by Jackie Johnson Jackie Johnson No Comments

Fluoropolymers in the Food Industry

High-performance fluoropolymers are incredibly vital for use in food and drink manufacturing industries. Setting them apart from general-purpose plastic such as PVC and PE, fluoroplastics enjoy a range of unique properties:

  • Thermal: Resistant to very low and very high working temperatures
  • Chemical: Total resistance to chemicals and solvents
  • Mechanical: Low friction, non-stick characteristics and tensile strength
  • Environmental: Resistant to weather, UV light and corrosion
  • Health: Non-toxic and high purity

Fluoropolymers such as PTFE (Polytetrafluoroethylene), FEP (Fluorinated Ethylene Propylene) and PFA (Perfluoroalkoxy Alkane) bring an abundance of benefits to the food and drink production, from cooking equipment to food coverings, conveyor belt rollers, UV lamp coatings, temperature sensor casing and non-stick surface covers. Because of this, fluoropolymers have kept products uncontaminated, workers safe and production running smoothly for years now.

In this week’s blog post, we will discuss the various ways the fluoropolymers are used in the food industry.

Beverage Dispensing

The requirement for a biologically harmless tubing product coupled with intermittent high temperatures over a long period of time present a challenge for hot beverage dispensing machines. Fluoropolymers such as PTFE and FEP are used as a tried and tested, FDA, NSF and EU compliant solution. Build of residue is greatly reduced due to the smooth internal surfaces provided by fluoropolymer materials. Not only are they FDA compliant, but they are low maintenance as well!

Food Packaging

In packaging and processing food, it is extremely important that the materials used are safe. As such, fluoropolymers such as PVDF, or Polyvinylidene Fluoride Fluoropolymer, are highly regarded in the food packaging industry for a variety of reasons. First, they are incredibly stable materials, and highly resistant to most chemicals, mineral acids, organic acids and other food preservatives. In addition, they are non-toxic and resistant to bacterial and fungi growth.

PVDF is particularly useful in food processing industry due to its unique chemical resistance when temperatures go as high as 300 degrees Fahrenheit (or around 149 degrees Celsius).

PTFE Coatings

With the invention of PTFE, also known as Teflon, non-stick and low friction coatings have played a vital role across the food industry.

For years, PTFE has been used as a coating for cooking applications where particularly sticky or abrasive products are used, such as commercial waffle irons, bread pans, mixers and beaters, hoppers, dough rollers and blades. This allows them to function much more effectively, and the use of oils or other release agents can be substantially reduced or even eliminated.

With ease of use also comes ease of cleaning, and PTFE coating can reduce the intensity and frequency of the cleaning process. It also acts as a hygienic barrier between the food and the surface of the component. These combined save significant employee time and effort, which ultimately reduces labor costs, saving both time AND money.

Belt Conveyors

In the cooking and food processing industries, belts and conveyers made with PTFE coatings are used for mass-produced foods such as bacon, chicken, hamburgers and eggs.

Because of its nonstick properties, the PTFE coating allows food to easily come off, with little mess. This facilitates a high volume of production for commercial food processors.

Industrial Bakeware

Fluoropolymer coatings assure high-quality coating solutions for bakeware used by industrial bakeries. This helps bakeries not only drive efficiency, but also improve the hygiene and safety of their operations. It also improves the quality of the final baked product, with less waste and less butter and/or grease used to keep the product from sticking to the pan.

Home Cookware Manufacturing

We have talked about how fluoropolymers are across the commercial industry, but they are just as equally prevalent in our homes as well.

The use of nonstick pans has been popular in homes since the 1950s, when a French engineer begun coating his fishing gear with Teflon to prevent tangles. His wife then suggested using the same method to coat her cooking pans. In 1956 the Tefal company was formed and began manufacturing non-stick pans.

And nonstick cookware is popular to manufacture as they can be machined and coated relatively easily.

Other Uses

As discussed, fluoropolymers have many uses in the food industry, and many more that we did not cover. Some of these include

  • Shatterproof Coatings for Heat Lamps
  • Encapsulated Temperature Sensors
  • FEP Roll Covers
  • Laser Marked and Printed Tubes for Identification
  • And more!

