What is it?

Simply stated, in this process two liquid components - - component "A", a formulated polymeric isocyanate, and component "B", a formulated polyol blend, are mixed in a high pressure head and then pumped into a mold cavity. A reaction then occurs in the mold, resulting in a high density polyurethane structural foam part.

How, Why & When to Use It:

1. To produce covers, bases, keyboards, bezels and housings for computers, business machines and medical applications.
2. For prototype through medium volume applications (1 - 2,000 pieces).
3. There is considerable design freedom to produce complex shapes.
4. Molds can be resin, spray metal, cast aluminum or machined aluminum.
5. Tooling is low cost and allows for ease of modification.
6. A variety of castings, sheet metal and threaded inserts can be molded in place.
7. Alternative foams are available which offer a range of insulating properties.
8. UL traceability.

Design & Technical Information

Size

Up to 48 in.

Weight

Up to 18 lbs.

Finish

If required:

• No bake prime and paint
• RF shielding
• Silk screening

Wall thickness

Can vary but should not be less than 1/4 in., although local thicknesses of 1/8 in. can be produced.

General tolerance
Note: tighter tolerances can be negotiated.

  0 in. -   3 in. +/- 0.010 in.
  3 in. -   6 in. +/- 0.015 in.
  6 in. - 12 in. +/- 0.020 in.
12 in. - 18 in. +/- 0.030 in.
18 in. - 48 in. +/- 0.040 in.

Holes

All holes molded to size.

Draft

Recommended 1 - 2 degrees, but no draft is possible when specified.
Radii and fillets - should be as liberal as possible (1/8 in. to 1/4 in.).

Density

Can be varied, depending on foam used, to offer a variety of insulation properties.

A variety of materials are available which offer a range of insulating and mechanical properties with 94V-0.
Detailed specification sheets are available on request (email requests to sales@armstrongmold.com)

Material

Units

R I M

Polystyrene

ABS

Modified
PPO

Specific gravity

0.85

0.85

0.89

0.85

Thickness

(in.)

0.25

0.25

0.25

0.25

Flexural modulus

(psi)

220,000

275,000

240,000

261,000

Flexural strength

(psi)

9,500

5,700

6,000

6,800

Tensile strength

(psi)

5,800

2,300

3,000

3,400

Elongation

(%)

10

20

- -

16

Gardner impact + +

(in-lb)

74

28

52

55

Falling ball

(ft-lb)

- -

- -

- -

18

Dart impact

(ft-lb)

- -

- -

10

- -

Heat distortion temperature

  @ 66 psi

(F)

212

183

177

205

  @ 264 psi

(F)

180

168

162

180

The above properties are intended as a guide only and may vary depending on thickness and shape.