1. What is the definition of shear rate (γ̇)? A) Force per unit area B) Difference in flow velocity between fluid layers divided by distance C) Volume flow rate D) Temperature gradient
2. The unit of viscosity is: A) Pa·s B) N/m² C) 1/s D) m/s
3. What happens to polymer viscosity as temperature increases? A) It increases B) It decreases C) It remains constant D) It becomes zero
4. Which flow behavior is characteristic of polymer melts? A) Newtonian B) Dilatant C) Structurally viscous (pseudoplastic) D) Bingham plastic
5. What has NO influence on the viscosity of polymer melts? A) Temperature of the melt B) The direction of the shear stress C) The shear rate D) The length of the molecules
6. In a viscosity curve for polymer melts, what happens at high shear rates? A) Viscosity increases B) Viscosity decreases due to molecular orientation C) Viscosity remains constant D) Flow stops
7. The relationship η = τ/γ̇ defines: A) Shear stress B) Shear rate C) Viscosity D) Flow rate
8. What is the typical behavior of polymer melts compared to Newtonian fluids? A) Higher viscosity at all shear rates B) Lower viscosity at all shear rates C) Shear-thinning behavior D) Temperature independence
9. Which material shows dilatant behavior? A) Water B) Polymer melts C) Honey D) Cornstarch suspension
10. The term "structurally viscous" refers to: A) Viscosity increasing with shear rate B) Viscosity decreasing with shear rate C) Constant viscosity D) Temperature-dependent viscosity only
11. What causes the shear-thinning behavior in polymer melts? A) Temperature increase B) Molecular orientation under shear C) Pressure decrease D) Chemical reactions
12. In the flow diagram for polymer melts, what does the curved line represent? A) Newtonian behavior B) Non-Newtonian behavior C) Linear relationship D) Temperature effect
13. Which parameter is measured in Pa (Pascal)? A) Shear rate B) Viscosity C) Shear stress D) Flow rate
14. The dimension of shear rate is: A) Pa·s B) 1/s C) N/m² D) m/s
15. What is the relationship between viscosity and processing temperature for polymers? A) Higher temperature = higher viscosity B) Higher temperature = lower viscosity C) No relationship D) Exponential increase
16. Which is NOT a zone of a 3-zone extruder screw? A) Feed zone B) Compression zone C) Heating zone D) Metering zone
17. What is the primary function of the compression zone in an extruder? A) Material feeding B) Pressure generation and melting C) Temperature control D) Material discharge
18. In a twin-screw extruder, what is a major disadvantage? A) Poor mixing B) Low throughput C) Expensive and high wear of screws D) Cannot handle additives
19. What is coextrusion used for? A) Single material processing B) Merging different polymer melts C) Temperature control D) Pressure reduction
20. The haul-off speed in extrusion affects: A) Temperature only B) Pressure only C) Strand dimensions D) Screw speed
21. What is the purpose of calibration in pipe extrusion? A) Temperature control B) Pressure measurement C) Dimensional accuracy D) Material mixing
22. In extrusion, what causes strand widening? A) High temperature B) Low haul-off speed C) High pressure D) Screw design
23. Twin-screw extruders are particularly good for: A) Simple melting only B) Mixing, homogenizing, and degassing C) Low-cost production D) Single-component materials
24. What is the function of the metering zone in an extruder? A) Material feeding B) Compression and melting C) Consistent material flow D) Temperature control
25. Vacuum degassing in twin-screw extruders is used to remove: A) Heat B) Volatile components C) Solid particles D) Pressure
26. What is NOT influenced by the pressure curve during injection molding? A) Surface quality B) Dimensional accuracy C) Tool wear D) Burr formation
27. The typical temperature range for injection molding is: A) 50-100°C B) 100-150°C C) 200-300°C D) 400-500°C
28. What is the purpose of holding pressure in injection molding? A) Cooling the mold B) Compensating for volume shrinkage C) Opening the mold D) Heating the material
29. Multi-component injection molding can be used to produce: A) Wheels including running surface B) Duroplast materials C) Rubberized housings D) All of the above
30. The clamping force in injection molding is used to: A) Heat the material B) Prevent mold opening due to pressure C) Cool the part D) Eject the part
31. What happens during the compression phase in injection molding? A) Material feeding B) Mold filling C) Melt compression D) Part cooling
32. The switching point in injection molding occurs: A) At the start of injection B) When the mold is full C) During cooling D) During ejection
