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.
|= Members Only|
Influence of Processing Conditions on the Mechanical Properties of Nylon 12 and LDPE Tubing
The effect of extrusion processing conditions on the mechanical and morphological properties of a range of nylon 12s and LDPEs was investigated. The results indicate that processing conditions had a more pronounced effect on the mechanical properties of nylon 12 tubes, in comparison to those produced from LDPE.
A Study on the Thermal Performance of Calibrators
In this work a numerical code able to model the heat transfer in calibrators for extruded profiles is described and validated. For assessment purposes the numerical predictions are compared with analytical models and numerical results obtained with a commercial software. The routines developed are then used to identify the main process parameters and to estimate their relative importance.
Analysis of Flow in a Spiral Mandrel Die
For rheological design of spiral mandrel dies the most common calculation methods are segmenting the die into simplified geometries and calculating the characteristics of each flow segment analytically. In the past, one-dimensional flow was considered, but this assumption is deficient especially for low depth segments. In recent investigations IKV has studied three-dimensional flow conditions in a transparent test die and in 3D-FEA calculations. The results of these studies give the key to improve the calculation of spiral mandrel dies significantly.
Screw Design for Cooling Extruders
This paper presents a theoretical approach to the prediction of melt temperature profiles in cooling extruders. The effect of screw design on cooling performance in discussed. A new screw geometry is presented will substantially improved cooling capability. Initial performance data on a 200-mm cooling extruder are presented.
Gentle Compounding of Natural Fiber Filled PVC Composites
Compounding of thermoplastics with wood flour or natural fibers presents a number of challenges. The temperature and shear sensitivity of the thermoplastic matrix such as PVC, presence of moisture in the cellulosics, and the critical process temperature limitations of the composite are some of them. Lower shear history and melt temperature during primary compounding operations of such composites generally result in better mechanical properties of the finished product. This paper investigates the suitability of CK Continuous Kneader to surmount the imposed process limitations effectively.
Processing Polyethylene Terephthalate on a Single Screw Extruder without Predrying Using Hopper- and Melt Degassing
Conventional PET processing requires pre-drying, an energy- and cost-consuming process limiting production flexibility. The paper presents combined hopper- and melt degassing in a single screw extruder as a real alternative to predrying and investigates the influence of extrusion- and degassing parameters, screw-design and water content on both intrinsic- and melt viscosity.
Practical Approach to Screw Breakage and How to Avoid Failures
The use of practical mathematical expressions can be used to evaluate the mechanical strength of a rotating shaft. Similar expressions can be used in the design of a feedscrew. The purpose of this paper is to investigate the factors that influence the mechanical strength of a feedscrew and to show how to use these expressions from a practical standpoint to avoid failure during operation.
Effect of Screw Surface Properties on Extruder Performance
The surface condition of the screw and die can have a significant effect on extruder performance; however, little information about these effects is available in the open literature. This paper discusses various aspects of the screw surface conditions and how these can change the characteristics of the process and extruded product quality.
Die Lip Sensitivity in Cast Film Dies
Die designs for production of cast polymer films typically include a flex lip for varying the geometry of the lip opening. The cast film process requires die lip gaps ranging from 0.4 mm to 0.8mm. Flex lip gap and the adjustment of said gap becomes increasingly difficult to control as it is reduced. An examination is made of the issue of die lip sensitivity with different polymers extruded at different lip openings.
Metering Channel Flows and Troubleshooting Single-Screw Extruders
The manufacturing costs for a process depend highly on the proper operation of the extrusion equipment. In general, proper operation requires that the metering section of the screw be the rate-limiting step. Using drag flow and pressure flow calculations for the metering section is a simple method to determine if the section is the limiting step. This paper shows how these types of calculations can be used to determine if the screw and process are functioning properly.
Reactive Extrusion of Starch-Polyacrylamide Graft Copolymers
Graft copolymers of starch and polyacrylamide have been prepared using a twin screw extruder. The effects of monomer/starch ratio and moisture content on conversion, graft efficiency, graft molecular weight, and frequency of grafting are discussed. Conversion of monomer to polymer exceeding 90% and grafting efficiencies exceeding 60% can be achieved by this process, with residence times of approximately 250 seconds or less.
