HMC Electronics DP100 User Manual

3

3M™Scotch-Weld™Structural Adhesives

Product

1

Matching 3M structural adhesives
to your performance requirements

Selection

Guide

Documentation Provided By HMC Electronics

33 Springdale Ave. Canton, MA 02021

http://www.hmcelectronics.com

[phone]

Tensile Shear

Peel

Cleavage

Tensile is pull exerted equally over the entire joint. Pull

direction is straight and away from the adhesive bond.

Shear

is pull directed across the adhesive, forcing the substrates

to slide over each other.

Cleavage

is pull concentrated at one edge of the joint, exerting
a prying force on the bond. The other edge of the joint is
theoretically under zero stress.

Peel

is concentrated along a thin line at the edge of the bond
where one substrate is flexible. The line is the exact point where
an adhesive would separate if the flexible surface were peeled
away from its mating surface. Once peeling has begun, the
stress line stays out in front of the advancing bond separation.

Simplifying adhesive decisions for your application

The following questions will help you narrow adhesive choices to
two or three possibilities for evaluation.

Q1 What surfaces are to be bonded?

Understanding surface conditions is the first step to determining
how much bonding strength will be needed and which adhesives
may work best. For example, is the surface painted and with what
kind of paint? If the material is a plastic

, what kind? For bare metals,

will the surface be clean?

Q2 What are the general characteristics of the structural

adhesive types?

As a rule of thumb, 3M

™

Structural Strength Adhesives bond the
load-bearing parts of a product with a minimum of 1,000 psi overlap
shear strength.

• Epoxy adhesives in one and two-part formulations

provide the highest strength at elevated temperature and
chemical resistance of all 3M adhesives.

• Acrylic adhesives bond the widest variety of substrates including

hard-to-bond plastics and oily metal. The distinction is high
strength bonding without the surface preparation needed for
epoxies and urethanes

• Urethane adhesives are generally lower cost and cure quickly to an

elastic bond in applications requiring flexibility between dissimilar
materials. Impact resistance is a distinctive characteristic.

• Cyanoacrylate adhesives are high strength liquid formulations

known as instant adhesives. On rigid plastic, glass, metal, rubber

,
and other low porosity substrates, they harden in seconds
through reaction with surface moisture.

Q3 What is the present bonding or joining method?

When the answer provides likes/dislikes and advantages/disadvantages
of the current method, it is easier to determine if structural adhesive
can improve the end product quality and/or the production process.

Q4 What is the preferred bonding range?

This is often the biggest clue to help understand which product will
work best. Start with worklife – the amount of time you have to
apply and reposition – and then ask about time to handling strength
and full cure.

This could lead to productivity improvements.

Q5 Can simple surface preparation be included in the

production process?

Maximum bond strength and environmental resistance can be easily
achieved by cleaning with IPA/water (50:50 mix) and abrading with
Scotch-Brite

®

Surface Conditioning Products if the surface is very smooth.

Q6 What is the joint design and how will parts fit together?

For the best adhesive bond, there should be at least a .003"-.005"
gap between the parts for shear and 0.015" - 0.020" for peel. The
gap should be as consistent as possible.

Q7 To what types of environments and stresses

will the bond be subjected?

Consider bond line stresses, inside/outside end use, UV

exposure,

chemical exposure, moisture, and temperature ranges.

Strength can be readily matched to the substrate and stress
characteristics to which the bond will be subjected. Most adhesives
and tapes perform better when the primary stress is tensile or shear.
In most industrial applications, however, a combination of stresses
are involved that may include cleavage and peel.

In general, epoxies hold up best to harsh environments.

Q8 What is the preferred method of application?

Depending on formulation, 3M structural adhesives are available in
a variety of cartridge sizes, 5-gallon pails, and 55-gallon drums.

You

can apply manually or with automated bulk systems.

