Micro-Injection Molding LSR: Exploring the Limits of What’s Possible Without us noticing, tiny plastic parts are increasingly making inroads into our lives: in cars, medical technology, mobile phones and wearables. Increasing numbers of these micro-parts are made of silicone. But what challenges does micro-injection molding pose for processors? Is liquid silicone, which is seeing increasingly widespread use, making processes more complex than they already are for thermoplastics? And where will the journey take us—how far can the limits of what is feasible be pushed?Get more news about Micro Precision Cold Extrusion Part Exporter,you can vist our website! The trend towards miniaturization has gained considerable momentum in recent years. Many products—and with them the parts they are made of—are becoming smaller, more delicately complex and more compact. Micro-injection molding is used to produce many of these complex, delicate parts. In medical technology, examples include the increasing numbers of minimally invasive operations or new methods of analysis. Another target group for micro-molding is consumer electronics with very small electronic and optical precision components for smartphones, among other things. Even luxury goods such as watches increasingly contain tiny components made of thermoplastic—for example, cog wheels in watch movements or clips—and silicone for tiny seals. It is the latter material, in particular, that is gaining increasing market share because of its special properties. Due to trends toward electromobility and autonomous driving, the automotive industry will also require larger numbers of micro-parts made of liquid silicone rubber (LSR) in the future. Micro-injection molding means working with part weights of significantly less than one gram. Right now, some manufacturers are already achieving part weights below one milligram—although it makes a big difference here whether the raw material is a thermoplastic with a low specific weight or a liquid silicone with higher density (typically 1.10 to 1.50 g/cm3). Micro-parts made of silicone are generally heavier than thermoplastic micro-parts, but they can be smaller—and more challenging—in terms of dimensions. But before we turn to the differences between LSR and thermoplastic in processing, it's worth taking a comprehensive look at the special challenges of micro-injection molding. These challenges exist independently of the raw material used, because some of the engineering challenges in micro-injection molding arise solely from the part—and part feature—dimensions and extremely low masses processed. Given a component 1.7 mm long and 0.9 mm in diam., the part weight made of LSR is 0.0005 g (Fig. 1). If you have 32 cavities, the total shot weight (including sprue) is then 0.125 g. This is the equivalent of about 125 grains of sugar. For comparison's sake, a sugar cube contains about 20,000 to 30,000 grains. Such small quantities as in this example—connecting elements used in instruments for ophthalmic diagnostics—now must be uniformly and repeatably distributed over all the cavities. The micro-injection unit, the sprue channel and thermal management are enormously important here in terms of quality, precision and repeatability. The sprue channel alone illustrates how much technical know-how micro-injection molding requires. Its volume must be in a balanced ratio to the volume of the molded part(s). Several boundary conditions have to be weighed against each other and the overall process optimized. Key factors are process management, the waste and energy statistics, the material price and cycle time. All this poses the greatest challenges for the equipment manufacturer and for the manufacturer of the micro-parts.