Polyethylene Laminates Research Articles

Disinfestation of Basmati rice by the use of γ‐radiation

SummaryThe effect of low‐dose γ‐radiation on prepacked Basmati rice was studied in order to achieve disinfestation. Basmati rice procured from the local market was repacked in 1 kg pouches made from high‐density polyethylene (HDP) and biaxially oriented polypropylene : low‐density polyethylene (BOPP/LDP) laminate and irradiated at doses from 0.25 to 1.0 kGy. Within 1 month of storage at room temperature, non‐irradiated (control) Basmati rice developed heavy infestation. No infestation was observed in any of the irradiated samples even at 0.25 kGy and the rice could be stored for 6 months in a clean state. Irradiation (at 0.25 kGy) did not alter the moisture content of the rice. Likewise, no significant change was noted in the functional properties of irradiated rice, such as the swelling index, water absorption and in total volatile components responsible for the flavour of Basmati rice. During organoleptic evaluation, no significant difference was found between the acceptability of irradiated (0.25 kGy) and control rice. These results are significant in view of the high export potential of Basmati rice and the transit losses which are at present owing to infestation.

Grease resistance and mechanical properties of isolated soy protein‐coated paper

AbstractGrease‐resistant paper has been produced by coating paper with isolated soy protein (ISP). Tensile strength (TS) of ISP‐coated paper is 28–30 MPa (between the TS of paper and of ISP film). TS of the ISP‐coated paper (2.3 kg/ream) was highest (36.0 MPa) among other ISP‐coated papers, but elongation (E) of the papers seemed to decrease (though not statistically significantly) as the thickness of the ISP coating increased. ISP‐coated papers were highly impermeable to grease penetration for the first 2 h of the test. The percent stained area of two commercially used polyethylene‐laminated papers was higher than those of ISP‐coated papers. As the amount of plasticizer (a mixture of glycerol and polyethylene glycol) was increased in ISP‐coated paper, the TS decreased and the E increased. When tested, the percent stained areas of the paper containing 0.6 and 1.0 g plasticizer/g protein were lower for the first 2 h than those of the papers containing 0.0 and 0.2 g plasticizer/g protein. Also, percent stained area increased with time. Grease resistance of papers coated with ISP at levels higher than 2.0 kg/ream was equal to or lower than that of polyethylene laminates used for quick‐service restaurant sandwich packaging.

The Mechanical Properties of Particulate-filled Aramid and Polyethylene Laminates

Some mechanical properties of particulate-filled polyethylene/epoxy and aramid/epoxy laminates are reported, following earlier work with particulate-filled glass/epoxy laminates. The behaviour of the organic fibre laminates was different from that of glass fibre ones, investigated and reported earlier. There was an increase in compression strength with increasing filler content, with both kinds of organic fibre reinforcement. The interlaminar shear strength values were significantly lower for the polyethylene laminates than the aramid ones at all filler concentrations, and they fell to little more than 10MPa at high filler levels. However, the impact damage zone in drop weight tests was generally smaller for the polyethylene laminates, and the visible crack damage was less apparent than in the aramid ones. The flexural strength and modulus values are also reported. © of SCI.

The Mechanical Properties of Particulatefilled Aramid and Polyethylene Laminates

The Mechanical Properties of Particulatefilled Aramid and Polyethylene Laminates

調剤時の分割分包損失率と粉体物性の関連性 みかけの付着の測定

In order to predict the weight loss of a powder on the dividing and packaging machine, adhesion of Lactose G® and Crystalline Lactose with sieving particle diameters of 32/50, 50/100, 100/200 and 200 mesh pass were investigated. The examination of the apparent adhesion to the polyethylene laminate glassine paper and to four types of materials (processed glass beads shot, teflon, ground and crude stainless steel 304) used in the dividing and packaging machine showed a larger adhesive in the smaller size of both lactoses. There were significant correlations between the apparent adhesion and weight loss to the glassine paper and to the ground stainless steel 304 in each of the lactoses. No correlation was seen between the adhesive force of polyethylene laminate glassine paper obtained from the shear test and wall friction test on weight loss.It is concluded that the measurement of apparent the adhesion of powder is suitable for the anticipation of weight loss.

ニフェジピン持効性細粒の溶出特性と光安定性

A sustained release nifedipine fine granules, Sepamit R Granules® (SP-RG), is a product prepared by using the technique of solid dispersion. Dissolution behavior of nifedipine from SP-RG was tested based on the results of incompatibility. The photostability of SP-RG was also tested. Dissolution rate of nifedipine from SP-RG was 12.5% in JP XII 1st disintegration test fluid (pH 1.2) and 100.9% in JP XII 2nd disintegration test fluid (pH 6.8). Dissolution of nifedipine in JP XII 2nd fluid was delayed by moisture absorption during storage (relative humidity of 75% at 20° for 30 days). Dissolution of nifedipine from SP-RG in JP XII 1st fluid was increased by mixing of SP-RG with sodium bicarbonate or heavy magnesium oxide during storage (relative humidity of 75% at 20° for 30 days).Nifedipine in SP-RG packaged with polyethylene cellophan laminate paper completely decomposed after 72 hours, under exposure to light (500 lux), while it was stable even after 30 days with aluminium polyethylene laminate paper.

