SPE Library


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.

The SPE Library is just one of the great benefits of being an SPE member! Are you taking advantage of all of your SPE Benefits?

Not an SPE member? Join today!

Use % to separate multiple keywords. 


Search SPE Library
    
    




Sort By:  Date Added   Publication Date   Title   Author

Conference Proceedings

Process Monitoring Using UV-VIS Spectroscopy
J.C.J. Bart, May 2000

The paper describes process monitoring applications by spectroscopic methods for polymer/additive analysis, polymer melt analysis, additive quantitation, QA/QC purposes, on-line compositional polymer analysis, in-situ reaction monitoring (cure kinetics, polymerisation, color designation, molecular interactions, monitoring of extrusion processes, real-time measurements and use of fiber optics. In particular, the current status of on-line multicomponent additive analysis in the polymer melt by means of UV-VIS spectroscopy will be illustrated.

Effects of Processing Conditions on Extruded Polystyrene Sheet Feedstock Quality
Kolapo P. Adewale, Robert Roberts, May 2000

This work investigates the influence of various extrusion parameters on the physical properties of rubber modified polystyrene sheets. The extrusion parameters under consideration are melt temperature, chill-roll temperature, line speed and sheet thickness. Optimum extrusion conditions for producing polystyrene sheet feedstock are discussed.

Design for Rotational Molding
Jordan I. Rotheiser, May 2000

This paper will cover the details of piece part design particular to the rotational molding process. Ribs, bosses, wall thicknesses, parallel walls, internal and external corners, openings, draft angles and undercuts will be discussed. Joining features, such as inserts, hinges and molded-in threads, will also be reviewed.

Designing for the Process? (Design Details to Avoid)
Kenneth Bather, May 2000

At first glance the Rotomold process is a fairly simple one. Its capabilities are exiting and have opened new avenues for creative industrial designs including complex shapes and rugged structural parts. Successful Rotomolded designs can be obtained by keeping a few guidelines in mind from concept through to product generation. This portion of the program will cover the areas that need to be considered during the design process. Items to be highlighted are basic design guidelines, features that can compromise, complicate and delay a project and what to ask a molder about specific designs.

Fracture and Fatigue Properties of Injection-Molded Short Glass Fiber-Reinforced Poly(cyclohexylene-dimethylene-terephthalates)s (PCT) as a Function of Molding Conditions
J. Karger-Kocsis, T.J. Pecorini, May 2000

Summary The static fracture toughness (Kc) and fatigue crack propagation (FCP) behavior of injection-molded short glass fiber (GF) reinforced poly(cyclohexylene-dimethylene- terephthalate) (PCT) composites were determined as a function of material parameters (with and without flame retardant) and molding conditions (injection speed and plaque thickness were varied). The anisotropy in the fracture mechanical response of GF-PCT, determined on compact tension (CT) specimens notched along and transverse to the mold filling direction (L- and T-notching, respectively) was interpreted by considering the molding-induced microstructure (GF layering and alignment). It was established that the effect of injection molding speed is negligible at the same specimen thickness. By contrast, increasing thickness strongly affected the GF structuring and thus the related fracture mechanical response.

Toughening of Epoxy Resins by Partially Decomposed Polyurethane Waste
J. Karger-Kocsis, J. Gremmels, May 2000

Hygrothermally decomposed polyurethane (HD-PUR) of polyester type has been used as a cost-efficient impact modifier in tri- and tetrafunctional epoxy (EP) resins. The PUR modifier was added between 5 and 80 wt.% to the EP prior its crosslinking with a diamine compound (Diaminodiphenylsulphone, DDS). The fracture toughness (Kc) and -energy (Gc) of the modified resins were determined on static loaded compact tension (CT) specimens at ambient temperature. The mean molecular weight between crosslinks (Mc) was determined from the rubbery plateau modulus of dynamic mechanical thermal analysis (DMTA) spectra. The change in the Kc and Gc as a function of Mc followed the prediction of the rubber elasticity theory. The efficiency of the PUR modifier was compared with that of a carbonyl terminated liquid nitrile rubber (CTBN). DMTA and fractographic inspection revealed that the PUR modifier was not only present in a dispersed phase of the EP matrix but participated in the build-up of the EP crosslinked network structure. Thus HD-PUR works as active diluent and phase separating additive at the same time. As HD-PUR can be regarded as an amine-functionalized rubber, it was used as hardener alone (by replacing DDS) in some EP formulations.

