United States

Case studies




Snack on it!  

The love of snack foods in the world has grown significantly. We eat them during sport events, holidays, parties, and just because. We cannot stop eating them! Can you imagine a potato turning into a potato chip without a person touching the potato? You will be the first as you reach inside the bag after you open it. 


Elmo Rietschle vacuum pumps are used instrumentally in packaging snack foods. The vacuum is used to hold open the bag so the chips can fill to the desired portion. After filled the packaging machine shown will cut and seal bag. Each individual machine requires a small  VLT40 dry vane type vacuum pump with a 2.5 hp motor.    

Elmo Rietschle pumps are used by many of the major snack food brands you see at the grocery store. In this case one of them was using (70) packaging machines (each containing a vacuum pump from various suppliers including Elmo Rietschle) in one of the largest facilities in this country. The total installed horsepower was 175 hp. Due to energy savings, customer replaced all (70) vacuum pumps with (6) VLR500 claw type vacuum pumps. Selling price of this system was $145,000.00.   

We have five operating and one standby. Total installed horsepower here is 75. Customer saves 100 hp. The electrical cost is $0.06 per hp-hr. Plant operates 7500 hours per year. Central system saved this customer $45,000.00 per year in electricity. In addition, the customer factored in maintenance cost savings of $400.00 per pump annually, creating an additional savings of $30,000.00. Total result was annual savings of $75,000.00. Factoring installation cost by the customer this system paid off in less than 4 years. The system is also shown below.  

Take-away Food  

Trends indicate that this is expected to continue to increase by another 20% in the next 10 years, a faster growth than any other segment of food sales. 

All of that take out food requires attractive, durable, environmentally friendly, and often brand recognizable containers, to keep all of that hot food hot, and the cold food cold. (typically ranging from +265F to -40F) This includes the plates, bowls, trays, lids, clam shell containers, and many other containers in various colors and shapes which we see every day. 

Elmo Rietschle products play a significant part in nearly all phases of the manufacture of these food containers at many of the world’s largest food container manufacturing facilities.  Almost certainly,  you have many times,  held in your hands and taken home food containers, from the most popular worldwide restaurant chains, from the corner deli and also from the local grocery store salad bar, which were created and delivered for your use, utilizing our products. 

In short summary, the process starts from small plastic pellets to the final product containers we all know. Here’s how the process works: resins and additives are delivered in bulk in railcars to the manufacturing facility. Dry running claw series, as well as our side channel series, vacuum pumps and pressure blowers pneumatically convey these components from the railcars into large storage silos.  Elmo Rietschle advantages are in part, the higher vacuum and pressure capabilities as well as high cfm/HP of the claw pumps versus alternate technologies, as the very quiet operation and extremely low maintenance performance of the side channel units.  

Our claws as well as our side channel series, vacuum pumps and pressure blowers then convey the resins and additives from the storage silos to the blending stations and are then introduced into the barrel of the extruder machine. In the extruder, large screws in the barrel push the resins and additives along while heat is added to melt, blend and pressurize the components. Elmo Rietschle dry screw Twister series vacuum pumps, Once Through Oil lubricated pumps (OTO’s), our liquid ring vacuum pumps, and now even our dry claw Zephyr vacuum pumps, pull vacuum on the molten plastic at appropriate stages of the screws, to degas and remove volatiles which may cause such quality issues as voids, weaknesses and leaks in the extruded plastic sheet (or any other extruded potentially complex shape product). 

Elmo Rietschle Products offer a significant advantage in this extruder barrel venting application, as we have the ability to allow the customer to have the best choice vacuum pump technology for their specific needs. Whether the material being extruded is a polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), hi impact polystyrenes (HI, HIPS), acrylics, or oriented polystyrenes (OPS), or a variety of other materials, each which offer there own specific challenges to the vacuum system, we at Elmo Rietschle Products do not have to force our customers to take a single technology from a limited product line, instead, Elmo Rietschle can choose from our widest product line offering in the industry and offer the BEST vacuum technology, and engineered packaged system, specifically to reliably and efficiently, meet needs of the customer. 

In the food package manufacturing application, most typically the extruder creates a wide and thin sheet of polymer (plastic) that cools and is collected on a large roll (often about 7 feet wide and 6 feet in diameter.)  These rolls are then transported by robotic forklift to the thermoforming area, and loaded onto the receiving end of a thermoforming machine.  The thin sheet is introduced into a heated oven where the plastic is softened, and then enters a clam shell forming/press chamber where a steel mold presses the sheet into the form of the food container. Where does Elmo Rietschle come in?? To insure the proper form and shape is taken in the mold, and that all of the details of the container such as company logos, and other verbiage stamped into the container are precise and without void, VACUUM ASSIST is introduced into this forming/molding process. Elmo Rietschle oil lubricated rotary vane pumps and central vacuum systems provide the vacuum for this part of the process. The details of the thermoforming process are extensive and also reserved for a future article. Suffice it to say that a major Elmo Rietschle customer boasts in advertisement of the precision of their thermoformed product through the difficulty in distinguishing the visual appearance of their disposable marble plastic plate as compared to a $110.00 real polished marble plate. 

After the thermoforming process, the plastic containers are trimmed to their final form and trim scraps are removed utilizing Elmo Rietschle radial scrap collection blowers, as well as the side channel vacuum blowers to central scrap collection bins. 

An intermediate step at this point is often the printing of ink based logos onto the products, Elmo Rietschle pump provided vacuum, holds the containers in place while the print ink is applied on the printing machine. 

Finally, the finished plastic containers are picked up from the thermoforming line, or print machine, via vacuum suction cups on the ends of robot arms, and placed into shipping crates to be delivered to the restaurants and stores for our use.  And yes, the vacuum provided to the suction cups is provided by Elmo Rietschle Products’ side channel blowers!! 

