TASK™ 21

Description

This performance urethane casting resin offers mechanical characteristics similar to ABS plastic.

TASK™ 21 provides high compressive and flexural strength, is odorless, and easy to process. The mix ratio is 2A:1B by weight or volume, with a working time of 6 minutes and handling strength reached in 60 minutes at room temperature, depending on mass and configuration.

TASK™ 21 features a low mixed viscosity of 500 cps and de-airs itself when cast into molds.

It can be colored with SO-Strong™ or IGNITE™ colorants and modified with various powder fillers to alter performance or appearance.

Applications

Rapid prototyping
Casting strong and highly detailed models
Making holding/assembly fixtures
Figurines and decorative castings

Note: Cannot be cast into platinum-cure silicone molds; tin-cure silicone or urethane rubber molds with a release agent are recommended.

Technical Properties

Mix Ratio By Volume: 2A:1B
Mix Ratio By Weight: 2A:1B
Pot Life: 6 minutes
Cure Time: 1 hour
Shore Hardness: 75 D
Specific Gravity: 1.07 g/cc
Specific Volume: 0.93 cm³/g
Color: White
Tensile Strength: 37.9 MPa
Tensile Modulus: 1,862 MPa
Elongation @ Break: 7.5%
Flexural Strength: 48.9 MPa
Flexural Modulus: 1,724 MPa
Compressive Strength: 48.9 MPa
Heat Deflection Temp: 62°C
Compressive Modulus: 541 MPa
Shrinkage: 0.0058 mm/mm
Mixed Viscosity: 500 cps

Instructions

Storage and Preparation

Store and use materials in a warm environment (23°C).

These products have a limited shelf life and should be used promptly.

All liquid urethanes are moisture sensitive and will absorb atmospheric moisture. Use clean mixing tools and metal, glass, or plastic containers. Mix in a well-ventilated area. Wear safety glasses, long sleeves, and rubber gloves to minimize the risk of contamination.

Mixing

Mix ratio is 2A:1B by volume or weight. Shake or stir Part A & Part B before using. Add Part A to Part B and mix thoroughly. Stir slowly and deliberately, ensuring to scrape the sides and bottom of the mixing container several times. Avoid splashing low viscosity material out of the container. Higher mass concentration accelerates gelling and curing. Do not delay between mixing and pouring.

Pouring

Pour the mixture in a single spot at the lowest point of the mold and let it seek its level to minimize air entrapment. Casting thickness should not exceed 1.27 cm (½ inch).

Curing

Use with proper workshop ventilation or near a forced-air outlet vent, and do not inhale fumes. Fumes dissipate quickly with adequate ventilation. Castings with significant mass may be hot to the touch and may irritate the skin immediately after cure. Let the casting cool to room temperature before handling. Demold time depends on mass and mold configuration.

Safety and Handling

Warning: Fumes may be visible as the product starts to gel and cure. Only use with room-size ventilation and do not inhale fumes. Castings will be extremely hot immediately following cure and may burn the skin. Let cool to room temperature before handling. If machining cured plastics, wear a dust mask or other apparatus to prevent inhalation of residual particles.

Additional Tips

Applying A Release Agent: If unsure about surface compatibility, perform a trial casting on a similar surface finish. Polyurethane, latex, or metal molds should be dry and require a coat of suitable release agent. Apply a liberal coat of release agent onto all surfaces that will contact the plastic. Lightly brush the release agent onto all surfaces with a soft brush, then apply a light mist coating, and let it dry for 30 minutes.

Vacuuming: The material is low-viscosity and does not require vacuum degassing. If vacuuming, subject the mixture to 29 h.i.g. mercury in a vacuum chamber until the mixture rises, breaks, and falls. Allow for 3 to 4 times volume expansion in the mixing container.

Foam Backfilling: For rotational or hollow castings, backfilling with a rigid foam (Foam-iT! 5 or other) provides lightweight reinforcement. Foam backfilling is recommended if castings will be subjected to temperatures above 30°C.

Specifications

Color	White
Mixed Viscocity	500 cps
Cure Time	1 hour
Pot Life	6 minutes
Flexural Strength	7,100 psi
Flexural Modulus	250,000 psi
Specific Volume	25.9 cu. in./lb.
Specific Gravity	1.07 g/cc
Mix Ratio By Weight	2A:1B
Shrinkage	0.0058 in. / in.
Mix Ratio By Volume	2A:1B
Tensile Strength	5,500 psi
Elongation At Break	7.5 %
Shore D Hardness	75
Heat Deflection Temp	144 °F
Compressive Strength	7,100 psi
Tensile Modulus	270,000 psi
Compressive Modulus	78,500 psi

