Variations and Extension to the Injection-Molding Process

Injection Blow Molding. 

A preform (this looks like a test tube with bottle cap threads) is injection molded in one cavity, removed and then placed into another where it is pressurized with gas to stretch the hot preform into a thinnerwalled

seamless bottle or container such as a milk bottle or gas tank. This is depicted in Figure 7. This is an extension of injection molding more than a variation.

Injection Compression/Coining. 

With this technique the mold is only partially closed during injection. At the appropriate time and with the right amount of plastic in the mold, the clamp is then completely closed, forcing (compressing) the plastic to the shape of the mold cavity. A variation on this is coining.

The clamp is closed but the mold has components that compress the plastic in the cavity as the plastic cools. Coining is where the cavity volume is changing during the solidification of the plastic. Plastic is injected into the cavity and then the movable platen closes completely, or a mold component moves to compress the

plastic to compensate for shrinkage or densification.

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“Injection Molding” in EPSE 2nd ed., Vol. 8, pp. 102–138, by I. I. Rubin, Robinson Plastic Corp.

JOHN W. BOZZELLI

Midland, Michigan

Members of Design Teams

The number and type of individuals that comprise a design team is largely determined by the size of the design project. Even though an individual is assigned to a team, all members may not be involved at all times. In a concurrent engineering environment the team members work together to meet the common goal. Typical members of a design team might include:

I. Product design engineer-responsible for the overall product design.

2. Product manager-the person who has the ultimate responsibility for a design and its team.

3. Mechanical engineer-responsible for mechanical and electromechanical product development.

4. Electrical engineer-responsible for electronic components of the design.

5. Manufacturing engineer-responsible for the manufacturing processes used to create the product.

6. Software engineer-responsible for any computer software code needed for a product.

7. Detailer/drafter-assists the engineers with the 3-D modeling and documentation of the product.

8. Materials engineer-responsible for the selection of the material hest suited for a product.

9. Quality control engineer-responsible for meeting the quality guidelines for the product and its

manufacture.

10. Industrial designer-responsible for the product's appearance, form. and human factors analysis.

II. Vendor representatives-responsible for any outsourcing required by the company making the design.

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The Engineering Design Process

Bertoline-Wiebe-Miller: Fundamentals of Graphics Communication,

The McGraw-Hill Companies, 2001

Mechanical properties

Strength

The nominal yield strength shall be in the range of 235 N/mm2 to 690 N/mm2. The nominal tensile strength shall be in the range of 300 N/mm2 to 1000 N/mm2.

Ductility

The elongation after fracture on proportional gauge length shall be at least 15 %, for nominal yield strength not greater than 460 N/mm2; and shall be at least 10 % for nominal yield strength greater than 460 N/mm2.

The tensile strength to yield strength ratio shall be at least 1.2 based on nominal values, or at least 1.1 based on actual values, for nominal yield strength not greater than 460 N/mm2.

NOTE Conversion of elongation values measured not based on proportional gauge length is necessary and shall be performed according to BS EN ISO 2566-1.

Impact toughness

As a minimum, the product shall be able to absorb at least 27 J of impact energy at 20 °C.

NOTE Depending on other factors including the thickness and minimum service temperature, the impact toughness should also conform to the appropriate requirements as given in BS 5950-1.

Through thickness deformation properties

Where appropriate, through thickness deformation properties shall be specified to guarantee adequate

deformation capacity perpendicular to the surface to provide ductility and toughness against lamellar tearing.

NOTE Specification of through thickness deformation properties can be referred to BS EN 10164.

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Design Guide on Use of

Alternative

Steel

Materials

to BS 5950

a touche design production @ 6743 5450

BCA Sustainable Construction

Series – 3

200 Braddell Road Singapore 579700

Cold runner

Expenditures runner of the mold.

Way of the runner of the mold usually closely related to the type of gate is used. From this emerged a two plate mold design and three-plate mold. Gate Mold type: strip gate, tunnel gate and gate flash,

if there is no requirement or a specific form of the product, mold will be designed with two plates.

At the time of mold starts to open, regardless of the sprue runner R for pin carried by runners who have undercut at the edges.Meanwhile, the gate tunnel cavity disconnected from the product because it was interrupted by the lip of the pit gate. At the opening of the next runner mold and product driven by the stripper plate, the runner forcibly detached from the undercut at the end of the  runner-pin, then fell with the product. Here can be seen, that the mold with a tunnel gate will produce a product that has been separated from the runner. Being a product with a strip gate still hung with runnernya, to require additional work to cut the tow runner from the product.

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