Compressed Air Knives Perform Better than Blower Air Knives for this Bottle Drying Application

Sometimes you need more power.  I spoke with a customer from a beer bottling facility that was using blower operated air knives, not compressed air air knives.  They were needing to increase the amount of force to dry the bottles.  Their production rate was 580 bottles/min, and they were seeing issues in the labeling process due to residual moisture being left on the bottles.  Their operation consisted of a wash cycle, rinse cycle, drying cycle, then labeling.  They determined that the bottles were not getting dry enough before the labels were applied.  They used a blower system, and they were having difficulty when they reached the maximum bottle rate.  This meant that they would have to increase the size of their blower system; and, with the capital cost of blower systems, they decided to call EXAIR to see if we could help them with their drying application at a lower purchase price.  

Compressed air is the best way for establishing a strong blowing force.  Instead of air pressures in the range of inches of water, the compressed air system can generate over 40 times the amount of force than a typical blower system.  EXAIR products use the power of the compressed air system to give a wide range of blowing forces for drying, cooling, or moving products.  With our Super Air Knives, we have a 40:1 amplification ratio which means for every 1 part of compressed air, we bring in 40 parts of ambient air.  This adds mass to the airstream to make our Super Air Knives very efficient and effective. 

For the customer above, their system filled two different sizes of beer bottles.  The first bottle had a capacity of 16.9oz (500ml) with a height of 10 ½” (267mm); and the second bottle had a capacity of 28.7oz. (850ml) with a height of 12” (305mm).  For optimum blowing, we wanted to set the air knife at an angle to force the water to the bottom of the bottle.  We also want to have good contact time and blow in a counter-flow direction.  This will keep the bottles that have been dried, dry.  For Food and Beverage applications, EXAIR offers two types of stainless steel, 303SS and 316SS.  Since this was a non-contact drying application, 303SS was appropriate.  So, I recommended two units of a model 110218SS Super Air Knife kit to place one knife on each side of the bottles.  This would cover the entire bottle height with an appropriate blowing angle. 

110218SS Super Air Knife Kit

The kit includes the Super Air Knife, a filter, a regulator, and a shim set.  They mounted one knife on each side of the bottles to blow off and remove the liquid after the rinse cycle.  Even at the increased bottle speeds, the EXAIR Super Air Knives had no issues in keeping the bottles dry.  With the regulator and shim set, it was easy for them to dial in the correct amount of force without using too much compressed air.  The labels remained glued and the bottling process ran smoothly.  Because this company was impressed by the Super Air Knives, they wanted to comment on the comparisons between the blower knife and the Super Air Knife.

Comparison EXAIR Super Air Knife vs Blower type
  1. Cost:
    1. Blower System – The reason for contacting EXAIR.  Blower-type air knives are an expensive system.  They need a blower, ducting, and knives.  To have any variability in force, a control panel with a VFD will be needed.
    1. Super Air Knife – It is a fraction of the cost.  With their system, we were roughly 1/10 the cost; even with the kit.  No capital expense report would be needed for the two air knives.    
  2. Installation:
    1. Blower System – They stated that it took them a week to install the entire system before they were able to use.  They had to run electrical wires, controls, ducting, and they even had to change the conveying system slightly to accommodate the blower size. 
    1. Super Air Knife – They mounted the filter and the regulator on the conveyor, and ran compressed air line to the Super Air Knives.  Even with a fabricator to make a bracket for the Super Air Knife, they had the system up and running is less than two hours.    
  3. Size:
    1. Blower System – The foot print of the blower is large and it takes up floor space.  The 3” (76mm) ducting had to be ran to oversized air knives.  With the congestion of the bottle system, it made it difficult to optimize the position and the blowing angle to adequately dry the bottles.      
    1. Super Air Knife – With the compact design, the Super Air Knife packs a large force in a small package.  It has a footprint of 1 ¾” (44mm) X 1 ½” (38mm) X 18” (457mm) long.  The air knife only required a ¾” compressed air line to supply the compressed air.  It opened up the floor space as well as the bottling area. 
  4. Maintenance:
    1. Blower System – The blower filter had to be changed regularly, and the system had to be checked periodically.  Being that the blower motor is a mechanical device, the bearings will wear and the motor will fail over time.  These items should be checked quarterly as a PM which increases the cost to run the system.    
    1. Super Air Knife – No moving parts to wear out.  The only maintenance would be to change the filter within the Filter Separator once a year. 
  5. Quiet:
    1. Blower System – With the blower and turbulent air flow, the units are very loud.  It had a sound level near 93 dBA, and with the operators working around the system, they needed PPE for hearing. 
    1. Super Air Knife – These units are very quiet.  At 80 PSIG, the sound level is only at 71 dBA for the Super Air Knife.  This was very nice for the operators to work around as it wasn’t a constant noise nuisance. 

