3M 4991

3M 4991 Datasheet
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  • Description for 3M 4991

    • Gray, closed-cell acrylic foam carrier • Conformable • Good adhesion to many painted metals • Plasticizer resistant • UL 746C

    *See Terms of Use Below

    Application Type Bond
    1 Part or 2 Part 1 Part
    Material Form Tape
    Substrate Acrylic paint, Aluminum, Ceramic, Glass, Metal, ABS, Polycarbonate, Polyester paint, Polyurethane paint, PVC, Enameled Steel, Stainless steel, Plasticized Vinyl, Galvanized Steel, Epoxy, Galvanized Steel, PBT, Foam, Nickel Coated ABS, A wide variety of plastics, Painted metals
    Industry Ideal for use in many interior bonding applications, Ideal for use in many exterior bonding applications
    Manufacturer 3M
    Chemistry Acrylic
    Cure Method Pressure sensitive
    Color Gray
    Chemical Resistance Resistance to plasticizer migration
    Relative Solvent Resistance Chemical Resistance: Excellent solvent resistance
    High Temperature Resistance (°C) 93, 121, 90, Outstanding durability
    Low Temperature Resistance (°C) -35, Outstanding durability
    Density (g/cm³) 0.720
    Key Specifications UL746C Listings - File MH 17478

  • Technical Data for 3M 4991

    *See Terms of Use Below

    Overview
    • Application Type
    • 1 Part or 2 Part
      • 1 Part or 2 Part - 1 Part
    • Material Form
      • Tape
    • Substrate
    • Industry
      • Interior - Ideal for use in many interior bonding applications
      • Industrial - Permanent fasteners, Foils, Rivets, Spot Welds
      • Industrial Exterior - Ideal for use in many exterior bonding applications
      • Construction
    • Chemistry
    • Application Method
      • Dispenser - P.U.R. application equipment
      • Contact
    • Cure Method
      • Pressure Sensitive (min) - Pressure sensitive
    • Color
      • Gray
    • Key Specifications
      • UL (Underwriters Laboratory), ULC (Underwriters Laboratories of Canada), NFPA (National Fire Protection Association) - UL746C Listings - File MH 17478
    Specifications
    Cure Specs
    Application Temperature (°F) 59, 70 to 100
    Bond Strength
    General Bond Strength (psi) Good
    Peel Strength (piw) High, 22 (lb/in) Test Method
    Shear Strength (psi) High, 65, 1000 (grams), 500 (grams), 500 (grams) Test Method
    Tensile Strength (psi) High, 70 Test Method
    Material Resistance
    Chemical Resistance Resistance to plasticizer migration
    Relative Solvent Resistance Chemical Resistance: Excellent solvent resistance
    High Temperature Resistance (°C) 93, 121, 90, Outstanding durability Test Method
    Low Temperature Resistance (°C) -35, Outstanding durability
    Moisture/Humidity Resistance Excellent
    Conductivity
    Dissipation Factor 0.02450, 0.03740 Test Method
    Dielectric Strength (V/mil) 360 Test Method
    Dielectric Constant 2.29, 1.99 Test Method
    Thermal Conductivity (W/m°K) 0.08
    Surface Resistivity (O) 2.7e14 (ohm/sq) Test Method
    Volume Resistivity (O) 2.1e14 (ohm-cm) Test Method
    Hardness
    Flexibility Conformability
    Modulus (psi) 3e5 (Pa) Test Method
    Other Properties
    Coefficient of Thermal Expansion (CTE) 180e-6 (m/m/°C)
    Density (g/cm³) 0.720
    Business Information
    Shelf Life Details All 3M™ VHB™ Tapes have a shelf life of 24 months from date of shipment when stored at 40°F to 100°F (4°C to 38°C) and 0-95% relative humidity. The optimum storage conditions are 72°F (22°C) and 50% relative humidity. Performance of tapes is not projected to change even after shelf life expires however, 3M does suggest that 3M™ VHB™ Tapes are used prior to the shelf life date whenever possible.
    Shelf Life Temperature (°F) 40 to 100
    Shelf Life Type From date of shipment
    Shelf Life (mon) 24

  • Best Practices for 3M 4991

    *See Terms of Use Below

    1. Surface Preparation

      Most substrates are best prepared by cleaning with a 50:50 mixture of isopropyl alcohol (IPA*) and water prior to applying 3M™ VHB™ Tapes.

      Exceptions to the general procedure that may require additional surface preparation include: Heavy Oils: A degreaser or solvent-based cleaner may be required to remove heavy oil or grease from a surface and should be followed by cleaning with IPA/water.

      Abrasion: Abrading a surface, followed by cleaning with IPA/water, can remove heavy dirt or oxidation and can increase surface area to improve adhesion.

      Adhesion Promoters: Priming a surface can significantly improve initial and ultimate adhesion to many materials such as plastics and paints.

      Porous surfaces: Most porous and fibered materials such as wood, particleboard, concrete, etc. need to be sealed to provide a unified surface.

      Unique Materials: Special surface preparation may be needed for glass and glass-like materials, copper and copper containing metals, and plastics or rubber that contain components that migrate (e.g. plasticizers).

      Refer to 3M Technical Bulletin “Surface Preparation for 3M™ VHB™ Tape Applications” for additional details and suggestions. (70-0704-8701-5)

      *Note: These cleaner solutions contain greater than 250 g/l of volatile organic compounds (VOC). Please consult your local Air Quality Regulations to be sure the cleaner is compliant. When using solvents, be sure to follow the manufacturer’s precautions and directions for use when handling such materials.

