Neoprene Materials Research Articles

Effect of wetsuit outer surface material on thermoregulation during surfing

While some research does exist on wetsuit thermoregulation, there is currently a paucity in the literature describing how various types of neoprene materials affect skin temperatures. The purpose of this study was to test the hypothesis that the slick neoprene would lead to higher skin temperatures in comparison to the jersey material. Participants wore a custom wetsuit with the torso made of half slick and half jersey neoprene materials (n = 78). Participants either participated in one of two field studies or engaged in a simulated surfing session in a flume after sunset, where the influence of direct sun exposure was eliminated. In the field, participants wore four thermistors placed on either side of the chest and the upper back (n = 27) or the abdomen and the lower back (n = 31). Skin temperatures were measured across typical surfing sessions. In the laboratory, the participants (n = 20) wore all eight sensors in the anatomical locations described above, and skin temperatures were recorded across a simulated surfing session. In the field study, the mean skin temperatures under the slick neoprene were significantly higher when compared to the jersey neoprene for the upper chest (p < 0.001), upper back (p = 0.001), and lower back (p < 0.001) at all time points. In the laboratory study, skin temperatures were significantly higher under the slick neoprene at the upper chest and lower back (p < 0.001). These findings may be a result of greater heat absorptive properties of slick neoprene during exposure to the sun and the water-retaining properties of jersey-lined neoprene.

Noble-gas-infused neoprene closed-cell foams achieving ultra-low thermal conductivity fabrics.

Closed-cell foams are widely applied as insulation and essential for the thermal management of protective garments for extreme environments. In this work, we develop and demonstrate a strategy for drastically reducing the thermal conductivity of a flexible, closed-cell polychloroprene foam to 0.031 ± 0.002 W m−1 K−1, approaching values of an air gap (0.027 W m−1 K−1) for an extended period of time (>10 hours), within a material capable of textile processing. Ultra-insulating neoprene materials are synthesized using high-pressure processing at 243 kPa in a high-molecular-weight gas environment, such as Ar, Kr, or Xe. A Fickian diffusion model describes both the mass infusion and thermal conductivity reduction of the foam as a function of processing time, predicting a 24–72 hour required exposure time for full charging of a 6 mm thick 5 cm diameter neoprene sample. These results enable waterproof textile insulation that approximates a wearable air gap. We demonstrate a wetsuit made of ultra-low thermally conductive neoprene capable of potentially extending dive times to 2–3 hours in water below 10 °C, compared with <1 hour for the state-of-the-art. This work introduces the prospect of effectively wearing a flexible air gap for thermal protection in harsh environments.

네오프렌 소재의 레이저 커팅기법 적용에 따른 물성 및 드레이프 형상 변화 연구

A wide variety of fashion materials focus on good drape property and softness. Among the recently emerging materials, Neoprene that consists of laminated knit on both sides of foamed neoprene sheet seeks a unique appearance that is considerably deviated from the current flow. Diverse processing methods for the newly released material heighten the value in function and beauty among trends of fashion materials by enhancing the appearance, touch and material property. Laser-cutting technique is one of the processing methods that is consistently used in the textile area. This study aimed to find the basic materials for applicability of laser-cutting technique to clothing goods after consideration of the changes in material property and drape shape, and to furthermore enforce different pattern conditions to Neoprene material, one of the newly attractive materials in the fashion area. In this study, we applied laser-cutting technique to Neoprene material sample under different conditions of pattern appearance, size and distance, based on current evaluation and theoretical background of Neoprene material, fashion trend and laser-cutting technique. Drape property can improve and the drape direction could also be controlled by a wide variety of laser-cutting techniques applied to Neoprene materials that have uniquely different appearances from most other textiles. This technique could be applied to the design for diversification of Neoprene clothing goods in the future.

Effects of glovebox gloves on grip and key pinch strength and contact forces for simulated manual operations with three commonly used hand tools

This study examined the effects of glovebox gloves for 11 females on maximum grip and key pinch strength and on contact forces generated from simulated tasks of a roller, a pair of tweezers and a crescent wrench. The independent variables were gloves fabricated of butyl, CSM/hypalon and neoprene materials; two glove thicknesses; and layers of gloves worn including single, double and triple gloving. CSM/hypalon and butyl gloves produced greater grip strength than the neoprene gloves. CSM/hypalon gloves also lowered contact forces for roller and wrench tasks. Single gloving and thin gloves improved hand strength performances. However, triple layers lowered contact forces for all tasks. Based on the evaluating results, selection and design recommendations of gloves for three hand tools were provided to minimise the effects on hand strength and optimise protection of the palmar hand in glovebox environments.

The pilosebaceous unit—a phthalate-induced pathway to skin sensitization

Allergic contact dermatitis (ACD) is caused by low-molecular weight compounds called haptens. It has been shown that the potency of haptens can depend on the formulation in which they are applied on the skin. Specifically the sensitization potency of isothiocyanates, a group of haptens which can be released from e.g. adhesive tapes and neoprene materials, increases with the presence of phthalates; however, the underlying mechanisms are not clear. A better understanding of the mechanisms governing the potency of haptens is important, e.g. to improve the risk assessment and the formulation of chemicals in consumer products. In this study we have explored phthalate-induced effects on the sensitization potency, skin distribution, and reactivity of fluorescent model isothiocyanate haptens using non-invasive two-photon microscopy to provide new insights regarding vehicle effects in ACD. The data presented in this paper indicate that the sensitization potency of isothiocyanates increases when applied in combination with dibutylphthalate due to a specific uptake via the pilosebaceous units. The results highlight the importance of shunt pathways when evaluating the bioavailability of skin sensitizers. The findings also indicate that vehicle-dependent hapten reactivity towards stratum corneum proteins regulates the bioavailability, and thus the potency, of skin sensitizers.

