Welcome!

Although I have only had a few opportunities to process natural rubbers, it is an interesting experience.

Processing PBT – Polybutylene Terephthalate, PBT, is a semi-crystalline polymer which is heated above the Melting Temperature (Tm) before processing. In this state, it flows very easily and is usually melted using a straight or reverse barrel temperature profile. Because the polymer is processes above the melting temperature, it flows relatively easily. Most amorphous synthetic polymers such ABS or Styrene, do not have a melting temperature, but are processed above the Glass Transition Temperature (Tg) which is a softening temperature present in all polymers.

Processing Natural Rubbers – Natural Rubber, or Polyisoprene, is an amorphous polymer which is often processed at a temperature near or below it’s Glass Transition Temperature. This makes it more difficult to mold, resulting in a behavior similar to the molding of many PVC materials. As with PVC, you tend to use a forward temperature profile, and require a special screw configuration, often with a high flow check ring… or no check ring at all.

The molding of natural rubbers can be a messy business and there are many variations of these materials depending on the degree of polymerization and molecular weight distribution.

-Andy

6-Axis articulated robotics are becoming increasingly common because of the following reasons:

1. They can perform complex movements – This allows injection molders to remove complex geometries from the mold, as well as simplify automation by allowing the robot to peroxide some of the secondary operations.

2. They are very reliable – Believe it or not, many 6-axis robotics are as reliable as their 2, 3, and 4-axis counterparts.

3. They are inexpensive – I have seem some 6-axis robots that are less expensive than many popular 4-axis robots.

6-axis robotics tend to be slower than their 2, 3, and 4-axis counterparts. In most cases, the difference in speed tends to be less than 1 second increase for 6-axis robotics.

-Andy