ISSN:0193-7197    

DOI:10.1002/vnl.730130302

出版商:Society of Plastics Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractThe optimization of the extrusion of a simple rigid PVC compound in both single and twin screw machines is considered. Mass throughput, short term mechanical properties (tensile and impact). degree of mixing, and energy efficiency were selected as important parameters of the process. Using a statistically based experimental design, regression polynomials of the above variables were defined. The corresponding responses were superimposed and adequate processing windows were defined. Generally, processing rigid PVC at high screw speeds, small die resistances, and medium to high temperature profiles led to the most adequate values of the process parameters.

ISSN:0193-7197    

DOI:10.1002/vnl.730130303

出版商:Society of Plastics Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractFlexible PVC applications can be categorized as requiring either general or higher performance characteristics. In many application areas, specification requirements are becoming increasingly more severe requiring the use of polymeric polyester plasticizers in compounding. Polymeric plasticizers provide excellent migration, volatility, fluid chemical extraction, and/or weathering resistance in higher performance applications compared with that obtained from monomeric plasticizers alone.

ISSN:0193-7197    

DOI:10.1002/vnl.730130304

出版商:Society of Plastics Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractVariation in the results obtained in the Light Scattering Film (LSF) Test, also referred to as the Fog Test, presents problems both for the investigator as well as the formulator. The results are often confusing (two similar formulas will produce widely different results) and seldom repeatable. In the Fog Test high fog values are desired because high fog values mean less fog. The results of this study demonstrate that the standard deviation for multiple tests on the same sample decreases with increasing fog value. The values obtained when little LSF is produced (high fog values) vary only slightly while the values obtained for heavy LSF (low fog values) fluctuate as much as 30 points. Several explanations are offered for this lack of repeatability, but they condense down to the fact that all of the variables which affect the results are not presently controlled.The tests cited in this report were conducted using Di‐2‐ethylhexyl phthalate, Diisodecyl phthalate, and Di‐(1‐heptyl, nonyl, undecyl) phthalate as neat plasticizers from commerical suppliers. DOP was used because it is currently used by the SAE as an industry standard. The remaining two plasticizers were used because they are typically used in flexible PVC for automotive interiors. Results of this study confirm that the variations encountered in the LSF Test are inherent in the test itself and not due to the material being evaluated. Fluctuations which occur around a given LSF value occur to the same degree irrespective of the material producing the light scatteri

ISSN:0193-7197    

DOI:10.1002/vnl.730130305

出版商:Society of Plastics Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractThe thermal degradation of PVC compound involves the development of color. The evaluation of this degradation, and the associated additive performance, is often limited to that perceived by the human eye. This technique provides limited accuracy and precision. A quantitative technique incorporates the use of a colorimeter. Essentially errorless, laborless performance analyses are achieved with automated colorimetry. Elaborate data processing of the computer‐acquired digital information is then availabl

ISSN:0193-7197    

DOI:10.1002/vnl.730130306

出版商:Society of Plastics Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractAzodicarbonamide has been widely used for many years as the blowing agent of choice for expansion of vinyl foams. It has been especially useful in chemically embossed flooring because the sensitivity of the blowing agent to various factors affecting its decomposition temperature permits control of the degree of expansion of the foam. Considerable work has been done by a number of investigators to elucidate these factors. Mechanisms for the decomposition of azodicarbonamide have been proposed in the literature to explain the activating or retarding effect of many compounds on the decomposition temperature. The use of Differential Scanning Calorimetry with an active reference is shown to be an extremely useful tool in determining small effects of various additives on the decomposition temperature of the blowing agent.

ISSN:0193-7197    

DOI:10.1002/vnl.730130307

出版商:Society of Plastics Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractA common system of primary lubricants in rigid PVC extrusion compounds is calcium stearate plus paraffin wax. Secondary lubricants are frequently added to this system at low concentrations with the intention of improving such properties as metal release, thermal stability, plateout, extrudate surface appearance, etc. This paper discusses the results of laboratory studies designed to evaluate the contribution to these properties of two commonly used secondary lubricants: AC629A, an oxidized low molecular weight polyethylene, and K175, an acrylic “lubricating processing aid.” Surprisingly, the testing showed little improvement in performance when these auxiliary lubricants were ad

ISSN:0193-7197    

DOI:10.1002/vnl.730130308

出版商:Society of Plastics Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractAn experiment was conducted to compare the variability of the Brookfield Viscometer, the Severs Extrusion Rheometer, and the Haake Rotational Viscometer in measuring flow characteristics of PVC plastisol. The author discusses variability of the different test methods involved with the Severs and the Haake viscometers. Also discussed are operator, environmental, and day‐to‐day variat

ISSN:0193-7197    

DOI:10.1002/vnl.730130309

出版商:Society of Plastics Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractA new complex ester additive has been developed for polyvinyl chloride (PVC) food wrap film. This material imparts significantly improved fog resistance and exhibits superior anti‐static characteristics compared to conventional systems. A “mushroom sensitivity” test shows that this new anti‐fog agent has no effect on color or consistency of mushrooms. Effects of conventional anti‐fog systems and this new proprietary product in PVC films are compared in: (a) fog tests at room temperature and at 2°C–5°C, (b) static decay measurements, and (c) thermal stability and optic

ISSN:0193-7197    

DOI:10.1002/vnl.730130310

出版商:Society of Plastics Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractDry blends of a PVC resin with various plasticizer mixtures were processed at different temperatures to produce samples of different degrees of fusion. The ease of fusion increased with decreasing the solid‐gel transition temperature (Tm) of the plasticizer mixture. Nevertheless.Tmwas not necessarily a linear function of the individual concentration of plasticizers in the mixture. Therefore, the ease of fusion showed in some cases an optimum at a given concentration of the plasticizer mixtur

ISSN:0193-7197    

DOI:10.1002/vnl.730130311

出版商:Society of Plastics Engineers    

年代:1991

数据来源: WILEY