Thermoplastic Elastomers of Poly(ethylene terephthalate) and Grafted Rubber Blends
N. Papke, J. Karger-Kocsis, May 2000

Thermoplastic elastomers containing 50 wt.% poly(ethylene terephthalate) (PET) and 50 wt.% rubber with and without glycidyl methacrylate (GMA) functionalization were produced by melt blending. In some cases the method of dynamic curing was also adopted. The static tensile properties and dynamic-mechanical thermal analysis (DMTA) response of the systems were studied. The phase morphology of the blends was of interpenetrating network (IPN) type according to fractographic and DMTA results. It was established that the best mechanical performance exhibited those blends which contained a GMA-grafted nitrile rubber (NBR-g-GMA). The effect of dynamic dynamic curing, for which a two-step procedure was developed, was marginal. Cost reduction opportunities of the recipes by using high-volume polyolefins have also been explored.

Structure/Process/Part Quality Relationship for BMC Injection Molding
Stéphane Menio, Eric Lafranche, José Pabiot, Claude Ollive, May 2000

Thanks to its qualities and performances, BMC injection molding has nowadays reached a satisfactory maturity level. But nevertheless, this technology remains complex. Thus, the aim of the present study is to determine the technological parameters capable of improving the surface quality of the molded parts. The experiments are performed with a semi-industrial mold for rectangular plate. A first Taguchi Design Of Experiments was used in order to quantify the effect of the feeding, filling, holding and curing parameters on the surface quality. It was completed by a second hybrid DOE, the aim of which was to estimate more precisely the incidence of the main key factors (mold surface temperature, injection flow rate and holding pressure) previously identified. These results have been then confirmed with a different gate location and a modified geometry.

Aesthetics, Industrial Designers, and Designing for Rotational Molding
Gene Bothun, May 2000

Roto-mold is a versatile process which accomplishes many objectives which are difficult or impossible in other processes. It also has some special problems which complicate the aesthetic aspects of a design. Industrial designers working with engineers are uniquely qualified to design for this process.

The What, How and Why of Rotational Molding
Glenn L. Beall, May 2000

Rotational molding is a plastics molding process that is noted for producing seamless, hollow parts. The process is capable of molding complex, thin-walled, hollow parts in small and extremely large sizes. This paper will explain what the process is, how it works, and why the manufacturers of durable plastic products should be aware of this process's impressive capabilities.

Nylon and Moisture: The Real Story behind the Effects of Drying Resin and Conditioning Molded Parts on Final Properties
Michael P. Sepe, May 2000

The influence of absorbed moisture on the performance of nylon products is well documented. Similarly, the effects of excess moisture on the processing of nylon are well established. But confusion often arises in the processing community regarding the reasons for the brittle behavior of nylon parts. This paper is designed to follow the role of moisture from the pellet through to the conditioned part and separate the fact from the fiction regarding the effects of moisture on nylon properties.

Effects of Aspect Ratio on Performance Properties of Mica Reinforced Polypropylene and Nylon
Levy A. Canova, May 2000

This paper reviews a study designed to determine the effect of aspect ratio on properties of mica reinforced polypropylene and nylon composites. The study was made possible by recent developments in particle analysis software that permits determination of aspect ratio of non-spherical materials.

