The SPE Library contains thousands of papers, presentations, journal briefs and recorded webinars from the best minds in the Plastics Industry. Spanning almost two decades, this collection of published research and development work in polymer science and plastics technology is a wealth of knowledge and information for anyone involved in plastics.
Natural insecticide, pyrethrum, and insect repellent DEET were added to poly(lactic acid) (PLA) fibers via extrusion and spraying. GPC analysis showed that the addition of DEET caused an increase in depolymerization with the increase of DEET concentration. Contact Irritancy Assay (CIA) showed that DEET-treated PLA fabrics caused the lowest percentage escape response with an escape frequency of 33.3 ± 3.3%. This was followed by the extruded natural pyrethrum-treated PLA fabrics with an escape frequency of 80 ± 6.3%. PLA fabric spray-treated with natural pyrethrum caused an escape frequency of 98.3 ± 1.7%. All treated fabrics caused repellency.
The shish-kebab structure has been investigated for many years and it has been widely applied in many field, while the formation of the structure has still been found in limited materials. In this study, different electrospun poly(ε-caprolactone) (PCL) blended nanofibers with poly (ε-caprolactone-co-lactide) (PLCL), polylactic acid (PLA) and graphene (GO) were applied as shish materials in the self-induced crystallization and different crystalline structure were obtained. The PCL blended fibers with different internal crystalline structure led to different induced crystal lamellae morphology. By comparing with the surface crystalline structure, it seems that the formation of self-induced nanohybrid shish-kebab (SINSK) structure is regulated simultaneously by a lattice matching mechanism and a soft epitaxy effect in the crystallization process. This study might help people to explore the materials for creation of SINSK structure.
Polylactic acid (PLA), derived from bio-resources, is an environmentally friendly plastic which has attracted tremendous interests in both academia and industry. This paper investigates the feasibility of direct injection molding of PLA/wood fiber composites and their mechanical behavior. Response surface methodology was adopted to study the effects of molding parameters, as well as their interacting effects, on the tensile strength of the composites. Melt temperature, hold pressure, injection speed were chosen as the molding parameters studied. Additionally, the analysis of variance was applied to identify the most significant factors. The statistical model would improve our understanding of the tensile strength behavior of PLA/wood fiber composite, and provide the guidance for selecting proper molding parameters to maximize the tensile strength.
This study describes the preparation and characterization of electrospun films made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) produced by mixed bacterial cultures derived from a cheese whey (CW) industrial by-product. A mild thermal post-processing step carried out on the electrospun fibers mat, at a temperature below the biopolymer’s melting point, yielded a film with high transparency, enhanced crystallinity, and potentially sufficient mechanical and water barrier properties for sustainable packaging applications.
Poly(lactic acid) (PLA) is arguably the most well-known biodegradable plastic. However, its degradation behavior is far from ideal. The goal of this work is to prepare PLA blends that exhibit accelerated biodegradation performance whilst retaining adequate mechanical properties. To accomplish this a copolymer consisting of poly(L-lactic acid) and poly(glycolic acid) (PGA) structural units was synthesized and subsequently melt blended with a commercially available PLA homopolymer. The anaerobic degradation behavior of the polymer blend was greatly enhanced as a result of the incorporation of 20 wt% of the copolymer. A moderate change in mechanical properties including a 20% reduction in stiffness and strength and an 80% increase in elongation to break was also observed.
Although tissue engineering has shown great advances in recent years, creating proper mechanical properties and cell growth microenvironments is still challenging. In this study, electrospun poly (lactic acid), PLA, nanofibrous membranes were hot embossed to develop 3D hierarchical micro/ nanostructures. Human umbilical-vein endothelial cells (HUVECs) were then cultured on these structures. The hot-embossed membranes exhibited not only superior mechanical properties (the tensile strength was 7.01 ± 0.18 MPa and the tensile modulus was 166.91 ± 15.54 MPa), but also better cell viability as evaluated through a CCK-8 assay and fluorescent dye. The grating arrays of the micropatterned fiber mats encouraged the HUVECs to proliferate. The approach proposed here—combined electrospinning and hot embossing—has great potential for biomedical applications, including for use as polymer scaffolds in tissue engineering.
