Hot-fillable vinyl bottles

The use of plastic containers will grow 11% per year over the next ten years as metal and glass decline. Plastic is the material of choice for food containers in all areas of food processing including hot-fill and retort packaging. This is due in large part to the strides that have been made in barrier property improvement, better manufacturing, and improvements in the economics, esthetics, and physical properties of plastics. Hot-fill and retort packaging account for approximately 64% of the total packaged foods, and in the next 10 years this is expected to increase to 68%. Of the two, the hot-fill method reportedly will gain in importance while retorting will decline by about 1% per year in effect pushing the growth in hot-fill packaging to about twice that of the overall food packaging business. Since 1980, PVC bottles have grown from 100 MM lbs to more than 200 MM lbs of resin in 1987 (growth of approximately 15% per year). However, PVC bottles still represent only 7% of all plastic bottles and only 1% of all materials used to make rigid containers—an indication of great future potential. One of the serious disadvantages of PVC, however, is its low heat resistance which limits the service temperature of finished articles to about 70°C. Further penetration by PVC bottles can be accelerated by raising the heat resistance above the hot-fill levels of 85°C–100°C. This would permit PVC to be used for many food applications such as fruit juices and table syrups. Now an additive is available that can be formulated with PVC to form miscible, transparent blends with increased service temperatures. The miscibility of the glutarimide acrylic copolymers in PVC allows it to significantly improve heat resistance without effecting the optical properties of the container. As a result, single layer PVC bottles can be made on conventional blow molding equipment that can be hot-filled at 85°C–100°C, have glass-like clarity, with good impact and moderate oxygen barrier resistance. The discussion will include guidelines for compounding the imide copolymer with PVC, properties attainable, and a look at the economics versus other hot-fillable containers.     

Vinyl composites—fiberglass reinforced PVC

Glass fiber reinforced PVC has several distinctive and useful properties. Its tensile strength can be twice that of unreinforced PVC. Excellent coupling of the glass fibers to the PVC matrix is required for good retention of tensile strength when exposed to warm water, Its modulus can be twice that of unreinforced PVC and equal to that of wood. PVC's high load carrying capability is not significantly increased to higher temperatures by adding glass fibers as judged by its 264 psi heat deflection temperature. However, by changing the polymeric matrix, glass reinforced vinyl with an increased HDT of 86°C has been produced for higher use temperature. The coefficient of linear thermal expansion of PVC can be cut in half by the addition of glass fibers and has a coefficient equal to that of aluminum. Glass fiber reinforced PVC has exceptionally good resistance to crack propagation and resists shattering as judged by sawing, punching, stapling, and hammering. When properly formulated for weathering resistance, glass fiber reinforced PVC has good color retention, impact retention, and outstanding dimensional stability. As for all glass fiber reinforced plastics, processing equipment must be built for high abrasion resistance for long economical manufacturing runs.     

High heat applications for SMA modified PVC: Cost effective engineering performance

SMA polymer modifiers for PVC, of the ELIX 300 type, increase the practical heat resistance of rigid PVC blends to > 100 C, allowing cost effective competition with high heat fire retardant engineering resins. The PVC/SMA blend technology, physical property characteristics, and fire retardant properties are presented. A definition of practical heat resistance and the correlation of practical heat resistance to Vicat heat resistance measurements are given with comparisons to competitive high heat fire retardant plastics. Current commercial application experience in rigid injection molding and profile extrusion is described which has confirmed the cost/performance advantage of PVC/SMA blends. Potential market opportunities for PVC/SMA blends will be presented for discussion.     

