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.
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Conference Proceedings
IMPROVED DIMENSIONAL STABILITY OF
THERMOFORMED POLYLACTIC ACID ARTICLES
The shrinkage of thermoformed articles of polylactic acid are studied as a function of amount of modifier and dwell time in heated molds. Shrinkage is minimized by longer dwell times. Higher crystallinity causes lower shrinkage. Crystallinity in a thermoformed article dwelling in the heated mold is shown to rise to a higher level that predicted from laboratory tests due to supplemental crystallinity generated in the pre-heat step and forming or stretching step.
IMPROVED DIMENSIONAL STABILITY OF THERMOFORMED POLYLACTIC ACID ARTICLES
The shrinkage of thermoformed articles of polylactic acid are studied as a function of amount of modifier and dwell time in heated molds. Shrinkage is minimized by longer dwell times. Higher crystallinity causes lower shrinkage. Crystallinity in a thermoformed article dwelling in the heated mold is shown to rise to a higher level that predicted from laboratory tests due to supplemental crystallinity generated in the pre-heat step and forming or stretching step.
SIGNIFICANT ACCELERATION OF A UV-CURED COATING
Except for rare cases, increased cure speed of a UV-cured coating is greatly desirable. Our client approached us with a thiol-ene floor coating plagued with an excessively slow curing rate (9 cm/sec) and desired a 10x improvement. A wide range of process and reactant changes were explored but to little avail. Success was ultimately achieved when an alternate ene monomer was chosen despite literature references that indicated the monomer would instead decrease the reaction rate.
DECORATING METHODS FOR INJECTION MOLDED PARTS
This paper will discuss various decorating methods for
injection molded parts, including industry wide definitions,
descriptions and a comparison of the various methods. It
will cover basic process descriptions, definitions,
advantages of each, and their relationship to part design
and end usage. How do I select the decorating method
most suitable for my part?
LASER MARKING DAY/NIGHT PLASTICS
Day/Night applications surround us! Take a look around you they are in our cars trucks airplanes cell phones and the list goes on. The potential for this type of application is huge and laser marking is helping move it forward. Today's laser technology is helping to enhance and expand the field of day/night marking.
LASER MARKING DAY/NIGHT PLASTICS
The combination of advance controls, diode technology, and specially ground lenses mean high-quality, high-readability in Day/Night Components.
FLAME RETARDANCE OF ACRYLONITRILE BUTADIENE STYRENE-LAYER DOUBLE HYDROXIDE NANOCOMPOSITES
Flame retardant layer double hydroxide (LDH) Zn2Al(OH)6PTS/Acrylonitrile butadiene styrene (ABS) nanocomposites were prepared by melt blending. The morphology and flammability properties were characterized by X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and UL-94 test. XRD shows the microstructure of the composites with appearance of intercalation and exfoliation. The UL-94 test results shows that the LDH is an unprecedented flame retardant with improved flame extinction properties.
ACCELERATED AGING BEHAVIOR OF A RUBBER TOUGHENED ACRYLIC COPOLYMER AFTER GAMMA IRRADIATION
The material property changes of an acrylic multipolymer after gamma irradiation are determined with respect to time and temperature. Empirical models are developed using a design of experiments approach. The effects of thermoforming on the aging behavior are examined. Experimental variables include irradiation dose level, aging temperature, and aging time. The models developed are used in conjunction with real time ambient temperature aging to derive Q10 factors for the material as defined in ASTM F1980.
ACCELERATED AGING OF POLY(P-PHENYLENE-2,6-BENZOBISOXAZOLE) FILAMENTS
Poly(p-phenylene-2,6-benzobisoxazole) fiber is a high performance fiber. Unfortunately, the fiber reportedly degrades rapidly when exposed to moisture and heat. The objective was to perform accelerated aging of PBO filaments that would potentially lead to the development of an improved process to improve the mechanical properties of PBO fibers when exposed to moisture and heat. Results indicated the need to perform additional aging on rovings due to the large standard deviations of the filament data.
NEW OPTIONS IN SPECIAL EFFECT PIGMENTS
The current range of products designed to attain special effects continues to expand. Growth was driven by designers demanding new options to color plastic parts. Producers of effect pigments continue to respond with technological innovations and modifications of existing pigments and additives. This paper will discuss this expanded pallet and the effects and applications for which they were intended. The primary focus is on Industrial grade pearlescent pigments, synthetic grade pearlescent pigments (including colored pigment coated pearls), high density coated pearl pigments and novel metal oxide coated pearlescent pigments.
