Paw CustRub mech txt - Karmaseal

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www.pawling.com/custom

Table of Contents

Market Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7

Profile Constructs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Secondary Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Available Materials

Thermoplastic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Thermoset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Tolerance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Standard Profiles and Stock Items . . . . . . . . . . . . . . .14-16

www.pawling.com/custom

Pawling Custom Rubber and Plastic Products4

VAB Double Bulb Door Seal

Market: Aerospace/Construction

Material:EPDM

Detail: A large EPDM double bulb extrusion is used toseal the edges of the Vertical Assembly Building (VAB)Doors at the Kennedy Space Center in Cape Canaveral,Florida. This design allows for horizontal movementbetween the bulbs while the door is operational andprovides dual sealing surfaces to keep the weather out.

This part is extruded using our largest extruder andspliced in the field by our technical staff.

Multi-Laminate Silicone Wing Flap Seal

Market: Aerospace/Defense

Material:Silicone, Fabric, and Polyester

Detail: This part requires three unique materials to becompression molded into one compete gasket. The fab-ric outer layer is used to reduce the part’s co-efficientof friction and to increase useful life. Silicone is used tohandle temperature extremes and the rigid polyesterbase is used to prevent seal pullout from its housing.This seal is manufactured utilizing special molds andlong presses to conform to the tight tolerances requiredfor this application.

Market Solutions

Pawling Engineered Products specializes in the custom design and manufacture of seals, gaskets, and other engineered rubberproducts. Advanced compounding, molding, extruding, and fabricating coupled with testing equipment and other techniquesenable us to address your most demanding needs for highlydurable and reliable rubber fabrications.

www.pawling.com/custom 5

Low Outgassing Expansion Joint

Market: Cleanrooms/Laboratories

Material:Silicone

Detail: Ductwork enclosing a conveyor belt connectsseveral clean rooms together, allowing for materialmovement between rooms. To address outgassing concerns and to account for slight movement in theducting, Pawling designed a molded expansion jointmade from a low outgassing silicone material (70643).Manufacture of this molded gasket is tightly controlledas any contaminants could compromise the clean room environment.

One-Piece Zipper Gasket

Market: Transportation/ Construction

Material: Flexible PVC

Detail: This zipper design replaces a traditional two-piece sealing system where a smaller gasket would beinstalled into the mating channel of a larger gasket.

During installation, the gasket is placed onto the aluminum frame. The glass is then inserted into theinside channel and the zipper is pushed into place. Thisaction locks the gasket and window together, whichimproves the part’s effectiveness and ultimately lowersoverall unit cost.


Market Solutions

Roof Window Gasket

Market: Construction

Material:EPDM

Detail: A unique, multi-faceted profile is spliced into apicture frame which serves as a seal between the roofwindow housing and frame. This part is manufacturedusing a high quality EPDM (E787M) with multiple sealing points, which reduces potential leakage.

Using a dedicated work cell, Pawling manufacturesthese gaskets on demand through use of a uniquemolding and extruding process.

Chemical Processing Seal

Market: Electronics/Semi-Conductor Processing

Material: Fluorosilicone

Detail: Fluorosilicone is used to combat both high temperatures and aggressive chemicals. In this application, semi-conductor assemblies are treated in a large chemical bath. The fluorosilocone P-strip isused to seal the cover while the machine is operational.


Fabric Reinforced Valve Seat

Market: Power Plant/Construction

Material:Natural Rubber

Detail: Using our unique long press capabilities, Pawlingmanufactures an 8” (203 mm) wide, fully molded fabricreinforced expansion joint in long continuous lengthsused for large pipe assemblies in power plants.Diameters approaching 8-10 feet (2438-3048 mm) arenot uncommon. Depending on the requirements, thispart can either be molded and spliced endless or can bestep-cured into a complete gasket.

Magnetic Sterilizer Gasket

Market: Medical/Sterilizers

Material:Silicone

Detail: This sterilizer gasket withstands the rigors ofhigh temperatures and latches the door by using magnets which are installed within the seal. This dualsystem combines the seal and latch into one unit, which simplifies design. Silicone is used to ensure thegasket maintains its effectiveness even under high temperatures.


Profile Constructs

Dense - The majority of our parts are manufac-tured using dense materials. Dense profiles areresilient and extrudable whereas some other constructs can only be molded.

