prototyping-materials

Rigid Polyurethanes for
Twin-Tube and Machine Dispense Production

These polyurethane casting systems are designed for processing using twin-tube cartridges and machine dispensers, mixed through static mixers. These products have low mixed-viscosities, short working times and faster demold times, to allow quick cycling of molds. Most products listed here obtain full properties with room-temperature cures.

All products are listed with mix ratios shown by weight and by volume. You will find a page showing recommended static mixers for each product. Other static mixers may be sufficient, but those we suggest have been tested in our applications lab and have been proven to work.

You will find our casting systems to be among the highest performing available on the market. Products like PT8902 and PT8952, with our fast-setting hardeners, generate the highest impact strengths for hard, rigid polyurethanes with room-temperature cures. A few of these products are certified to UL94-V0 flame-retardant specifications, and PT8902 is certified to USP Class-VI requirements.

Some of the same products listed in this group are also shown with slower-setting hardeners in another section called Hand-Cast and Vacuum-Cast Products. Normally, those materials set up too slowly for twin-tube or machine casting, except where you need the extra working time for very large castings. We suggest using PTM&W urethane-based color dispersions for color-casting. Pigments from other manufacturers may work, but some have proven to be incompatible with our urethanes, resulting in streaking or molted colors or retarded cures and tacky surfaces.

Click on the product number below for more information:
PT8902 PT8907 PT8908 PT8925
PT8917, PT8918 and PT8919 PT8959 PT8970 PT8976

Product Description

PT8902
This urethane system is designed to allow you to produce the toughest parts available for prototype applications! It is a low viscosity urethane system with a very useable pot life. PT8902 forms an extremely tough white, opaque solid when cured. PT8902 has a notched Izod impact strength of over 2.0! PT8902 is Certified to USP Class VI requirements.

PT8907
A fast urethane casting system for machine dispensing that provides tough, durable parts with high impact strength. Two hardeners are available: Part B for fast demold at room temperature, and Part B1 for larger parts. Parts B and B1 can be blended for intermediate working times to suit the application. Both hardeners are black. A buff-colored version is available - the part number is PT8909.

PT8908
A fast urethane casting system for machine dispensing. This is a modification of our PT8907, with a longer pot life and lower mixed viscosity, to allow casting of larger parts. It develops strength quickly, and allows fast demold times for more cycles per day. PT8908 is not brittle in thin sections, and its heat resistance is very good.

PT8925
Transparent, water-white urethane casting system that is very useful for the production of tough, impact resistant clear parts. Three hardeners are available for producing various size parts from thin-walls to mass castings. Hardener B3 works well in machine dispensing use. Hardeners B1 and B2 are more appropriate for hand cast and vacuum casting uses. The cured parts have excellent toughness and durability.

PT8917, PT8918 and PT8919
PT8917, PT8918 & PT8919 are very low viscosity, modified polyurethane systems that provide tough cured parts with excellent heat resistance. They have easy-to-measure, 1 to 1 mix ratios for convenient use in dispensing machines or hand-packed cartridges. These products are identical, except for color, for casting versatility: The clean white color of PT8919 and the translucent natural color of PT8918 provide attractive castings, and they are very easy to dye or pigment for a wide variety of colored parts. PT8917 is black in color, and parts made with it have a rich, opaque, deep black appearance. These products have a fast, 60 second gel time, which allows quick demolding of the parts, and more production in a day. Their very low mixed viscosity allows complete mold filling, even though they have a fast setting time.

PT8959
PT8959 is a fast gelling fire retardant system for machine or cartridge dispensing uses. It has a low mixed viscosity that allows easy filling of thin mold areas. This system allows fast demold times for quick mold turnaround and more cycles per day. PT8959 is UL Listed for UL 94 V-0 at 0.12” thickness (UL File No. E238713.

PT8970
PT8970 is a Shore D-70 urethane system that has a high degree of toughness, and excellent stability for this hardness range. It is a good material for various types of tools and fixtures. Panels and parts made with PT8970 have high impact strength and resistance to cracking, for long, durable service. Part B hardener is more suited to hand casting larger parts, and Part B1 is intended for machine and cartridge dispensing. Black versions of both hardeners are available.

PT8976
PT8976 is a Shore D-80 urethane system that provides a unique combination of physical properties to enable the production of very tough and durable parts and assemblies. Parts made with PT8976 will have good rigidity and stiffness due to its very high modulus, and excellent resistance to breakage due to its very high tensile and impact strengths.