Coagulant Concentration in Optimizing Latex Glove Formulations Application note

Figure 1. Brief diagram for glove manufacturing process

The current method for analyzing any dispersion stability may take up to one year, depending on the required simulated time. This too requires many ovens leading to an increase in laboratory bench space as well as the analysis being heavily laborious and subjective. The LUMiFuge is an analytical centrifuge that measures instantaneously the extinction of transmitted light across the full length of your sample using the STEP-Technology®. It is the only instrument in the world that enables you to perform physically accelerated, direct and efficient stability testing and ranking of your formulations.

The parallel light illuminates the whole sample from top to bottom. Even the smallest changes across the entire sample height are detected by a sensor featuring high optical and spatial resolution. Immediate data collection ensures the ability to measure everything that occurs in your sample, no matter how simple or complex.

There is no need to dilute or to know any material constants; just input your samples and you have your results. By looking at the fingerprint patterns of the whole sample, you can classify and understand the causes of instability, e.g., creaming, sedimentation, or flocculation, as well as measure and rank stability.

In this application note, the latex dispersion was measured and simulated for a total shelf life of six months. The total measurement time required to simulate a period of six months only required two hours as the samples can be accelerated in the LUMiFuge up to 2,300 times gravitational force. Coagulants were added into the sample and measured at different temperatures, 25°C and 60°C, to study the effects of coagulant concentration as well as temperature on the latex dispersion sample.

Figure 2. Latex dispersion measured at 25°C

Figure 3. Latex dispersion measured at 60°C

The latex dispersion was observed to be the most stable at 25°C after the addition of 0.005M coagulant (lowest instability index value – sample is most stable). To achieve the best coagulation process at 25°C, a coagulant concentration of 0.003M should be added to the latex dispersion (highest instability index value – sample is least stable). In contrast, the addition of 0.001M coagulant into the latex dispersion at 60°C was observed to provide close to three times the efficiency of the coagulation process.

Using the LUMiFuge to analyze the latex dispersion:

• Optimized formulations can be easily achieved in a short period of time – time-saving
• Chemical concentration addition into dispersions can be determined and optimized to avoid raw material wastage, hence reducing overall cost spending
• Leads to higher success of research and development rate
• Selection of bulk raw materials can be streamlined by comparing between various manufacturers