Silpak, Inc

Foam

Rigid Urethane Foams

SP-328-2, 4, 4TH, 8 and 12 are liquid, two-component, low density, closed cell, water blown, self-skinning, rigid urethane structural foams with easy 1:1 by volume mix ratios.

Applications:
Furniture production, duck decoys, floats, light weight furniture parts, picture frames, light weight mold shells (SP-328 4TH), models, patterns, custom sculpting blocks (SP-328-4), any application where a high-density, light-weight part is required.

Typical Properties of Liquid Components: 
                        Component A         Component B
Viscosity,cps:     150-190                 900-1300
Specific Gravity:  1.12                      1.04

Processing Characteristics:

Reactivity Data @ 77F (25C)
Mix Ratio: By Volume--100 A to 100 B    By Weight--52 A to 48 B 
Cream Time: 1 minute
Rise Time: 2 min / 30 sec.
De-Mold: 10-15 min.

Mold Preparation:

Polyurethane foams adhere to most surfaces and a release agent should be applied prior to casting. Silicone RTV and hard tool molds (Aluminum, Fiberglass, Plaster, and Epoxy) can be used to mold foam parts. Prepare mold surface with proper mold release such as R-80 or MOLD WAX prior to casting when using non-silicone molds. Mold should also be completely free of any moisture. For optimal castings, mold should be heated to 75-85F for initial casting. Once heated and cycled, mold should maintain heat for continued production.

Mixing:

Mix materials by volume at recommended ratio--off ratios can result in poorly formed parts and surface. Mix A & B with high‑speed mixer for 15‑20 seconds, and pour immediately into mold cavity, swishing liquid over mold surface to improve product’s surface skin. Several experimental parts will be needed to adjust the amount of material to achieve a satisfactory part.

Curing:

Over-packing foams by 3-5% over their free-rise density is recommended to achieve best surface detail and mold fill. Proper mold venting such as the use of bleeder paper or a vented lid that allows air to escape as foam rises should be firmly clamped in place prior to material rise. Once rise begins, avoid agitating or moving molds, which may cause foam cells to collapse. Castings should remain in mold until cured.

ACCESSORIES
*R-80 Mold Release–Wax solution used for hard or rubber tooling molds to improve skin quality on cast part
*CU-Pigments—Custom color parts--Red, Blue, Black, White, Brown, Fleshtone, Yellow

Storage: Area should be maintained between 65F and 86F.
Shelf Life: 6 Months Unopened, sealed containers.

The information and data contained herein are based on information we believe reliable. Each user of the material should thoroughly test any application and independently conclude satisfactory performance before commercializing. Suggestions of uses should not be taken as inducements to infringe on any particular patent.