In Conclusion

With the strength and versatility of fluoropolymers, it is no wonder that it is such a popular material within the food and drink industries.

Because of its high temperature and chemical resistance, nonstick and non-toxic surface, many health organizations have recognized it’s inherit value and, as such, have made fluoropolymers the gold standard within the food industry.

To learn more about fluoropolymers, visit our page by clicking the link here. And if you need PTFE sealing solutions, contact us today!

by Sara McCaslin, PhD Sara McCaslin, PhD No Comments

Spring-Energized Seals for the Food and Dairy Industries

The food and dairy industries are tough on seals, whether its extreme pressures and temperatures or the limitations posed by using only FDA-approved materials. Spring-energized seals, however, can prove an excellent solution for the challenges posed by these industries. In this week’s blog post, we will discuss spring energized seals in the food and dairy industries. 

Issues for Seals in the Food and Dairy Industries

There are several key issues involving seals for the food and dairy industries. The most obvious is FDA approval, but these seals are also exposed to both extreme temperatures and high pressures. Sanitation procedures are extremely harsh, often involving steam, hot water, and aggressive chemicals to achieve hygienic conditions. In addition, the seals will often be exposed to water for extended periods of time, which could be absorbed by the seal material and result in compromising dimensional changes. Lubrication can also be an issue, which means seals may have to be self-lubricating. Finally, the seals must be reliable, able to perform in less than ideal circumstances.

Spring-Energized Seals

Unlike traditional seals, spring-energized seals include an energized seal provides permanent resilience to the seal jacket. The energizer compensates for hardware misalignment, jacket eccentricity, and wear. These seals are typically made of strong, corrosion-resistant stainless steel with a polymer jacket.

FDA Approved Materials

FDA CFR 177, contained in Title 21 of the Code of Federal Regulations, deals with indirect food additives (i.e., substances that inadvertently make their way into food) in the form of polymers. In addition to FDA regulations, there are other standards in place that apply, including (EU) 1935/2004, NSF/ANSI standard 61 for drinking water systems, and 3A Dairy sanitary standards 18-03 and 20-27.

Spring-energized seals are available in materials that are FDA approved. These materials include UHMW PE (Ultra High Molecular Weight Polyethylene) and PTFE (both virgin and certain grades of mineral-filled) and are both known for low friction, chemical inertness, and the ability to handle rugged sterilization and cleaning procedures that can involve steam, hot water, and aggressive chemicals. Other polymers that might be considered  dependent on the application are certain grades of PEEK and Acetal. In addition, UHMW PE, PTFE, and Acetal are also 3A-Dairy and USDA compliant.

Extreme Temperatures and Extreme Pressures

Food and dairy seals must provide reliable performance in extreme pressures and temperatures. Spring-energized seals are able to maintain a tight seal in temperatures and pressures that would cause more traditional seals to fail. This is primarily due to the spring-energizer that keeps the seal lip intact regardless of dimensional changes due to temperature variation as well as pressure fluctuations. Spring-energized seals are well known for their sealing ability at extreme pressures, including vacuum pressures. In addition, they work extremely well in cryogenic temperatures.

Sanitation Procedures for the Food and Dairy Industries

Food and dairy applications almost invariably involve harsh sanitation procedures that can compromise the performance of typical seals. For example, steam and hot water can cause a significant temperature difference, but the spring-energizer is able to maintain a positive seal even if the seal lip changes dimensions. The right choice of an FDA-approved material can ensure that the seal jacket will remain undamaged in the presence of any aggressive chemicals used. 

Hygroscopic Effects

When seals are exposed to moisture, water, or humidity for extended times, the seal jacket material may absorb that moisture. This can lead to dimensional changes that compromise the performance of the seal. However, with a spring-energized seal, the energizer allows the seal to maintain contact regardless of those dimensional changes. And with a material such as PTFE or UHMW PE for the seal jacket, the possibility of moisture absorption and associated hygroscopic effects is further reduced.

