RTV stands for Room Temperature Vulcanization. It refers to a rubber material that will completely cure at room temperature. By encapsulating your part in silicone, we can create a rubber mold that will allow us to make a number of copies of the part using, in most cases, polyurethane.

RTV (Room Temperature Vulcanization) silicone molding is a well-recognized rapid tooling method for producing small quantities of production-like prototypes of plastic injection molded parts. Short mold lead times are coupled with exceptional detail and surface finish. Complex parts with undercuts can be produced using this process. RTV molding is very cost-effective at low quantities while maintaining good accuracy and excellent detail. Prototype parts can be colour-matched and textured with a variety of material characteristics. Durometers range from very soft foams or rubbers to very rigid nylon-like materials. Some functional testing can be performed.

The RTV mold is created from a master pattern, typically an RP model. The pattern is used to create a silicone rubber mold. The silicone is poured around the pattern to produce a core and cavity of a mold. The RP model is then removed, leaving a negative image into which polyurethane is cast. These molds can produce up to 20 parts per mold, and they can be made as family or multi-cavity molds.

Reaction Injection Molding (RIM) is the process by which molded polyurethane parts are made. In the process, 2 liquid components are mixed and injected into the mold where they chemically react and cure.
Polyurethane molded parts can be rigid and solid like an injection molded ABS or they can be a structural foam or elastomeric like rubber.
Two liquid reactants – the polyisocyanate component and resin mixture are held in separate temperature-controlled feed tanks equipped with agitators. From these tanks, the polyol and isocyanate are fed through supply lines to metering units that precisely meter the reactants, at high pressure, to the mix head. When injection begins and valves in the mixhead open, the liquid reactants enter a chamber in the mixhead at pressures between 1,500 and 3,000 psi where they are intensively mixed by high-velocity impingement. From the mixing chamber, the liquid flows into the mold at approximately atmospheric pressure and undergoes an exothermic chemical reaction, forming the polyurethane polymer in the mold. Shot and cycle times vary, depending on the part size and the polyurethane system used. An average mold for an elastomeric part may be filled in one second or less and be ready for demolding in 30- 60 seconds. Special extended gel time polyurethane RIM systems allow the processor to fill very large molds using equipment originally designed for molds with smaller volumes.

Ready-to-shoot injection molds in 2-3 weeks!
LK-Mould provides ready-to-shoot Aluminum tools (QC7) for customers who need production parts in short order. For our customers who cannot wait 12-16 weeks for traditional or offshore tooling to be made, LK-Mould offers Low-Volume Injection Mold Tooling and Parts.
In contrast to our Rapid Injection Molding offering, Low-Volume Injection Mold Tooling Parts has no geometry limits on part dimensions and allows any commercially available material and surface finish.
With press sizes ranging from 20 tons to 3,500+ tons, LK-Mould can meet your injection needs;

Our high-speed CNC machining operation allows us to facilitate short lead times and competitive pricing on precision CNC rapid prototypes and masters, and also for short-run needs, hybrid molds, and presentation models. We operate the latest software and machines manufactured by Fadal and HAAS, including part beds up to 84″ x 30, which are equipped with 4th-axis motion. Complex feature and contoured surface programming is handled with the latest version of Mastercam, a package that programs quickly and runs NC check to verify each setup and cutter path is accurate.

Low Quantity Injection Molding For Life Sciences Industry
The Reaction Injection Molding (RIM) process economically produces low-quantity injection molded parts for the Life Sciences industry. Medium to large enclosures and housings can be produced in low quantities from low-cost tooling. Designing for the RIM process is easier than designing injection molded parts because the RIM process allows much more design freedom.

The RIM process is relatively new and perhaps the least understood, most underutilised of the low-pressure processes for plastic parts. Recent developments in resins have allowed this high-value process to compete with injection molding. Thin wall parts that meet UL flame requirements can be produced with faster cycle times. Plastics experts call RIM the low-pressure process that comes closest to duplicating injection molding attributes. It has impressive large-part, small quantity, and low initial investment capabilities.

OEMs in the Life Sciences industry are using RIM instead of injection molding, vacuum forming, pressure forming, structural foam, sheet metal, or metal casting. RIMs lower cost tooling allows them to get their products to market faster and to change them more.

The answer to this question highly depends on the part geometry and choice of material, but typically you can expect a single rubber mold to yield about 25 parts.

The physical tolerances on our SLA models are about +/- 0.005. For parts over 5, we can hold around +/- 0.001 to 0.0015 per inch. Part geometry and build orientation can also have an effect on tolerances.