Review of PE Pipe Lifetime Prediction Based on Pent Test

I. Sedat Gunes, Feina Cao, Sadhan C. Jana, May 2010

A new method of evaluating polyethylene (PE) pipe brittle failure time has been recently proposed. The method consists of an extrapolation of the failure time in standard PENT test to brittle failure time of PE pipes of arbitrary diameter and wall thickness at various loads and temperatures. The method is based on several assumptions that have not been adequately addressed in [1]. This paper presents a detailed review of the theoretical and experimental basis of the extrapolation proposed in [1] and reveals its limitations. A fracture mechanics analysis of the PENT test is presented. It requires evaluation of parameters in power law" equation of the slow crack growth (SCG). Thus a specimen whose stress intensity factor (SIF) is independent of crack length has been used to serve this purpose. Such specimen allows an accurate determination of crack growth rate vs. SIF relationship and thus predicts the duration of SCG stage of brittle fracture process at various temperatures. The study indicates that the formula proposed in [1] can be used for materials ranking with respect to SCG resistance within a limited temperature range but is inadequate for estimation of lifetime in brittle fracture."

Water Vapor Transport Properties of Shape Memory Polyurethane Nanocomposites

I. Sedat Gunes , Feina Cao , Sadhan C. Jana, May 2010

In this paper water vapor permeability (WVP) of thermoplastic polyurethane nanocomposites with crystalline soft segments was evaluated. Organoclay nano-size silicon carbide (SiC) and a high structure carbon black (CB) were mixed with shape memory polyurethane (SMPU) based on semi-crystalline soft segments. All nanocomposites were prepared by bulk polymerization using a Brabender internal mixer. Compression molded specimens were used in the determination of WVP. The results indicated that the presence of silicon carbide augmented WVP by reducing the soft segment crystallinity whereas that of organoclay reduced the WVP considerably due to excellent exfoliation.

Renewable Resource-Based Composites for the Automotive Industry

Dejan Andjelkovic, September 2009

The incorporation of renewable resources in composite materials is a viable means to reduce environmental impact and support sustainability efforts in the composites industry. This paper will focus on unsaturatedpolyester resins prepared from renewable resources and their use in composite materials. Applications of these resins in the automotive industry will be described including a comparison of properties and performance vs. typical petroleum-based resins.

Economical Preform Production for Conventional & Natural Fiber Composites

Anthony Mascarin, September 2009

This paper presents an independent cost analysis for a novel slurrybased preform technology in order to understand its potential benefits across a range of component and reinforcement scenarios. Specifically the economics for small medium and large automotive composites reinforced with glass carbon and natural fibers through the use of manual sprayup automated P-4 and slurry preforming are examined and compared through technical cost analysis. The molding economics of SMC RTM and SRIM are also addressed in detail.

Improved Matrix Materials for High-Performance Carbon Fiber Aromatic Thermosetting Copolyester

Zeba Farheen Abdul Samad, September 2009

The use of new aromatic thermosetting copolyester (ATSP) is described and compared to the best available epoxies for high performance composites. ATSP oligomers display liquid crystalline behavior which was identified using optical microscopy with cross-polarizers.ATSP tailored to have a liquid crystalline structure has reduced stresses at the fiber/matrix interface and better thermal fatigue resistance compared to epoxy.

Low Temperature Cure Polyurethane Adhesive for Primerless" Composite Bonding "

Michael Barker, September 2009

A new polyurethane adhesive has been developed that provides excellent adhesion to SMC HSU and RTM without surface preparation and requiring only a room-temperature cure or greatly reduced postbake temperatures. This presentation will review where such an adhesive will find application its general chemistry and supporting data.

Bentley Motors Develops Unique Directional Carbon Fibre Preforming Process for Chassis Rails

Antony Dodworth, September 2009

Details are presented on an automated process for manufacturing net-shape charges for compression moulding using a spray-deposition technique. The novel process uses a resin-spray technique and magnetic fibre to position and hold fibres onto the tool face. The process is intended for producing structural components using discontinuous bundles for medium-volume applications.

Reducing Setup Costs: Tooling Force Prediction in Resin Transfer Moulding (RTM) & Compression RTM

Andrew Wabran, September 2009

Mould tools used for processes such as RTM and compression RTM must withstand significant forces generated by the fluid resin and the fibrous reinforcement. Prediction of these forces will allow for optimizations in setup costs and time and maximize the usage of the capabilities of peripheral equipment (such as presses). SimLCM is being developed at the University of Auckland as a simulation package with the capability to predict clamping forces and stress distributions during complete moulding cycles for RTM and CRTM.