    2. Application

      Bond strength is dependent upon the amount of adhesive-to-surface contact developed. Firm application pressure develops better adhesive contact and helps improve bond strength. Typically, good surface contact can be attained by applying enough pressure to insure that the tape experiences approximately 15 psi (100 kPa) pressure. Either roller or platen pressure can be used. Note that rigid surfaces may require 2 or 3 times that much pressure to make the tape experience 15 psi.

      Ideal application temperature range is 70°F to 100°F (21°C to 38°C). Pressure sensitive adhesives use viscous flow to achieve substrate contact area. Minimum suggested application temperatures:60°F (15°C): 3M™ VHB™ Tapes 4941, 4945 families.

      Note: Initial tape application to surfaces at temperatures below these suggested minimums is not recommended because the adhesive becomes too firm to adhere readily. However, once properly applied, low temperature holding is generally satisfactory.

    3. Curing

      After application, the bond strength will increase as the adhesive flows onto the surface (also referred to as “wet out”). At room temperature approximately 50% of ultimate bond strength will be achieved after 20 minutes, 90% after 24 hours and 100% after 72 hours. This flow is faster at higher temperatures and slower at lower temperatures. Ultimate bond strength can be achieved more quickly (and in some cases bond strength can be increased) by exposure of the bond to elevated temperatures (e.g. 150°F [66°C] for 1 hour). This can provide better adhesive wetout onto the substrates. Abrasion of the surfaces or the use of primers/adhesion promoters can also have the effect of increasing bond strength and achieving ultimate bond strength more quickly.

  • Comparable Materials for 3M 4991

    *See Terms of Use Below

    Spec Engine® Results

    • 3M
      4956F(3M)

      • Gray, closed-cell acrylic foam carrier • Conformable • Good adhesion to many painted metals • Plasticizer resistant • UL 746C

    • 3M
      4941(3M)

      • Gray, closed-cell acrylic foam carrier • Conformable • Good adhesion to many painted metals • Plasticizer resistant • UL 746C

    • 3M
      4941F(3M)

      • Gray, closed-cell acrylic foam carrier • Conformable • Good adhesion to many painted metals • Plasticizer resistant • UL 746C

    • Compare All
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Peel Strength Test Methods
Peel Strength Type Cure Time Substrate Test Temperature Test Method
High
22 (lb/in) 90° Peel strength 4,320 min Stainless steel 25°C Based on ASTM D3330 -To stainless steel, room temperature, jaw speed 12 in/min (305 mm/min). Average force to remove is measured. 72 hour dwell.
Tensile Strength Test Methods
Tensile Strength Cure Time Substrate Test Temperature Test Method
High
70 psi 4,320 min Aluminum 25°C ASTM D-897 - To aluminum, room temperature, 1 in2 (6.45 cm2), jaw speed 2 in/min (50 mm/min.) Peak force to separate is measured. 72 hour dwell
Shear Strength Test Methods
Shear Strength Type Cure Time Substrate Test Time Test Temperature Test Method
High
65 psi Dynamic overlap shear strength 4,320 min Stainless steel 25°C ASTM D-1002 - To stainless steel, room temperature, 1 in2 (6.45 cm2), jaw speed 0.5 in/min (12.7 mm/min.) Peak force to separate is measured. 72 hour dwell.
1000 (grams) Static shear strength Stainless steel 600,000 sec 22°C ASTM D3654 - To stainless steel, tested at various temperatures and gram loadings. 0.5 in2 (3.22 cm2). Will hold listed weight for 10,000 minutes (approximately 7 days). Conversion: 1500 g/0.5 in2 equals 6.6 lb/in2, 500 g/0.5 in2 = 2.2 lb/in2.
500 (grams) Static shear strength Stainless steel 600,000 sec 66°C ASTM D3654 - To stainless steel, tested at various temperatures and gram loadings. 0.5 in2 (3.22 cm2). Will hold listed weight for 10,000 minutes (approximately 7 days). Conversion: 1500 g/0.5 in2 equals 6.6 lb/in2, 500 g/0.5 in2 = 2.2 lb/in2.
500 (grams) Static shear strength Stainless steel 600,000 sec 93°C ASTM D3654 - To stainless steel, tested at various temperatures and gram loadings. 0.5 in2 (3.22 cm2). Will hold listed weight for 10,000 minutes (approximately 7 days). Conversion: 1500 g/0.5 in2 equals 6.6 lb/in2, 500 g/0.5 in2 = 2.2 lb/in2.
High Temperature Resistance Test Methods
High Temperature Resistance Test Method
93°C Long Term Temperature Tolerance - Maximum temperature where tape supports at least 250 g load per 0.5 in2 in static shear for 10,000 minutes. (Represents continuous exposure for days or weeks).
121°C Short Term Temperature Tolerance - No change in room temperature dynamic shear properties following 4 hours conditioning at indicated temperature with 100 g/static load. (Represents minutes, hours in a process type temperature exposure).
90°C
Outstanding durability
Dielectric Constant Test Methods
Dielectric Constant Test Method
2.29 at 1 kHz, ASTM D150
1.99 at 1MHz, ASTM D150
Dielectric Strength Test Methods
Dielectric Strength Test Method
360 V/mil ASTM D140
Dissipation Factor Test Methods
Dissipation Factor Test Method
0.02450 at 1 kHz, ASTM D150
0.03740 at 1MHz, ASTM D150
Surface Resistivity Test Methods
Surface Resistivity Test Method
2.7e14 (ohm/sq) ASTM D257
Volume Resistivity Test Methods
Volume Resistivity Test Method
2.1e14 (ohm-cm) ASTM D257
Modulus Test Methods
Modulus Temperature Test Method
3e5 (Pa) 25°C Shear modulus, 1 Hz