Ribs are a feature in plastic injection molded parts. They are thin extensions that run perpendicular from a wall or plane. They are commonly used to provide additional support and strength to a part as shown in Figure Q1. Recommend the guideline to design the ribs for plastic injection molded parts. Figure Q1: Plastic part with ribs

An injection molded polyethylene part has a dimension of 6.25 cm. A new material, polycarbonate, is used in the same mold. What is the expected corresponding dimension of the polycarbonate molding?

a-c explained fully please thanks!

Which of the following are reasons why injection molding of thermosets is more difficult than injection molding of thermoplastics (two best answers): O allowances must be made for cross-linking of thermosets O barrel temperatures must be hotter for thermosets O cycle times are longer because of curing thermosets are denser O two injection units are required

Define the term perfectly plastic?

Question 3 The diameter of an extruder barrel is 65 mm and its length is 1.75 m. The screw rotates at 55 rev/min. The screw channel depth is 5.0 mm, and its flight (helix) angle is 18°. The head pressure at the die end of the barrel is 5x10° Pa. The viscosity of the polymer melt is given as 100 Pa-s. Calculate the volume flow rate of polymer in the barrel. The drag flow is given by the equation: Qa = 0.5 n2 D² N d̟ sinp cosp The back pressure flow is given by the equation: Pn D dễ sin²o Qb 127L The details of the extruder screw are given in figure 3.1 W. Perpendicular channel width Helix angle (O) Pitch Channel depth de Axial |light| width Axial channel width Perpendicular fight -Direction of mass flow- Figure 3.1. Schematic illustration of a typical "Archimedean" extruder screw. width Root diameter diameter

Question 3 The diameter of an extruder barrel is 65 mm and its length is 1.75 m. The screw rotates at 55 rev/min. The screw channel depth is 5.0 mm, and its flight (helix) angle is 18°. The head pressure at the die end of the barrel is 5x10° Pa. The viscosity of the polymer melt is given as 100 Pa-s. Calculate the volume flow rate of polymer in the barrel. The drag flow is given by the equation: Qa = 0.5 n² D² N d̟ sinp cosp The back pressure flow is given by the equation: Pn D dễ sin²4 Qb 127L The details of the extruder screw are given in figure 3.1 W. channel width Perpendicular Pitch Helix ( p angle () D Channel depth de |Axial |light| width Axial channel width Perpendicular flight -Direction of mass flow- Figure 3.1. Schematic illustration of a typical "Archimedean" extruder screw. width Root diameter diameter

As the lead engineer for a LPG storage project, you are overseeing the design of pressure vesselssuch as those shown below. Identify which test (or tests) is mostsuitable to pick a material and thickness for the spherical shell of the pressure vessel. Why these are the relevant tests. Explain what information these tests provide and why it is important to determining material and thickness.

The figure shown below (Fig. 2) is a schematic representation of a scissor jack in two different positions. The maximum load that this mechanism must withstand is 800 kg. 4 are proposed different materials to make the jack arms and spindle. The mechanical properties and some Physical characteristics of each material are shown in Table 1. a) Based on the properties of each material and the cross section of the arms and the screw, Propose what would be the most suitable material for its manufacture. The length of each arm is 150 mm. The stress on the arms and the spindle must not exceed the yield strength of the material selected for neither of the two analysis positions. b) Using the mechanical properties of the material you selected, calculate the change in dimension that the arms and the spindle of the jack were tested for the two analysis positions. The length of the spindle is 280 mm.

Please solve accurate and exact answers sir please!! (it must be typed not handwritten)  Thanks!!