Deck 15: Thermoforming

Question 1

Which process is most suited to developing a deep thermoformed product?

A) matched-mold forming
B) vacuum forming
C) pressure-bubble plug-assist vacuum forming
D) mechanical forming

Answer 1

C

Question 2

Ductwork, pallets, and plastics cases are formed by ____. 

A) twin sheet thermoforming
B) air-slip forming
C) mechanical forming
D) free forming

Answer 2

A

Question 3

Skylight panels and aircraft canopies are made by ____.  

A) twin sheet thermoforming
B) air-slip forming
C) mechanical forming
D) free forming

Answer 3

D

Question 4

This image shows an acrylic bubble-formed side window for a helicopter. What is most likely to have formed this product?  

A) free forming
B) trapped-sheet contact-heat pressure forming
C) mechanical forming
D) pressure-bubble vacuum snap-back forming

Question 5

In what kind of thermoforming is a heated sheet trapped and formed between male and female dies?

A) matched-mold forming
B) vacuum forming
C) drape forming
D) mechanical forming

Question 6

A disadvantage of straight vacuum forming is that ____.

A) high pressures must force the plastics into the mold
B) formed pieces usually must be trimmed
C) equipment is costly
D) processing time is long

Question 7

In____, air pressures of over 2.7 MPa may be used to blow a hot plastics sheet through the silhouette of a female mold.

A) snap-back forming
B) twin sheet thermoforming
C) free forming
D) mechanical forming

Question 8

A possible remedy for markoff in the production process is to ____.  

A) increase chilling time
B) add vacuum holes
C) check the vacuum system
D) clean the mold

Question 9

The main difference between straight vacuum forming and drape forming is that drape forming ____.    

A) is less costly
B) uses higher pressures
C) uses a female mold
D) uses a male mold

Question 10

A disadvantage of plug-assist vacuum forming is that ____.

A) it has a long cooling cycle
B) close temperature control is needed
C) equipment is costly
D) processing time is long

Question 11

Complex parts with recesses can be formed with ____.

A) drape forming
B) matched-mold forming
C) plug-assist forming
D) straight vacuum forming

Question 12

In ____, the sheet is heated and then stretched by air pressure, which allows deep drawing and the formation of complex parts.

A) vacuum forming
B) free forming
C) mechanical forming
D) pressure-bubble vacuum snap-back forming

Question 13

A process called solid phase pressure forming (SPPF) is most similar to ____.

A) drape forming
B) matched-mold forming
C) plug-assist forming
D) straight vacuum forming

Question 14

This image shows an example of a product made by ____.

A) vacuum forming
B) free forming
C) mechanical forming
D) drape forming

Question 15

In ____, no vacuum or air pressure is used to form the part. Only the force of bending, stretching, or holding the hot sheet is used.  

A) vacuum forming
B) free forming
C) mechanical forming
D) drape forming

Question 16

This process is like straight vacuum forming except air pressure and a vacuum assist may be used to force the hot plastics into a female mold.

A) free forming
B) trapped-sheet contact-heat pressure forming
C) mechanical forming
D) pressure-bubble vacuum snap-back forming

Question 17

Which method is used to make thin-wall hollow products?

A) snap-back forming
B) free forming
C) mechanical forming
D) twin sheet thermoforming

Question 18

Flaws or marks left on the finished product from the mold are called ____.     

A) markoff
B) thinning
C) extrusions
D) stretch marks

Question 19

Complex parts with recesses can be formed with ____.    

A) drape forming
B) matched-mold forming
C) plug-assist forming
D) vacuum snap-back forming

Question 20

Air-slip forming is similar to ____ with the exception of the method used for creating the stretch bubble.

A) twin sheet thermoforming
B) mechanical forming
C) snap-back forming
D) free forming