Thin wall product designs

Due to SPS s unique low viscosity (an example is shown in Fig. 14.9), it is often injection-molded into parts with thin wall sections ( 0.7mm). Injection molding of thin-walled parts will push polymer and equipment to their design limits. Parts with wall thickness less than 0.7 mm and length to thickness ratios over 150 will require extra care in the product design phase. As wall sections become thinner, the fundamental design principles outlined in section 14.2.1 should be closely followed. 

---

Foamed fluoroplastics have been used in coaxial cables since the 1960s, but they are receiving increased interest for twisted-pair applications since the dielectric performance of all solids can be improved by the uniform addition of voids. Current efforts focus on smaller and more uniform voids that can be incorporated into thin-walled products such as micro coaxial cables and twisted pair cables. The use of advanced foamed perfluoroplastic resins provides the cable designer with options for improving cable performance and/or reducing cable weight [14,15]. 

There is no available evidence that PBDs occur in FIBC operations and therefore no demonstrated need for thin walled Type B containers designed with a breakdown voltage of 4 kV or less [lOj. However, since Type B containers are commercially available and in principle may offer slightly less risk, they might be considered where thin walls will not have a detrimental effect on product quality (6-7.1.1). 

The flow properties of the polymer must be matched to the mold (or vice versa) in order to achieve optimum product quality. In particular, we must manage the pressure drop between the gate and the furthest extent of the flow path. Articles with thin walls, such as margarine tubs, require low viscosity resins. In other cases, the situation is more complex and the cavity may need to be designed so that the product is thicker near the gate than it is at its extremities. The development of complex products is aided by computer modeling of melt flow within the mold cavity. 

In the field of technical ceramics, these requirements are usually satisfied. Extrusion is practiced with well-prepared, homogeneous compounds conducive to constant, uniform production. On the other hand, extrusion involves very high pressures, often in excess of 200 bar, and, frequently, body that is difficult to extrude. This calls for extrusion tools - inch everything from the extruder itself to the die exit - of hydraulically optimized design. Moreover, the extrudates and honeycomb elements for technical applications must display high levels of exactitude. For example, the engineering of a honeycomb die for thin-walled honeycombs, i.e., ceramic monoliths, with web thicknesses of 0.15 mm and less demands a degree of precision that can only be achieved with state-of-the-art machine tools. 

Technical — Reduced mass for smaller, more ctmvenient products — New thin-walled or microscaled applications, e.g., in medical engineering — Shorter cycle times — Simpler and safer molding and mold design — Wider process window for more stable process... 

P963 is a liquid phenolic resole designed to be used with catalyst P964 (para tolune sulphonic acid phosphoric acid) for the production of hand-lay or low pressure/low temperature compression moulding. The resin contains 10% acetone to provide a useable mix viscosity, fast binder breakdown and reinforcement wet-out. Principal use is for thin-walled aircraft components. 

Aoki Y, Miyaiii Y, Ichikawa Y, Abe F (2002) Product Design and Development of Ultra Thin Wall Ceramic Catalytic Substrate. SAE Technical Ptqier 2002-01-0350... 

---