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Kalrez O-Rings and Seals
Pharmaceutical and Food Handling Applications

In pharmaceutical and food processing sealing applications where cleanliness is critical, PTFE has been the material of choice in the past. However, PTFE does not have true elastomeric properties or sealing abilities. Now Kalrez o-rings and seals offer the same level of cleanliness and universal chemical resistance as PTFE and Kalrez has become the compound of choice.

Kalrez o-rings and seals are made from the compounds 6221 and 6230 for pharmaceutical and food handling applications where FDA compliance is required. They give excellent chemical resistance and low contamination from extractables. These compounds are especially good in Water For Injection systems, Steam-in-Place cleaning and other critical systems.

General Chemical Resistance of Kalrez O-rings and Seals

The overall chemical resistance of EPDMs, silicone elastomers and fluoroelastomers (FKM) is limited by their respective polymer structures. Kalrez o-rings and seals, on the other hand, offer the same universal chemical resistance as PTFE, but unlike PTFE, they have elastomeric properties, which help them maintain their sealing capabilities. The table below lists the chemical compatibility of Kalrez o-rings and seals as well as other elastomers used as sealing materials in the pharmaceutical and food handling industries.

Kalrez® Chemical Compatibility*
Chemical
Kalrez® 6221/6230
EPDM
SI
FKM
Acetic Acid
A
A
A
B
Acetone
A
A
C
U
Citric Acid
A
A
A
A
Hydrogen Peroxide
A
B
B
B
Isopropyl Alcohol
A
A
A
A
Methyl Ethyl Ketone
A
A
U
U
Mineral Oil
A
U
B
A
NaOH
A
A
B
B
Nitric Acid
A
B
B
A
Sodium Hypochlorite
A
B
B
A
Soybean Oil
A
C
A
A
Steam (<150°C [302°F])
A
A
C
U
Steam (>150°C [302°F])
A
C
U
U
Toluene
A
U
U
A
Xylene
A
U
U
A

A = little or no effect B = slight swelling and/or loss of physical properties C = moderate to severe swelling and/or loss of physical properties/limited functionality U = not suitable or recommended.

* Data has been drawn from DuPont tests and industry sources. Data is presented for use only as a general guide and should not be the basis of design decisions. Contact Problem Solving Products, Inc. for further information.


Thermal Stability

Unlike other elastomeric seals made with FDA compliant elastomers, Kalrez o-rings and seals are thermally stable up to 260°C (500°F), permitting use in applications such as Stage II Sterilization processes, where other elastomers lose their sealing capabilities.

Aggressive Water Resistance

In aggressive pharmaceutical and semiconductor processing environments, seal failure from excess swelling, embrittlement or decomposition can cause unscheduled downtime or product contamination. Elastomeric materials that come in contact with highly pure and aggressive water (e.g., Water For Injection systems) must be chosen with care in order to prolong seal life. The perfluoroelastomer compounds used in Kalrez o-rings and seals have been shown to have extremely low to non-detectable extractable levels in aggressive water systems. Because the perfluoroelastomer polymer in Kalrez parts is fully saturated, it is also well suited for Ozonated Deionized Water service. Kalrez o-rings and seals also exhibit very low swell and loss of mechanical properties after repeated steam cycling.

Typical Physical Properties of Kalrez O-rings and Seals**
Compound Kalrez 6221 Kalrez 6230
Durometer Hardness, Shore A, points ±5 70 75
100% Modulus, psi (MPa) 1,050 1,020
Tensile Strength at Break1, psi (MPa) 2,200 2,400
Elongation at Break1, % 150 170
Compression Set2, 70 hr at 160°C (320°F) 20 18
Color White Black*

1ASTM D412, 20 in/min (500 mm/min)
2ASTM D395 B, Size 214 O-rings

**Typical physical properties should not be the basis of design decisions. Contact Problem Solving Products, Inc. for further information about Kalrez o-rings and seals.


Problem Solving Products, Inc. is certified by DuPont to sell Kalrez O-rings and Seals

The only way to be sure that you are getting genuine Kalrez o-rings and seals is by dealing with a certified dealer. Only manufacturers like us, Problem Solving Products, Inc., who have signed a formal agreement with DuPont can sell genuine Kalrez. All the certified dealers are carefully selected by DuPont for their knowledge, quality standards and ability to help you select the correct type of Kalrez for your application. A well-written specification will help us to give you the most cost-effective recommendation.

The information set forth herein is furnished free of charge and is based on technical data that DuPont and Problem Solving Products, Inc. believe to be reliable. It is intended for use by persons having technical skill, at their own discretion and risk. Handling precaution information is given with the understanding that those using it will satisfy themselves that their particular conditions of use present no health or safety hazards. Since conditions of product use and disposal are outside of our control, we make no warranties, express or implied, and assume no liability in connection with any use of this information. As with any material, evaluation of any compound under end-use conditions prior to specification is essential. Nothing herein is to be taken as a license to operate or a recommendation to infringe on any patents. While the information presented here is accurate at the time of publication, specifications can change. Check with us before making a decision about which product to use.

DuPont™ and Kalrez® are trademarks or registered trademarks of E.I. du Pont de Nemours and Company or its affiliates. All rights reserved.