Product usage

I want to use a reticulated ceramic foam filter when pouring my metal, but I am casting thin-wall parts and need to get the metal in the mold as fast as possible. What can I do to maximize flow rate through the filter?

Our US experts recommend:

There are several parameters of both the metal and the filter that control and effect flow rate of molten metal through a ceramic filter. First, concerning the specific metal alloy, the metal’s fluidity, cleanliness, temperature, and metal head height over the filter, all play a role in the flow rate. 
Regarding the filter, the manufacturer has the ability to adjust parameters when sizing the filter for your application. Metal flow rate through the filter is a function of the filter diameter 
(round) or length and width (rectangular), filter thickness, as well as filter pore size. 
To maximize flow rate, you would want to use the largest di-ameter, most open pore size, and thinnest filter that the manu-facturer recommends and that would physically fit into your mold space or pouring cup.  These same parameters also affect filtration efficiency and must be balanced with what you are trying to achieve. 
ASK Chemicals has been manufacturing reticulated ceramic foam filters for over 30 years and offers the technical support to recommend the best filter choice for the specific applica-tion, along with the manufacturing expertise to provide a consistent product with every order.

So, consult with your ASK Chemicals contact for the best overall recommendation.

Q:Is it possible to use the high-efficiency riser systems commonly used with iron castings instead for steel castings?

A: Yes, high-efficiency riser systems commonly used for iron can be employed with steel castings, creating many advantages for the operator and the foundry. However, there are a few important details to bear in mind about this application. First, to review the relevant details of the application, recall that a riser (sometimes referred to as a feeder) is a reservoir built into a metalcasting mold to prevent cavities from forming during solidification as a result of shrinkage. Most metals are less dense in liquid form than solid, so a casting may shrink as the metal cools, which may result in a void at the final point of solidification. The optimal riser system depends on the current molding system in use by the foundry. If the foundry employs a high-pressure, horizontally parted green sand system, ASK Chemicals’ EXACTCAST OPTIMA riser would provide the best solution. If the foundry employs a no-bake molding system, ASK Chemical’s EXACTCAST KMV riser would provide the best solution. With these solutions in place, the operators would recognize the following improvements over traditional fiber riser systems: 1) Improved yield due to mini-riser feeding efficiency; 2) Reduced riser contact areas, reducing finishing and grinding costs; and, 3) No fiber material contamination in the molding system. Additionally, ASK Chemicals’ OPTIMA riser creates a perfect residue-free molding with improved compaction and a clean, clearly defined breaker edge directly on the casting. Steel casting temperatures can be significantly higher when compared to iron castings. This higher temperature profile demands higher refractoriness from the exothermic feed mixture. ASK Chemical’s EXACTCAST product line has developed special, high refractory formulations to meet these requirements. Another factor to be recognized is that steel castings typically have significant volume requirements. ASK’s KMV and OPTIMA risers are effective in addressing this need. These products reduce riser volumes by 50% or more, allowing current melt production to be used in other casting applications. An important criterion in the foundry’s selection of a riser are the process costs associated with removing risers from the cooled casting. A traditional riser system requires lancing or cutting tools. The KMV risers’ reduced contact areas and Optima’s cleanly defined breaker edges allow risers on steel castings to be knocked off easily with a hammer. This adds value to the casting while reducing metal loss with foundry operations. Additionally, due to the solidification morphology of steel alloys, riser necks may require larger contact areas. ASK Chemical’s KMV and Optima risers can be used with full contacts or varying breaker strategies where larger contacts become necessary. At ASK Chemicals we aim to provide solutions to assist our customers to achieve greater profitability. Let’s pour more castings and less risers!


A: Currently there are three chemistries used for 3D printing of sand: furan resin, cold hardening phenolic (CHP) resin, and inorganic resins based on silicates. There are differences in the ways that each chemistry is used.

How are they different?

All three technologies use a co-reactant, catalyst, or activator package that is mixed onto the sand prior to the sand being layered in the print bed. The binder systems differ in the resins that they produce and the casting properties that result.

Inorganic resins offer good casting quality and have the benefit of low emissions during printing and casting – because they are inorganic. These resins require a microwaving or baking step to facilitate curing after the build box exits the print area. 

Furan resins are known for resistance to veining and excellent shakeout result. These systems are typically air cured.

Cold-hardening phenolic resins give excellent casting surface finish but can be problematic in the shakeout sequence, due to a secondary curing at metalcasting temperatures. These resins have excellent print dimensional accuracy. CHP printed sands typically are exposed to IR heat or an oven to drive the initial cure.

CHP resins also have different storage requirements to ensure maximum shelf-life. 

Binder technology


Casting material

INOTEC 3D High-volume founders, Prototype founders Aluminum
ASKURAN 3D High-volume, low-volume, prototype founders all types of casting
Novaset 3D high-volume, low-volume, prototype founders all types of casting, esp. steel and ductile cast iron

Are there issues with print-head compatibility and maintenance down time ?

The physical and chemical parameters of each of three resin types are adapted to the needs of the print head, to ensure reliable binder jetting and maximum open-nozzle time. More open-nozzle time means less down time for your 3D printer, to help your foundry recoup its investment and maintain productivity.

A matching cleaner chemistry is typically applied to avoid print-head damage.

Will we need a coating for 3D-printed sands?

Depending upon the chosen chemistry and desired casting properties, yes … a coating might be necessary. Your ASK Chemicals representative can assist with the choice of an appropriate coating.

These resins sound like the no-bake resins we are familiar with… Can we use standard no-bake resins in a 3D printer?

No. To ensure the best-possible print resolution, these resins are specially formulated and filtered to be effective with 3D printers. 3D printers are less tolerant of higher viscosities and small particulate matter than common foundry continuous or batch mixers.

Does ASK Chemicals offer these binder formulations?

ASK Chemicals offers resins for all three chemistries:

  • INOTEC 3D – Inorganic binder system consisting of the liquid INOTEC 3D printing fluid , the INOTEC PROMOTOR and a INOTEC additive; a three part system
  • NOVASET 3D – Cold hardening phenolic resin; a two part system
  • CHEM-REZ JET SET 3D – Acid cured furan resin; a two part system

Which system should I choose?

Based on your application and cast metal requirements, our 3D binder portfolio for binder jetting offers the flexibility of choice prior to the purchase of your machine.  A joint consultation with your ASK Chemicals representative and the 3D printer manufacturer may be necessary.