TRUECAST XL-5500 is a low viscosity, urethane-molding compound specifically formulated to create a tough very durable polymer with low hardness that is especially well suited for creating wear resistant parts and surfaces.

Application and Mix Ratio

Material Processing

Component A as supplied does not require premixing. Component B should be premixed at the start of each work day to ensure even distribution of color pigment. Component A may crystallize and need to be warmed up to return to a liquid phase for processing. Once the Component A has crystalized it will need to be reheated to 120˚F (8-12 hours) to melt the crystalized material. After melting, the material will remain liquid for several days at lower temperatures (i.e. 70 – 80˚F) but with time, will return to a crystalized state. Normal warehouse temperatures of 70-90F are acceptable storage temperatures for this material to ensure a shelf life of 6 months. The material may be in acceptable condition after exceeding the 6 month shelf life, but will be need to be reacted (Component A with Component B) to produce samples for evaluation. Usually the hardness is the first physical property to indicate a reduction in reactivity due to prolonged shelf life, specifically softer than specification. Calibrated Shore A Hardness meters (ASTM-D-2240) can be purchased from Pacific Transducer incorporated (PTC, Inc.) 310-478-1134, Type A Meter Model# 305-L.

Heating supply line and dispensing hoses are recommended and can be done with simple vinyl heat tape wrapped around hoses and pumps then covered in inexpensive flexible insulation, commonly used for air conditioning applications. The vinyl heat tape is available from Spray Quip Corp 713-923-2771.

Hand mixing, carefully measure out Component A (100 parts) to Component B (48.9 parts) by Weight or 2A:1B by Volume. Use a flat metal spatula and mix for 1 minute then pour into another clean container and mix again for 1 minute then pour into mold. Using two mixing containers when mixing by hand ensures that no unmixed material will be included into the molded part. Unmixed material (part A or B) will cause weak spots in the molded part and early failure of the part.

When working with plural component equipment, differential heating of components A and B is desirable to balance the viscosity for better mixing. Depending on the plural component equipment and mixing nozzles the temperature may vary. Generally component A at 140°F combined with a component B at 110°F will produce satisfactory mixing. Avoid prolonged temperatures of over 160°F for both component A and component B.

Heated molds at 140˚F will allow rapid demold and handling of the parts. Avoid prolonged temperatures
of above 160˚F.

Adhesion Promotion

To achieve a chemical bond between the new TrueCast XL-5500 and older TrueCast XL-5500, thoroughly clean the cured polymer with a generous application of MEK (Methyl Ethyl Ketone) applied to cloth towel and allow to dry 30 minutes at 72˚F before applying the new TrueCast XL-5500.

Properties

Working Properties

Mix Ratio By Weight

100 parts A / 48.9 part B

Mix Ratio By Volume

100 parts A / 50 parts B

Viscosity @ 72°F (A Side)

10,000 - 12,500 CPS

Viscosity @ 72°F (B Side)

70 - 90 CPS

Viscosity @ 72°F (Mixed)

3500 - 3700 CPS

Color

Part A:

Clear

Color

Part B:

Black (other colors available)

Color

Mixed:

Black

Working Life @ 72°F

15-20 minutes

Working Life @ 150°F

6-8 minutes

Full Cure @ 72°F

72 hours

Full Cure @ 150°F

18 hours

 

Physical Properties

Specific Gravity (Part A)

1.00

Specific Gravity (Part B)

0.98

Specific Gravity (Mixed)

0.99

Weight/Gallon Part A

8.36 lbs.

Weight/Gallon Part B

8.17 lbs.

Weight/Gallon Mixed

8.29 lbs.

Cubic inch per lb. of product

0.0359 in3/lb.

Hardness @ 72° F

ASTM D-2240

55-65 Shore A

Linear Shrinkage

 

0.005%

Tear Strength

 

300-400 lb./in.

Tensile Strength

ASTM 412 Die C

2,000-3,000 psi

Elongation

ASTM 412 Die C

600-700%

 

Clean Up

Clean application equipment immediately after use with Isopropyl Alcohol (dry) or Toluene

Storage and Shelf Life

The containers should be stored in a cool dry area that is protected from direct sunlight and moisture.
Storage temperatures should not exceed 70˚- 90°F. The shelf life of factory sealed containers stored
under these conditions is six months.

Shipping

Class 55 Non-hazardous