EXAIR commonly works with plastic injection molding companies. They produce top quality plastic parts from both commodity and engineering-grade resins for many diverse industries. The customer reached out to us with a problem. A mold that they were running was having some issues. The parts were not releasing and ejecting properly, causing the need to use a mold release, which was slowing down the process by a manual operation to the process. Also, the parts were seeing push pin marks, causing cosmetic issues with the parts. The customer wanted to explore using compressed air to blow the parts free.
Based on the mold size and layout, a pair of 12″ Super Air Knives was installed. The knives are oriented to blow straight down along the face of the mold, one knife per part tree. The strong laminar flow of air hits the parts causing them to release and drop without the use of release agents. Also, the push pin marks are within normal standards, eliminating the the cosmetic concerns.
This is just one example of how intelligently using compressed air can help improve a process. By using air knives for wide areas or using a 1″ Flat Super Air Nozzle for very small parts, or anywhere in between, we can help to solve your part ejection issues and make your process run better, faster, and with higher quality.
If you would like to talk about Super Air Knives, Flat Nozzles or any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.
A manufacturer of forged, steel parts contacted EXAIR today and spoke to me about an application that was really giving them some trouble.
The application involved placing a molten piece of steel into a die. The press would come down and mold the piece into a ring shape. As it opened, a solenoid valve connected to a compressed air supply was actuated to push the falling part with the compressed air to a bin behind the press. The manufacturer made a home-made nozzle by flattening a piece of ¾” pipe and directing it at the part. (Reference picture below). The operator had a cycle time of roughly 8 seconds. During that time, the compressed air was actuated for 1 second to push the part away from the die. An issue occurred if the part rotated 90 degrees as the die opened, and the compressed air would shoot through the open center of the part without pushing it into the bin. The part would rest on the bottom die, causing a slowdown in production because the part had to be removed manually.
The part weighed 2.2 lbs. (1 Kg) and had an outer diameter of 3.5” (89mm). The customer was operating the ¾” pipe “nozzle” at 90 psig (6.2 bar), and it was located 12” (305mm) away from the die. This gave me some good information to find an appropriate nozzle. While reviewing the force and air pattern needed, model 1112SS (3/4 NPT Stainless Super Air Nozzle) would be the best product. This Super Air Nozzle would be able to withstand the radiant heat within the application and can produce a force of 4.5 lbs. (2 Kg) at 80 psig (5.5 bar). At 12” (305mm), it produced an airflow diameter of 7.5” (191mm). Even if the part rotated, the air pattern and force was large enough to push the part from the die even if it rotated, eliminating the need for manual intervention.
Not only did the production rate get back on target, but as an added bonus, Model 1112SS was able to save the customer compressed air. The advantage of using the Super Air Nozzles, is that they entrain ambient air to work with the compressed air, increasing the overall mass flow toward the target, making it much more efficient than a flattened pipe. Even with the compressed air being turned on for 1 second during the 8 second cycle time, the Super Air Nozzle is projected to save the customer over $1,500.00/year when comparing its air consumption to that of an open 3/4″ pipe.
Whenever you have an urge to flatten an end of a pipe to create a home-made nozzle, you should contact an Application Engineer at EXAIR to see if we can help. Like the customer above, we were able to solve their production problem, and able to save them money.