Polymer Forming Processes

Question 1

What is vacuum forming commonly used to make?

Answer 1

Box inserts, yoghurt pots, coffee cups

Question 2

What is the bed of a vacuum forming machine called?

Answer 2

Platen

Question 3

What is the use of the vacuum pump in vacuum forming?

Answer 3

To suck polymer onto mould

Question 4

What scale of production would regular vacuum forming be used for and why?

Answer 4

Small scale/batch production because it’s a slow process

Question 5

What is thermoforming mainly used for?

Answer 5

Used to mould additional detail into the surface of a polymer

Question 6

What are two products which use thermoforming?

Answer 6

Baths, fruit punnets

Question 7

What is the difference between vacuum forming and thermo forming?

Answer 7

There is an additional mould that is pressed into the surface of the polymer sheet

Question 8

What is the use of the vacuum in thermoforming

Answer 8

To suck the polymer onto the mould below

Question 9

What is the main use for calendering?

Answer 9

Smoothing and rolling out materials and making sheet and film stock forms of polymers

Question 10

What consistency must the thermoplastic pellets be heated to in order for them to be able to be pushed through the heated rollers?

Answer 10

Dough-like

Question 11

What is line bending used for?

Answer 11

To create bends in sheet thermoplastics

Question 12

What are three products which use laminating in production?

Answer 12

Boats, yachts, kayaks, cars for theme park rides, scenery props

Question 13

During process of lamination what would the mould which is in the shape of the product be made from?

Answer 13

Timber, plywood or manufactured board

Question 14

During lamination what would the mould be coated with to prevent the polymer from sticking?

Answer 14

Release agents such as wax or pvc

Question 15

During lamination a gel coat is applied. What is this coat generally made up from?

Answer 15

Polyester resin mixed with a colour pigment and/or additives ( for example to prevent UV degradation)

Question 16

In lamination of CFRP what is the place overnight in which curing takes place?

Answer 16

Autoclave

Question 17

In lamination what type of matting is placed on the former?

Answer 17

Fibreglass matting

Question 18

What is injection moulding generally used to make?

Answer 18

Complex items made from thermoplastics

Question 19

What classification of polymer is vacuum forming used for?

Answer 19

Thermoplastics

Question 20

What is the maximum thickness of polymer which vacuum forming can process?

Answer 20

6mm

Question 21

What is the main benefit of thermoforming?

Answer 21

You can add additional detail due to the positive mould

Question 22

What scale of production is thermoforming used in?

Answer 22

Industrial production

Question 23

What scale of production is calendering used for?

Answer 23

Industrial production method used in continuous production

Question 24

What scale of production is line bending used in and why?

Answer 24

Small scale or limited batch production because it’s slow and labour intensive

Question 25

In injection moulding, what two elements are used to move the polymer granules through the heaters?

Answer 25

Archimedean screw thread connected to hydraulic motor

Question 26

In injection moulding, how is the polymer injected into the moulds?

Answer 26

Hydraulic ram forces screw thread forward so that polymer is forced into mould

Question 27

What is blow moulding commonly used to produce?

Answer 27

Bottles and hollow products

Question 28

What are the most common polymers used in BLOW MOULDING?

Answer 28

PET, LPDE, HDPE, PP

Question 29

What scale of production is BLOW MOULDING, commonly used in and why?

Answer 29

Continuous production because of high setup costs of equipment and moulds

Question 30

What polymers are commonly used in ROTATIONAL MOULDING?

Answer 30

HDPE and PP

Question 31

What stock form of polymer is used in ROTATIONAL MOULDING?

Answer 31

polymer powder or granules

Question 32

In ROTATIONAL MOULDING, how many rotations per minuet does the rotation speed stay below?

Answer 32

20 rpm

Question 33

In ROTATIONAL MOULDING, what temperature is the oven set between?

Answer 33

260-370 degrees

Question 34

What scale of production is ROTATIONAL MOULDING most commonly used for and why?

Answer 34

Large scale batch or mass production because setup costs are high

Question 35

In EXTRUSION, what stock form of polymer is used?

Answer 35

Polymer granules

Question 36

What is the difference between EXTRUSION and INJECTION MOULDING?

Answer 36

INJECTION MOULDING, uses moulds and EXTRUSION uses dies

Question 37

What is EXTRUSION commonly used to make?

Answer 37

Used to coat electrical wire for insulation, solid rod, hollow tube, angle sections

Question 38

what scale of production is EXTRUSION used in?

Answer 38

Continuous production

Question 39

what classification of polymer is used in COMPRESSION MOULDING?

Answer 39

thermoset polymers

Question 40

In COMPRESSION MOULDING, why does the mould remain closed after hydraulic pressure is applied?

Answer 40

To allow time for the cross linking takes place and thermoset cures

Question 41

What urea formaldehyde products are made using COMPRESSION MOULDING?

Answer 41

Electrical light fittings, switches, electrical plugs

Question 42

What melamine formaldehyde products are made using COMPRESSION MOULDING?

Answer 42

polymer plates, mugs and bowls