SGPU 385 VC is a polyurethane vacuum casting resin with excellent mechanical properties for products with high impact resistance and elasticity. SGPU 385 VC is a fire-retardant material and has been specifically developed for use in gravity vacuum casting machines. The product is approved for through the UL94 V-0 certification.
Mixing ratio: 100A: 120B (by weight) A = polyol, B = Isocyanate
Processing time (min.): 7 – 8
Demoulding time: 45 -60 min
Recommended processing thickness: maximum 15 mm
Viscosity: 350-850 mixed mPa.s
Density: 1.17 – 1.23 g / cm3
Tensile strength (N / mm2): 80 – 85.0 MPa
Hardness (Shore D): 85-90
Packaging: 1.835 kg, 9.175 kg
Flexural strength: 105 – 115 MPa
Flexural modulus: 2250 – 2750 MPa
Elongation at break: 6.0 – 8.0%
Linear shrinkage: <0.2%
Flame Retardancy: V-0 / UL94 3mm thickness
Clean the mold gently and then spray silicone release agent on the surface. Make sure the surface is dry before attaching the mold parts. Heat the mold in an oven to 60 – 70 ° C; this can take several hours if the mold is very large. Splitting the tool speeds up the heating process. We do not recommend the use of condensation-cured silicone rubber with this product.
Preparation of the resin:
Open both A and B packs and see if there is any crystallization of the material. In case of crystallization, place in the oven at 45 – 60 °. Both components of the resin must heated to 40 ° C before use. If using pigments, add the pigment to Part A. We recommend using 1-3% max. of pigment.
Processing – mixing & pouring:
Weigh the polyurethane PART A in cup A and urethane part B in mixing cup B. When making the first mix, allow an extra amount of A to account for the pouring loss in the cup. Degas for 5 – 10 minutes while slowly mixing Beaker B. After degassing, pour A into B while mixing. Mix the A and B components for 45 seconds, this one ensures thorough mixing of the components. When mixing is complete, pour the mixed material into the mold.
Immediately after pouring, put the mold in an oven at 70 ° C for 45-60 minutes. The curing time, especially in the thin sections, depends on the temperature of the mold. The warmer the mold, the faster the curing. We do not recommend pouring more than 15mm thick. A post-treatment can be applied to the product to improve its temperature resistance.
Allow the product to cure for 24 hours at room temperature and then heat for 1 hour at 60 ° C, 1 hour at 80 ° C, followed by 3 hours at 100 ° C. To avoid deformation during the post cure cycle, the unit must be placed on a conformer. After curing, let the unit cool slowly to room temperature, preferably in the oven. Sudden changes in temperature can cause deformation or warping. After the product has hardened, shrinkage may increase.
The above shrinkage value is given as a guide only. The shrinkage varies with each casting, due to factors such as shape size and shape geometry that can affect it.
In general, large, thick castings will have a higher shrinkage than the small and thin castings. Other factors such as mold temperature and resin temperature can also have an effect on this. Post-curing of the part can also lead to a greater degree of shrinkage. N.