EFFECT OF LAYER SEQUENCING ON THE IMPACT PROPERTIES OF MULTILAYERED, TRANSPARENT STRUCTURES
Conventional coextrusion and lamination
technologies were employed to characterize layer
sequencing effects on the impact properties of
multilayered, transparent structures incorporating high
impact resistant materials. Laminated structures utilizing
100 sheets of five-layered coextruded films were
successfully generated. Cross-sectional specimens of
these structures revealed no obvious weld lines. Most
importantly, layer sequencing had a distinct influence on
the impact failure modes and, therefore, on the impact
properties of the thick multilayered structures.
A NECESSARY STEP- SEPARATING THE SPECTRAL BANDPASS CORRECTION FROM TRISTIMULUS INTEGRATION
Current industry practices are examined with respect to the methods used for spectral bandpass correction. The variants in methodology are reviewed and the methods that will lead to every person knowing whether or not his spectra have been corrected are recommended. That will facilitate the user knowing what Tables are to be used to integrate the spectra. Methods of implementing the bandpass correction both algebraically and by matrix multiplication are related.
A BRIGHT FUTURE ' SINGLE PLY THERMOPLASTIC POLYOLEFIN ROOFING
Single ply thermoplastic polyolefin (TPO) has been the fastest growing commercial roofing membrane in the last decade due to its superior weatherability, heat-welded seam integrity, energy savings, and safe and easy installation. In 2008, TPO installed roofing systems exceeded EPDM and became the largest single ply roofing market segment. This paper discusses the heat-welded seaming, fire retardancy and UV stability of TPO roofing.
OPTIONS FOR IMPARTING MELT STRENGTH INTO OLEFIN BLOCK COPOLYMERS
Applications such as profile extrusion, blow molding and thermoforming require polymers that have high melt strength. This paper will discuss two modification strategies to enhance the melt strength of olefin block copolymers for use in profile extrusion and thermoforming. The effects of modification type and level of modification are explored and compared. Implications of modified microstructure on the mechanical properties of formulated compounds based on the modified elastomers will also be discussed.
ENVIRONMENTAL STRESS CRACKING OF CPVC PIPE BY MIXED GLYCOLS
CPVC pipe is often used for containment of water in fire sprinkler systems, usually with glycerol as the antifreeze, but too often with ethylene or propylene glycol. Environmental stress cracking has caused much distress and economic damage. This test program shows that a mixture of these two glycols can be more damaging to CPVC pipe than either of the glycols by itself. Earlystage cracks are also illustrated, as observed by Scanning Electron Microscope at 1000X magnification.
OPTIMIZING FLAVOR PERCEPTION IN PLASTICS
Polymeric articles are used in a wide variety of
applications, including some which require oral contact.
Direct incorporation of just flavorant into a polymer
results in an inferior flavor response. Three synergists
were tested in combination with a flavorant to evaluate
effect on flavor perception in a polymeric article. A
flavor panel test was designed to measure responses on
flavor identification and intensity to compare between
compositions with just flavorant and those in
combination with a synergist. It was found that the
application of a unique synergist could enhance flavor
perception dramatically.
DIE DESIGN FOR LAYER THICKNESS UNIFORMITY IN MULTILAYER COEXTRUSION
It is important to understand the effect of the flow channel shape on the final layer thickness distribution of multilayer products in coextrusion. This study presents examples of non-uniform polystyrene (PS) and polypropylene (PP) multilayers produced using existing layer multiplication dies and demonstrates that layer thickness non-uniformity is closely related to the flow channel shape of the multiplication die. Two other designs are proposed and compared with the existing design using both experimental and flow simulation techniques.
IMPROVE MOLD DESIGNS WITH CORRECTIVE ACTION ANALYSES
When the decision is made to clone a mold, past maintenance issues are seldom considered due to the difficulty involved in capturing, analyzing and acting on design changes that would improve performance. Few engineers will modify a seemingly adequate mold design based on log book scribbles or shop floor hearsay. A properly formatted corrective action analysis will provide information about mold designs that will lower tooling and labor costs and greatly enhance performance and reliability.
AN INFRARED EXAMINATION OF THE EFFECTS OF MELT ROTATION ON INJECTION MOLDED PARTS
During the injection molding process, the laminates close to the frozen layer in the melt delivery system undergo shear heating due to the high shearing. Once these high-shear laminates enter the part, they stay against the outside walls of the part. New technology allows the high-shear laminates to be moved into the center of the part. This study looks at the part temperature distribution in the part.
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