Foaming technology is a useful way to optimize material consumption in plastic processing, increasing the material cost/benefit ratio and improving some properties such as the impact resistance, the insulation properties, and the dimension stability, among others. For compostable biopolymers, the foaming technology should not affect the biodegradation properties of the material.This work is oriented to analyze the effect of foaming parameters on the density and material hardness in a foamed poly lactide acid (PLA) part. In the foaming process, the PLA pellets are exposed at room temperature to a highly pressurized gas in order to saturate the pellets, then the material is processed in an injection molding machine. The effect of saturation and desorption time before the injection molding process is studied.A PLA from Nature Works is used. The most recommendable process window for the foaming of the material is proposed.
More and more industrial plastics parts used in automobile are turning to be produced by extrusion blow molding (EBM). For directly obtaining high-gloss part in mold, a rapid thermal cycling extrusion blow molding (RTCEBM) technology was developed by integrating the dynamic mold temperature control strategy into the traditional EBM. The process principle was presented and process optimization by executing some molding operations in parallel was analyzed in detail. A typical automotive plastic part, i.e. spoiler, was taken as an example to illustrate the application of RTCEBM in actual production. The corresponding blow mold was designed and a two-step method was proposed and applied to optimizing the heating systems arranged in the mold cavity and core plates simultaneously. Finally, a prototype blow mold of spoiler was manufactured and used for molding the parts, it was found that the molded spoilers exhibit high-gloss surface appearance and could be directly used for the final assembly process without any secondary processing, as well as the molding cycle time was also in the accepted range.
Biaxial stretch blow molding is a process for producing a plastic container from a preform or parison that is stretched in both circumferential and axial direction when the preform is blown into its desired container shape. It is well established for the large scale production of high quality PET bottles with excellent mechanical and optical properties.The concept of "virtual prototyping" is nowadays well established in the stretch blow molding industry in order to improve the containers properties during the design phase. Still, a virtual optimization is yet connected with much manual work. Therefore, a process simulation and a testing simulation for stacking strength was integrated into an optimization cycle to design a preform geometry for improved mechanical properties of the corresponding bottle. The optimization performed with Newton based algorithms however lead to suboptimal mechanical properties. The investigations show, that the objective function indicating the mechanical properties of the bottle has several local maximum values which prevent the determination of a global maximum. Further investigations will focus und different optimization algorithms.
I would propose creating a summary of efforts to utilize PET in extrusion blow molding. The main processes for making PET bottles involve creating an expensive injection mold in combination with expensive blow mold tooling. This approach works for large volume production of 100million containers or more, but many potential packages for lower volume users are not well served. Resin suppliers have created grades of PET with increased melt strength that have begun to address this market need. These materials are imposing problems for recycling of PET which needs to be addressed. I think a summary paper of the activity that has taken place will be of interest to ANTEC attendees. I have not written the paper but will if the organizers wish a presentation.
In this report, we present preliminary results on the use of blow-molding simulation as a tool for optimizing processing conditions and preform / parison geometry to achieve a blow molded part with the desired thickness distribution. Simulations were carried out using the software B-SIM† in the context of stretch-blow-molding of PC injection-molded preforms for LED bulb cover applications. This application requires optical quality parts and imposes stringent requirements on tolerances for the thickness uniformity of the blow-molded cover. Baseline simulations -- with preform geometry matching that used in initial experimental trials, and employing processing conditions similar to those employed in the blow-molding trials – estimated thickness variations exceeding the tolerances imposed by the application. Virtual iterations with B-SIM† simulation trials were then employed to optimize the geometry of and initial temperature distribution within the preform, as well as the processing conditions to result in predictions of significant improvement in thickness uniformity of the blown part.
