Does DME offer Vortex products in larger inserts as a special?
Yes. As a special item, DME can quote your requirement for Vortex cavity inserts. Contact DME at 1-800-626-6653.
How long does it take to clean Porcerax II?
It depends on what you are trying to clean out of the Porcerax II. For EDM oil or water, you can put the Porcerax II in an oven at least 250 degrees F and that will evaporate the water and make the oil more viscous. This will eventually cause the oil to leak out of the material.
For resins, it depends on type of resin and how contaminated the pores are. I advise you check with your resin supplier for the recommendation on the best solvent to use to break down the resin.
How often should I clean the Vortex Core Pins or Plugs?
As an approximate guideline, for Engineering resins you should clean the Porcerax II® every 15k-20k shots. For Commodity resins you should clean the Porcerax II® every 25k-30k shots.
Additionally, it is a good idea to view the surface pores under a digital microscope over the life of the Porcerax II® insert. Follow the cleaning instructions in the Application Guide for Vortex Core Pins & Plugs found on the DME website under Resources/Application Guides.
How thick should I go when designing my Porcerax II insert application?
Thickness of the Porcerax II insert is very important for a couple of reasons. First, you want a thick enough part that will withstand injection pressure. If you go too thin you run the risk of cracking the material. The material has a base hardness of 30‐40 HRC and can withstand most of the variables regarding injection molding. Second, by using a piece of Porcerax II that is large enough to put in a drilled and tapped hole for an NPT fitting, you allow the Porcerax II material to be cleaned much easier. After the solvent has cleaned most of the trapped materials in the pores, place your NPT fitting in the Porcerax II material, plug it into your shop air, and let it blow through the Porcerax II material.
Should I keep spare Porcerax II products on hand?
It is advisable to have spare sets of the Vortex Core Pins or Plugs so you can install them while you have your previous products cleaned.
What about materials with flame retardants like ABS?
Due to the fact flame retardants emit more gas than regular polymers, they require more frequent cleanings. A good way to provide for cleaning Porcerax II® is to have a blow back system in place in the mold, so that as the mold opens to eject the part, reverse the air flow and have a blast of air go through the Porcerax II® into the cavity. This accomplishes two things: First, it will help aid with the ejection of the part, and second, it will help purge any film that might build up on the Porcerax II® from the flame retardants.
What is the maximum temperature of Porcerax II? What is the recommended way to re‐open the pores of Vortex pins & plugs after machining?
Do not take Porcerax II over 800 Degree F.
What size pore should I use for my resin?
Depending on the emissions or gas residue given off during molding, the molder may have to evaluate whether to use a 7 or 20 micron pore size. Resins such as ABS, polypropylene, soft PVC, polyethylene, acrylic, polyurethane, and polystyrene work very well with a 7 micron (.0003") pore size. For low viscosity or talc filled resins, it may be necessary to have an automated system reverse the airflow after each shot to purge the impurities from the pores. NOTE: Rigid PVC resins will work with limited success until the corrosive gases close the pores. This can still be a feasible method if disposable Porcerax II® inserts are used. Please note the 20 micron pore size (.0008") will vent about 25% more gas than the 7 micron pore size.
Your literature states that polishing to an 800‐1000 grit finish opens the pores for a 7 micron insert. What can we do to achieve the airflow we require?
You can polish Porcerax II to an 800‐1000 grit finish for the 7 micron and 400‐600 grit finish for the 20 micron.
However, you need to blow air, 40 to 60 psi, back through the Porcerax II along with wearing a mask and eye protection, while you are polishing the Porcerax II to push out the grit and compound that is being forced down into the pores during polishing. You then need to clean the Porcerax II several times, using Acetone in an ultrasonic cleaner and blow Acetone back through the Porcerax II in the opposite direction of the venting air flow several times at 80 to 100 psi. (NOTE: It is important the Porcerax II be cooled to room temperature before ultrasonic cleaning.)
Use proper safety guidelines when doing this. Acetone only breaks down the lubricants that were used. Acetone will not affect the grit and compound. Using the blow back air during polishing will push the grit and compound out during the polishing. To try and open your pores you can try and do the cleaning of the Porcerax II as mentioned above. If this does not work, you will need to EDM the surface down to get below the clogged pores and then polish as discussed above. After polishing, clean again. If your location is not permitted to use Acetone, then find a solvent that will breakdown the lubricants that were used during machining.