Life Cycle Cost Analysis for Passenger Cars: Steel vs. Composites

Seyed Hamed Khoonsari, September 2009

Pushtrusion™ Direct In-Line (D-LFT) Compounding Technology versus LFT Pellets & GMT Sheet

Eric Wollan, September 2009

PlastiComp’s direct in-line (D-LFT) compounding process provides processors of fiber-reinforced thermoplastics a simple and affordable alternative to pre-compounded pellets and GMT sheet while yielding equivalent and in some cases slightly higher mechanical properties. This paper summarizes a comparative study of the properties of D-LFT vs. traditional LFT pellets in an injection-molding process as well as D-LFT vs. GMT sheet in a compression-molding process.

High Performance Reinforcement: A Pathway to Density Reduction while Maintaining Physical Properties of Polyolefin Composites

David Lake, September 2009

To achieve significant part weight reductions of 15-20% Milliken Chemical's high performance reinforcing (HPR) additive may be an excellent choice for the replacement of talc and other mineral fillers in polypropylene composites. For instance vs. talc HPR will typically provide comparable or superior performance with only about one-third of conventional talc concentrations. Furthermore these improvements may be realized without any detrimental effects on aesthetic properties.

Innovative PPS Blow-Molded Air Duct for Turbocharged Diesel Engine

Duane Emerson, September 2009

A new patented in-mold assembly process forms an optimized assembly using a combination of blow molding and injection molding for a turbo-charged diesel charge air duct. The process incorporates a 15%-GF-reinforced blow-molding grade and a 30%-GF-reinforced injection molding grade of polyphenylene sulfide. PPS was the material of choice due to its superior heat and chemical resistance.

Advances in Thermoplastic Composites Using CBT

Fred Deans, September 2009

The use of cyclic-polybutylene terephthalate (C-PBT) for manufacturing high-performance composites is taking on new roles. Advances in injection molding RTM molding pultrusion and composite tooling are benefiting from the use C-PBT thermoplastic resins leading to the development of new C-PBT technologies and applications.

Alternative Methods to Enable the Powder Priming of SMC

Hamid Kia, September 2009

Previous work has shown that the newly developed SMC systems are powder-primer ready in straight-through operations. However after an extended stoppage in the operation – such as July shutdown – the success of the powder application depends on the severity of temperature ramp in the oven. To overcome this issue alternative methods are proposed such as 4 min. of preheating in the oven at 180°C or 3 min. of IR exposure.

The Influence of SMC Formulation Inner Panel Thickness & Bond Stand-Offs on Bond-Line Read-Through Severity

Kedzie Fernholz, September 2009

Two experiments designed to understand the relationship between material and process factors and bond-line read-through (BLRT) severity will be discussed. Regression analyses of the data collected in these experiments were able to establish relationships between the experimental factors and BLRT severity with at least 80% correlation.

Flexibility in the Direct Strand Moulding Compound (D-SMC) Process

Tobias Potyra, September 2009

In order to improve quality issues as well as to establish an integrated and continuous process for compression-moulded parts a direct processing technology has been developed. This presentation should demonstrate the flexibility of the new direct-SMC technology in terms of use of alternative and new raw materials and formulations.

Recent Advances in Class A Polyurethane Long Fiber Injection (LFI) Composites

Usama Younes, September 2009

Recent advances in related polyurethane chemistry have increased the commercial viability of the long fiber injection (LFI) process for producing very-large composite parts such as entry-door skins truck body and spa panels and recreational boat hulls. These advances enable the LFI process to achieve previously unattainable extended gel times on an open hot mold retain a relatively short demold time and form defect-free surfaces that can lead to the Class A surfaces required for large automotive body panels.

Composite Power-Train Components: Reducing Warranty Costs & Improving Part Quality

Toai Ngo & Mayur Shah, September 2009

Sheet-molding compound has been used in underhood applications and is extending its reach to drivetrain components. This presentation will show how vehicle manufacturers have reduced costs and improved quality through product designs that eliminate hardware enhance capability and improve system performance.

Automotive Composites Consortium Structural Composite Underbody

Libby Berger, September 2009

The Automotive Composites Consortium Focal Project 4 (ACC FP4) is a joint program between GM Ford and Chrysler to develop structural automotive components from composite materials. Part of this project is a structural composite underbody capable of carrying crash loads. Phase 2 of the project involves a full design of the underbody including design for durability and feasible component manufacturing and vehicle assembly scenarios.

BMC Composites: High Value Metal Replacement Material Alternative for Automotive Powertrain Applications

Jim Cederstrom, September 2009

Performance requirements for underhood components are increasing making historically used thermoplastics unsuitable for next-generation engines. The need for higher thermal chemical and mechanical resistance is opening the door to thermoset bulk-molding compounds (BMC) for critical metal-replacement opportunities successful examples of which will be presented.