Protective Effect of Both a Barrier Cream and a Polyethylene Laminate Glove Against Epoxy Resin, Glyceryl Monothioglycolate, Frullania, and Tansy

This preliminary placebo-controlled double-blind patch test study evaluated the ability of a polyamine salt of a linoleic acid dimer (Stokogard outdoor cream; Stockhausen-Skin Protection Division, Greensboro, NC) to protect sensitized individuals from allergic contact dermatitis (ACD) to epoxy resin, glyceryl monothioglycolate (GMTG), Frullania, and Tansy. Stokogard was found to prevent ACD to Tansy in five of seven allergic volunteers after an 8-hour exposure to the allergen and in four of seven volunteers after a 48-hour exposure to Frullania. It was not convincingly effective in preventing epoxy or GMTG ACD. Additionally, a polyethylene laminate glove (4-H glove; Safety 4 Company, Lyngby, Denmark) was tested using the same format in volunteers allergic to epoxy resin and GMTG. It protected two of two volunteers sensitive to epoxy resin after both an 8-hour and a 48-hour exposure to the allergen. The 4-H glove was also effective in preventing ACD in GMTG-sensitive volunteers, protecting four of four patients after an 8-hour exposure and two of three after 48 hours.

Protective Effect of Both a Barrier Cream and a Polyethylene Laminate Glove Against Epoxy Resin, Glyceryl Monothioglycolate, Frullania, and Tansy

This preliminary placebo-controlled double-blind patch test study evaluated the ability of a polyamine salt of a linoleic acid dimer (Stokogard outdoor cream; Stockhausen-Skin Protection Division, Greensboro, NC) to protect sensitized individuals from allergic contact dermatitis (ACD) to epoxy resin

Effect of Flavor Sorption On Adhesive and Cohesive Bond Strengths in Laminations

The effect of sorption of flavor volatiles on the adhesive and cohesive bond strength of multilayer laminations was investigated. Two polyester/polyolefin adhesive laminates coated with a polyvinylidene chloride-polyvinylchloride copoly mer were surface-exposed to lemon juice and a hot sauce product, as well as to food simulant systems at 45°C. Sorption of flavor volatiles resulted in delamination of both laminates following exposure to the respective food products. A Dynamic Headspace Concentrator, interfaced with Capillary Gas Chromatography, identified d-limonene as the primary component sorbed by the laminates upon exposure to lemon juice. Us ing Electron Spectroscopy for Chemical Analysis and Scanning Election Microscopy, adhesive bond failure with the linear low density polyethylene (LLDPE) laminate was identified, while cohesive bond failure occurred within the ethylene vinyl ace tate copolymer (EVA) laminate Bond strength was quantified using a peel test Sig nificant reductions in bond strength occurred upon exposure to the food products.

Adhesion between aluminum and copolymers of ethylene and vinyltrimethoxysilane

AbstractThe adhension between aluminum and poly(ethylene‐co‐vinyltrimethoxysilane) (EVS) and poly(ethylene‐co‐butylacrylate‐co‐vinyltrimethoxysilane) (EVSBA), respectively, have been studied. For comparison an ordinary low density polyethylene (LDPE), a poly(ethylene‐co‐butylacrylate) (EBA), and an ionomer regarded as a bonding polymer were studied as well. The peel strength of laminates obtained by pressing were measured by a T‐peel test. The structure of the fracture surfaces were investigated by reflection‐IR, ESCA, and SEM. The peel strength of the LDPE and the EBA samples were 100 and 700 N/m, respectively. Although the amount of vinylsilane was low, about 0.2–0.3 mol %, its presence had a pronounced influence on the adhesion: 1800 and 3000 N/m for EVS and EVSBA, respectively. This is even higher than the value observed for the ionomer, 1560 N/m. Although there was a marked difference in surface topology, the SEM and ESCA analysis showed that the fracture was cohesive for both EVS and EVSBA. Immersion in water at 85°C increased the peel strength even more, especially in the case of EVSBA (up to 9000 N/m), in contrast to what is normally observed with aluminum polyethylene laminates. The results suggest that strong and nonhydrolyzable bonds, e.g., covalent bonds, have been formed across the polymer‐metal interface for the ethylene copolymers containing vinylsilane.

INFLUENCE OF STORAGE CONDITIONS ON QUALITY OF COWPEA SEEDS AND PRODUCTS PROCESSED FROM STORED SEEDS

Effects of storing cowpeas (Vigna unguiculata) at 2°C/65% R.H., 21°C/55% R.H., and 35°C/65% R.H. for 10 months in open metal cans, in high density polyethylene bags flushed with 100% CO2, and in nylon/saran/curpolymer/polyethylene laminate bags flushed with 100% CO2 were determined. No major adverse quality changes occurred in cowpeas stored at 2 or 21°C and evaluated as a reconstituted boiled vegetable. Peas stored at 35°C absorbed less water during soaking and required greater force to shear after boiling than peas stored at 2 or 21°C. The rate of death of yeasts and molds on cowpeas stored at 2°C was slower than the rate of death at 21 or 35°C. Decortication efficiency improved under the conditions of storage utilized and may be related to an increase in seed hardness. Cowpeas stored at 2 and 21°C produced akara (fried cowpea paste) with better overall sensory quality than peas stored at 35°C.

Infrared reflection studies of the mechanism of oxidation at a copper—polyethylene interface

Reflection spectroscopic techniques in the infrared region have been applied to a study of the mechanism of the early stages of oxidation of a copper—polyethylene laminate. The combination of internal reflection and reflection—absorption techniques shows that between 57 and 75°C in the presence of 1 atm of oxygen, one of the most important components of the oxidation is a surface reaction which occurs directly at the copper-polyethylene interface. Copper carboxylate salts, potential catalysts for the oxidation of the polyethylene, are formed early in the reaction and are concentrated initially on the metal surface. These carboxylates appear to decompose at higher temperatures and their ability to persist may be responsible for the increasing role of copper catalysis as temperatures are lowered. The relevance of these results to mechanisms of inhibition by copper deactivators is discussed briefly.

Techniques of Delaminating Polyethylene Laminates

Techniques of Delaminating Polyethylene Laminates