Intermittent extrusion blow molding is increasingly being used in polymer forming processes for the production of complex thermoplastic industrial parts with short cycle times. During this process residual stresses caused by inhomogeneous cooling and relaxation of polymer chains, often result in shrinkage and warpage of the final part. One challenging quality requirement of industrial blow molded parts is geometric tolerances. Therefore part deformation, due to cooling and solidification, needs to be controlled and optimized according to specific design criteria. In particular, the complex design shapes of plastic fuel tank (PFT) shells exacerbate these challenges which need to be resolved upfront, in the early stages of product development and tool design. Consequently, the development of an accurate simulation tool, well suited for industrial applications, to predict thermoplastic part deformations due to cooling and solidification, has become essential for part designers to help achieve an efficient production with minimum manufacturing cost. The aim of this work is to present the latest advancements in predicting the shrinkage and warpage deformation of a curved PFT, designed for agricultural machinery, using NRC’s BlowView software. This case study validation considers the entire blow molding stages (i.e., polymer flow in the die, parison formation, inflation, and finally in and out of mold cooling during part solidification). The simulation results, in terms of thickness distribution and displacements, are compared to an actual scanned part using the best fit technique in order to exemplify the accuracy and reliability of the modelling approach.
Fluoropolymers are well known materials in the architectural industry. Films made from these materials can be made into aesthetically pleasing building skins. But it’s a challenge to bond them to other materials.Multilayer optical film technologies can be used to manage building features while maintaining architectural aesthetics. The technology has been applied, for example, to the creation of visibly transparent IR mirror films, visible mirrors and decorative films. But not all of these are outdoor stable.3M‘s proprietary nanostructuring process allows for almost universal bonding of fluorpolymers.But a process needs to be applied to a material to become a product.
We studied the efficiency of sodium carboxy methyl cellulose (a Polymer) in the inhibition and control of corrosion of aluminum on acidic medium. Sodium carboxymethyl cellulose was diluted into five different concentration levels and applied on several prepared and polished aluminum coupons for a weight loss experiment. Metal coupons previously cleansed and weighed were totally immersed in 100ml of 0.5M solution of HCl in an open beaker. The beaker was placed in a water bath maintained at varying temperatures. The procedures were conducted with and without the various concentrations of the inhibitor (Na-CMC) at temperatures 35oC, 45C, 55C, and 65C. At every time interval, the immersed metal specimen was withdrawn from the test solution, washed, dried and reweighed. The weight loss being the difference in weight of the specimen before and after immersion in the water bath was recorded for every coupon sample.The effects of concentration, temperature and time on weight loss, corrosion rate and inhibition efficiency were studied from the various plots and from the graph, it was observed that increase in the concentration of the inhibitor increases the inhibition efficiency. Also increase in the temperature of the operating environment decease the inhibition efficiency and vice versa. The relationship between the inhibitor efficiency, IE; concentration, C; temperature, T; and time t, was established through a model IE= 58.4770C0.5148-0.8913T + 50.4194t-0.1061, the proportion of variance explained (R^2) = 0.9128 (91.28%) and the prob(t) is 0.00001. Keywords: corrosion, weight loss, aluminium, inhibition efficiency, concentration
Titanium dioxide is a common pigment used in plastic applications to provide opacity and provide protection of the polymer matrix against photo-oxidation The color and photo-durable functions of pigmentary titanium dioxide are the most relevant for plastic applications which experience exposure to wavelengths less than 700 nm and greater than 300 nm from solar or artificial light exposure, i.e. visible and ultraviolet wavelengths. TiO2 efficiency to deliver the functions of color and photo-durability is related to the TiO2 surface coating, concentration of TiO2 and certain organic stabilizer additives. This paper describes the relationship of these factors by monitoring the decay of polypropylene gloss based under accelerated exposure conditions.
Effectively dispersing organic pigments within polymeric matrices is essential in maintaining consistent color and physical properties. Each and every pigment is chemically and physically unique, allowing for a myriad of potential molecular and macroscopic interactions to take place. This paper will discuss the physical (e.g. particle size, shape, distribution, morphology, surface area, porosity, etc.) and chemical (surface energy, polarizability, zeta potential, solubility, hydrophilicity, hydrophobicity, etc.) properties impacting a pigment’s interaction with its environment.