Co-Extruded - Some applications require twotypes of material (usually having different durome-ters) to be joined together to form one part. A typi-cal application involves a rigid component that actsas a retainer and a flexible component to act as aseal or bumper.

Sponge - Sponge extrusions provide a soft, suppleseal while optimizing material usage. Sponge profiles should not be used where compression setis important, because the part will eventually takea permanent set.

Fabric Reinforced - Fabric reinforcement servesmany purposes. Embedded fabric can strengthen a part’s tensile strength which will allow it to withstand harsh applications. It also can be usedon a part’s surface to reduce coefficient of friction.

Multi-Laminate - Multi-laminate designs are used in severe applications where part failuremust be minimized. Aerospace applications use amulti-laminate construct of fabric, silicone, andpolyester. The fabric reduces the part’s coefficientof friction and the rigid polyester molded insertensures that the part does not pull out of itsretainer.

Finishing Options

Butt Splice - Butt Splices are the most commonmethod to finish an extrusion into a gasket orseal. Some materials can be heat welded whileothers need to be vulcanized. Extruding and butt7splicing is usually more cost effective than fullymolding a part.

Mitre Splice - Applications requiring a pictureframe configuration can be spliced using a 45degree mitre to form the frame.

Molded Corners - When function and reliabilitymust be optimized, corners are molded separatelythen butt spliced into a frame. This process movesthe vulcanized splice away from the corner, whichmakes it stronger. Molded corners can be designedfor gentle radii up to a full square.

Notched Corners - Notched corners employaspects of the mitre splice, but accomplish it without having to fully cut the extrusion. Thismethod works particularly well with P-strip or J-seal designs (see page 14).

Notching/Punching/PSA Application - Whether in-line or as a secondary operation, parts can benotched, punched, or PSA (pressure sensitiveadhesive tape) can be applied to improve functionality.



Common Name/ASTM Designation TPE Alcryn TPU Flexible PVC Rigid PVC(TPV) (Vinyl) (Vinyl)

Chemical Name Thermoplastic Melt Processible Thermoplastic Polyvinylchloride PolyvinylchlorideElastomer Rubber Urethane (Flexible) (Rigid)

Hardness Range

Shore A 30-90 40-95 60-85 60-96

Shore D 75-82

Rockwell

Specific Gravity 0.87-1.35 1.10-1.17 1.14-1.19 1.37-1.45 1.33-1.41

Tensile Strength, psi 500-3000 1200-1900 3300-5600 1300-3000 6000-6600

Elongation% 210-600 200-500 620-870 240-430

Flexural Modulus, psi 0-54 200-500 n/a n/a 395,000-400,000

Notched Izod Impact, ft.lbs./in. 4-20

Abrasion Resistance VG VG E G VG

Water Resistance E E G E E

Ozone Resistance E E E E E

Weather (UV) VG-E E F-G G G

Acids E E F G G

Alkali E E F G G

Oil F E G F F

Gas Permeability F G F F F

Heat Aging G G G F F

Low Temperature G E VG-E G F

n-Hexane G E G P P

Xylene/Toluene (RT) F P P P P

Methylethylketone (RT) G P P P P

Trichloroethylene P P P P P

Gasoline P G G-VG F F

2.5% Detergent Solution E E VG E E

Antifreeze G G G P P

Dioctyl Phthalate E n/a E P P

Ethyl Alcohol VG G F G G

Available Materials

Thermoplastic

The appropriate thermoset and/or thermoplastic material is deter-mined primarily by the function of your finished product. Durability,flexibility, and strength vary with the type of plastic or rubber chosen. We continue to broaden our range of material capabilities tobetter address our customers’ needs and keep a close eye on newlyavailable materials. Please contact us if you have more specificrequests. Our Sales Engineers will be happy to assist you.

E = Excellent VG = Very Good G = Good F = Fair P = Poor


Common Name EPDM or EP Neoprene SBR Nitrile Natural Butyl Silicone Fluorosilicone FluorocarbonRubber (Buna-N) Rubber

Chemical Name Ethylene Chloroprene Styrene Acrylonitrile Natural Isobutylene Silicone Fluorosilicone FluorocarbonPropylene Butadiene Butadiene Isoprene Isoprene *(Viton®)