Formulating technology for rigid cellular PVC sheet

Rigid vinyl can be considered as a highly versatile thermoplastic, finding its way into many different applications. Vinyl's capacity for innovation is virtually limitless, thanks in part to advances in formulation additives, which have enlarged vinyl's processing and end-use performance capabilities. The importance of formulating is particularly evident in rigid cellular PVC, which can be extruded into a variety of shapes, such as profile, pipe, and sheet, all made with less PVC than their solid counterparts. The sheet application can be especially challenging, and it has been made the subject of this paper. The various types of extrusion processes, formulations, and uses for rigid cellular PVC sheet that are found in North America and Europe are compared. The effect of certain types of formulation ingredients on sheet density, surface, and impact strength is described. Reference is made to coextrusion of solid/cellular PVC layers as an economically feasible approach to handling industrial regrind PVC.     

A comparison of oven sag temperature and heat deflection temperature for measuring heat resistance

The plastics industry places great emphasis on heat deflection temperature (HDT) as a measure of heat resistance when designing a plastic product. However, many manufacturers will evaluate a material's heat resistance by exposing a finished part to meximum use temperature under gravity load rather than the high loadings associated with the heat deflection test. The oven sag test is an alternate method which looks at the sag of a molded bar under gravity load. One end of the bar is clamped while the other end is free to sag. By employing a range of temperatures, the temperature at which gross sag takes place can be found. This study investigated how well the heat deflection temperature test and the oven sag test correlate to the performance of an injection molded box subjected to high temperatures using one and two phase PVC blends. The oven sag test was found to provide a more practical and more accurate measure of a material's performance under high temperatures and no external load. It is particularly well suited for evaluating two phase polymer blends.     

Vinyl molding compounds: Formulation and performance evaluation

Today's vinyl molding compounds are successfully meeting the combined challenges of physical properties, appearance, processability, and cost requirements in a variety of specialty injection molding applications such as appliance parts, business equipment, and electrical enclosures. One of the major reasons why vinyl materials are so versatile is that the poly(vinyl chloride) resins on which they are based can be easily modified with a wide variety of additives to tailor the particular performance features of the compounds to their intended applications. Determination of an appropriate combination of PVC resin and additives to produce an effective and cost-competitive compound, however, is not a simple process. Important considerations in formulating a vinyl molding compound and evaluating its performance are discussed here.     

Thermoplastic elastomers from NBR and polyvinyl chloride

This paper will discuss recently developed technology that demonstrates the effectiveness of a thermoplastic polyvinyl chloride/nitrile rubber alloy versus commercially available thermoplastic elastomers and conventionally cured rubbers. Compounding variations, mixing and processing of thermoplastic elastomers such as low temperature properties, compression set, heat resistance, flex properties, and oil and fuel resistance will be examined. Compounding variations of the PVC/NBR allows will be explored to show how recipe changes can affect these important properties.     

PVC／HRA共混物耐热与力学性能研究

以ＰＭＩ－Ｓｔ－ＡＮ三元共聚物为热改性剂,以ＡＣＲ为抗冲改性剂,对ＰＶＣ进行耐热和抗冲改性研究,探讨了共混温度及两种改性剂用量等对共混物物理。力学性能和耐热性能的影响,通过优化制备了耐热,抗冲性能兼备的ＰＶＣ共混改性新材料。     

N-苯基马来酰亚胺的合成方法、应用及市场展望

通过分析耐热ABS及PVC的市场状况及国内外N-苯基马来酰亚胺的产需状况,对国内N-苯基马来酰亚胺的发展前景进行了预测。     

N-苯基马来酰亚胺的合成方法、应用及市场展望

通过分析耐热ABS及PVC的市场状况及国内外N-苯基马来酰亚胺的产需状况,对国内N-苯基马来酰亚胺的发展前景进行了预测.     

PVC thermoplastic elastomers

The paper describes the development and properties of a new family of thermoplastic elastomers based on polyvinyl chloride. Comparisons of the new products with traditional flexible PVC's will be presented, pointing up differences in specific gravity, low temperature properties, heat resistance, melt viscosity, and general physical properties such as tensile modulus and elongation. The elastomeric properties of the new materials are explored and compared to some typical cured elastomers—chloroprene, chlorosulphonated polyethylene. The common thermoplastic elastomers based on block copolymers and polyurethanes are also considered in relation to the new compositions. Such properties as compression-set, flex and fatigue resistance, oil and chemical resistance, weatherability, and performance at elevated temperatures are detailed. The unique feature of this technology that allows one to tailor the surface characteristics from typically high PVC gloss to the fine dull satin finish of cured elastomers is discussed.     

