Film deposition and consolidation during thin glove coagulant dipping

Abstract

In this article, we examine the rate of film build-up and the evolution of polymer volume fraction in coagulant dipped films. The results are for nitrile and natural rubber compounds. We describe a model for the build-up of a latex film that coagulates onto a former as a wet gel and consolidates by a wet sintering process. We achieve this by applying diffusion and reaction kinetics for the coagulant transporting from a former into the latex bath. Wet sintering, the underlying mechanism for serum exudation from the wet gel, is modelled for a consolidating aggregate of latex particles. The parameters used in the models are either measured in separate experiments or are available from the literature. We compare the model predictions with the experimental results. The first, rapid, stage of film build-up is modelled successfully by simple diffusion of the coagulant cations. At longer dwell times, it is found that the reaction between coagulant and surfactant is the primary mechanism for the rate reduction. The rate of consolidation of the wet gel could be modelled reasonably well using a previously developed equation for latex film formation. The rate was chiefly dependent on the stress relaxation modulus of the polymer.

Cationic Sterically Stabilized Diblock Copolymer Nanoparticles Exhibit Exceptional Tolerance toward Added Salt

“…It has been recognized for more than a century that charge-stabilized colloidal particles can aggregate in the presence of salt. , This phenomenon can be explained in terms of the Deryaguin–Landau–Verwey–Overbeek theory , and is commercially exploited for the industrial manufacture of latex gloves . Faraday was the first to demonstrate that protein-stabilized particles typically exhibit significantly higher colloidal stability in the presence of added salt: indeed, some of his gelatin-coated gold sols remain stable more than 160 years after their synthesis .…”

“…1,2 This phenomenon can be explained in terms of Deryaguin-Landau-Verwey-Overbeek (DLVO) theory 3,4 and is commercially exploited for the industrial manufacture of latex gloves. 5 Faraday was the first to demonstrate that proteinstabilized particles typically exhibit significantly better colloidal stability in the presence of added salt: indeed, some of his gelatin-coated gold sols remain stable more than 160 years after their synthesis. 6 For certain applications such as enhanced oil recovery, colloidal dispersions that can exhibit extreme salt tolerance at both ambient and elevated temperature are desirable.…”

A Variable Stiffness Magnetic Catheter Made of a Conductive Phase‐Change Polymer for Minimally Invasive Surgery

“…The thickness of a layer increases with a longer dipping time. [ 38 ] Additionally, the temperature of a rod dipping into the mixture influences the thickness of a coating. [ 41 ] A higher temperature for the tool leads to a thicker coating.…”

“…Silicone was chosen as the encapsulation material due to its low thermal conductivity (on the order of 0.2 W m −1 K −1 ) and high electrical breakdown strength (on the order of 53 V µm −1 ). [36,37] While the dipping technique itself has been widely used in industry due to its high precision control of deposit thickness, [38,39] this is the first time it has been used for coating PTFE tubes with CSMP. In previous work, the CSMP mixture was deposited only on planar surfaces.…”

In Situ Modification of Polyisoprene by Organo-Nanoclay during Emulsion Polymerization for Reinforcing Natural Rubber Thin Films

“…One of the crucial end-use properties of these products, which is highly required by the users and a selling point of these products, is the film thickness [3]. In general, users prefer these rubber film products as thin as possible since touch sensitivity is better while wearing a thinner film [4]. However, reducing a thickness of the rubber films is usually accompanied by a decrease in the mechanical properties [5].…”