Available in Polyurethane Resin

Product	Cure Time	Specific Gravity	Specific Volume	Color	Tensile Strength	Tensile Modulus	Compressive Strength	Compressive Modulus	Flexural Strength	Shrinkage	Heat Deflection Temp	Elongation At Break	Flexural Modulus	Mixed Viscocity	Mix Ratio By Volume	Mix Ratio By Weight	Pot Life	Shore D Hardness	Color	Mixed Viscocity	Cure Time	Pot Life	Flexural Strength	Flexural Modulus	Specific Volume	Specific Gravity	Mix Ratio By Weight	Shrinkage	Mix Ratio By Volume	Tensile Strength	Elongation At Break	Shore D Hardness	Heat Deflection Temp	Compressive Strength	Tensile Modulus	Compressive Modulus	Handling Time	Handling Time	Heat Deflection With Post Cure	Heat Deflection With Post Cure	Shore A Hardness	Die C Tear Strength	Hundred Percent Modulus	Hundred Percent Modulus	Die C Tear Strength	Shore A Hardness
TASK™ 2	60 min.	1.12 g/cc	24.7 cu. in./lb.	White	6,650 psi	290,000 psi	8,300 psi	78,000 psi	9,500 psi	0.005 in. / in.	134 °F	6 %	288,000 psi	150 cps	1A:1B	115A:100B	7 min.	80	White	150 cps	60 min.	7 min.	9,500 psi	288,000 psi	24.7 cu. in./lb.	1.12 g/cc	115A:100B	0.005 in. / in.	1A:1B	6,650 psi	6 %	80	134 °F	8,300 psi	290,000 psi	78,000 psi	-	-	-	-	-	-	-	-	-	-
TASK™ 3	90 min.	1.12 g/cc	24.7 cu. in./lb.	White	6,650 psi	290,000 psi	8,300 psi	78,000 psi	9,500 psi	0.0025 in. / in.	134 °F	6 %	288,000 psi	150 cps	1A:1B	115A:100B	20 min.	80	White	150 cps	90 min.	20 min.	9,500 psi	288,000 psi	24.7 cu. in./lb.	1.12 g/cc	115A:100B	0.0025 in. / in.	1A:1B	6,650 psi	6 %	80	134 °F	8,300 psi	290,000 psi	78,000 psi	-	-	-	-	-	-	-	-	-	-
TASK™ 4	16 h.	1.167 g/cc	23.9 cu. in./lb.	Ivory	6,500 psi	130,000 psi	7,400 psi	75,000 psi	9,000 psi	0.0035 in. / in.	110 °F	4 %	204,000 psi	250 cps	-	100A:100B	20 min.	83	Ivory	250 cps	16 h.	20 min.	9,000 psi	204,000 psi	23.9 cu. in./lb.	1.167 g/cc	100A:100B	0.0035 in. / in.	-	6,500 psi	4 %	83	110 °F	7,400 psi	130,000 psi	75,000 psi	-	-	-	-	-	-	-	-	-	-
TASK™ 5	24 h.	1.1 g/cc	25.2 cu. in./lb.	Tan	4,530 psi	200,000 psi	6,700 psi	83,000 psi	6,480 psi	0.007 in. / in.	145 °F	5 %	216,000 psi	600 cps	1A:1B	1A:1B	3 min.	77	Tan	600 cps	24 h.	3 min.	6,480 psi	216,000 psi	25.2 cu. in./lb.	1.1 g/cc	1A:1B	0.007 in. / in.	1A:1B	4,530 psi	5 %	77	145 °F	6,700 psi	200,000 psi	83,000 psi	15 min.	15 min.	-	-	-	-	-	-	-	-
TASK™ 6	24 h.	1.07 g/cc	25.9 cu. in./lb.	Tan	5,200 psi	146,000 psi	5,570 psi	65,000 psi	6,200 psi	0.0031 in. / in.	162 °F	4 %	182,500 psi	800 cps	1A:1B	1A:1B	7 min.	75	Tan	800 cps	24 h.	7 min.	6,200 psi	182,500 psi	25.9 cu. in./lb.	1.07 g/cc	1A:1B	0.0031 in. / in.	1A:1B	5,200 psi	4 %	75	162 °F	5,570 psi	146,000 psi	65,000 psi	75 min.	75 min.	-	-	-	-	-	-	-	-
TASK™ 7	10 min.	1.2 g/cc	23.1 cu. in./lb.	Off-White	3,390 psi	150,700 psi	5,140 psi	57,600 psi	5,450 psi	0.0111 in. / in.	131 °F	15.1 %	148,900 psi	200 cps	1A:1B	104A:100B	2.5 min.	73	Off-White	200 cps	10 min.	2.5 min.	5,450 psi	148,900 psi	23.1 cu. in./lb.	1.2 g/cc	104A:100B	0.0111 in. / in.	1A:1B	3,390 psi	15.1 %	73	131 °F	5,140 psi	150,700 psi	57,600 psi	-	-	-	-	-	-	-	-	-	-
