Shearing edge

R. Byron Pipes and I. M. Daniel, Moir6 Analysis of the Interiaminar Shear Edge Effect in Laminated Composites, Journal of Composite Materials, April 1971, pp. 255-259. 

Mold construction FRP spray metal, cast aluminum gusket seal, air vents, self-sealing injection port FRP FRP, spray metal, cast aluminum, pinch (land) Metal, shear edge High grade steel shear edge... 

Part trim equipment Generally expected mold life (parts) 3,000 Yes 1,000 3,000 With optimum shear edges, minor trimining only 150.000+ 150.000+ ... 

Once the boundary conditions are applied, the pressure field can be solved using the appropriate matrix solving routines. Note that for mold filling problems, there is a natural boundary condition that satisfies no flow across mold boundaries or shear edges, dp/dn = 0. Once the pressure field has been solved, it is used to perform a mass balance using eqn. (9.144) or (9.145). Once the flowrates across nodal control volume boundaries are known, a simulation program updates the nodal control volume fill factors using... 

Standard profile Shear edge profile Box profile... 

Two other variations are used to avoid the bending forces that occur with simple ASTM D 1002 specimens the laminated lap shear specimen (ASTM D 3165) shown in Fig. 20.6a and the double-lap specimen (ASTM D 3528) shown in Fig. 20.6b. These specimens minimize the joint eccentricity and provide higher strength values than does the singleoverlap specimen. For the specimen in Fig. 20.6a, the overlap joint can be made from saw cuts in the top and bottom substrates of a bonded laminate. This process negates the effects of extruded adhesive at the edges of the lap and the sheared edge of the standard type of lap shear specimen. As a result, the chances of deformation and uneven surface preparation are lessened. 

Mold design is a decisive factor for the molding success such as dimensioning and location of the sprue gates, dimensioning of shear edges, flow aids, cooling and ejector techniques, etc. 

With backpressure the process is performed in conventional injection molding machines (IMMs) (Chapter 4). The cover stock is inserted and located in an open mold. A shear edge mold permits draw-in of the cover stock during the closing cycle to avoid wrinkles and damage by stretching of the fabric. Molds require special attention. They generally use a hot runner system with its shut-off nozzle(s). All mold elements such as ejector, core pulls, and slides have to be on the injection side mold half. 

The most critical step in cryopelletization is droplet formation, which is influenced not only by formulations-related variables such as viscosity, surface tension, and solids content but also by equipment design and the corresponding processing variables. The diameter and design of the shearing edge of the holes on the container plates are critical. For instance, the diameter of the holes determines the flow rate, which,... 

Fig. 6-3. Schematic of closed mold using a shear edge around the cavity periphery.

Part trim equipment Yes With optimum shear edges, minor trimming only ... 

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