Corona Treatment for Nanotransfer Molding Adhesion

The effect of various corona treatments of cotton card sliver on yarn and fabric properties and on spinning performance has been investigated. The corona increased yarn strength, especially at low twist levels and for coarse counts, without adversely affecting yarn evenness. At a given twist the corona treatment gave less end-breaks than untreated cotton. It also increased fabric strength but harshened fabric hand, both before and after wet finishing.

Download Full-text

High Oxygen Barrier Polyethylene Films

Polymers and Polymer Composites ◽

10.1177/096739111702500802 ◽

2017 ◽

Vol 25 (8) ◽

pp. 571-582 ◽

Cited By ~ 1

Author(s):

Carmen Fernández Ayuso ◽

Alejandro Arribas Agüero ◽

Jose A. Plaza Hernández ◽

Antonio Bódalo Santoyo ◽

Elisa Gómez Gómez

Keyword(s):

Food Packaging ◽

High Oxygen ◽

Oxygen Barrier ◽

Layer By Layer ◽

Insulating Layer ◽

Polyethylene Films ◽

Barrier Films ◽

Film Substrate ◽

Corona Treatment ◽

Thermal Stability Of

“Layer by layer” technology was used to create transparent, thin and high barrier polyethylene films to use in food packaging. These films were made by inserting successive layers of polyacrylamide and montmorillonite (Cloisite Na+, non-organic modification) grown onto a low density polyethylene (LDPE) film substrate submitted to corona treatment. Excellent oxygen permeability results were reached with only 9 bilayers, with a reduction of 99.92%, compared to the pure polyethylene. This allowed the oxygen barrier film to change from poor to high (3.66 cm3/m2·day), with a total thickness of 48 microns, due to the structure formed over the film to create a tortuous path for oxygen molecules. Optical properties were analysed, showing a ≥92% transparency in all samples. Thermal stability of polyethylene was slightly improved and this was attributed to nanoclays presence forming an insulating layer. The result of this research is a thin structured film which is a good candidate for common barrier films replacement in food packaging thanks to its high oxygen barrier capacity, optical transparency, microwaveability and recyclability.

Download Full-text

Corona Treatment of Filled Dual-polymer Dispersion Coatings: Surface Properties and Grease Resistance

Polymers and Polymer Composites ◽

10.1177/096739111702500402 ◽

2017 ◽

Vol 25 (4) ◽

pp. 257-266 ◽

Cited By ~ 2

Author(s):

Sami-Seppo Ovaska ◽

Pavel Geydt ◽

Ringaudas Rinkunas ◽

Tadeusz Lozovski ◽

Robertas Maldzius ◽

...

Keyword(s):

Surface Energy ◽

Direct Current ◽

Photoelectron Spectroscopy ◽

Rapeseed Oil ◽

Surface Composition ◽

Surface Elasticity ◽

Contact Angles ◽

Treatment Unit ◽

Barrier Coating ◽

Corona Treatment

Dispersion coating layers consisting of hydroxypropylated starch, 0–30 pph of barrier-grade talc and 0–10 pph of styrene-butadiene latex were subjected to both positive and negative direct-current corona treatments utilizing a specially developed dynamic treatment unit. The effects of the surface composition (barrier coating) on the response to the direct current corona treatment were evaluated by measuring contact angles and determining the surface energy. The effects of corona treatment on the properties of the barrier coating were further determined by measuring the contact angle of rapeseed oil and the grease resistance. It was found that the grease resistance of the corona-treated barrier coatings was substantially lower than that of untreated samples, which was ascribed to holes caused by corona discharge strike-through and to chemical changes on the treated surfaces. The corona treatment lowered the surface energy of the coatings, as indicated by an increase in the contact angles of water and rapeseed oil. Changes in the dispersion part of the surface energy were recorded, particularly after positive treatment voltage, whereas a negative discharge led to greater changes in the polar part of the surface energy. X-ray photoelectron spectroscopy (XPS) tests revealed an increase in the proportion of talc at the surface after corona treatment, which indicates a migration caused by the applied electric field. The peak force tapping mode of an atomic force microscope revealed moderate topographical changes in the coatings and a decrease in surface elasticity, supporting the migration of talc particles. In addition, significant changes in the physicochemical properties of the untreated reverse side were observed.

Download Full-text