Poly(vinyl chloride) in medical device and packaging applications

Poly(vinyl chloride) (PVC) is the leading polymeric material used in medical device and packaging applications in terms of total volume consumed. It offers a uniquely broad range of properties for a wide variety of applications in the medical and health care industry. It fulfills an extensive range of performance and processing requirements such as gloss, transparency, chemical resistance, scuff resistance, flexibility, bondability, sterilizability by steam, ETO, or high energy irradiation. This paper examines fundamental chemsitry and physical structure of PVC to provide a clear insight and a better understanding on how versatile properties and performance are rendered. The paper also illustrates how specific mechanical and thermal properties can be tailored via compounding and fabrication processes to serve specific purposes in medical applications.     

Colorants based on renewable resources and food‐grade colorants for application in thermoplastics

A series of colorants based on renewable resources and food‐grade colorants have been evaluated for use in polypropylene (PP) and polyvinylchloride (PVC). It has been found that most of these colorants can be processed in PP at 200°C or even 260°C while maintaining good color intensity and color brightness. The colorants evaluated cover a large part of the color spectrum. In PP, the light stability of alizarin (red), carmine (red), indigo (blue), purpurin (red), quinizarin (red), and the aluminium lakes of quinoline yellow (yellow) and indigo carmine (blue) is close to the requirements for indoor applications. The blue colorants indigo and the aluminium lake of indigo carmine are, in principle, sufficiently light stable in PP for indoor applications. A few colorants showed bleeding from PP. Bonding of migrating colorants to the reactive carrier maleic anhydride grafted polypropylene, however, reduced bleeding of the colorant to a large extent. Also after processing in PVC at 200°C, good color intensity and saturation is maintained. Quinizarin, a structural analog of alizarin and purpurin, shows a light stability performance that is close to commercial lead chromate/molybdate orange based colorants. The best performing natural colorants are sufficiently heat and light stable for applications where moderate properties concerning heat resistance and (UV) light stability are required, such as underground PVC water drainage pipes and indoor PP applications. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2961‐2969, 2004     

N-苯基马来酰亚胺的合成方法、应用及市场展望

综述了N-苯基马来酰亚胺的合成方法和其作为新一代树脂耐热改性剂在ABS及PVC树脂改性以及其它方面的应用.通过分析耐热ABS及PVC的市场状况及国内外N-苯基马来酰亚胺的产需状况,对国内N-苯基马来酰亚胺的发展前景进行了预测,并提出了发展建议.     

Successful extrusion of small diameter CPVC pipe

Chlorinated polyvinylchloride (CPVC) pipe is a rapidly growing market, especially 25.4 mm (1″) pipe and smaller. Extrusion of CPVC pipe presents a greater challenge than PVC, because CPVC has less heat stability and higher viscosity. However, CPVC has good physical properties, particularly with respect to heat, and can be used to make hot water pipe. This paper discusses some of the basic factors involved in screw and pipe head design for CPVC extrusion, and gives some examples of successful applications.     

Preparation and structural characterization of nanocrystalline poly(vinyl chloride)

This article describes the development of novel nanocrystalline poly(vinyl chloride) (PVC) for potential applications in PVC processes and reports improvements in the mechanical properties and thermal resistance. Before the preparation of nanocrystalline PVC via jet milling, PVC was spray‐treated and heat‐treated to improve its crystallinity. The pulverization and degradation, morphology, crystalline structure, and melting‐point changes of postmodified PVC during jet milling and the relationship between the distributions of the particle size and processing temperature were investigated. X‐ray analysis and density testing indicated increased density and improved crystallinity. The crystalline region of nanocrystalline PVC was less than 80 nm, with a particle size distribution of 5–20 μm and a melting point of less than 128°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 563–569, 2004     

