SIMPLE TEST FOR LATEX RUBBER STABILITY

Secomak’s latest latex testing machine determines the mechanical stability of concentrated natural and synthetic latex rubber when subjected to high speed mechanical stirring or mechanical shear. Available for operation on 110V or 240V, this system tests latex in accordance with British, European and ASTM standards.*

The machine runs at a high speed of 14,000 rpm but at a low torque. If the latex rubber thickens or thins during stirring, the motor speed changes and indicates a material failure. As latex instability – or the end point – is approached there is usually a drop in meniscus of the latex, accompanied by loss of turbulence and a change in the sound of the stirring action.

The end point is confirmed by the presence of an increased amount of coagulated rubber after 15 seconds of additional rotation. The latex is subsequently given a mechanical stability value based on the number of seconds that elapsed between the start and end of the test.

A key feature of the machine is its highly reliable series wound motor. This is electronically controlled and incorporates a feedback system to accurately maintain the selected speed. Additionally, it comes with visual confirmation in the form of coloured LEDs and is supported by a matt black aluminium bracket on a chrome plated column. The glass (synthetic) or Perspex (natural) beaker is retained in its aluminium table.

* BS 6057 Part 3 Section 3.1 (ISO 35) and BS 6057 Part 3 Section 3.14 (ISO 2006).
ASTM Designation D1076 – 88. Standard Specification for Rubber – Concentrated, Ammonia Preserved, Creamed and Centrifuged Natural Latex.
ASTM Designation D1417 – 90. Standard Test Methods for Rubber Latices – Synthetic.