Unlock access to all the studying documents.
View Full Document
Chapter 16: Expansion Processes
Copyright Cengage Learning. Powered by Cognero.
1. An expanded plastics is similar to a sponge, bread, or whipped cream because all are ____ in structure.
2. What method for turning resins into expanded plastics involves forcing pentanes, hexanes, halocarbons, or moistures of
these materials into the plastics particles under pressure?
whipping air into the resin and rapidly curing or cooling
dissolving a gas that expands at room temperature
thermal breakdown of a chemical blowing agent
3. Vinyl esters, urea-formaldehyde (UF), phenolics, polyesters, and some dispersion polymers are made cellular by
utilizing ____ methods.
4. In molding, which part is represented by “A”?
Chapter 16: Expansion Processes
Copyright Cengage Learning. Powered by Cognero.
5. Cellular plastics with an integral skin are known as ____.
6. The most popular and economical method used for large parts is ____.
Chapter 16: Expansion Processes
Copyright Cengage Learning. Powered by Cognero.
7. The ____ properties of cellular materials are particularly useful in food containers like this coffee cup.
8. In ____ processing, the heated melt is forced into the mold with pressures of 30 to 140 MPa.
9. In one of the processes of high-pressure processing, what is represented by the letter “B”?
Chapter 16: Expansion Processes
Copyright Cengage Learning. Powered by Cognero.
10. In one of the processes of high-pressure processing, what is represented by the letter “A”?
11. Astroturf consists of a foamed ___ pad beneath the turf.
Chapter 16: Expansion Processes
Copyright Cengage Learning. Powered by Cognero.
12. What product is commonly produced in the form of small beads containing an expanding agent which are preheated
before placing them in the mold?
13. Dielectric molding makes use of ____ to expand beads.
high-frequency radio energy
14. Polyurethanes, polyethers, urea-formaldehyde, polyvinyls, and phenolics are often processed by ____.
high-frequency radio energy
15. A product formed by expanding in place, in which the expanded plastics and the mold together become the finished
product is a(n) ____.
16. Large slabs or blocks of flexible polyurethanes are cast in open and closed molds and cut into slabs for _____.
flotation material in boats
17. What type of product is made by blending microscopically small hollow balls of glass or plastics in a resin matrix
Chapter 16: Expansion Processes
Copyright Cengage Learning. Powered by Cognero.
18. Extruded polyvinyl materials, which may be expanded as they emerge from the die or stored for future expansion, are
often used in the ____ industry.
19. Reaction injection molding (RIM) creates products that are greatly improved in terms of stability by the addition of
____.
20. Fillers that are added to artificial turf products to prevent matting are usually ____ or olefin.