Author Question: List three advantages of the moveable system versus the rotary system for continuous extrusion blow ... (Read 53 times)

cnetterville · **on:** Aug 19, 2018

List three advantages of the moveable system versus the rotary system for continuous extrusion blow molding.

What will be an ideal response?

Question 2

Identify four advantages and two disadvantages of using aluminum rather than tool steel to make cavities for injection molds.

What will be an ideal response?

Question 3

What is the purpose of cold-well extensions?

What will be an ideal response?

amit · **Reply #1 on:** Aug 19, 2018

Answer to Question 1

The moveable mold system has fewer molds than the rotary system and therefore less investment. The moveable mold system is less complicated mechanically and is therefore less costly to buy and to maintain. The moveable system need not be synchronized as precisely as the rotary system.

Answer to Question 2

Aluminum advantages:

Lower initial cost due to lower machining time Shorter delivery time
More even heat distribution
Shorter cycle from higher thermal conductivity Lighter weight

Easier to cast should that be the preferred fabrication method

Aluminum disadvantages:
Must be anodized to get hardness and anodizing may wear off
Long-term wear us high

Answer to Question 3

These extensions of the runners are placed at points where the runners change directions and are a means of capturing the cold, leading front of the resin. By capturing the cold end of the resin flow, some assurance is given that the resin will flow smoothly through the gate without plugging.