Optimization of Cooling Systems in Injection Molds by an Easily Applicable Analytical Model
Natti S. Rao, Guenter Schumacher, Nick R. Schott, Keith T. O’Brien, May 2000

The production rate of injection-molded articles is determined by the cooling time of the polymer melt in the mold. By using state-of-the-art numerical software the mold design can be optimized in order to achieve fast cooling. However, the efforts required to apply this software do not always justify its use in dealing with the daily design problems. Taking the changing mold wall temperature into account a straightforward analytical procedure for optimizing the cooling channel lay-out for a thermoplastic resin has been developed. The equations in the model can be easily solved by means of a hand-held calculator, thus enabling quick estimates of the effect of relevant parameters on mold design. Results of numerous simulations and a worked-out example illustrate the application of the model which has led to good results in the practice.

Thermorheological Investigation of Entangled Branch Polybutadienes Having Different Architectures and Arm Lengths
M.T. Islam, J. Juliani, L.A. Archer, May 2000

Rheological behavior of entangled six-arm and eight-arm 1,4-polybutadiene melts of the types A3-A-A3 and A3-A- A2-A-A3 is investigated using low amplitude oscillatory shear and viscosity measurements. Experiments covered a time (frequency) and temperature range broad enough to characterize the complete relaxation spectrum. In oscillatory shear, three separate relaxation modes are identified. At high frequencies a maximum in the loss modulus is linked with segmental relaxation. At intermediate frequencies a new relaxation mode characteristic of the arms is observed. Finally, at low frequencies a terminal relaxation process is identified. This process is characterized by a lower plateau" modulus and is thought to reflect cross-bar reptation in an enlarged tube."

Prediction of Degradation of Polyethylene during Rotational Molding
M.C. Cramez, M.J. Oliveira, R.J. Crawford, May 2000

During rotational molding the plastic is subjected to relatively high temperatures for long periods of time. This often causes degradation of the polymer at the inner surface of the molded article. The resulting degraded layer is responsible for the deterioration of the mechanical properties of the part. In practice, the optimum processing temperature and/or heating time must be obtained by means of an extensive molding and testing program. Moreover, as the degradability of polyethylene depends on many factors, such as the molecular structure of the material, the type and concentration of stabilizers and the thermal history experienced during processing, an optimization program that takes into account all these variables is very expensive and time consuming. In this work the degradation of polyethylene is studied using a technique widely used in the assessment of degradation resistance in the pipe industry - Oxygen Induction Time (OIT). The method enables the onset temperature of degradation to be identified using only a few milligrams of material. The data obtained from simple and quick experiments was used to produce an empirical model to predict the optimum inner air temperature for rotational molding of the materials. It is shown that whilst the maximum internal air temperature experienced during rotational molding is a good quality control parameter, there are many other important factors, such as the heating rate of the mold, the thickness of the mold material, etc.

Mixing Characteristics and Mechanical Properties of Polypropylene-Clay Composites
Kyu-Nam Kim, Hyung-Su Kim, Jae-Wook Lee, May 2000

Polypropylene(PP)-clay composites were prepared by melt mixing in an intensive mixer. Three grades of PP's having different melt viscosities were employed to investigate the mixing characteristics of the composites with various clays which belong to organically modified montmorillonite(org-MMT). Depending on the matrix viscosity and nature of the organic layer in MMT, significant variations in the phase structure of the composites were found. In addition to the simple combination of PP and clay, modified PP's having various content of maleic anhydride were also incorporated. Major interest was focused on the effect of varying thermodynamic affinity between the components on the phase evolution and mechanical properties of the composites. Requirements for the effective dispersion of clay in the PP matrix are discussed in terms of both rheological effect and thermodynamic interaction.

Virtual Instruments for Polymer Characterization and Processing
Ian R. Harrison, May 2000

It's expensive in terms of time and equipment to give students the necessary exposure to a wide variety of polymer behavior in different areas of characterization and processing. 'Virtual instruments' (VIs) consist of interactive software that simulates the response of a particular characterization instrument or a process. A characterization 'suite' contains many thermal instruments; other instruments are under development. A blown film process line has also been assembled relating film properties to operational parameters.