Lubrication

In food and dairy applications, it may not be possible to lubricate seals because of the possibility of contamination. Choosing the right FDA-approved material for a spring-energized seal can eliminate the need for a lubricant because both UHMW-PE and PTFE are dry running, self-lubricating materials.

Reliable Performance

Seals are critical in food and dairy processing: a failed seal can contaminate goods and, if undetected, can put consumers in danger. Spring-energized seals are extremely reliable, both for the reasons already discussed as well as their ability to compensate for issues such as wear, out-of-roundness, eccentricity, and issues with the surface of the shaft. These seals can perform where traditional seals would fail, again thanks to the spring-energizer that keeps the lip of the seal in contact with the shaft. 

Additional Benefits of Spring-Energized Seals

Spring-energized seals can also be used as direct replacements for traditional seals that have failed, even for failures. Because of their durability and resistance to corrosion and contamination, spring-energized seals last longer which in turn leads to reduced downtime and repair costs.

Conclusion

Spring-energized seals are needed in various applications related to the food and dairy 

Industry, including blenders, homogenizers, mixers, process vessels, and hygienic piping systems. For reliable, durable, high performing seals for the food and dairy industries, consider the use of spring-energized seals.

by Sara McCaslin, PhD Sara McCaslin, PhD No Comments

Why PTFE Rotary Shaft Seals Are a Great Choice for Food Processing Applications

While there are several options when it comes to approved polymeric or elastomeric seals for food processing applications, PTFE is one of the more popular choices–and that includes rotary shaft seals, as well.

Why are PTFE rotary shaft seals good for food processing applications? Rotary shaft seals for food processing equipment have to do more than an ordinary seal:  they also need to withstand aggressive cleaning and sanitation regimens that may involve corrosive chemicals, be approved for contact with food, and offer effective, reliable performance. 

How PTFE Rotary Shaft Seals are Used in Food Processing Applications

Food processing machines that make use of shaft seals include mixers, food portioning equipment, dry product filling systems, ice cream dispensers, milk dispensers, high-pressure homogenizers, water purification equipment, and distilled water pumps. They may be used with adhesives, flavorings, water, powders, preservatives, sauces, condiments, steam, and various fluids.

Operating Conditions

Rotary shaft seals for use in the food processing industry must be able to handle the standard operating conditions involved such as speed, temperature, and pressure. However, their operating environment can involve more than that: consideration has to be given to the type of media they will be exposed to (e.g., powders, extremely viscous fluids). 

PTFE is one of the polymers that have a proven track record with rotary shaft seals that have to function over a wide range of temperatures, pressures, and speeds, with various grades available that can offer more customized performance.

CIP/SIP

Rotary shaft seals must withstand the sterilization or cleaning procedures involved. CIP (Clean in Place), SIP (Sterilize in Place), and COP (Clean Out of Place) methods often require aggressive cleaning agents and/or superheated steam, powerful disinfectants, and potentially corrosive acids. 

PTFE is highly resistant to a wide range of aggressive chemicals, can handle repeated exposure to hot water and superheated steam, and will not react chemically to the powerful disinfectants and sanitizers that food processing equipment is exposed to.

Safe for Contact with Food

Any part of a rotary shaft seal that comes into contact with food must conform to the appropriate regulations, such as  FDA 21 CFR 177.1680, (EC) No. 1935/2004, and/or USP Class VI. Such approval is not easy to achieve: it takes into account whether the material releases any chemicals, tends to absorb moisture, goes through physical changes when exposed to high temperatures, reacts chemically to ingredients that are acidic, exhibits off-gassing, and more. 

PTFE comes in grades that are fully compliant with regulations regarding contact with food and FDA approved, making it a safe choice for rotary shaft seals for food processing equipment. In addition, it is the most chemically unreactive polymer on the market today.

Conclusion

Finally, PTFE rotary shaft seals have proven themselves to be highly reliable, which is why you will see them used in dangerous, mission-critical applications where safety and ruggedness are vital, such as those found in the oil and gas or aerospace industries. If you are looking for an FDA-approved rotary shaft seal for use in food processing applications, PTFE seals should be at the top of your list.