Superior balance of weatherability and impact performance with acrylic‐capped vinyl siding

Vinyl siding, particularly in darker colors, has to be durable and be able to retain most of its original color when exposed outdoors. As the color palette for vinyl siding has been expanding and more and more colors are being offered to the homeowner, the need exists to improve color hold. A new acrylic capstock polymer, based on core‐shell technology, which can be coextruded onto vinyl siding, has been shown to provide excellent color retention, with good processability, impact and impact retention, and suitable gloss. The properties of this new capstock polymer are compared to other choices for capping vinyl siding. J. VINYL ADDIT. TECHNOL., 13:26–30, 2007. © 2007 Society of Plastics Engineers.     

Weatherability of rigid vinyl siding

Vinyl siding is described as a product in the early maturity stage of business development. The competitive position of rigid vinyl siding vis-a-vis other products is discussed. Total weathering exposures from point sources not usually thought of are reviewed. Methods of control for weathering caused changes as well as resistance evaluation are covered. The impact on the industry of the voluntary product standard PS55-72 is mentioned.     

Rigid cellular PVC—the next house siding material?

The technology for extruding rigid cellular PVC has grown substantially over the past decade. Formulation additives, tooling, and processing expertise have made possible a variety of applications—relatively complex profiles, foam-core pipe, thermoformable foam sheet, and house siding. In the U.S. market, vinyl house siding is typically a relatively thin extrusion that is folded into a final shape that resembles wood cladding in appearance. An alternative to conventional form vinyl siding could be a foam structure that is thicker and stiffer than the solid form, and with a density similar to that of wood. This paper presents several performance advantages of rigid cellular PVC cladding in comparison to the current solid product, in addition to mentioning certain limitations that exist in the foam product that is produced with the technology available today.     

Expanding PVC as a building material

Rigid vinyl foam can currently be found in applications such as profile, sheet, and foam core pipe, but it is still a curiosity in house siding and other wood replacement applications. This paper looks at the potential for vinyl foam as an alternative for wood, comparing its end-use capabilities. In addition, the various types of extrusion processes, and formulations, are compared, and the effect of certain types of formulation ingredients on density, surface quality, and other physical properties are described.     

Attack of the artillery fungus on vinyl siding

The artillery fungus, Sphaerobolus stellatus, ejects dark‐colored spores for a distance of several meters. These are enclosed in an adhesive layer comprised of carotenoid pigments. On exposure to sunlight, the pigment layer resinifies and develops a strong bond to vinyl siding capstock. The damage is compounded when the homeowner removes the bonded spores abrasively, destroying the protective capstock layer. Strategies to protect vinyl siding or to defeat the microorganism are discussed. J. VINYL. ADDIT. TECHNOL., 11:63–64, 2005. © 2005 Society of Plastics Engineers     

A novel impact modifier system for vinyl siding and profile substrate

The use of a newly developed ABS impact modifier in coextruded vinyl siding and window profile substrate is discussed. Considerations of toughness at room and low temperature, output, reduced lubricant levels, and weatherability of the finished siding are reviewed. Actual outdoor weathering results are presented, along with long-term heat aging tests, showing the modifier to have good property retention characteristics.     

Formulations for vinyl house siding: History,present, future

In the early 1960s, vinyl house siding was first commercialized. The colors were pastels and included white, green, yellow, and gray. All siding tended to bleach and fade (oxidize) to an extent where medium and dark colors were unacceptable, since the fading is more noticeable in deeper colors. All the early siding was made from cubes on single-screw extruders. Powder compounds were first introduced in the late 1960s, as was twin-screw extrusion. At the same time higher processing temperatures were used on, both twin- and single-screw extruders. That led to a well-fused and tougher product. Formulation changes reduced bleaching and fading and permitted such medium-depth colors as tan, gold, beige, blue, and olive. This technology allowed rapid growth in the vinyl siding industry in the late 1970s. Surface distortion (oil canning) was recognized as a potential problem with the early gray color and recognized as a major problem with dark colors; it was resolved only by understanding the fundamental principles involved. Another major problem was the fading in dark colors and here again extensive research into the principles of weathering led to the use of a thin, highly weatherable capping as a cost-effective solution. For the future, many technical developments can be expected in this rapidly growing market. However, judging by the occasional withdrawal of a formulation from the market, and by an occasional homeowner complaint, present performance in several properties must be judged as just adequate. For this market to continue its rapid growth, future performance should be better than today's. This can be accomplished without hurting economics by careful understanding of all parameters involved. Formulation changes will allow better performance. Standards must be raised to control product performance, especially surface distortion and color stability in darker colors, and to insure retention of physical properties after long-term weathering.     

