Results 241 to 250 of about 128,191 (280)

Foam Extrusion of Polystyrene Blown with HFC-134a

Cellular Polymers, 2002
There is much interest in developing industrial processes to manufacture extruded polystyrene foam that do not involve ozone depleting blowing agents. A popular alternate candidate is HFC-134a. It has a zero ozone depletion factor and is nearer in chemical structure to standard blowing agents (CFC-22 and HCFC-142b) than carbon dioxide.
Richard Gendron, Michel Huneault, Jacques Tatibouët, Caroline Vachon   +3 more
openaire   +1 more source

Blown Film Extrusion Optimization-Control and Screws

Journal of Plastic Film & Sheeting, 1991
On-line film gauging, gravimetric feeding, innovations in blown film dies and wind-up equipment, and improved data handling have made pos sible the production of blown film to higher quality standards. However, ade quate cost control and effective material utilization will require even greater uniformity of the process and property performance of the ...
E.W. Veazey, N. Barrera
openaire   +1 more source

Optimized cooling and gauge tolerances in blown film extrusion

Polymer Engineering & Science, 1997
AbstractNumerical calculations of the air flow and heat transport processes in film blowing have been made, considering the turbulence of the air flow. The parameters air mass flow, air temperature, air velocity, and angle‐of‐attack have been varied. The results have shown that the air massflow has the strongest influence on cooling in the processing ...
B. Feron, D. Wolf, J. Wortberg
openaire   +1 more source

Studies on blown film extrusion. III. Bubble instability

Journal of Applied Polymer Science, 1975
AbstractAn experimental study has been carried out to investigate flow instabilities in blown film extrusion. Two types of flow instabilities were observed, depending on whether a bubble was under uniaxial or biaxial stretching. Under biaxial stretching, the phenomenon of a surface wave‐type instability was observed, yielding wavy bubble shapes which ...
Chang Dae Han, Jong Yoo Park
openaire   +1 more source

Lldpe Resins for High Output Blown Film Extrusion

Journal of Plastic Film & Sheeting, 1991
We take a closer look at the output rate improvements which can be achieved as a result of the improved melt strength of 0.5 MI resins.
D.L. Cooke, M. Koyich
openaire   +1 more source

Blown Film Extrusion of Post-Consumer Recycled Lldpe Film

Journal of Plastic Film & Sheeting, 1993
In this work, the properties of blown film made from post consumer recycled material were studied. Post-consumer recycled LLDPE film was blended with a virgin LLDPE resin at several levels in a twin-screw ex truder, and the melt index, storage modulus, and loss modulus of these blends were measured.
S.J. Hebert, C. Tzoganakis, J. Perdikoulias   +2 more
openaire   +1 more source

Foam Extrusion of PS Blown with a Mixture of HFC-134a and Isopropanol

Cellular Polymers, 2004
Use of mixtures of blowing agents in foam extrusion has gained interest in the past few years. Reasons for blending physical foaming agents (PFA) are numerous. The incentives may be economical, environmental or technical. With respect to that latter factor, blending suitable PFAs is often regarded as providing a better control of processing conditions.
Richard Gendron, Caroline Vachon, Michel F. Champagne, Yadi Delaviz   +3 more
openaire   +1 more source

Photonic Crystals of Oblate Spheroids by Blown Film Extrusion of Prefabricated Colloidal Crystals

Langmuir, 2009
Three-dimensional photonic crystals (or photonic band gap materials) have been fabricated with oblate spheroids as the photonic building block. The nonspherical shape was realized by the blown film extrusion process of a prefabricated colloidal photonic crystal of spherical polystyrene particles, with its voids infiltrated by polyvinyl alcohol.
Tao, Ding, Zhan-Fang, Liu, Kai, Song, Koen, Clays, Chen-Ho, Tung   +4 more
openaire   +2 more sources

The Use of Deformation Rates in the Scale-Up of Polyethylene Blown Film Extrusion

Journal of Plastic Film & Sheeting, 1992
It is often desirable to scale up a process from a lab scale system, where most research occurs, to a large scale industrial system with minimal ex penses of time and money. This work will show that under appropriate process ing conditions, blown films can be produced under similar strains that yield comparable crystalline morphologies and therefore ...
David M. Simpson, Ian R. Harrison
openaire   +1 more source

A Novel Processing Aid for Greater Flexibility in Blown Film Extrusion

Journal of Plastic Film & Sheeting, 1987
The high melt viscosity of linear low density polyethylene (LLDPE) presents several problems, particularly melt fracture, when this resin is processed on blown film equipment which has been designed for use with high pressure, low density polyethylene (LDPE) resin.
openaire   +1 more source