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Surface-applied mulches help retain soil moisture and optimize soil temperature while preventing weed growth and benefiting many horticultural crops. The most common mulch material is low-density polyethylene (LDPE), is typically landfilled, buried, or burned at the end of growing season causing negative environmental impacts. The goal of this research was to develop soil-biodegradable, liquid-applied (i.e., hydromulch) alternatives to LDPE mulch and optimize formulations that are acceptable for organic horticulture. Hydromulch (HM) treatments contained mixtures of paper pulp, wood fiber, or hemp hurds (Cannabis sativa L.) combined with various tackifiers and water. The tackifiers were guar gum (Cyamopsis tetragonoloba (L.) Taub.), psyllium husk (Plantago ovata L.) , and camelina meal (Camelina sativa (L.) Crantz), included at various proportions. Hydromulch samples were tested for physical properties (density, water holding capacity, C:N ratio, soil adhesion) and mechanical properties (tensile strength, puncture resistance). Hydromulches containing no tackifiers were included as controls to determine if the addition of tackifiers resulted in enhanced mechanical properties. The results showed addition of 6 % guar gum tackifier improved the tensile strength and puncture resistance by 182 % and 91 % respectively compared to control sample, and HM formulations containing paper were 200 % or more stronger than those containing wood or hemp hurds. Increased tackifier proportion was found to improve most mechanical properties, with guar gum performing best. Blending of tackifiers resulted in an interaction that decreased strength. Hydromulches containing wood fiber and hemp hurds did not show promising results. Paper in HM formulations helped to reduce mulch porosity and improved adhesion to soil. Results from the study provide a foundation on optimal formulations for expanded trials at field-scale. • Hydromulch (HM) manufactured using paper, wood fibers, hemp hurds and organic tackifiers. • Paper based HM demonstrated high mechanical properties compared to wood fiber and hemp hurds. • Guar gum and psyllium husk are most promising tackifiers. • The amount of tackifier has direct influence on the puncture resistance and tensile strength of HM. [ABSTRACT FROM AUTHOR]

Extrusion coating experiments of flame retarded low density polyethylene (LDPE) onto a standard machine finished Kraft paper have been carried out. A pilot extrusion coating line was used in order to investigate the potential of halogen-free flame retardant system based on azoalkanes such as azocyclohexane (AZO) and 4′,4-bis(cyclohexylazocyclohexyl)methane (BISAZO) for fire resistant coating applications. In comparison, experiments were performed using FlameStab ® NOR116, magnesium dihydroxide (MDH) and a brominated additive Luvogard MB81/PE as reference flame retardants. The concentration of azoalkane flame retardants was varied between 0.5 and 1 wt.%. The maximum extrusion temperature was varied between 260 and 290 °C and the coating layer weight from 12.9 to 25.0 g/m 2 . The obtained multilayer facings containing azoalkanes exhibited significantly improved flame retardant properties, especially at the low coating weight of 12.9 g/m 2 . Under all of the used experimental conditions the runnability on the pilot line was flawless for azoalkane formulations. In contrast, our pre-trials using MDH/LDPE (50:50) formulations failed due to poor film quality and visible white aggregates. Moreover, the multilayer facings containing the FlameStab ® NOR116, Luvogard MB81/PE or mixtures thereof, showed inferior flame retardant properties compared to azoalkane based facings. [ABSTRACT FROM AUTHOR]

The study aims to establish if the packages based on paper or LDPE modified with extract of thyme and garlic are efficient in preserving the summer salame during storage, as compared with the unmodified packages. Eight different types of packages based on paper or LDPE impregnated in the aqueous extracts of thyme and garlic were prepared and used to test their preservation activity during the storage of the summer salame, a Romanian meat product, at room temperature and light. The eight types of packages are as follows: product impregnated in extract of thyme (IP thyme) and garlic (IP garlic), summer salame packaged in unmodified paper (H) and LDPE (LDPE), summer salame packaged in paper impregnated in extract of thyme (IH thyme) and in extract of garlic (IH garlic), summer salame packaged in LDPE impregnated in extract of thyme (ILDPE thyme) and in extract of garlic (ILDPE garlic). At 0, 3 and 6 days, the following physico-chemical parameters were monitored during storage: acidity, pH, water, salt and protein content. Additionally, the changes of the organoleptic characteristics were established. It was observed that the most reduced decrease of the acidity and protein content during storage occured in the summer salame impregnated in the thyme extract and in the salame packaged in the paper impregnated in the garlic extract. Moreover, the organoleptic characteristics of the samples impregnated in the thyme and garlic extract, excepting those in packages based on LDPE were not significantly changed during storage, at room temperature and under light. [ABSTRACT FROM AUTHOR]

In this study, the effect of heat treatment on barrier and functionality of polyolefin-coated papers was investigated. The aim was to find the optimal improvements on barrier without losing the applicability of the materials due to physical damages. The results of the study proved considerable improvement in barrier characteristics of the structures. Both water vapor and oxygen transmission rates of LDPE-coatings decreased linearly following the set-temperature until 200°C. At this point, the treatment caused a continuing decrease in oxygen transmission achieving 10 × lower transmission levels than the untreated structure, whereas moisture transport faced corresponding but lower increase. This was considered to be caused by the difference in diameter of the H2O and O2 molecules; the smaller water molecules are able to penetrate between spherulites, whose size increased due to higher treatment temperature followed by cooling. [ABSTRACT FROM AUTHOR]

• Hydropulping and selective dissolution/precipitation separate Tetrapak® constituents. • Effective separation of paper, AL and LDPE is achieved. • LDPE from inner layers exhibits properties comparable to virgin LDPE grades. Tetra Pak cartons, i.e. multilayer packaging consisting of paper, low density polyethylene (LDPE) and aluminium, are widely used as aseptic packages in the food and beverage industry. Paper can be easily recovered from this type of post-consumer beverage cartons (PCBCs) by the pulp industry. The remaining LDPE/aluminium by-product, however, cannot be easily separated to its constituents so currently it is mostly downcycled or used for energy recovery. The aim of this work is to develop an effective process that separates and recovers LDPE and aluminium of high purity and good quality from Tetra Pak cartons. To this purpose, following paper recovery by hydropulping, LDPE and aluminium are separated using a selective dissolution-precipitation (SDP) process. The recovered LDPE is characterized by FTIR spectroscopy, thermogravimetric analysis (TGA), differential scanning (DSC) and melt flow rate (MFR) measurements. The findings reveal that the SDP separation process is an effective method to recover LDPE and aluminium from PCBCs. [ABSTRACT FROM AUTHOR]