in Liquid Rubber & Plastic for Moldmaking & Casting

Prototypes & Tooling

Poly 1512: Poly Urethane Liquid Plastic
Artloft Offers High Praise on a Difficult Project

     Poly 1512 Liquid Plastic has been used extensively by model makers and prototype shops for casting a myriad of decorative and functional plastic objects. Artloft, Inc., in Bensalem, PA, is just such a company that specializes in sculpting, pattern making, and prototyping services for the toy and collectible industries as well as for numerous other industrial clients. For the past several years, Artloft has been using Poly 1512 as their staple liquid plastic when cast polyurethane parts are needed. Poly 1512 is a 1:1-mix, high-performance, white, polyurethane liquid resin with a long working time and low mixed    viscosity.
     Poly 1512 is such a versatile system that it can used for almost every application where a cast plastic part is needed, such as a sales model, a pre-production casting, a trade show or advertising model, or even a completely functional part. Poly 1512 is easy to work with and very tough when cured—two very desirable properties for model makers.
     In a recent project completed at Artloft, Poly 1512 was used to create 60 large trays that became working components of an automatic inventory system. The design and function of these trays placed demanding constraints on the casting material. As seen from the photo, this tray is long, deep, and thin-walled, with many holes and locating slots throughout the part. Each casting required over 5 pounds of plastic. Due to its size and geometry, a low-viscosity plastic with a long working time was a necessity.
     To assist in filling the mold properly, the mixed and degassed 1512 was placed into a pressure pot where 20 psi of air was used to force the thin liquid into the silicone mold cavity from both ends (see photo) and out a series of strategically placed vents. With a wall thickness of approximately 1/8 inch on a 40-inch-long part, this method insured uniform resin distribution before gelling occurred. Artloft found the 20-minute working time to be a real benefit. For times when a faster demold is necessary, Poly 1512X, which has a 5-minute working time, can be used.
     Amazingly, these trays were made without the use of traditional pressure-casting techniques, yet were free of bubbles and defects! Upon demolding, the vents were removed and the parts were sanded. Poly 1512 sands, drills, and machines extremely well, and it can be readily patched with polyester fillers and glued with acrylates, if necessary. No painting was required to finish the trays since the 1512 itself was pigmented a light gray. Poly 1512 is very easily color-cast with a variety of easily obtained colorants such as Tints All pastes found at many home supply and hardware stores. Color-casting is a popular technique with polyurethane plastics such as 1512, so that in the event a part gets scratched or chipped, the color will remain the same.
     Every tray was a success. The strength and nonbrittleness of 1512 in thin sections made it ideal for an application like this. As Jim Sadlik of Artloft summarized, "Poly 1512 flowed beautifully and could be counted on for its consistency in performance and physical properties." Poly 1512 is also becoming widely accepted as one of the more cost-effective prototyping plastics in the industry, with properties that have been previously associated with more-expensive products. In addition to Poly 1512, Artloft often uses Easy-Flo™ 60 Poly Urethane plastic for fast-cast applications and Poly 1420 for clear-cast parts.
     For more information on Poly 1512 or other Poly Urethane Liquid Plastics from Polytek®, please contact Polytek®'s technical support depar™ent at (610) 559-8620 or email sales@polytek.com.

Polypoxy® Epoxy Resins Can Take the Heat Polypoxy® Resins—Products That Help "Shape" Our Lives

     Vacuum-forming and thermoforming techniques are used to create the diverse array of shapes of many plastic objects that surround us day to day. Whether it be a plastic box for keeping pizzas hot while out on delivery, a babytooth holder, or even a motorcycle windshield, vacuum and thermoforming techniques are typically employed.
     Regal Plastics in Littleton, CO, vacuum- and thermoforms virtually every plastic material available, with the help of Polytek®'s PolyPoxy® Epoxy Resins. Polyethylene, ABS, styrene, and Kydex are just a few of the plastics that are routinely formed by Regal. Leonard Koenig of Regal Plastics says, "PolyPoxy® 1030 and Poly Cure 1230 are great products for this application. The 1030/1230 epoxy flows into and picks up perfect detail, and the ambient cure is excellent. The tools just last forever."
     PolyPoxy® 1030 Resin is heavily filled with aluminum powder. The aluminum content is great enough in PolyPoxy® 1030 that the tool acts almost like a solid block of aluminum. Aluminum has the desirable quality of quickly and uniformly conducting heat, which means a tool can be kept at a uniform temperature during the forming process or can be precisely cycled through various temperatures, as is required when working with materials such as polypropylene that are subject to warping when cooled too quickly.
     When mixed, the 1030/1230 system exhibits a low initial mixed viscosity for such a heavily filled aluminum epoxy and has a very long working time. Even with a 120-minute working time, a casting can still be demolded after 24 hours at room temperature. Unlike PolyPoxy® 1030, many other epoxies used for vacuum-forming applications need to be heat-cured to obtain a complete overnight cure or to develop sufficient heat resistance. Heat curing is awkward for larger tools since it requires a large oven. Although the thermal resistance of PolyPoxy® 1030 with 1230 is more than adequate for most vacuum-forming applications, heat-curing can decrease the demold time of the tool as well as improve its heat resistance for higher-temperature applications. Don't forget to consider Polytek®'s new Poly 15-8 aluminum-filled polyurethane plastic for similar heat-resistant applications.

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