The Plastics industry is obviously one to be driven by ever more GREEN technologies.  Development of polymers such as polyactic acids (PLA) which is not only disposable but also compostable, made of biodegradable and sustainable materials, is one way to achieve GREEN. But they also must look at their manufacturing processes, and from the Company’s Green Statement of one key Elmo Rietschle end user, they publish, “High efficiency vacuum pumps help recycle up to 15 tons of oil per year from residual vapors during the manufacturing process.”  We are proud to say, these are Elmo Rietschle Products. 

Vacuum Cooling Keeps Produce Fresh  

Have your ever wondered how the lettuce you get in the supermarket stays so fresh, especially since it has probably traveled thousands of miles by truck? The process that keeps the lettuce fresh and increases shelf life is called “evaporative cooling” or what we would call vacuum cooling. It is the same effect you feel when you get out of a swimming pool in a very hot (110F) dry climate, you feel cool, if only for a minute or two. Fresh lettuce is usually picked in high temperature climates, such as Southern California. Each head of lettuce can have an internal temperature of 100F.  

 To lower the temperature, the lettuce is placed in a vacuum chamber, and then the pressure is lowered to the boiling point of water. Typical vacuum levels are 5 torr (29.8 in. vacuum) and temperatures of 36F.   

 The Elmo Rietschle VC-900 and VWP-2500 vacuum booster are the pumps of choice for several OEM customers who manufacture these large 40 foot long systems.    

Just after the harvest the lettuce is placed into cardboard boxes stacked on top of each other, then loaded into the chamber and the process begins. Once the vacuum pumps are turned on, the water on the lettuce starts to evaporate. As the pressure is lowered more water vapor is removed and the temperature of lettuce is reduced even further until the correct vacuum level is achieved. Although some of these systems are automated most are under the watchful eyes of an operator who will make sure the temperature and vacuum level are within specifications, otherwise the lettuce could freeze. At the end of the cycle the internal temperature of the lettuce is around 36-40F. It’s then loaded on to refrigerated trucks for shipment all around the country.  

So just remember the crispy lettuce you eat, such as iceberg and romaine is kept that way by packagers using Elmo Rietschle vacuum pumps.

Elmo Rietschle Licks the Competition in the Envelope Industry 

The Elmo Rietschle VLR-1000 vacuum pump was introduced in late 2009 as an extension to the C Series Rotary Claw line which has been available is the United States for over ten years now. The VLR-1000 is almost double the capacity of the former largest model, VLR-500. Rated at 671 CFM and 30 Horsepower, the VLR-1000 is all alone in the marketplace; no other manufacturer offers a contactless or dry running pump design that can compete. 

  The VLR-1000 is ideal for applications requiring mid-range rough vacuum such as paper converting. We recently sold a 7 pump system to provide a central vacuum source to operate numerous die-cutting, folding and gluing operations in a plant that manufactures envelopes. The seven pumps have a total nominal capacity of just under 4,700 CFM while using only 210 total nameplate Horsepower. This equates to an efficiency of 22.4 CFM/HP, extremely energy efficient compared to any other technology in this vacuum range. In order to justify replacing their aging oil lubricated screw and oil-sealed liquid rings, the customer took advantage of a custom rebate from the local electrical utility. The rebate, along with ongoing energy savings associated with the pump design made the return on investment very attractive. 

The other cost savings provided by switching to rotary claw technology is maintenance. Having no oil in the pumping chamber, there is no need to oil separation filters, oil changes, or related clean up issues with oily discharge. The Elmo Rietschle solution requires only annual gear lube changes, resulting in thousands of dollars saved annually in both maintenance parts and labor. 

The C-Series Rotary Claw is just one example of the industry leading and environmentally conscious products designed and manufactured under the Elmo Rietschle brand. The VLR-1000 is a valuable extension of an already great, time tested product offering. 

 Meat Packaging  

An established producer of meat products had experienced an assortment of problems with vacuum pumps in their Tennessee plant:

  • Oversized pumps on some production lines, wasting precious energy
  • Vanes that deteriorated causing expensive down-time and pump repairs
  • Difficult access to filters and other service points
  • Unreasonably high cost of service and repair parts

This company obtained quotations for new vacuum pumps and was pleasantly surprised to find that an Elmo Rietschle pump  was smaller in size than that quoted by the competition. The meat packer has since purchased several Elmo Rietschle models over and has saved money in several ways.

Engineering assistance by Gardner Denver has helped to provide the ideal size of Elmo Rietschle VACFOX for each packaging line.  Also, the deep vacuum level and high air flow per horsepower has allowed this customer to seal more packages per minute than with their previous brand of vacuum pump.  Finally, the customer has experienced first-hand how well his Elmo Rietschle pumps have performed in cold, humid conditions, and how simple they are to maintain.

 Vacuum Hold-Down for CNC Router (Woodworking)   

A US manufacturer of fireplace mantels was experiencing repeated failures and excessive down-time caused by the carbon vanes breaking or wearing out in rotary vane vacuum pumps. Some of the failures were linked to a high ambient temperature in the plant during the summer. The cost of frequent vane changes was also a drain on the company's operating budget, even if they were changed in time.

The customer purchased an Elmo Rietschle claw ZEPHYR C-VLR 251. The C-VLR uses a "claw technology" instead of vanes. There are no vanes to service or replace, and the customer did not experience any issues related to the temperature of the plant. The customer was also very pleased that the C-VLR-251 provided the same performance as his carbon vane pump but with a smaller motor. Electrical consumption for this vacuum application dropped by 25%!


How can we help you?