Fpinnovations

Pulp and Paper Research Institute of Canada

Norman Roberts

Wadood Yasser Hamad

Shunxing Su

Michelle Agnes Ricard

Chuanwei Miao

John David Hoffmann

Robert W Gooding

Otman Oulanti

Robert S Hart

A composite and method for producing the composite by incorporating wood or wood pulp fibres with a suitable thermoplastic polymer and coupling agent are described. Homogeneous, void-free transparent/translucent thermoplastic materials in the form of pellets, films or three-dimensional moldable products are produced. The wood pulp fibres can be discrete natural fibres, and flexible assemblies of nano to micro elements, e.g., assemblies of aggregated carbon nanotubes. It is also possible to use our vacuum-assisted co-extrusion process to produce hybrid composites comprising the wood pulp fibre and a further rigid fibre, like glass or carbon fibres, and a flexible fibre or fibrillar network, like cellulose fibres or cellulose filaments. The thermoplastic resin can be, but not limited to, polyolefins, like polypropylene or polyethylene, or polyesters, like polylactic acid, or co-polymers, like acrylonitrile-butadiene-styrene terpolymer.

Vacuum-assisted co-extrusion of flexible fibres and the moldable thermoplastic composites produced

A method and apparatus are described for continuously sampling a process stream, or reservoir of aqueous cellulosic pulp and detecting oversize contaminants in the sampled stream. This serves the overall objective of estimating the level of contamination in the process stream or reservoir during a given period of production; the method may include the following stages: 1) a continuous sample stream is drawn from the process or main stream, 2) the stream is passed through a centrifugal device which divides the sampled stream according to density, 3) the stream with the higher level of contaminants from the centrifugal device is passed to a screen which isolates the contaminants, and 4) the contaminants are flushed from the screen so that they can be quantified; these measurements are used to assess the purity of the material being produced. One useful application of this invention is to assess the presence of trace amounts of plastic contaminants in the production of the cellulosic pulp. Compared to manual methods for inspecting for plastic, this invention provides a measurement which is more accurate, more convenient, and less subjective.

System for detecting contaminants

Growing community of inventors

Burnaby, Canada

Norman Roberts