In using compressed air, the EXAIR Super Air Knives are engineered to be very efficient and effective.  But, even with the use of compressed air, the customer still wanted to share the ease of installation, the effectiveness of blowing, and the improvements to their process.  With the five points noted above, the customer wished that they would have contacted EXAIR at the beginning.  Now, they were able to dry the bottles to allow for a strong adhesion of the labels.  If you wish to speak to an Application Engineer about your cleaning, drying, blowing or cooling applications, we will be happy to hear from you. 

John Ball
Application Engineer
Twitter: @EXAIR_jb

Solving a Static Electricity Problem when Applying Labels

Gen4 Static Eliminators

A company was applying labels to their plastic containers.  The labels were 4” (10cm) wide by 9” (23cm) long in size with a protective backing.  The backing material had to be removed prior to applying the label to a 9” (23cm) tall container.  With their label applicator, the label would wrap around the container.  They started to see misalignment and wrinkles in the labels when they were applied.  For the nonconforming parts, they had to remove the label and clean the surface to reapply another label.  This was time-consuming and a pain in the neck.  Since winter is here in the Northern Hemisphere, the drier air makes static very easy to create and will cause issues.  They contacted EXAIR to ask about our Gen4 Static Eliminators.

 With non-conductive materials like plastic and paper, static is easily generated; especially during cooler weather.  Static can be in a negative state or a positive state depending on the type of material.  With opposite charges, things are attracted to each other and will “stick” like magnets.  For similar charges, they will repel each other.  The higher the static charge, the stronger the force.  Static is generated from rubbing, hitting, and peeling which can cause electrons to be stripped from a surface.  For the customer above, the peeling away of the backing from the label caused the negative electrons to build on one surface.  And with the containers shifting, bumping and moving along the conveyor; static was also being generated.  Since like charges repel each other, the labels were not able to stay aligned and were creating bubbles on the surface.

When it comes to removing static, EXAIR is a leader in this market.  We have a large product line of different types of Static Eliminators.  Our design generates both positive and negative ions to remove any type of static charge up to 20 feet (6m) away.  In this application, I wanted to target two areas where static is present; the labels and the containers.  Since we could get close proximity to the label and the containers, I recommended using the Gen4 Ionizing Bars.  With a quick static decay rate, we can remove the static right before applying the label.  For this application, I recommended the model 8006 6” Gen4 Ionizing Bar and two model 8009 9” Gen4 Ionizing Bars.

EXAIR’s power supplies are what gives the Gen4 Ionizing Bars energy to create ions.  EXAIR offers two models of Gen4 Power Supplies; model 7960 which can power up to two Static Eliminator products and model 7961,  which can power up to four Static Eliminator products.  Since the Gen4 Ionizing Bars were mounted in the same area, the model 7961 Gen4 Power Supply was used to run three Ion Bars at once.  This helps to save money as they did not need to buy multiple power supplies.

Together, it was very easy to mount and start using.  The model 8006 was mounted right after the backing was removed from the label.  One model 8009 was positioned in the front of the container; and the second model 8009 was positioned in the back of the container.  Now they were able to remove all the static before the label was placed on the container.

EXAIR stocks lengths from 3” (76mm) up to 108” (2743mm), and we can ship a solution the same day.  When you are losing time and working hours due to static buildup like the company above, the Gen4 Static Eliminators can resolve it quickly and easily.

If you are having problems with static in alignment, jamming, contamination, or shocking staff; you can contact an Application Engineer at EXAIR.  The Gen4 Static Eliminators can remove the static and keep your process running smoothly.

John Ball
Application Engineer

Twitter: @EXAIR_jb