3D-shapeable thermoplastic paper materials

• The purpose of this work was to investigate to what extent it is possible to improve the thermoplastic properties of paper materials so that 3Dshapeable paper products can be manufactured. For that purpose, the addition of various chemical adjuvants, known to improve both tensile strength index and strain at break, was investigated. Adding polylactide latex was found to significantly improve both the tensile strength properties and strain at break of paper materials. To enhance their strainability, the paper sheets were cured at an elevated temperature of 150°C. The improved strainability after curing is hypothesized to relate to the spreading of the polylactide latex (minimum filmforming temperature of 90°C) on the fibre surfaces, improving the relative bonded area. Both the tensile strength index and strain at break improved significantly with no densification of the paper sheets. A second aim was to make double-curved board structures in a hydroforming equipment, using the sheets treated with polylactide latex under various conditions. Double-curved sheets with a nominal strain at break of over 20% could be formed by adding 20% polylactide latex. Hydroforming had to be done at temperatures exceeding the minimum film-forming temperature of the polylactide latex to significantly improve the strain at break during the forming operation.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Pappers-, massa- och fiberteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Paper, Pulp and Fiber Technology (hsv//eng)

Nyckelord

Bleached kraft pulp

Deep-drawing

Hydroforming

Polylactide latex

Strain at break

Tensile index

Thermoplastic board

Three-dimensional packaging materials

Publikations- och innehållstyp

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