivered to Stratasys.

Optimized Performance for Hands-Off Part Cleaning

The Stratasys 3D Printing systems that use Fused Deposition Modeling extrude plastic through a heated nozzle to build parts one layer at a time.  There are actually two nozzles. One puts down the building material and the other a support material that is dissolved in warm water that is slightly base.  The best way to remove that support material is to put it into a warm bath where the part is gently tumbled so that the water can works its way evenly into the part.  Stratasys tried several solutions for a companion washing system and eventually came to PADT and asked if we would try our hand at building a robust and efficient system.

The result was the SCA-1200.  Launched at the end of 2008 it met the design requirements for reliability, part cleaning time, and noise.  Over 7,000 of these systems were shipped and saw heavy usage. In fact, if you have a Stratasys FDM system there is a good chance you have an SCA-1200.  It contained a unique shower head design that was optimized with simulation, and a modular assembly that could be repaired easily in the field.

Based upon the success and lessons learned from the SCA-1200, we released the SCA-1200HT in 2014.  With the same basic form factor, this design replaced the off-the-shelf magnetically coupled pump with a simpler and more reliable custom design from PADT. The new unit also had a more pleasing visual design, several usability enhancements, and a greater temperature range. It has sold over 3,000 units and continues to be a popular system.  The latest release includes a no-temperature setting that allows it to be used to clean Stratasys Polyjet parts.

The success of both system lead to a request to look at building a larger machine that could clean more parts at one time as well as larger parts.  The SCA 3600 has three times the volume but shares many internal parts with the SCA-1200HT.  Both of the new systems are doing well in the field with even better reliability and faster part cleaning times. They are also simpler to debug and repair.

The SCA systems are sold as stand alone devices or are bundled with key Stratasys FDM machines.  You can learn more about them on our SCA page:  www.padtinc.com/sca or you can contact whoever you buy your Stratasys equipment from.

Here is a video for the SCA-1200HT that talks all about what it does:

Practicing what We Preach

One of the most rewarding aspects of designing and manufacturing the SCA family of products was that it forced us to practice what we preach. We talk to companies every day about using simulation, 3D Printing, design for manufacturing, proper product development processes, and many more things needed to get a product right.  With the SCA we were the customer. We had to Walk the Walk or stop talking the talk.

 

It has been a phenomenal experience that has made us even better at helping our customers produce their new products. We used CFD to optimize the gentle agitation design and shower head and worked closely with our vendors to minimize the cost of manufacturing.  The worst part was that when the schedule slipped, we couldn’t blame the customer (only slightly joking).  One of the best set of lessons came from doing the repair and refurbishment of systems that failed. Even though the failure rate was low, we learned a lot and were able to make improvements to future designs. Now when we sit across from a customer and talk about the design, test, and manufacture of their product, we can really say that we understand where they are coming from.

 

 

 

 

 

The Chemistry Behind Soluble Support Removal in Fused Deposition Modeling

fdm-support-chemestry-1In the Fused Deposition Modeling (FDM) process, support structures are needed for features with overhang incline angle less than 45-degree from horizontal. Stratasys developed a series of support materials for different model materials: SR-30TM for ABS, SR-100TM for polycarbonate and SR-110TM for nylon. Also, they developed the Waterworks Soluble Concentrate, P400-SC, to be used to dissolve these support materials. In this blog post, I develop a theory for the chemical reaction how P400-SC Waterworks dissolves SR-30TM, SR-100TM and SR-110TM support materials. As part of this, I explain how PADT’s Support Cleaning Apparatus (SCA) tank, with its heating and unique circulation and agitation capabilities that are important for the support dissolving process.

Materials Introduction

We begin by looking at the composition of the different materials involved in the table below.

stratasys-support-removal-chemestry-table-01Adapted from Stratasys.com

How P400-SC Works for Support Materials Removal

Polymer can swell and then dissolve into water as a consequence of abundant hydrophilic groups, like carboxyl group (-COOH), ether group (-O-), hydroxyl group (-OH) and so on in its molecular structure. Theoretically, SR-30TM and SR-100TM /SR-110TM Soluble Support Materials including a carboxyl group (-COOH) in their repeat unit are likely to be water soluble. However, they also have a hydrophobic ester group (-COO-) in their repeat unit, which counteracts the efficacy of the hydrophilic group on the long carbon chain. Thus, the key to making SR-30TM and SR-100TM /SR-110TM soluble, is to somehow get rid of the ester group.

A great example of supports on an FDM part. The part on the right has had the supports dissolved away
A great example of supports on an FDM part. The white material on the part to the left is the soluble support material. The part on the right has had the supports dissolved away

Hydrolysis of ester in pure water is a slow process even the system is heated. Both acid and alkaline conditions can catalyze and speed up the process. Under the acid condition, the hydrolysis is a reversible process until it reaches an equilibrium state, whereas alkaline conditions promote a thorough hydrolysis with a stirring and heating system.

P400-SC Waterworks contains sodium carbonate, sodium hydroxide, sodium lauryl sulfate and sodium metasilicate. The last two constituents, with 1-5 wt% respectively, are auxiliaries in the P400-SC Waterworks. The remaining two react with carboxylic acid and ester group per the following chemical reaction:

  1. R-COOH + NaOH =  R-COONa+ + H2O (neutralization reaction)
  2. 2 R-COOH + Na2CO3 =  2 R-COONa+ + H2O + CO2
  3. R1–COO-R2 + NaOH ≜ R1-COONa+ + R2OH (ester hydrolysis under alkaline condition)

where R is the remaining carbon chain apart from carboxyl group and R1, R2 represent the two-side segments of ester group. Ester hydrolysis is the main reaction we need, which ionizes the ester group and makes it water soluble with an increased polarity. These reactions would happen when SR-30TM or SR-100TM /SR-110TM supports are dropped into a tank with P400-SC Waterworks cleaning solution inside.