Predicting How the Cooling and Resulting Shrinkage of Plastics Affect the Shape and Straightness of Extruded Profiles
Randy J. Brown, May 2000

During the extrusion of complex plastic profiles, the parts often distort and bow during the cooling phase of the process. The traditional methods of dealing with this are to use heat lamps to re-warm certain sections to remove the bow or to apply jigs to distort the part in the opposite direction so that when it cools, it comes back into the proper shape. A method to look at the cooling requirements of a particular profile is proposed along with a method to calculate how the part should be cooled in order to avoid distortion and bow.

Clear and High Heat Resistant TPEs
Y. Martin Lu, Joe Kutka, May 2000

There is a market need for soft (35 - 70 Shore A) clear TPEs with heat resistance high enough for repeated boilable applications. Flexible PVC meets most of the requirements, but it is out of the scope of this work. Styrenic Block Copolymer based compounds have been developed to fill this need. Important parameters, such as molecular weight of the base polymer, surface quality of the molded part and rheology of the material, have been correlated with clarity and heat resistance. Some of the myths about the clarity of SBC compounds will also be discussed.

Orientation Measurements Online
Abdellah Ajj, May 2000

Orientation of polymers enhances many of their properties, particularly mechanical, impact, barrier and optical etc.. Orientation processes all involve extrusion prior to deformation and can generally be classified into three categories: fibers, films, and parts (sheets, bottles, rods, ...). The knowledge of the polymer orientation produced by the different processes is critical for establishing the process conditions and the final properties of the oriented polymer. There is a long history of investigations of orientation in polymers, mainly from off-line measurements, involving techniques such as birefringence, infrared spectroscopy, X-ray scattering, Raman, NMR, fluorescence, ultrasonic etc. In this presentation, we will focus on techniques which are or could be used for on-line monitoring of orientation processes. These include birefringence, spectroscopy, fluorescence and ultrasonic.







SPE-Inspiring Plastics Professionals

© 2024 SPE-Inspiring Plastics Professionals.
All rights reserved.

84 countries and 60k+ stakeholders strong, SPE unites plastics professionals worldwide – helping them succeed and strengthening their skills through networking, events, training, and knowledge sharing.

No matter where you work in the plastics industry value chain-whether you're a scientist, engineer, technical personnel or a senior executive-nor what your background is, education, gender, culture or age-we are here to serve you.

Our members needs are our passion. We work hard so that we can ensure that everyone has the tools necessary to meet her or his personal & professional goals.

Contact Us | Sitemap | Data Privacy & Terms of Use

Links

Locations

SPE US Office
83 Wooster Heights Road, Suite 125
Danbury, CT 06810
P +1 203.740.5400

SPE Australia/New Zealand
More Information

SPE Europe
Serskampsteenweg 135A
9230 Wetteren, Belgium
P +32 498 85 07 32

SPE India
More Information

SPE Middle East
More Information

3Dnatives Europe
157 Boulevard Macdonald
75017, Paris, France
More Information

Powered By SPE

SPE-Inspiring Plastics Professionals

SPE-Inspiring Plastics Professionals

SPE ImplementAM

SPE-Inspiring Plastics Professionals

SPE-Inspiring Plastics Professionals

SPE-Inspiring Plastics Professionals




spe2018logov4.png
  Welcome Page

How to reference articles from the SPE Library:

Any article that is cited in another manuscript or other work is required to use the correct reference style. Below is an example of the reference style for SPE articles:

Brown, H. L. and Jones, D. H. 2016, May.
"Insert title of paper here in quotes,"
ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
Available: www.4spe.org.

Note: if there are more than three authors you may use the first author's name and et al. EG Brown, H. L. et al.

If you need help with citations, visit www.citationmachine.net