2

1

Documentation Provided By HMC Electronics

33 Springdale Ave. Canton, MA 02021

http://www.hmcelectronics.com

[phone]

Product
(Color)

Key
Features

Mix Ratio
(Volume)
B:A

Approximate
Viscosity
75°F (24°C)
(cps)

Approximate
Mixed Worklife
at 75°F (24°C)

Approximate
Time to Handling
Strength at 75°F
(24°C)

Average
T-Peel at
75°F (24°C)
(piw)

Overlap Shear (psi)

-67°F
(-55

°C)

75°F
(24°C)

180°F
(82°C)

1:1

13,000 5 minutes

20 minutes

2

900 1,500 300

1:1

8,500 4 minutes

20 minutes

10

3,000 3,500 200

1:1

95,000 5 minutes

20 minutes

2

900 1,500 300

1:1

80,000 6 minutes

20 minutes

2

1,250 2,200 800

1:1

6,500 5 minutes

20 minutes

35

3,500 2,000 150

1:1

55,000 8 minutes

20 minutes

20

2,700 3,500 250

1:1

50,000 8 minutes

20 minutes

20

2,500 2,500 200

1:1

52,500 25 minutes

2.5 hours

35

3,400 4,300 400

1:1

15,000 25 minutes

2.5 hours

35

4,000 2,500 150

1:1

80,000 90 minutes

10 hours

20

1,500 2,500 400

1:1

10,000 80 minutes

6 hours

20

3,500 1,200 150

3M™Scotch-Weld™Structural Adhesives in Duo-Pak Cartridges and Bulk

Epoxy

3M™ Scotch-Weld™ Structural Adhesive EC2216
bonds honeycomb to aluminum for common
applications in aerospace and transportation.

3M™ Scotch-Weld™ Epoxy Adhesive DP420
bonds the stainless steel shaft into the stainless
steel head of a golf club with handling strength
in two hours.

3M™ Scotch-Weld™ Low Odor Acrylic Adhesive
DP810 requires minimal surface preparation for
bonding metal hinges into awning frames.

Note: The technical information and data on these pages should be considered representative or typical only and should not be used for specification purposes.

* Available in Duo-Pak Cartridges only.

Duo-Pak Cartridges continued on next page.

General Purpose
Rigid bonds

Very flexible
Colorless

General Purpose
Non-sag

Flame Retardant
UL94 V-0 rating

Very flexible
Colorless

General Purpose
Flexible bonds

General Purpose
Flexible bonds

High Performance
Very flexible bonds

High Performance
Very flexible bonds

High Performance
Flexible bonds

High Performance
Flexible bonds

High Performance
Very flexible bonds

Rigid potting compound
Non-corrosive

Tough durable bonds
High impact resistance

Tough durable bonds
High impact resistance

Tough durable bonds
Non-sag

Tough durable bonds
High impact resistance

Tough durable bonds
Non-sag

DP100
(Clear)

DP100 Plus
(Clear)

DP100NS
(Translucent)

DP100FR
(White)

DP105
(Clear)

DP110
(Gray)

DP110
(Translucent)

DP125
(Gray)

DP125
(Translucent)

DP190
(Gray)

DP190
(Translucent)

EC2216*
(Gray)

DP270
(Black, Clear)

DP420
(Off-White)

DP420
(Black)

DP420NS
(Black)

DP460
(Off-White)

DP460NS
(Off-White)

3

2:3

80,000 90 minutes

10 hours

25

3,000 3,200 400

1:1

12,000 60 minutes

3 hours

2

1,200 2,500 300

2:1

30,000 20 minutes

2 hours

50

4,500 4,500 450

2:1

30,000 20 minutes

2 hours

50

4,500 4,500 1,250

2:1

180,000 20 minutes

2 hours

50

4,500 4,500 1,250

2:1

30,000 60 minutes

4 hours

60

4,500 4,500 700

2:1

125,000 60 minutes

4 hours

60

4,900 4,650 1,350

2

3

4

Documentation Provided By HMC Electronics

33 Springdale Ave. Canton, MA 02021

http://www.hmcelectronics.com

[phone]