Heat distortion temperature modification of rigid PVC and chlorinated PVC: A method to produce low smoke compositions

The use of a new low smoke, heat distortion temperature modifier for rigid PVC and chlorinated PVC is discussed. This material, CN-1427, is a tetrabromobisphenol A carbonate oligomer which is compatible with vinyl compositions. The carbonate oligomer can be compounded into PVC resin to improve heat distortion temperature of PVC and CPVC by 20–30°C. Unlike conventional HDT modifiers, brominated carbonate oligomers do not increase smoke evolution during flammability testing. Thus, using carbonate oligomer technology, it is possible to achieve low smoke, Class I (ASTM E-84) and V-O flammability (UL-94) performance. Vinyl compositions, modified with the carbonate oligomer described in this work, can be utilized as an alternative to expensive engineering thermoplastics. This paper reports recent studies on the use of carbonate oligomers as heat distortion temperature modifiers for low smoke vinyl applications. Formulation information addressing flammability and physical property performance is presented in detail.     

Predicting heat buildup due to the sun's energy

PVC building products such as siding, windows, and roofings are exposed to the sun. Absorption of the sun's energy leads to a temperature rise, which may cause dimensional control problems, such as expansion and, in severe cases, distortion of the PVC products. The amount of heat buildup in the product depends on the color and/or pigment system of the PVC compound. Generally, the darker the color, the more the sun's energy is absorbed and the higher the temperature heat buildup. Because of the growing demand for darker colors of PVC building products, a test for measuring temperature rise to predict performance of the product in actual use is needed. A laboratory test method for predicting maximum heat buildup due to the sun is described in this paper. The effects of the sample thickness and gloss, carbon black and titanium dioxide levels, and the distance of an infrared heat source from the sample on the heat buildup are also presented in the paper.     

环保醚酯型增塑剂TP-95在PVC中的应用

研究了环保醚酯型增塑剂TP-95和几种常用增塑剂对聚氯乙烯(PVC)的塑化效果、力学性能、耐寒性、耐热性及耐抽出性能的影响。结果表明:与添加的几种增塑剂相比,TP-95具有显著的增塑软化作用;随着增塑剂用量的增加,最低转矩明显下降,塑化时间缩短,塑化效果随之增强;与DOP和TOTM相比,TP-95表现出良好增塑效应及耐寒性;增塑剂用量均为50份时,TP-95的PVC开始热降解温度高于DOP和DOA;在水和环己烷介质中,随着随着增塑剂用量的增加,抽出损失随之增加;在环己烷介质中,TP-95的抽出损失为4.40%,低于TOTM和DOA,具有良好的耐抽出性。     

Properties of poly(vinyl chloride) fibers crosslinked by 2-dibutylamino-4,6-dimercapto-1,3,5-triazine

PVC fibers, fastened to a needle frame, were crosslinked by 2-dibutylamino-4, 6-dimercapto-1,3,5-trizine in the presence of tetra-n-butylammonium bromide and alkali in water at 96°C. Solvent resistance, characterized by the gel fraction of THF, improves markedly. Mechanical properties of the fibers investigated by tensile tests at 20°C show that both the modulus and tensile strength at break increase, while elongation at break decreases over 40% gel content. Creep tests indicate that the resistance to heat deformation improves by crosslinking. The heat distortion temperature increases by 12°C at 75% gel content. Results of dynamic tests show that the T_g of PVC fibers determined by a peak in the loss modulus (E'') increases from 40% gel content. Dynamic modulus (E') increases by 74% at 23°C and the T_g by 37°C in the case of crosslinked PVC fibers having a 92% gel content. The shrinkage of PVC fibers in hot water at 94°C for 30 min decreases more than 50% over 75–80% gel content indicating the improved resistance to heat deformation.