Density reduction behaviors and cell morphology in extrusion of LLDPE/wood fiber composites with physical and chemical blowing agents

2020 ◽  
Vol 137 (26) ◽  
pp. 48829 ◽  
Author(s):  
Gangjian Guo
Keyword(s):  
Cell Morphology ◽  
Wood Fiber ◽  
Fiber Composites ◽  
Blowing Agents ◽  
Density Reduction ◽  
Chemical Blowing Agents ◽  
Physical And Chemical

Processing and cell morphology relationships for microcellular foamed PVC/wood-fiber composites

1997 ◽  
Vol 37 (7) ◽  
pp. 1137-1147 ◽  
Author(s):  
Laurent M. Matuana ◽  
Chul B. Park ◽  
John J. Balatinecz
Keyword(s):  
Cell Morphology ◽  
Wood Fiber ◽  
Fiber Composites

Foam extrusion of PP-based wood plastic composites with chemical blowing agents and the Celuka technique

2016 ◽  
Vol 53 (6) ◽  
pp. 623-638 ◽  
Author(s):  
Christina Hoffmann ◽  
Marieluise Lang ◽  
Peter Heidemeyer ◽  
Martin Bastian ◽  
Katja Fischer ◽  
...  
Keyword(s):  
Fibre Length ◽  
Base Material ◽  
Wood Plastic Composites ◽  
Blowing Agents ◽  
Foam Extrusion ◽  
Density Reduction ◽  
Plastic Composites ◽  
Twin Screw ◽  
Chemical Blowing Agents ◽  
Wood Content

Wood plastic composites have gained relevance in recent years as an alternative to wood boards. However, because the cavities in wood fibres are compressed by high processing pressure during the extrusion of wood plastic composites, the product densities show a range of up to 1.5 g/cm3 depending on wood content and base material. Particularly in large-sized products, this may be disadvantageous for processors and end users. Foaming of the plastic matrix is a promising approach to reduce the density of wood plastic composites products. This article discusses the foam extrusion of PP-based wood plastic composites with chemical blowing agents in combination with the Celuka technique. Integral wood plastic composites foam with a rigid and plain outer layer was produced using a parallel, counter rotating twin screw extruder. The profiles obtained were analysed with respect to foam structure and mechanical properties. It was possible to achieve a density reduction of up to 0.7 g/cm3 in the foamed wood plastic composites profiles. Furthermore, we demonstrate that wood fibre length and type of chemical blowing agent have a strong effect on the resulting foam morphology.

Cell morphology and property relationships of microcellular foamed pvc/wood-fiber composites

1998 ◽  
Vol 38 (11) ◽  
pp. 1862-1872 ◽  
Author(s):  
Laurent M. Matuana ◽  
Chul B. Park ◽  
John J. Balatinecz
Keyword(s):  
Cell Morphology ◽  
Wood Fiber ◽  
Fiber Composites

A Novel Design for Producing Fine-Celled Foams of Plastic/Wood-Fiber Composites

2000 ◽  
Author(s):  
Ghaus M. Rizvi ◽  
Chul B. Park
Keyword(s):  
System Design ◽  
Cell Morphology ◽  
Fiber Composite ◽  
Wood Fiber ◽  
Fiber Composites ◽  
Wood Fibers ◽  
Blowing Agent ◽  
Composite Foams ◽  
Innovative System ◽  
Novel Design

Abstract This paper presents an innovative system design for production of plastic/wood-fiber composite foams based on a chemical blowing agent (CBA). Wood-fiber inherently contains moisture, which adversely affects the foam processing and the resultant cell morphology. To improve the cell morphology, the moisture content in the final foam should be minimized. A novel system design is presented for achieving this goal. Undried wood-fibers were processed together with HDPE, CBA and a coupling agent (CA) in a tandem extrusion system. At the interconnection of the two extruders, a vent was provided to purge the moisture into the atmosphere. HDPE/wood-fiber composite foams were produced on this system and on a single extruder without the vent, for comparison. The cellular morphology and volume expansion ratios of the foamed composites were characterized. The foams produced on the newly developed tandem system exhibited significantly improved cell morphology and surface quality.

Foaming of Vulcanized PP/EPDM Blends Using Chemical Blowing Agents

1992 ◽  
Vol 65 (4) ◽  
pp. 778-791 ◽  
Author(s):  
A. Dutta ◽  
M. Cakmak
Keyword(s):  
Percent Density ◽  
Degree Of Cure ◽  
Blowing Agents ◽  
Blowing Agent ◽  
Density Reduction ◽  
Low Degree ◽  
Foaming Behavior ◽  
Rubber Phase ◽  
Chemical Blowing Agents ◽  
Optimum Balance

Abstract Using two different chemical blowing agents, foaming behavior of partially vulcanized PP/EPDM blends with high EPDM ratio has been studied. The objective was to induce foaming within the EPDM phase prior to complete curing. The results suggest that with proper choice of blowing agent and by optimum balance of curative loading, foams with densities as low as 0.55 g/cm3 could be obtained. This corresponds to nearly 90 percent density reduction which is significantly greater than the 15 to 20% afforded by similar fully-vulcanized dynamically cured blends reported previously. The degree of cure in the rubber phase was determined to play a key role in determining the overall foamability. In particular, the foamability of the blend was found to decrease linearly with increase in the gel content. In addition, the compounding technique also plays a major role in controlling foamability of these blends. Attempts at extrusion foaming of these blends, however, were successful only for blends with a rather low degree of cure.

UV aging of poly(propylene)/wood-fiber composites

2004 ◽  
Vol 25 (5) ◽  
pp. 543-553 ◽  
Author(s):  
Ragnar Seldén ◽  
Birgitha Nyström ◽  
Runar Långström
Keyword(s):  
Wood Fiber ◽  
Fiber Composites ◽  
Uv Aging ◽  
Poly Propylene

scholarly journals Uso de almidón de papa modificado como agente acoplante en compuestos polímero-fibras de madera/The effect of potato starch modified as a coupling agent in polymer-wood fiber composites

Prospectiva ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 107-113
Author(s):  
Yenny Marlén González Mancilla
Keyword(s):  
Coupling Agent ◽  
Potato Starch ◽  
Wood Fiber ◽  
Fiber Composites

En los materiales compuestos es importante lograr una buena unión entre la matriz y el refuerzo, para lo cual se utiliza un agente de acoplamiento. Se estudió el efecto del almidón de papa modificado como agente acoplante, en la resistencia mecánica y en la morfología de la interfase, de un compuesto polímero-aserrín de madera. Se utilizó polietileno de baja densidad (PEBD) reciclado de 70 a 80 % p/p, fibras de madera (aserrín) 15 a 25 %, que fueron secadas y clasificadas a tamaño de malla 60 y almidón de papa modificado (5 a 15 %), como agente acoplante. Las materias primas fueron mezcladas, conformadas por extrusión en caliente, a 110 °C (entrada) y 210 °C (salida). El material obtenido fue moldeado y prensado. Se fabricaron 4 mezclas y se obtuvieron láminas para fabricar probetas para ensayos de tracción y de flexión, se seleccionaron 32 por cada mezcla. Los resultados mostraron que el almidón de papa modificado incrementó la resistencia a la tracción y a la flexión del compuesto, con respecto a las muestras sin agente acoplante. Se observó la impregnación de las fibras con la matriz al usar almidón de papa modificado como agente acoplante, a lo que se atribuye el aumento en la resistencia.

Sign in / Sign up

Export Citation Format

Share Document