ASTM Designation EP CR SBR NBR NR IIR VMQ FVMQ FKM

Hardness Range 40-90 20-80 40-90 50-95 50-70 40-75 40-80 40-70 70-90

Tensile Strength, psi >2000 >2000 >2000 >2000 >2000 >2000 >1200 >1200 >1400

Tear Resistance G G F F G G F P P

Abrasion Resistance G-E VG G-E G E G P F G

Compression Set G G G G E F VG E E

Resilience Cold G G G F G P E G F

Resilience Heat VG VG G G F VG E E E

Radiation Resistance E G n/a P F-G G G E E

Impermeability to Gases G G F G F E F F E

Dielectric Strength E VG G P E G G G VG

Electrical Insulation G-E F-G G P G-E G E E G

Adhesion to Metals G E E E E G E E F-G

Adhesion to Fabrics G E G G E G E E G

Acid Resistance

Mild Dilute E E F-G F-G P-F E E E E

Strong Concentrated G G F-G F-G P G F G E

Solvent Resistance

Aliphatic Hydrocarbons P F-G P E P P P G E

Aromatic Hydrocarbons P P P P P P P E E

Oxygenated (Ketones, etc.) G P P P P G P F F

Resistance To:

Swelling in Lubricating Oil P G P VG P P P E E

Oil and Gasoline P G P E P P F G E

Animal Oils F F P E P F G E E

Water Absorption VG G VG VG VG VG E E E

Oxidation E VG F G P-F E E E G

Ozone E VG P F P-F F-G E E E

Sunlight Aging E VG P P P-F VG E E G

Heat Aging VG G G G F-G G E E E

Low Temperature VG G VG F-G G G E G F

Flame P G P P P P F E E

Vegetable Oils F G P G P F P E E

Chlorinated Hydrocarbons P P P F P P P-F F G

*Viton® is a trademark of E.I. Dupont Demours and Co.

Thermoset

E = Excellent VG = Very Good G = Good F = Fair P = Poor


Tolerance DataBecause of rubber’s variability from lot to lot, rubber manufacturers use these tolerances in order to ensure part conformity.

Standard Extruded Cross Sectional Tolerances (Metric Units)

1 2 3RMA Class High Precision Commercial

Precision

Drawing Designation E1 E2 E3

Dimensions (mm)

Above Up To +/- +/- +/-

0 1.5 0.15 0.25 0.40

1.5 2.5 0.20 0.35 0.50

2.5 4.0 0.25 0.40 0.70

4.0 6.3 0.35 0.50 0.80

6.3 10 0.40 0.70 1.00

10 16 0.50 0.80 1.30

16 25 0.70 1.00 1.60

25 40 0.80 1.30 2.00

40 63 1.00 1.60 2.50

63 100 1.30 2.00 3.20

Standard Extruded Cross Sectional Tolerances (English Units)


Precision

Drawing Designation E1 E2 E3

Dimensions (inches)

Above Up To +/- +/- +/-

0 0.06 0.006 0.010 0.015

0.06 0.10 0.008 0.014 0.020

0.10 0.16 0.010 0.016 0.027

0.16 0.25 0.014 0.020 0.031

0.25 0.39 0.016 0.027 0.039

0.39 0.63 0.020 0.031 0.051

0.63 0.98 0.027 0.039 0.063

0.98 1.57 0.031 0.051 0.079

1.57 2.48 0.039 0.063 0.098

2.48 3.94 0.051 0.079 0.126

Cut Length Tolerances for Unspliced Extrusion (Metric Units)


Precision

Drawing Designation L1 L2 L3

Dimensions (mm)

Above Up To +/- +/- +/-

0 40 0.70 1.00 1.60

40 63 0.80 1.30 2.00

63 100 1.00 1.60 2.50

100 160 1.30 2.00 3.20

160 250 1.60 2.50 4.00

250 400 2.00 3.20 5.00

400 630 2.50 4.00 6.30

630 1000 3.20 5.00 10.00

1000 1600 4.00 6.30 12.50

1600 2500 5.00 10.00 16.00

2500 4000 6.30 12.50 20.00

4000 0.16% 0.32% 0.50%

Cut Length Tolerances for Unspliced Extrusion (English Units)


Precision

Drawing Designation L1 L2 L3

Dimensions (inches)

Above Up To +/- +/- +/-

0 1.60 0.03 0.04 0.06

1.60 2.50 0.03 0.05 0.08

2.50 4.00 0.04 0.06 0.10

4.00 6.30 0.05 0.08 0.13

6.30 10.00 0.06 0.10 0.16

10.00 16.00 0.08 0.13 0.20

16.00 25.00 0.10 0.16 0.25

25.00 40.00 0.13 0.20 0.40

40.00 63.00 0.16 0.25 0.50

63.00 100.00 0.20 0.40 0.63

100.00 160.00 0.25 050 0.80

160.00 0.16% 0.32% 0.50%

Tolerance Tables and Glossary of Terms are courtesy of the Rubber Manufacturers Association (RMA).For more information, please visit their web site at www.rma.org.