Fourier transform infrared micro spectroscopy mapping. Applications to the vinyl siding industry

Fourier transform infrared (FT-IR) micro spectroscopy is a powerful analytical technique capable of yielding high quality information with a spatial resolution as low as 10 microns. When coupled with an automated mapping stage it can offer unique evaluation capabilities. This paper describes a number of applications of FT-IR micro spectroscopy mapping to the vinyl siding industry. Examples will focus on determining, in single sample mapping experiments, the compositional changes associated with capstock to substrate transition and evaluating the degradation species and level observed during weathering exposure throughout the thickness of the siding panel.     

Volatiles released during the weathering of PVC

Volatile organic compounds and organochlorine species liberated by UV exposure of poly(vinyl chloride) (PVC) siding samples have been identified and preliminary quantification made. These volatiles included those remaining in a PVC sample after weathering or laboratory UV exposure and which could be released by thermal desorption. In addition, by using a flow-through cell and granular carbon adsorbents, volatile species directly desorbed during laboratory UV exposure were measured. Total directly desorbed organochlorine compounds were about 1/20 of the weight of hydrogen chloride as measured by conductometric analysis, Quite similar products were observed from old (～1984) and current (1995) commercial siding formulations. Observed volatile compounds are proposed to come from the TiO₂-controlled photo-oxidation of both PVC and its additives such as impact modifiers.     

Compound requirements for vinyl siding

Basic principles of good compounding for weatherable vinyl siding are discussed. Appropriate level of stabilizer is such that 50 percent of initial should remain after the extrusion process. Balanced lubrication is necessary. Judicious choice of pigments and impact modifiers is called for. The cited references give added substance to this review paper.     

UV stabilizers: Their effects on vinyl compounds

Poly(vinyl chloride) (PVC) is the polymer of choice in a wide variety of applications on account of its comparatively low cost, high chemical resistance, good mechanical properties and electrical insulating capabilities. The even wider application of the material has been restricted by its low thermal and photolytic stability. This paper reviews the various light degradation and stabilization mechanisms that have been postulated recently for PVC. The importance of the thermal stabilizer system to the photostabilization of the material is also stressed. Finally the market opportunity for a cost effective UV stabilizer system for rigid PVC is discussed emphasizing the versatility that such a product would give to the vinyl siding manufacturer.     

Options for poly(vinyl chloride) feedstock recycling. Results of research project on feedstock recycling processes

Abstract

Feedstock recycling processes for treating poly(vinyl chloride) rich waste streams should be capable of recovering both the chlorine and hydrocarbon contents of the stream; the chlorine in the form of purified hydrochloric acid or salt and hydrocarbons in the form of energy or as feedstock for the petrochemical industry. Results of a research project to consider treatment of poly(vinyl chloride) rich waste streams are presented, together with recommendations on potential processes and technology for the development of a demonstration plant.     

Ignitability Analysis of Siding Materials Using Modified Protocol for Lift Apparatus

This paper reports on the ignitability of common siding materials that could be exposed to wildland fires. When exposed to brands or fires, structures will experience piloted ignition, which is requisite for sustained ignition involving burn-through and surface flame spread in various directions. In this study, the Lateral Ignition and Flame Spread Test (LIFT) apparatus (ASTM E1321 and E1317) was used to test various siding materials (plywoods, softwoods, and vinyl), some of which were painted, humidified, or sawed. A recently developed protocol provided useful, accurate values of the following thermophysical properties: surface emissivity, surface ignition temperature, thermal conductivity, and thermal diffusivity. Full consistency was achieved with independent literature values of these properties and can be used directly in the database of fire growth models.     

Weatherable rigid PVC: The effect of light and thermal stabilizers

Rigid PVC compositions used in outdoor applications such as siding, profiles, windows, and soffit predominantly contain a tin mercaptide thermal stabilizer. It is well known that tin mercaptides impart outstanding thermal stability to vinyl compounds, however, it is also well known that they provide only marginal light stability. Mercaptides can be used in these applications primarily because they are combined with high levels of titanium dioxide. They are not well suited for dark colored PVC and compositions without titanium dioxide. These require a more weatherable thermal stabilizer, such as a tin carboxylate. In this paper, principles for formulating rigid weatherable vinyl will be discussed. The influence of thermal stabilizers and the interdependence of light stabilizers and thermal stabilizers on PVC photostability will be emphasized. Data will be presented showing how one can formulate weatherable dark brown and pastel PVC through the use of tin carboxylate thermal stabilizers, the appropriate light stabilizers, and pigments. Traditional approaches to achieving weatherability will be compared to what can be attained by capitalizing on the latest advances in stabilization technology. Finally, methods for reducing TiO₂ concentration will be shown.     