The reduction of VOCs (volatile organic compounds) in polymers is becoming more important as many automotive producers and OEMs are seeking to meet stringent specifications regarding VOCs in automobile cabins. In addition, “cosmetic organoleptics” are becoming more important as polymers continue to replace other materials such as metals, and as consumers remain generally wary of polymers in their lives from a health and safety perspective. Herein, synthetic aluminosilicate polymer additives are shown, quantitatively, to reduce the VOCs/odors resultant from processing and the end-use of polymeric articles. Various gas chromatography experiments are utilized to quantitatively show the chemical species that are captured by this powerful additive, as well as human sniffing testing to qualitatively show the effects on the perceived odor. In addition to size exclusion mechanisms, this synthetic mineral additive derives its specificity from the inherent hydrophilic/hydrophobic nature of the different zeolite crystal lattices.
The versatile solid-state chemistry of Bismuth allows for a variety of coordination complexes and the generation of new and robust inorganic pigments as a result. Bismuth has been used in combination with a few inorganic elements, and is most readily found as complexes containing amines and amides, alkoxides, carboxylates, thiolates, and halides. Bismuth Nitrate is amongst one of the most common starting materials for synthesizing Bismuth complexes, and from this starting material the first Bismuth Vanadate pigments (PY.184) were formulated in 1985. There has been continued innovation in this pigment chemistry over the years, and in 2015 a groundbreaking Bismuth orange with a unique color index, PO.86, was launched (proprietary technology of DCC). Since their commercial introduction in 1990 (first production for Ciba, The Netherlands) into the coatings & plastics markets, Bismuth Vanadate pigments have increased in importance as their field of application has grown. These bright yellow, highly saturated pigments are characterized by their outstanding opacity/hiding power, chemical resistance, excellent weathering and durability. DCC’s 3rd innovative generation of Bismuth Vanadate pigments have expanded the limitations of this chemistry to cover a wider color gamut from greenish-yellow to orange hues. Advances such as improving the heat stability has increased the utilization of Bismuth Vanadate products in engineering resins e.g. Nylon 6. Increasing the color strength has created value in use for many customers who want to use less pigment whilst maintaining the hiding power within their system. Moreover, introducing Stir-In technology has helped to reduce operating costs by making the pigment easier to disperse, therefore reducing pressure rise in the extruder and reducing the number of extruder screen changes required during production. Improvements in our manufacturing technologies have allowed DCC to attain the most demanding and specific performance attributes such as heat stability & dispersibility. Through intensive research DCC has been able to introduce an exciting new inorganic pigment into the market, based on Bismuth and identified by a new color index: PO.86. This clean yellow shade inorganic orange has outstanding hiding power, typical of inorganic pigments and represents an excellent starting base for orange colour matches. Additionally, PO.86 is non-warping and has very good heat stability (up to 250 °C): it is therefore strongly recommended for use in polyolefin based plastics, and architectural, industrial, powder, automotive & coil coating applications. There are only a few options for formulators in this shade area (most of which are based on organic starting materials), but none of these alternatives have the same level of durability and opacity as PO.86. This paper will illustrate how Bismuth Vanadate and Bismuth Orange pigments compare to other colorants in the green shade yellow to orange shade areas, with particular reference to performance attributes such as heat stability, dispersibility, weather-fastness, warp resistance and reference how these products perform in different polymer systems. This presentation is thus ideal for those who work & formulate with color and would like to develop a greater understanding of how PY.184 and PO.86 pigments influence the plastics they work with.
AbstractExploring a common thread amongst car owners worldwide, color. We will look at how and why car colors are popular regionally and what drives these global markets.What are the major influences that determine whether your car color will remain as the “hot trendy color” or be outdated in a few years.We will address the evolution of a car color, from the upstream design ( could be up to 5 years) to the development of the OEM/Refinish perspective.We will also take some unique examples of color outliers that have been and will be a forcein color selection.George Iannuzzi Senior Sales Manager Sandream Impact LLC
This paper seeks to enlighten the newcomer to formulating color and additives masterbatches for thermoplastics with an overview on the issues of shrinkage and warpage. First, the two concepts will be defined and differentiated followed by a description of how they are quantified or characterized in the literature. Some of the many variables that impact warpage will be touched on after which the special role organic pigments can play will be elucidated. Finally, there will be a brief review of the recent developments in non-warping pigments and other strategies formulators use to mitigate warping.
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ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
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