Glossary of Terms

Abrasion Resistance - The resistance of a material to loss of surface particles due to friction. When high abrasion resistance is required, Polyurethane (either thermoset or thermoplastic) is preferred.

Autoclave - A pressure vessel into which materials orarticles can be placed and exposed to steam under pressure. It is commonly used to vulcanize carbon-basedpolymers, like EPDM, CR, Nitrile, and SBR.

Butt Joint - A joint made in a rubber part before or aftervulcanization by placing the two pieces to be joined edge-to-edge. A butt joint is preferred over a miteredjoint as the butt joint is typically stronger.

Compression Set – The residual deformation afterremoval of the force which has subjected the specimen tocompression. Compression set is a key factor whendesigning a part that will be compressed for long periodsof time.

Creep - The deformation, in either cured or uncured rubber under stress, which occurs with lapse of time afterthe immediate deformation.

Durometer – An instrument for measuring the indenta-tion hardness of rubber; also, sometimes used as a syn-onym for hardness. For thermoset rubber and thermoplastic vulcanizate (TPV) materials, durometer isdefined using the Shore A scale where the lower the valuethe softer the material.

Elongation – The maximum elongation prior to rupture.

Friction - Produced from the interference of two surfacesbrought together. Parts in light friction will slide alongeach other easily but as friction is increased slidingbecomes more difficult.

Low Temperature Flexibility - The ability of a rubberproduct to be flexed, bent, or bowed at specified low temperature without loss of serviceability. Silicone is typically the polymer of choice when low temperatureflexibility must be maintained.

Microwave Curing - Heating a thick cross section uniformly is difficult using conventional ovens. Microwavetechnology however is not affected by dimensional considerations as the microwaves rapidly heat the insidesand outsides of a profile simultaneously. A typicalmicrowave extruder has a microwave unit at the end ofthe extruder to rapidly heat the extrusion and a HAV unitfollowing to maintain temperature while vulcanizing. A significant benefit gained from microwave curing is thatextremely long lengths can be achieved.

Modulus – The tensile strength recorded when the specimen is elongated 100%. For dynamic propertieswhere the part will be stretched and compressed continually, a high modulus is preferred.

Permeability - To permit passage of gas through themolecular structure of a given material. Materials withlow permeability, such as Butyl or FKM, are preferred invacuum applications.

Tear Strength – The maximum load required to tear aparta specimen; the acting substantially parallel to the majoraxis of the test specimen. For applications where the partmay experience some shearing action, a high tear materi-al is preferred.

Tensile Strength – The maximum tensile stress appliedduring stretching a specimen to rupture. The higher thetensile strength, the stronger the material.

Vulcanization – An irreversible process during which arubber compound through a change in its chemical structure (for example, cross-linking) becomes less plastic and more resistant to swelling by organic liquidsand elastic properties are conferred, improved, or extended over a greater range of temperature.


Standard Cross Sections and Stocked Profiles

“P” and “J” Seals

1 1/8”

3/8”

1 1/4”

1/2”

2 1/2”

1 1/4”

1 1/4”

5/8”

6”

1/2”

1 1/2”

7/8�

5/16�

3/8”

3/4”

PR13541 (EP, CR, VMQ)

PR13542 (CR, VMQ)

1/4”

1”

PR13540 (CR, VMQ)

PR28910 (NBR)

X21337 (CR)

X21339 (CR)

1/2”

7/8”

X21338 (CR)

4”

1 3/4”

11/16”

PR18156 (CR)

PR15480 (EP)

1 1/8”

1/2”

PR19491 (FVMQ)2 1/4”

1”

1/4”

PR5919 (CR)

PR23333 (EP)

1/2”

6”

1 1/2”

PR16448 (CR)

4”

1 3/4”

3/8”

PR15415 (CR)

5/16”

3”

1”

PR15782 (CR)

Paw CustRub mech txt - Karmaseal

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