From the table above, we can see that ABS-M30TM and PC-10TM don’t have hydrophilic groups, which restrains their solubility into water. Nylon is semi-crystalline polymer and difficult to dissolve into water and most organic solvent, despite the presence of the hydrophilic group acylamino (-CONH-), which still results in a nice water-absorbing ability. All these model materials are common-use engineering plastic with nice chemical resistance (depending on their functional groups), they can be safe in the cleaning solution.

SCA1200HT-side1PADT’s Support Cleaning Apparatus (SCA)

The SCA tank offers an optimized environment with agitation and heating for the ester hydrolysis reaction. The tank has four preset temperature options (50 ℃, 60℃, 70℃, 85℃) for ABS-M30TM, PC-10TM, and FDMTM Nylon 12 model materials, due to their different thermal resistance. The innovative custom designed pump is key to cause the solution to effectively and efficiently dissolve and remove the support materials.

For more information on PADT’s entire line of SCA, please see http://www.supportremoval.com/

Press Release: Faster 3D Printing Support Removal of Wider Range of Materials with PADT’s New SCA-1200HT

IMG_7411We are very excited to announce that at the end of 2014 PADT shipped the first lot of our new Support Cleaning Apparatus, or SCA.  After almost 6 years of great service, the SCA1200-HT replaces the SCA-1200. The new system is a redesign based upon the 6,700 plus systems that PADT manufactured and supported around the world.  The biggest change to users is broader preset temperature range, allowing users to now remove support from their Nylon and Polycarbonate parts.  The motor and pump are a custom PADT design with better performance and durability. The control and ergonomic interface have also been modified for greater ease of use.

IMG_7507

If you are not familiar with PADT's SCAs and their use, they are accessories for the Stratasys line of Fused Deposition Modeling (FDM) additive manufacturing systems, commonly referred to as 3D Printers.  These systems extrude the build material and a water soluble support material that holds up any overhanging geometry.  The soluble material can be removed with gentle agitation in a slightly basic solution of warm water. We designed the SCA's as the easiest to use and fasted way to remove the support material.

Selling and supporting our own product has been a great experience for our team. Since the company was founded in 1994, we have been designing, simulating, and supporting our customer's products. With the SCA line we are able to practice what we preach on our own product. We have especially enjoyed supporting the products in Europe and Asia, allowing us to get to know the Stratasys Channel overseas as well as customers.

You can read more about the SCA-1200HT on our redesigned website: www.SupportRemoval.com. Here are a couple of videos that show how the system works and how to use it.  The official press release can be found here

 

You can also read the press release with more details below.  Contact your Stratasys supplier for more information.

IMG_7475

 

Press Release:

Faster 3D Printing Support Removal of

Wider Range of Materials  with PADT’s New SCA-1200HT

PADT ships a new generation of their popular Support Cleaning Apparatus product used to remove soluble supports from 3D Printed parts created using Stratasys Fused Deposition Modeling systems.  

 

Tempe, AZ – January 20, 2015 – Phoenix Analysis & Design Technologies, Inc. (PADT, Inc.), the Southwest’s largest provider of simulation, product development, and rapid prototyping services and products, is pleased to announce the release by Stratasys, Ltd. (SSYS) of the new SCA-1200HT support removal system. This new system is designed, manufactured, and supported by PADT and sold exclusively by Stratasys, Ltd for use with their Mojo, uPrint, Dimension, and Fortus Additive Manufacturing systems, also known as 3D Printers.   

The SCA-1200HT is an improved design based on the successful SCA-1200 that has been in use around the world since 2008. The new system features four preset temperature levels for use with a wider range of materials including polycarbonate and nylon. It also includes a proprietary custom pump with longer life, simpler repair and maintenance, and an overall lower operating noise level.  The controls, lid, and parts basket have been ergonomically redesigned while the internal systems have been simplified and made easier to replace by the user or local support provider.

Rey Chu, co-owner of PADT and the person behind the SCA line of products said “With over 6,700 of our previous systems in the field, we gathered a wealth of knowledge on performance and reliability. We used that knowledge to design a system that cleans parts faster, is easier to maintain, and gives a much better user experience.  The hands-off support removal provided by Stratasys’ Soluble Support Technology and PADT’s SCA is a huge advantage to people who use FDM technology for their 3D Printing.  With the SCA-1200HT that advantage just got larger.”

Once parts are printed, users simply remove them from their Stratasys system, place them in the SCA-1200HT, set a cleaning time and temperature, and then walk away.  The device gently agitates the 3D Printed parts in the heated cleaning solution, effortlessly dissolving away all of the support material.  This process is more efficient and friendly than other additive manufacturing systems using messy powders or support material that must be manually removed.

More information on the system as well as a video showing how the SCA-1200HT works is available at www.supportremoval.com.  Those interested in acquiring an SCA-1200HT should contact their local Stratasys reseller.

Phoenix Analysis and Design Technologies, Inc. (PADT) is an engineering service company that focuses on helping customers who develop physical products by providing Numerical Simulation, Product Development, and Rapid Prototyping products and services. PADT’s worldwide reputation for technical excellence and an experienced staff is based on its proven record of building long term win-win partnerships with vendors and customers. Since its establishment in 1994, companies have relied on PADT because “We Make Innovation Work.“  With over 75 employees, PADT services customers from its headquarters at the Arizona State University Research Park in Tempe, Arizona, its Littleton, Colorado office, Albuquerque, New Mexico office, and Murray, Utah office, as well as through staff members located around the country. More information on PADT can be found at www.PADTINC.com