33. What is the typical cooling temperature range for injection molded parts? A) 200-300°C B) 100-200°C C) 20-120°C D) 0-50°C
34. Volume shrinkage in injection molding is caused by: A) Pressure increase B) Temperature increase C) Crystallization and cooling D) Mold opening
35. Two-component injection molding allows: A) Faster processing B) Lower costs C) Multiple materials in one part D) Higher temperatures
36. Which parameters have significant influence on FDM 3D printing? A) Ambient temperature in installation space B) Traversing speed of the nozzle C) Nozzle temperature D) All of the above
37. Why is it difficult to recycle agricultural films? A) Sunlight ages the plastics B) Films are often reused C) Films are damaged by vehicles D) Films consist of several different layers
38. Blow molding is used to produce: A) Flat films B) Hollow bodies C) Solid rods D) Fibers
39. In calendering, the polymer is: A) Injected into a mold B) Rolled between heated rollers C) Blown into a film D) Extruded through a die
40. Rotational molding involves: A) High pressure injection B) Heating and rotating a mold C) Stretching a film D) Compression molding
41. What is the main advantage of blow film extrusion? A) High pressure capability B) Variable film dimensions C) Low temperature processing D) Solid part production
42. In stretch blow molding, what happens after preform heating? A) Direct molding B) Stretching and blowing C) Cooling only D) Compression
43. The Bobby car mentioned in the lecture is produced by: A) Injection molding B) Extrusion C) Blow molding D) 3D printing
44. Calendering is primarily used for: A) Hollow parts B) Film production C) Solid rods D) Complex shapes
45. What is critical for layer bonding in FDM 3D printing? A) Print speed B) Layer thickness C) Temperature maintenance D) Nozzle size
46. The modulus of elasticity of unreinforced, isotropic polymers does NOT depend on: A) Manufacturing process B) Loading speed C) Direction of load D) Ambient temperature
47. A drop of water under load does NOT behave like: A) A Hookean body B) A Newtonian body C) A viscoelastic material D) A fluid
48. For the strength at room temperature of an injection molded component, which parameter is NOT relevant? A) Melting temperature B) Holding pressure C) Component size D) Mold surface finish
49. How can the glass transition region be determined by DMTA testing? A) Minimum of damping B) Greatest change in storage modulus C) Maximum of attenuation D) Phase shift characterization
50. Which test conditions are NOT suitable for DMTA testing? A) -25°C under water influence B) Bending tests C) Hardness tests D) 400°C
51. In viscoelastic behavior, the retardation time τ is defined as: A) η/E B) E/η C) ησ/E D) E/ησ
52. The Burger model describes: A) Elastic behavior only B) Viscous behavior only C) Combined elastic and viscous behavior D) Brittle fracture
53. Typical retardation times for polymers are: A) Seconds B) Minutes C) Hours to hundreds of hours D) Days to weeks
54. What characterizes a Newtonian body? A) Stress-strain relationship B) Stress-strain rate relationship C) Time-independent behavior D) Elastic recovery
55. The relationship between shear strength, tensile strength, compressive strength, and flexural strength is: A) All equal B) Shear < Tensile < Compressive < Flexural C) Flexural < Compressive < Tensile < Shear D) Random relationship
56. Environmental moisture affects polymer strength by: A) Increasing crystallinity B) Hydrogen bonding with polymer chains C) Reducing temperature D) Increasing crosslinking
57. Crazing in amorphous thermoplastics is characterized by: A) Shear deformation only B) Density and orientation inhomogeneities C) Elastic deformation D) Temperature effects only
58. The storage modulus E' in DMTA represents: A) Energy loss B) Elastic and linear-viscoelastic deformation C) Viscous flow D) Plastic deformation
59. The loss modulus E'' in DMTA is proportional to: A) Elastic energy storage B) Work converted to heat C) Plastic deformation D) Brittle fracture
60. In semi-crystalline thermoplastics, fibril formation occurs through: A) Melting of crystalline regions B) Stretching of amorphous regions C) Chemical crosslinking D) Temperature increase only
Section 1 (Rheology): 1-B, 2-A, 3-B, 4-C, 5-B, 6-B, 7-C, 8-C, 9-D, 10-B, 11-B, 12-B, 13-C, 14-B, 15-B
Section 2 (Extrusion): 16-C, 17-B, 18-C, 19-B, 20-C, 21-C, 22-B, 23-B, 24-C, 25-B
Section 3 (Injection Molding): 26-C, 27-C, 28-B, 29-D, 30-B, 31-C, 32-B, 33-C, 34-C, 35-C
Section 4 (Other Processes): 36-D, 37-D, 38-B, 39-B, 40-B, 41-B, 42-B, 43-C, 44-B, 45-C
Section 5 (Mechanical Properties): 46-C, 47-C, 48-D, 49-C, 50-D, 51-A, 52-C, 53-C, 54-B, 55-B, 56-B, 57-B, 58-B, 59-B, 60-B
Good luck with your exam preparation!