An integral polymer grid with a plurality of interconnected, oriented polyethylene terephthalate strands and an array of openings therein is made from a polyethylene terephthalate sheet-like starting material having holes or depressions therein that form the openings when the sheet-like material is uniaxially or biaxially stretched. The grid has a higher tensile strength to weight ratio and a higher creep reduced strength to weight ratio than corresponding ratios associated with a grid made from a non-polyethylene terephthalate starting material.

An underlay cushioning sheet that is arranged on the surface of a foundation and that has a waterproof coating film formed thereon. The underlay cushioning sheet includes a cushioning layer having an overlay surface and a curing acceleration layer having a coating film formation surface on the opposite side from the overlay surface. A waterproof coating film including a polyurethane resin is formed on the coating film formation surface of the curing acceleration layer by applying a one pack-type liquid waterproofing material. The curing acceleration layer includes a reactive material capable of reacting with the liquid waterproofing material. The reactive material either (1) includes a functional group capable of reacting with an isocyanate included in the liquid waterproofing material or (2) reacts with a latent curing agent included in the liquid waterproofing material and generates a functional group capable of reacting with the components of the liquid waterproofing material.

The present invention relates to a multimodal polyethylene composition comprising: (A) 40 to 65 parts by weight, preferably 43 to 52 parts by weight, most preferred 44 to 50 parts by′ weight, of the low molecular weight polyethylene having a weight average molecular weight (Mw) of 20,000 to 90,000 g/mol, wherein the low molecular weight polyethylene has a MI2 of 500 to 1,000 g/10 min according to ASTM D 1238; (B) 5 to 17 parts by weight, preferably 10 to 17 parts by weight, most preferred 10 to 15 parts by weight, of the first high molecular weight polyethylene having a weight average molecular weight (Mw) of more than 150,000 to 1,000,000 g/mol or the first ultra high molecular weight polyethylene having a weight average molecular weight (Mw) of more than 1,000,000 to 5,000,000 g/mol; and (C) 30 to 50 parts by weight, preferably 37 to 47 party by weight, most preferably 39 to 45 parts by weight, of the second high molecular weight polyethylene having a weight average molecular weight (Mw) of more than 150,000 to 1,000,000 g/mol or the second ultra high molecular weight polyethylene having a weight average molecular weight (Mw) of more than 1,000,000 to 5,000,000 g/mol, wherein the density of the first high molecular weight polyethylene or the first ultra high molecular weight polyethylene and the second high molecular weight polyethylene or the second ultra high molecular weight polyethylene is in the same range and both densities are in the range from 0.910 to 0.940 g/cm3; and the molecular weight distribution of the multimodal polyethylene composition is from 18 to 30, preferably 20 to 28, measured by gel permeation chromatography, film comprising the multimodal polyethylene composition and the use thereof.

Multilayer polyethylene (PE) geomembrane liners for unconventional thermal conditions and methods of making them are disclosed. The liners have N co-extruded stacked layers, each layer being made from a PE masterbatch composition comprising a given amount of PE resin and additives, and of a PE metallocene based resin free of acid neutralizer compounds. Also disclosed are customized multilayer PE geomembrane liners of N co-extruded stacked layers, each layer being made from a PE masterbatch comprising a specific additive providing specific behaviour property to the layer; wherein at least two of the N layers comprise a different specific additive in order to provide a geomembrane liner having at least two layers with different behaviour property. The liners have a water-bath aging performance for about 6 months immersion at about 80° C. per ASTM D5322—modified for water, such that about 80% of high pressure OIT value retained per ASTM D5885.

The present invention relates to improved bentonite barrier compositions having enhanced low permeability over time in containment applications. Of the many embodiments provided herein, one embodiment includes a method comprising: providing a bentonite barrier composition comprising: bentonite; and a polyanionic low molecular weight polymer; and forming a containment using the bentonite barrier composition to provide at least partial separation for a containment from its environment.

A sheet material is provided that includes a woven layer having a first side and an opposing second side, the woven layer formed from strand including a polyolefin polymer and a nucleating agent; a first polymeric coating disposed on the first side of the woven layer; and optionally a second polymeric coating disposed on the second side of the woven layer. The sheet material exhibits reduced thermal shrinkage.

A composite drainboard includes a patterned substrate core having an inward surface, and opposed outward facing surface. The substrate core comprises a plurality of projections, forming concavities on the inward surface. A first geotextile membrane is attached to the substrate core and covers the outward facing surface. A second membrane is attached to the substrate core to cover the inward facing surface and the concavities to provide a substantially smooth coating to the inward surface. The second membrane at least partially absorbs a liquid applied waterproofing.

A welder for joining two polymeric sheets together using a wedged heating element allows for a heating profile on opposite faces of the heating element to be varied by controlling where each of the polymeric sheets contacts the corresponding face.

The absorption device includes a hydrophilic powder and a casing which is permeable to a liquid, the casing being composed of an upper layer which is superimposed on a lower layer, the lower and upper layers being connected to each other by strong connections which delimit a confinement zone for the hydrophilic powder in the casing. Advantageously, the lower and upper layers are connected to each other by first weak connections. The first weak connections delimit a plurality of adjacent cells in the confinement zone, each cell enclosing a quantity of hydrophilic powder sufficient to bring about the breakage of the first weak connections which delimit the cell when the hydrophilic powder absorbs a liquid.

A flow barrier for wastewater disposal ponds or pits used in oil and gas operations. The flow barrier includes a flake component, a fiber component, and a granular component. The disposal pond flow barrier may prevent the infiltration or leakage of aqueous fluids from the wastewater disposal ponds into the surrounding environment and ecosystems. A process for manufacturing and using the flow barrier in a wastewater disposal pond is also provided.