Permeation of Gasoline, Diesel, Bioethanol (E85), and Biodiesel (B20) Fuels Through Six Glove Materials

Biofuels and conventional fuels differ in terms of their evaporation rates, permeation rates, and exhaust emissions, which can alter exposures of workers, especially those in the fuel refining and distribution industries. This study investigated the permeation of biofuels (bioethanol 85%, biodiesel 20%) and conventional petroleum fuels (gasoline and diesel) through gloves used in occupational settings (neoprene, nitrile, and Viton) and laboratories (latex, nitrile, and vinyl), as well as a standard reference material (neoprene sheet). Permeation rates and breakthrough times were measured using the American Society for Testing and Materials F739-99 protocol, and fuel and permeant compositions were measured by gas chromatography/mass spectrometry. In addition, we estimated exposures for three occupational scenarios and recommend chemical protective clothing suitable for use with motor fuels. Permeation rates and breakthrough times depended on the fuel-glove combination. Gasoline had the highest permeation rate among the four fuels. Bioethanol (85%) had breakthrough times that were two to three times longer than gasoline through neoprene, nitrile Sol-Vex, and the standard reference materials. Breakthrough times for biodiesel (20%) were slightly shorter than for diesel for the latex, vinyl, nitrile examination, and the standard neoprene materials. The composition of permeants differed from neat fuels, e.g., permeants were significantly enriched in the lighter aromatics including benzene. Viton was the best choice among the tested materials for the four fuels tested. Among the scenarios, fuel truck drivers had the highest uptake via inhalation based on the personal measurements available in the literature, and gasoline station attendants had highest uptake via dermal exposure if gloves were not worn. Appropriate selection and use of gloves can protect workers from dermal exposures; however, current recommendations from the National Institute for Occupational Safety and Health should be revised to account for contemporary fuel formulations that routinely contain ethanol.

Estimation of permeation rate of chemicals through elastometric materials

Elastometric materials are used as barriers to protect workers against exposure to chemicals. The effectiveness of a polymer as a chemical protective material therefore depends on the rate of the permeation of chemicals through it. The permeation rate depends on the solubility and the diffusion coefficient of chemicals in the materials. The diffusion coefficient itself is a strong function of concentration of the chemicals in the polymeric material. Permeation rates can be measured directly using a permeation cell or they can be calculated from the solubility and the diffusion coefficient data. Sorption/desorption experiments can be used to determine solubility and an expression for the diffusion coefficient in terms of concentration. Experiments were conducted for the sorption and desorption of ethyl acetate in three glove (one butyl and two neoprene materials) and two garment (neoprene and chlorinated polyethylene) materials. The data collected were used to estimate the steady-state permeation rates of ethyl acetate through the materials. The results of the experiments show that the solubility of ethyl acetate in butyl rubber is 0.795 g/cm3, and the steady-state permeation rate is 0.32 μg cm−2 s−1. The solubility of the chemical through the three neoprene materials is in the range of 2.25–5.31 g/cm3, and the steady-state permeation rates vary from 27 to 43 μg cm−2 s−1. The solubility of ethyl acetate in the chlorinated polyethylene is 7.14 g/cm3, and the steady-state permeation rate is 62.43 μg cm−2 s−1. The experimental method is very simple to use and it requires a small sample of the material (less than 1 cm2) and only a few milliliters of the chemical. Sorption/desorption experiments can also provide information on the amount of additives extracted from an elastomeric material during contact with a chemical. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1265–1272, 2001

COMPARISON OF CHEMICAL PERMEATION DATA OBTAINED WITH ASTM AND ISO PERMEATION TEST CELLS—I. THE ASTM STANDARD TEST PROCEDURE

The two main permeation test methods used in testing the resistance to chemicals of protective gloves are ASTM F739-85 and the draft international standard ISO/DIS 6529. In this investigation the two test cells were used following the test procedure proposed in the ASTM standard method in order to study whether the results obtained are comparable. Two chemicals, toluene and 1,1,1,-tricholorethane, were tested with three neoprene gloves and two specially prepared neoprene materials. The collecting medium was nitrogen gas in an open-loop system with flow rates of 60, 90 and 120 ml min-1. The breakthrough time and permeation rate at steady-state were calculated as described in the ASTM standard test method. Breakthrough times were not significantly influenced by the flow rate of the collecting medium. The steady-state permeation rate, however, showed greater variation and the values obtained can be compared only on relative bases.

Protective Coatings and Linings in Neoprene

Neoprene is the name given to a synthetic elastomer based on polychloroprene. When neoprene is vulcanised, a. product having similar physical properties to cured natural rubber, but generally more abrasion‐ and chemical‐resistant, is produced. Various types of neoprene can be produced by different techniques in the manufacture of the polymer, all types having their own characteristics. This article surveys the neoprene materials used in the protective coating and lining fields—liquid and sheet neoprene, caulking compounds, putties and adhesives—and some of the practical applications to which they have been put.