Limitations

Mechanical
Fastening

Blood Collection

Tubes

Immediate

Full Strength

Easy to use

Removable

Tolerance Specific,

Not suitable for

smaller components

Difficult to

automate

Offer stress

concerntration

Adhesive

Welding

Syringes, Catheters, Oxygenators and

Surgical equipment such

as Endoscopes

and Laparoscopes

Even Stress

distribution, Fills

large gaps

Joins dissimilar
materials,
Aesthetically
acceptable

Easily automated

Longer Set Up and

Processing Time,

Requires fixture

time

Prior Surface

preparation is

required

Can cause

contamination

Solvent

Bonding

Catheters,

Membrane

Oxygenators,

Microfluidic

devices

Low cost and

adaptability to

high speed

production

High strength

to weight ratio

Fast Process

Health and safety

issues, Harmful for

operators because

of the fumes that

are generated

Not usable on

thermosets, Poor

gap filling

Solvent Can cause

stress cracking

Ultrasonic

Welding

Respiratory Filters,
Blood Filters,
Catheters,
Cannulas,
Luers, Trocars,
Masks, Blister
Packs

Most widely used
method due to
clean weld and
produce high
strength joints
consistently

Does not
introduce any
additional
materials such as
adhesives into
the device

Fast, clean,
efficient and
repeatable process

Cannot be used on

Thermosetic

Plastic, Plastics

must be compatible

Ultrasonic

vibrations can

damage

electric components

High capital costs

and Tooling costs

for fixtures are

high

Vibration
Welding

Surgical

instruments,

Filters, I-V units,

Bedpans,

Insulated trays

Capability of

welding more

than one part at a

time

Capable of

producing strong,

pressure-tight

joints and also

works with multiplane

surfaces

Surface preparation

not required,

Adaptable to

automation

Plastics must be

rigid/flat, Must have

either flat or slightly

curved interfaces

Not usable on

Thermosets

High capital costs,

Capital expenditure

and special tooling

are required

Spin

Welding

Valves, Fluid filters,

Flow diverters,

Surgical trocars

Joins circular
parts under
pressure with a
circular, spinning
motion

Ease Of Assembly,

Simple and highly

energy efficient

process

Provides fast cycle

times

Suitable for parts

with a circular joint

line only

Spin welding can

generate

particulates

Limitation to

Circular Areas

only

RF

Welding

IV bags,
Disposable
hospital products,
Blister packs,
Blood and Urine
Bags

One of the most

widely used

methods,

Exclusively used

for welding thin

sheets

Relatively fast and
Energy Efficient,
Typical cycle time
less than 5 sec

Does not require

any special joint

designs or solvents

and adhesives

Material Must have

a relatively high

dielectric constant

Material must

have a relatively

high dielectric loss

For limited joint

Complexity and

Component size

Infrared

welding

Instrument panels

and Filter

Assemblies

Particularly

appropriate for

higher-temperatures

processing

Non-contact

process, Joints

are free from

contamination

Suitable for

Complex curved

joints

Temperature

control requires

constant current

Higher tooling and
maintenance costs
(requires infrared
platen)

Process may

create smoke and

fumes

Hot plate

welding

Filter cartridges,

artificial joints,

braces and splints

For Complex

geometries,

large/multiple

small parts and

parts

For parts having
irregular shape, or
curved or internal
walls

Higher joint
strength and Cost effective

Higher power

consumption

(required for

heaters)

Require Warm-up

time (Preheating)

Higher tooling

costs

Laser

Welding

Microfluidic

Sensor, PTCA

catheter, Micro

Atomizer and Cell

culture Flask

Useful when

Micrometer

range is required

High Speed,

Shorter Cycle

time, Particle-free

processing

Precision,

cleanliness, and

High speed

Production

Laser welding

plants are

expensive

High Capital cost

of Equipments and

High maintenance

cost

Mainly Restricted
To flat shapes only

Plasma

Processing

Microtiter
Plates

Suitable for
chemical resistant
materials

Suitable for

Bonding mismatched

plastics

Improved lubricity

and surface

adhesion