Colloidal Stability Problem of HA Centrifuged Latex Concentrate

Manufacturer: We are having problems with a supplier of HA centrifuged  latex.

Latex gives us stability problems and tends to form coagulum. They send us their results that coincide with ours, but when the latices are vulcanized, they are destabilized.

What kind of tests do you advise us to do?

John Woon (Senior Latex Consultant): Thanks for the information I requested. I've gone through your specification and the test results. Most of these are quite satisfactory. But the specification and test results sometimes do not tell the whole story about the latex quality. For example, we would not know the actual history of the latex during its production processes, unless we conduct an audit at the suppliers/producer's factory site.

Things that concern me beyond the test results and specification include the following:

1) Has the raw field latex been properly handled to prevent bacteria attack?

2) Has this batch of the latex concentrate been blended with other batches of bad latex?

3) Has this batch of latex originally failed to meet the specification but was blended with good latex in order to pass the tests before delivering to you?

 

You could add more stabilizer/soap such as potassium laurate to the latex before compounding with other ingredients. You could also increase the level of KOH.

In your specification, you do not have the MST requirement and the supplier's specification is 650 seconds minimum. This is too low. I suggest you set a new spec. of 800 to 1200 seconds, i.e. always including the maximum figure.

 

(Note: Actual suggested tests are not included in this post)