Page 22 - Demo

OUTER CASING
1 Softens
2 Sinks
3 Continues to burn
4 No drips
5 Yellow / Orange flame
6 Fast burn
7 Small amount of black smoke
This information was gathered by following figure 16 (Plastics Identification Flow Chart) The plastic identified as as Polyurethane (TPUR PUR or PU)
MATERIAL
Polyurethane (TPUR PUR PUR or PU)
Polyurethane is a a a a a a a a polymer created by the linking of urethane urethane urethane (carbamate) to form a a a a a a a a a a a a structure Polyurethane can be either a a a a a a a a a a a a thermoplastic or or a a a a a a a a a a a thermosetting polymer in in in this case the the the the the casing is is is a a a a a a a a thermoplastic Polyurethane is is is created by mixing two two or or more liquid streams There are two two parts that make up polyurethane The The first part part is the the polyols which may also include other additives such as chain extenders cross linkers surfactants flame
retardants blowing agents pigments and fillers The second part is is the isocyanate or B-side Polyurethane has a a a a a a a a a a a a a wide range of of applications because of of its ability to adopt so so many different characteristics by changing the isocyanate polyol or additive percentages PART DESCRIPTION
The drill drill casing as as as mentioned houses and protects all the the the components of the the the drill drill It was held together by 7 threaded phillips head screws The outer skin of the the the casing (side which which the the the user handles) has has a a a a a a a glossy finish finish which which has has a a a a a a a smooth feel to it it The inside is is is unfinished with ribs and and bosses for mounting of components in in in in in a a a a a a fixed position while also directing heat away from the the motor and out the the slotted fins The layer provides protection against human
21
interaction and the the outside influences making the the mechanical properties of polyurethane an an an an excellent choice for this protective layer It has a a a a a a a a matt surface with gate marks left from the injection moulding If we we were unable to identify the the the the the manufacturing process from the the the the the gate marks on on on on the the the the the casing there are other signs which also guided to same conclusion The draft angle on on on on on both sides of of the outer case suggests injection moulding moulding was used Draft is a a a a a a a a a common feature of of injection moulding moulding as as as it it permits an easy removal of the the part from the the mould mould POLYURETHANE APPLICATIONS
Polyurethane has a a a a a a a a a a a wide range of applications This can can be be attributed to the the many characteristics that can can be be achieved in the the production process The most popular application for for polyurethane is is in in the form of of foam Polyurethane packaging is is so popular because of of its low cost and particularly effective cushioning As well as dominating the packaging industry industry polyurethane is prevalent in in in in in in in the the automotive industry industry with a a a a a a a a a a a a large selection of parts containing PU Other notable applications include apparel appliances building and construction electronics flooring furnishings marine and medical [14] COST
As referenced in the the the Bill of of Materials (page 8) the the the left and right sides of of the the the body came to to $4 02 each making an an $8 04 total for this part