TASK™ 8	15 min.	1.09 g/cc	25.4 cu. in./lb.	Off-White	5,840 psi	246,000 psi	8,760 psi	77,400 psi	8,280 psi	0.01 in. / in.	194 °F	4 %	271,000 psi	100 cps	1A:1B	120A:100B	2.5 min.	80	Off-White	100 cps	15 min.	2.5 min.	8,280 psi	271,000 psi	25.4 cu. in./lb.	1.09 g/cc	120A:100B	0.01 in. / in.	1A:1B	5,840 psi	4 %	80	194 °F	8,760 psi	246,000 psi	77,400 psi	-	-	263 °F	263 °F	-	-	-	-	-	-
TASK™ 11	16 h.	1.12 g/cc	24.7 cu. in./lb.	Translucent White	2,500 psi	-	-	-	-	0.0024 in. / in.	-	100 %	-	2,000 cps	-	100A:100B	20 min.	60	Translucent White	2,000 cps	16 h.	20 min.	-	-	24.7 cu. in./lb.	1.12 g/cc	100A:100B	0.0024 in. / in.	-	2,500 psi	100 %	60	-	-	-	-	-	-	-	-	-	-	-	-	-	-
TASK™ 12	16 h.	1.08 g/cc	26 cu. in./lb.	Clear Amber	2,700 psi	-	-	-	-	0.001 in. / in.	-	300 %	-	2,400 cps	-	100A:44B	20 min.	60	Clear Amber	2,400 cps	16 h.	20 min.	-	-	26 cu. in./lb.	1.08 g/cc	100A:44B	0.001 in. / in.	-	2,700 psi	300 %	60	-	-	-	-	-	-	-	-	-	-	-	-	-	-
TASK™ 13	20 min.	1.15 g/cc	24.1 cu. in./lb.	Black	1,800 psi	-	-	-	-	0.005 in. / in.	-	125 %	-	800 cps	-	100A:120B	3 min.	50	Black	800 cps	20 min.	3 min.	-	-	24.1 cu. in./lb.	1.15 g/cc	100A:120B	0.005 in. / in.	-	1,800 psi	125 %	50	-	-	-	-	-	-	-	-	-	-	-	-	-	-
TASK™ 14	45 min.	1.15 g/cc	24.1 cu. in./lb.	Black	1,800 psi	-	-	-	-	0.0035 in. / in.	-	125 %	-	800 cps	-	100A:120B	10 min.	50	Black	800 cps	45 min.	10 min.	-	-	24.1 cu. in./lb.	1.15 g/cc	100A:120B	0.0035 in. / in.	-	1,800 psi	125 %	50	-	-	-	-	-	-	-	-	-	-	-	-	-	-
TASK™ 15	1 h.	1.12 g/cc	24.7 cu. in./lb.	Opaque White	2,720 psi	126,000 psi	5,450 psi	60,000 psi	5,450 psi	0.0042 in. / in.	117 °F	20 %	170,000 psi	600 cps	-	75A:100B	6 min.	75	Opaque White	600 cps	1 h.	6 min.	5,450 psi	170,000 psi	24.7 cu. in./lb.	1.12 g/cc	75A:100B	0.0042 in. / in.	-	2,720 psi	20 %	75	117 °F	5,450 psi	126,000 psi	60,000 psi	-	-	-	-	-	-	-	-	-	-
TASK™ 16	24 h.	1.08 g/cc	25.64 cu. in./lb.	Light Yellow	2,264 psi	-	-	-	-	0.0025 in. / in.	-	233 %	-	1,400 cps	-	1A:2B	6 min.	30	Light Yellow	1,400 cps	24 h.	6 min.	-	-	25.64 cu. in./lb.	1.08 g/cc	1A:2B	0.0025 in. / in.	-	2,264 psi	233 %	30	-	-	-	-	90 min.	90 min.	-	-	80	197 pli	855 psi	855 psi	197 pli	80
TASK™ 18	16 h.	1.57 g/cc	17.6 cu. in./lb.	Metal Gray	3,250 psi	514,000 psi	8,420 psi	97,300 psi	10,700 psi	0.0006 in. / in.	149 °F	1 %	86,000 psi	4,400 cps	-	26A:100B	20 min.	88	Metal Gray	4,400 cps	16 h.	20 min.	10,700 psi	86,000 psi	17.6 cu. in./lb.	1.57 g/cc	26A:100B	0.0006 in. / in.	-	3,250 psi	1 %	88	149 °F	8,420 psi	514,000 psi	97,300 psi	-	-	-	-	-	-	-	-	-	-
TASK™ 21	1 h.	1.07 g/cc	25.9 cu. in./lb.	White	5,500 psi	270,000 psi	7,100 psi	78,500 psi	7,100 psi	0.0058 in. / in.	144 °F	7.5 %	250,000 psi	500 cps	2A:1B	2A:1B	6 min.	75	White	500 cps	1 h.	6 min.	7,100 psi	250,000 psi	25.9 cu. in./lb.	1.07 g/cc	2A:1B	0.0058 in. / in.	2A:1B	5,500 psi	7.5 %	75	144 °F	7,100 psi	270,000 psi	78,500 psi	-	-	-	-	-	-	-	-	-	-

Danger