Recycling postconsumer PVC bottles: Technology and market development

The drive to recycle individual polymers in a “closed-loop”—that is, bottles-to-bottles—began in the late 1980s. Technology and market streams for high-volume packaging plastics like HDPE and PET evolved first. Smaller-volume packaging plastics have followed. This article describes technology development and the state of the market, including general economics for vinyl recycling. Recycling of PVC packaging, to say nothing of recycling of other plastics, continues to evolve and should be viewed as a work-in-progress; still, closed-loop recycling of PVC bottles is a commercial reality.     

Emerging technical and society trends—opportunities for vinyl: A look at the future and how the vinyl industry can respond for growth and profit

The vinyl industry has a rich history of providing solutions to society's needs. These include flame‐resistant wire insulation, piping systems for safe drinking water, and weatherable, flame‐resistant systems for siding, windows, auto interiors, floors, and pool liners. Also included are shatter‐resistant clear containers with handles, safe blood supplies and intravenous solutions, and flame‐resistant computer housings and electrical boxes. These are but a few of the things of which the vinyl industry can be proud. The vinyl industry is mature, and as in many other mature industries, much of the technical and business effort goes into running the day‐to‐day businesses, putting out fires, reducing costs, and driving efficiencies. If poorly managed, this will be an all‐consuming effort, leaving no thought and no effort at all on longer‐term business opportunities. The future will look much different than today. Identifying future trends will allow well‐managed companies, looking for these future business opportunities, to seek out and set aside some efforts for developing future technologies and businesses. In this paper we discuss some future trends and needs, such as inexpensive and safe drinking water, personalized public transportation, prevention of resource depletion, high‐powered energy packages, nonpolluting energy sources, human genetic engineering, e‐bombs, and computers. The opportunities for the vinyl industry to participate in these changes also are discussed.     

Enhanced weatherability of exterior PVC building products

Poly(Vinyl) Chloride (PVC) is used extensively as a material for the growing building‐products market. The color preferences of consumers for markets such as vinyl siding have forced the industry to seriously reconsider the use of PVC especially for the medium‐to‐dark color palettes, where the performance is critical. Organotin mercaptides have always been the stabilizers of choice in the U.S. market because of their inherent outstanding heat‐stabilization properties. On the other hand, this technology is also known to be a compromise between processability and weathering characteristics. In a market that drives for excellence, all additives must be optimized to meet the final performance requirement. Organotin carboxylates and specifically maleates have long been known for excellent weathering but have not been used extensively in the industry owing to less‐than‐optimum intrinsic heat stabilization efficiency, and in some cases, troublesome lachrymatory properties. A new generation of organotin maleates has been successfully developed to address both issues. This paper describes the improved lachrymatory behavior of the new technology compared to standard organotin maleates and also shows its outstanding weathering performance in PVC capstock compared with conventional organotin mercaptide during natural aging.     

Vinyl durables recycling

The Geon Company and the vinyl industry have been very active in recycling for a number of years. A significant portion of that effort has been focused on the vinyl packaging, and the industry has been instrumental in getting automatic bottle sortation commercialized. This paper will focus more on vinyl durables recycling in wire and cable, computer and business equipment, and automotive. In addition it will address a number of environmental attacks currently leveled at vinyl.     

电石法氯乙烯精馏低塔尾气的利用

以40万t／a电石法聚氯乙烯装置为例,对氯乙烯精馏低塔尾气回收进行了详细的计算,表明以变压吸附的方法综合回收精馏尾气可获得显著的经济效益。     

Effectiveness of pre‐applied wetting agents in prevention of wildland urban interface fires

The purpose of the work described in this paper is to investigate the effectiveness of pre‐wetting structures, dead fuels, and landscaping plants in preventing fire spread from wildland fires to structures. Critical fluxes for fire growth were determined using intermediate‐scale testing for three wetting agents (water, type A foam, and gel) applied to 10 landscaping plants conditioned to 20% moisture, a mulch material, and four external structural materials (vinyl siding, plywood siding, asphalt shingle roofing, and cedar shake roofing). The critical flux for fire growth values was determined at 3‐min heat radiation exposure and simultaneous 300‐mm long flame exposure. Test specimens were exposed to various durations and intensities of drying prior to exposing them to heat radiation. Application of water or foam provided no noticeable protection. Gel was effective in providing protection even after 60 min of laboratory condition drying but was less successful when exposed to fire weather simulating accelerated drying. Some uncertainty is associated with the results of this work because of the variability of landscaping plants and gel wetting agent application uniformity. The intermediate‐scale test results were verified using full‐scale testing. Copyright © 2012 John Wiley & Sons, Ltd.