ARALDITE® F / ARALDITE® CY 221 / HARDENER HY 842

Encapsulating or potting of low voltage and electronic components

The chemical reaction initiated by mixing resin and hardener results in the generation of exothermic heat. The peak temperatures attained are determined by the initial temperature, size and shape of the casting being produced. Unfilled resin systems are suitable only for manufacturing castings weighing up to about 500 grams. Mineral fillers should be added to dissipate heat and damp the exothermic reaction when producing large castings. There is very little exothermic reaction when producing very small castings or thin layers as the generated heat is rapidly dissipated. Curing is consequently delayed and the surfaces of castings may remain tacky. In such cases, an infrared heater or oven should be used to effect full curing.

The addition of powdered inorganic fillers such as silica flour, microdol, chalk flour, Alumina, aluminium hydroxide etc., has been found to offer considerable advantages in many applications. Specifically, the use of such fillers:

• enhance important mechanical and electrical properties
• reduce shrinkage and exothermic temperature rise during gelling and cure
• impart a lower coefficient of thermal expansion
• improve thermal conductivity
• impart a greater elasticity modulus whilst reducing elongation at break

Key	Value	Unit	Test Method	Test Condition
Flexural strength (max. bending stress)	50 - 60	MPa	ISO 178	System 1
Surface strain (failure)	30 - 40	%	ISO 178	System 1
Elongation (max.)	5.5 - 6.5	%	ISO 178	System 1
Elongation (break)	12 - 13	%	ISO 178	System 1
Impact strength	20 - 60	kJ/m²	ISO 179	System 1
Tensile strength at 23°C	30 - 40	MPa	ISO 527	System 1
Tensile stress (max.) at 23°C	30 - 40	MPa	ISO 527	System 1
Tensile stress (break) at 23°C	10 - 15	MPa	ISO 527	System 1
Elongation (max.) at 23°C	8 - 9	%	ISO 527	System 1
Elongation (break) at 23°C	4 - 5	%	ISO 527	System 1
Tensile strength at 0°C	30 - 40	MPa	ISO 527	System 1
Tensile stress (max.) at 0°C	30 - 40	MPa	ISO 527	System 1
Tensile stress (break) at 0°C	10 - 15	MPa	ISO 527	System 1
Elongation (max.) at 0°C	6 - 9	%	ISO 527	System 1
Elongation (break) at 0°C	6 - 10	%	ISO 527	System 1
Tensile strength at -20°C	20 - 30	MPa	ISO 527	System 1
Tensile stress (max.) at -20°C	20 - 30	MPa	ISO 527	System 1
Tensile stress (break) at -20°C	5 - 10	MPa	ISO 527	System 1
Elongation (max.) at -20°C	4 - 6	%	ISO 527	System 1
Elongation (break) at -20°C	10 - 15	%	ISO 527	System 1
Martens dimensional stability under heat	30 - 40	°C	DIN 53 458	System 1
Loss factor tan δ at 23°C	2.6	%	DIN 53 483	50 Hz, System 1
Loss factor tan δ at 40°C	5.6	%	DIN 53 483	50 Hz, System 1
Loss factor tan δ at 50°C	7	%	DIN 53 483	50 Hz, System 1
Loss factor tan δ at 60°C	24.4	%	DIN 53 483	50 Hz, System 1
Dielectric constant εr at 23°C	3.9	-	DIN 53 483	50 Hz, System 1
Dielectric constant εr at 40°C	4	-	DIN 53 483	50 Hz, System 1
Dielectric constant εr at 50°C	4	-	DIN 53 483	50 Hz, System 1
Dielectric constant εr at 60°C	7.4	-	DIN 53 483	50 Hz, System 1
Volume resistivity ρ at 23°C	3.3*10¹⁴	Ω·cm	DIN 53 483	System 1
Volume resistivity ρ at 40°C	9.7*10¹³	Ω·cm	DIN 53 483	System 1
Volume resistivity ρ at 50°C	1.8*10¹³	Ω·cm	DIN 53 483	System 1
Volume resistivity ρ at 60°C	8.8*10¹⁰	Ω·cm	DIN 53 483	System 1
Dielectric strength at 25°C (2 mm plate)	23	kV/mm	IEC 243	System 1
Dielectric strength at 40°C (2 mm plate)	50	kV/mm	IEC 243	System 1
Dielectric strength at 60°C (2 mm plate)	60	kV/mm	IEC 243	System 1
HT arc resistance at 25°C	60 - 70	s	ASTM 495	System 1
Tracking resistance at 25°C	KA 3c	-	IEC 112	System 1
Electrolytic corrosion at 25°C	A 1	-	IEC 53 489	System 1

 

Water absorption as function of CY 221/Ar F in the resin matrix

Increasing % of CY 221 in the resin matrix

 

Shore hardness 4 mm plate as function of CY 221/Ar Fin the resin matrix

 

 

Increasing % of CY 221 in the resin matrix

 

Shore hardness 4 mm plate as function of CY 221/Ar F in the resin matrix

Increasing % of CY 221 in the resin matrix

• The flexibility of castings can be adapted to requirements by combining
• Araldit F and CY 221 resin in various proportions
• Low tendency to cracking

Casting

Contamination of the eyesby resin, hardener or casting mix should be treated immediately by flushing with clean, running water for 10 to 15 minutes. A doctor should then be consulted. Material smeared or splashed on the skinshould be dabbed off, and the contaminated area then washed and treated with a cleansing cream (see above). A doctor should be consulted in the event of severe irritation or burns. Contaminated clothing should be changed immediately. Anyone taken ill after inhaling vapours should be moved out of doors immediately. In all cases of doubt call for medical assistance.

Safety precautions at workplace:
protective clothing : yes
gloves : essential
arm protectors : recommended when skin contact likely
goggles/safety glasses : yes
respirator/dust mask : recommended
Skin protection
before starting work : Apply barrier cream to exposed skin
after washing : Apply barrier or nourishing cream
Cleansing of contaminated skin : Dab off with absorbent paper, wash with warm water and alkali-free soap, then dry with disposable towels. Do not use solvents
Clean shop requirements : Cover workbenches, etc. with light coloured paper Use disposable beakers, etc.
Disposal of spillage : Soak up with sawdust or cotton waste and deposit in plastic-lined bin
Ventilation:
of workshop : Renew air 3 to 5 times an hour
of workplace : Exhaust fans. Operatives should avoid inhaling vapours.

Store the components in a dry place at 18-25°C, in tightly sealed original containers. Under these conditions, the shelf life will correspond to the expiry date stated on the label. After this date, the product may beprocessed only after reanalysis. Partly emptied containers should be tightly closed immediately after use.

For information on waste disposal and hazardous products of decomposition in the event of a fire, refer to the Material Safety Data Sheets (MSDS) for these particular products.