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Injection manufacturing makes it possible to functionalize the surfaces of microtextured plastic parts without resorting to expensive post-treatments. An instrumented mold was developed and microtextures were etched in the cavity with a femtosecond laser. A setting methodology only following in situ parameters, especially cavity pressurizing velocity was used to complete process control. The quality of the replication was quantified by the ratio, R, of microtexture part height replication over etched texture depth in the cavity. Different setting parameters such as injection velocity, [V.sub.f], mold temperature, [T.sub.Mo], and holding pressure, [PH.sub.Max]> were investigated on two different injection molding machine. A statistical analysis enabled a validation of the protocol while showing that the influence of the injection molding machine is nonsignificant. Furthermore, injection velocity appeared as a key parameter, it acts at the same time on the thermal aspect of the flow front, frozen-layer fraction creation, but more importantly on the polymer's viscosity. An injection velocity threshold where above, mold temperature and holding pressure become secondary for better quality replication. This allowed as well to establish an empiric expression which makes it possible to calculate a pattern quality replication ratio, R, according to different parameters ([V.sub.f], [T.sub.Mo], [PH.sub.Max]) KEYWORDS injection molding, plastics, processing, sensors, 1 | INTRODUCTION Microinjection molding covers two types of manufacturing: parts manufacturing containing very small volumetric dimensions (submillimeter scale) [1] and the manufacturing of parts with larger dimensions that have [...]

Fieldbus systems are well known in the industrial automation world. Due to the increasing demand for scalability and capability of working in harsh environment, the use of wireless communication is gaining in importance. In the past, some efforts were pursued to encapsulate wired standards over wireless link, but their diffusion is limited by reliability and predictability requirements. In addition, event-driven protocols borrowed from the consumer world (as IEEE802.11 or IEEE802.15.4) are not well suited for some industrial applications. In this paper, authors present the design and the experimental evaluation of a wireless real-time communication protocol that tries to overcome these limits. It exploits standard hardware to lower cost and implements a hybrid medium access strategy. Time Division Multiple Access scheduling is used to ensure time deadlines respect, while Carrier Sense Multiple Access with Collision Avoidance is used for acyclic communications, as those involved in network management. It has been successfully adopted for temperature monitoring in plastic machineries. The prototype network adopts star topology and can manage up to 16 nodes with a refresh time of 128 ms. Index Terms--Low-power system, real-time systems, synchronization, wireless sensor network (WSN).

The univariant element, Q(sub 1) P(sub 0), and the multivariant elements, Q(sub 1)(super +) P(sub 0) and R(sub 2)(super +) P(sub 0), are compared for the numerical simulation of the flow in extrusion dies. The pressure distribution obtained by using the Q(sub 1) P(sub 0) element was found to be afflicted with the checkerboard pressure mode. On the other hand, the multivariant elements, Q(sub 1)(super +) P(sub 0) and R(sub 2)(super +) P(sub 0), gave accurate and physically reasonable velocity and pressure distributions. The computed values of the pressure drop across extrusion dies matched well with the pressure drop determined experimentally.