Compatibilizing of PET/PA Blends with a New Coupling Agent in a Twin Screw Extruder
Polyethylene terephthalate (PET) and Polyamide (PA) can be compatibilized in one process step on a twin screw extruder using a novel coupling agent. This reagent is able to react with PET as well as with PA which leads to Copolyesteramids. Until now a compatibilisation was only possible in a three step process, this new reagent makes a one step process possible.
Chemical Coupling of Rubber Polymers with Modified PTFE Micro Powder during the Rubber Mixing Process
A special mixing procedure has been developed for chemical coupling of PTFE micro particles with the polymeric matrix in rubber compounds. Beforehand the non-reactive PTFE is modified to enable the chemically coupling. It is supposed that parts with chemically bonded PTFE particles will show higher abrasion resistance and a better friction behavior compared to those with physically bonded particles. Thus the production of novel wear resistant elastomers should be possible.
The Effect of Multilayer Rheology on Coextrusion Die Design
Multilayer coextrusion is a process in which two or more polymers are extruded and joined together in a feedblock or die to form a single structure with multiple layers. This paper will discuss the proper techniques for using rheology data to design coextrusion dies based on experimental rheology data for monolayer and multilayer structures.
The Effect of Process Aids on Interfacial Instabilities in Coextrusion Flows: Theoretical and Experimental Investigation
In this paper, the effect of process aids on the interfacial instabilities in coextrusion flows is investigated theoretically via viscoelastic FEM simulations as well as experimentally. Theoretically determined processing/materials rules according to which a stabilization effect with process aids can be achieved are compared and discussed with experimental results.
Interlayer Adhesion of Co-Extruded Sheets before and after Biaxial Stretching
In order to quantify interlayer adhesion of co-extruded sheets with strong interlayer adhesion, a test method was developed to first initiate delamination by uniaxial stretching and then measure interlayer adhesion by peel test. The method was applied to co-extruded sheets before and after biaxial stretching. Interlayer adhesion with peel force as high as 5330N/m (30lb/in) have been measured for the as co-extruded sheets. Reduction of interlayer adhesion as a function of biaxial stretching was revealed.
Continuous Compounding of EPDM Formulations on Co-rotating, Intermeshing Twin Screw Extruders
A 58 mm twin screw trial was run to evaluate machine design, shear and heat transfer effects in a generic EPDM formulation. The effects of product rate, screw speed, screw design, barrel temperature, and screw cooling were evaluated on product temperature, Mooney viscosity, and cure time. Scale up is evaluated in terms of heat transfer (cooling), volumetric and torque limits. Operation at high specific rate, low barrel temperatures, and the use of screw cooling provide improvements for rate. Commercially viable throughput rates were achieved in the trial.
Ultrasonic Monitoring of Barrel Wear and Screw Status
Four types of high temperature (HT) ultrasonic sensors have been installed at barrels and a flange of a 30-mm twin-screw extruder to non-intrusively and non-destructively measure barrel and screw wear, as well as screw misalignment and deflection during polymer extrusion. The sensors included sol-gel sprayed ultrasonic transducers (UTs), non-clad and clad buffer rod sensors, and stand-alone HTUTs. This study has demonstrated the capability of these ultrasonic sensors in monitoring the barrel and screw statuses at the pumping, mixing and melting zones of the extruder.
Development of a Stiff, Void Free, Low Density Plastic Wood Replacement
Process studies attempting to produce a low density, wood like replacement involving Kenaf, Polypropylene and hollow glass spheres (bubbles") blends along with processing aids and compatibilizers have been investigated using a counter-rotating non-intermeshing (CRNI) twin screw extruder. Bubble breakage was higher than anticipated based on related work but in spite of the fairly low bubble survival rates nailability of the boards was improved. Bubble breakage and mechanical properties are presented along with a discussion of the narrow process window."
Hydraulic Conveying of Plastic Pellets
Today’s plastic production plants can have a yearly capacity of more than 400,000 t. New catalysts enable them to produce a great variety of increasingly softer product grades in the same reactor. Together with logistic concepts that increase conveying distances, the polymer industry has reached the limits of traditional dilute and dense phase pneumatic conveying systems.This paper presents a new concept to convey plastic pellets as water slurry to overcome the limitations of pneumatic conveying. A further benefit of this technology is the gentle handling of attrition sensitive plastics like Polycarbonate and Polyester.
We're sorry, but your current web site security status does not grant you access to the resource you are attempting to view.
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
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