Tag: mold release

EXAIR Atomizing Spray Nozzles For Food Tray Mold Release Agent

Published on by Russ BowmanLeave a comment

PET (polyethylene terephthalate) is one of the most common plastics that we see on a day-to-day basis. It’s what they make water and soda (or ‘soft drink’ or ‘pop’, depending on where you live) bottles out of, along with a lot of other products you find on the shelves and in the refrigerated cases of your local grocery store. A couple of times a week, we cook up a nice piece of fish from the seafood counter at our corner grocery: salmon if my wife stops in; whatever white fish is on sale if I do. Whichever becomes that night’s dinner, in any case, is packaged in a PET tray and sealed with plastic film.

I recently had the pleasure of talking with a caller whose company makes those trays. Turns out, they begin life as great big sheets, before they’re cut into smaller rectangles and formed in a mold press. Most anything that’s formed into a shape like that, with force and heat, needs to have some sort of lubricant – called a release agent – applied to the surface to make sure it exits the mold quickly and easily. In ANY molded product application, it’s advantageous to use as little as possible, for two reasons: specialty chemicals like these release agents can get expensive – especially the ones for food, beverage, or pharmaceutical use – and also because any remaining agent will get sealed up with whatever’s getting packaged.

Anyway, my caller’s molding machine came with spray nozzles that, no matter how low the flow was regulated, still sprayed too much. That meant the trays had no problem at all with falling right out of the mold, but the excess release agent was oftentimes causing HIS customer’s plastic film to not seal properly onto the finished food product, and he’d recently gotten an earful about it. He wished there was something he could use that didn’t spray much more than a light fog, because his supplier for the premium food grade release agent he used was always bragging that a light fog was all that was needed. In fact, the supplier actually recommended an EXAIR Model AF2010SS No-Drip Internal Mix, Flat Fan Atomizing Spray Nozzle.

With a flow rate as low as 1.2 gallons per hour, a one-second ‘spritz’ means 0.04 fluid ounces (that’s about a quarter of a teaspoon) gets spread out over the 16″ width of the mold. Which is just enough to let the freshly molded tray fall right out, with almost no residue left over.

When not-much-more-than-a-light-fog is called for, look no further than EXAIR Air Atomizing Spray Nozzles!

Whether your liquid spraying application involves pricey fluids that you don’t want to waste, or if you just don’t want to have to deal with the mess of over spraying, EXAIR has a wide selection of Air Atomizing Spray Nozzles to choose from. If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
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EXAIR Atomizing Nozzles in a Forging Plant

Published on by John BallLeave a comment

A steel forging plant was using a releasing agent in their process. This particular operation was to make a blank gear.  It started with a heated ingot that was placed in a two-part dual stamp die.  The front section of the die creates the hub of the gear, and the back section would finish the outer diameter of the gear.  The operator would use tongs to grab the hot part and place it in the front and back portion of the die.  Each time the press would cycle, a release agent would be sprayed onto the die so that the parts would not stick.  As you can see in the picture below, they had six liquid spray nozzles modified to spray the entire surface.  Two of the spray nozzles were blowing the release agent to the top portion of the die, and four spray nozzles would spray the entire bottom portion of the die.  Every time the press would cycle, the release agent would be sprayed.

Forging press with liquid spraying nozzles
Forging press with liquid spraying nozzles

At a rate of making a part every six seconds, much release agent was being sprayed. This lubrication for forging was not inexpensive, and it was adding cost to their operation.  They called EXAIR to see if we could help in this matter.

 

The EXAIR Atomizing Nozzles use compressed air to help “shear” the liquid into a very fine mist. The smaller the liquid particle size, the more surface area is created.  This is very beneficial in saving liquid material without reducing the required performance.  This customer purchased two Internal Mix Narrow Angle Round Pattern Atomizing Nozzles, model AN1040SS to replace the six liquid nozzles that he was using.  With a stainless steel construction as standard, it makes the Atomizing Nozzle very corrosion resistant and able to handle 400 deg. F (204 deg. C) temperatures.  With the narrow angle round spray pattern, they could position the Atomizing Nozzles to cover the entire top and bottom of the die (reference the photo below).  With the liquid adjustment valve, they could dial in just the right amount of release agent to keep the process running smoothly.  After the first week in modifying their operation with EXAIR Atomizing Nozzles, they noticed that they were using only half the amount of releasing agent.  This helped to cut cost in their operation, increasing their profit margin.

Forging press with EXAIR Atomizing Nozzles
Forging press with EXAIR Atomizing Nozzles

We can spray liquids very economically and efficiently. We have different types of spray patterns for three different styles.  We have the Internal Mix style for low viscosity fluids as purchased by the above customer; the External Mix for high viscosity fluids, and the Siphon Fed for unpressurized liquid systems requiring gravity or siphoning.  We can atomize liquids up to a rate of 5 gallons per minute (19 liters per minute).  If you believe that you are going through too much liquid in your process, you can contact an Application Engineer to see if we have the correct Atomizing Nozzle for you.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Super Ion Air Knife Improve Cycle Rates in an Injection Molding Process

Published on by John BallLeave a comment

A die manufacturer created a 12” wide by 24” long (30.5cm X 61 cm) tool for an injection molding machine that contained 80 cavities for an automotive supplier. As contracted with their customer, the goal was to have 30 injection per minute to create 2400 parts every minute.  The tool was designed with 2 chambers, each containing 40 cavities to control production rates.  Also as part of the contract, the automotive supplier required a pre-production approval before signing off on the purchase order.  As they attached the tool to the injection molding machine for a trial run, they began to notice that some of the parts were sticking to the cavities.  In the first 30 minutes, they stopped the machine as they only averaged 16 injections per minute with only 50% of the parts falling out of the tool.  They did notice that they could feel the static electricity on their arms when they reached into the tool to remove the parts.  To try and improve the cycle rate, they attempted to mount a 12” (30.5 cm) pipe with drill holes above the tool. Many manufacturers attempt this because it is simple and easy to do; but, this style of blow-off is very inefficient and not very effective.  As they began the next trial, they did see a slight improvement.  It increased the cycle rate to 19 injection per minute and it was removing 75% of the parts.  It still was not good enough for the automotive supplier.

Super Ion Air Knife Kit includes Super Ion Air Knife, Power Supply, filter, regulator and shim set.
Super Ion Air Knife Kit includes Super Ion Air Knife, Power Supply, filter, regulator and shim set.

The die manufacturer was under pressure to find a solution as he did not want to redesign or rebuild the tool. He noticed that EXAIR was a leader in Static Eliminators and Blow-off equipment, so he contacted us.  In our discussion, he explained how he needed to remove the static and remove the parts quickly out of the tool.  I suggested our model 111212 Super Ion Air Knife Kit.  It is 12” (30.5 cm) long, and it can be mounted easily across the width of the tool.  With a 40:1 amplification ratio and both positive and negative ion streams, it can remove the static and push the parts very effectively.  Once they installed the Super Ion Air Knife, they began the operation once again.  They initially noticed that all the parts were being ejected from the tool.  When they measured the cycle rate, it was running at 33 injection per minute (exceeding the requirement).  The tool was approved and the die manufacture was very pleased.

When it comes to removing static and blowing parts, EXAIR has a great range of products. We can do it very efficiently, quietly, and effectively.  If you have any issues with injection molding, EXAIR may have the product to help you.  You can discuss your applications further by contacting one of our Application Engineers.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb