摘要:

Injection molding is characterized by complex dynamics, which makes quality difficult to control. This is because the exact relations among the machine inputs, material properties, and molded part quality are not known precisely. Hence, the existing models for quality prediction have a limited accuracy and difficulty in application to general molding applications. This article investigates the integration of analytical process knowledge and artificial neural networks as a solution for quality prediction of molded parts, with accuracy increased toward quality control targets of three defects per million (60). This article describes the hybrid system based on the neural network and process knowledge, then compares its performances with conventional neural models for the prediction of the injection pressure.

ISSN:0360-2559    

DOI:10.1080/03602559909351556

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A three-phase study was conducted to investigate the effects of individual components in a vitamin E formulation (CF-120) on off-odor release, melt flow index, and yellowness index of high-density polyethylene (HDPE) resin pellets. CF-120 consists of vitamin E, glycerol, polyethylene glycol-400 (PEG-400), and glyceryl monocaprylate/caprate (GMC). The resin pellets were extruded from HDPE resin powder using a laboratory-scale single-screw extruder. Off-odor release from the resin pellets was evaluated using a sensory panel and gas chromatography/mass spectrometry (GC/MS) analysis. A Phase I (preliminary experiment) study showed that GMC greatly contributed to off-odor and melt flow index (MFI) reduction; vitamin E greatly contributed to yellow color formation. A Phase II (factorial experiment) study confirmed that GMC was the major off-odor contributor. A Phase III (response surface experiment) study showed that yellowness index and odor score reasonably correlated to vitamin E and GMC concentrations. In contrast, MFI and nonanal concentration had no correlation with vitamin E and GMC concentrations. The results are useful for designing a better vitamin E formulation for reducing the off-odor, without significantly enhancing yellow color formation.

ISSN:0360-2559    

DOI:10.1080/03602559909351557

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A simple test is proposed to obtain a dimensional crystal evaluation by diffused-light analysis. The theoretical basis is shown in the form of an example taken from real structural determinations of blown polyethylene films obtained by transmission electron microscopy. The diffraction model is used for an equivalent grating derived from a planar and regular pavement.

ISSN:0360-2559    

DOI:10.1080/03602559909351558

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Thermoplastic elastomers of the poly[ester-b-ether] copolymer type (PEE) comprising a hard block of poly(butylene terephthalate) (PBT) and oligoether soft segments, differing in the molecular weight of the oligoether [α, ω-dihydroxy poly(oxytetramethylene) (PTMO);Mn= 650, 1000, and 2900 g/mol] were synthesized and analyzed. Synthesized PEEs were modified by a dimer fatty acid (DFA,Mn= 570 g/mol) as a component of the soft segments. Each copolymer (consisting of one hard-segment component and two components of the soft segments) was obtained in a two-stage process involving transesterification and polycondensation in the melt. Elastomer series were prepared with a constant PBT mass ratio of 50; the content of PTMO and DFA segments was changed. Differential scanning colorimetry results showed a single glass transition temperature for the mixed PTMO-DFA soft phase, which indicates that ether and aliphatic units are able to create a homogenous amorphous phase.

ISSN:0360-2559    

DOI:10.1080/03602559909351559

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Short fibers attracted the attention of several researchers due to their good dispersion as well as their advantages on the physico-mechanical and dielectric properties. This work represents a systematic study on the electrical and physico-mechanical properties of styrene-butadiene rubber (SBR) reinforced with polyester short fibers. Next, we point out the influence of the adhesion system HRH (hydrated silica, resorcinol, and hexamethylene-tetramine), the fiber concentration, and aging on these properties of the investigated samples.

ISSN:0360-2559    

DOI:10.1080/03602559909351560

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This article deals with the investigation of high-molecular-weight poly-(methyl methacrylate) dilute solutions. The conformational transitions were followed as a function of temperature and solvent nature (ethyl acetate, butyl acetate, monochlorobenzene,o-dichlorobenzene) by using ultraviolet (UV) spectrophotometry and viscometry. The systems involving ethyl acetate as a solvent presented some peculiarities in the temperature dependence of the UV spectra.

ISSN:0360-2559    

DOI:10.1080/03602559909351561

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A Biopol-jute composite (BJC) was prepared using a hot-press treatment by reinforcing the Biopol polymer with hessian cloth (jute fabrics) placed in between the layers of Biopol polymer films. Both the tensile and bending strengths of the composite increased substantially, in comparison to the pure Biopol. Jute fabrics were treated with different additives to improve the composite properties. Among them, 2-ethyl hexyl acrylate (3%), γ-rnethacryloxypropyltrimethoxy silane (2%), and trimethoxy vinyl silane (0.5%) were found to be effective in enhancing tensile properties up to 80% with respect to Biopol. Mixed additives increased the tensile properties of the composites to some extent but not as much as the single additive did.

ISSN:0360-2559    

DOI:10.1080/03602559909351562

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Six different formulations were developed with an urethane acrylate oligomer (Ebcryl 264) in combination with a carboamide monomer (N-vinyl pyrrolidone) and a difunctional acrylated monomer (tripropylene glycol di-acrylate) in the presence of some filler (talc) and a plasticizer (diallyl phthalate). Thin polymer films prepared out of these formulations under ultraviolet radiation were characterized. The change of optical absorption of these films between 240 and 380 nm as a result of weathering and thermal aging was studied. The absorption spectra shifted toward higher wavelengths for thermal and weathering treatments. Loss of tensile strength (Ts) and elongation (Eb) was also investigated. The loss was observed to be dependent on the nature of formulations.

ISSN:0360-2559    

DOI:10.1080/03602559909351563

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The potential use of palm oil fatty acid additive (POFA) as a new rubber ingredient in carbon-black-filled natural rubber compounds was examined. It was found that the cure time (t90) and scorch time decrease with increasing POFA concentration. The Mooney viscosity of the rubber compounds was also decreased with increasing POFA concentration. The mechanical properties of the carbon-black-filled natural rubber compounds were enhanced by the addition of POFA, especially at a concentration of 2 phr. Results from the swelling measurement and scanning electron microscopy indicate that POFA has some effect on cross-link density and also improved filler dispersion.

ISSN:0360-2559    

DOI:10.1080/03602559909351564

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The effects of various bonding agents on natural rubber-oil palm wood flour (OPWF) composites were studied. Results indicate that the maximum torque increases with increasing OPWF loading and the incorporation of various bonding agents. Compared to the composite without a bonding agent, the incorporation of bonding agents improves the tensile modulus, tear strength, tensile strength, and hardness of the composites. Scanning electron microscopy studies and rubber-fiber interaction measurements indicate that the OPWF-rubber adhesion can be enhanced by the use of bonding agents.

ISSN:0360-2559    

DOI:10.1080/03602559909351565

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor