A method for producing a heat-shrinkable product is provided. First, a polymer composition containing a polymer, a crosslinking agent and a micro-encapsulated foaming agent uniformly dispensed therein is melt mixed. The foaming agent has a peak activation temperature which is higher than a temperature of the melt mixing. Next, the polymer composition is injection molded into a molded product. This carried out at the peak activation temperature to activate the foaming agent. Then, the molded product is crosslinked within the mold.

Methods for processing LDPE recyclates including, but not limited to, polyethylene and polypropylene and compositions therefrom are provided. LDPE recyclate can be visbroken to improve processing characteristics and/or devolatilized to remove waste byproducts to produce processed LDPE recyclates. Processed LDPE recyclates are compounded with pre-consumer polyolefins to produce blend compositions having acceptable or even improved processing characteristics. Such pre-consumer polyolefins can also be visbroken to further tailor processing characteristics of such polymer blends. A combination of extruders and/or extruder zones can be used at the same or different locations for visbreaking and/or compounding of both LDPE recyclate and/or pre-consumer polyolefins.

Methods for processing HDPE and/or MDPE recyclates including, but not limited to, polyethylene and polypropylene and compositions therefrom are provided. HDPE and/or MDPE recyclate feedstocks can be visbroken to improve processing characteristics and/or devolatilized to remove waste byproducts to produce processed HDPE recyclate and/or processed MDPE recyclates. Processed HDPE recyclate and/or processed MDPE recyclates are compounded with pre-consumer polyolefins to produce blend compositions having acceptable or even improved processing characteristics. Such pre-consumer polyolefins can also be visbroken to further tailor processing characteristics of such polymer blends. A combination of extruders and/or extruder zones can be used at the same or different locations for visbreaking and/or compounding of both HDPE and/or MDPE recyclate and/or pre-consumer polyolefins.

Methods for processing HDPE recyclates including, but not limited to, polyethylene and polypropylene and compositions therefrom are provided. HDPE recyclate can be visbroken to improve processing characteristics and/or devolatilized to remove waste byproducts to produce processed HDPE recyclates. Processed HDPE recyclates are compounded with pre-consumer polyolefins to produce blend compositions having acceptable or even improved processing characteristics. Such pre-consumer polyolefins can also be visbroken to further tailor processing characteristics of such polymer blends. A combination of extruders and/or extruder zones can be used at the same or different locations for visbreaking and/or compounding of both HDPE recyclate and/or pre-consumer polyolefins.

A method of forming shaped articles by welding.

A method of forming shaped articles by welding.

The present invention relates to a film structure comprising an outer layer, a core and an inner layer (or sealant layer). The outer layer comprises a polyolefinic material having a Vicat softening temperature of 85° C. or greater, and a total crystallinity in the range of 25 to 45%. The core comprises a linear low density polyethylene having a density of 0.925 g/cm.sup.3 or less, and a melt index of 4.0 g/10 min or less. The inner layer comprises linear low density polyethylene having a density of from 0.865 to 0.926 g/cm.sup.3 and a melt index of less than 4.0 g/10 minutes. The films of the present invention have less than 25% of polyethylenes having a density of 0.930 g/cm.sup.3 or greater. Further, the films of the present invention can be characterized by the substantial absence of polyamide, polyester, ethylene vinyl acetate, ionomers, polyvinyl chloride, and/or cyclic olefin polymers.

The present disclosure is concerned with a method of forming a seal with a polyethylene based film structure. The polyethylene based film structure has at least one layer formed with an oriented polyethylene having a predetermined melting temperature (T.sub.m). A conductive heat sealing device provides heat to form the seal, where a first sealing bar of the conductive heat sealing device operates at a first operating temperature of at least 10 degrees Celsius (° C.) below the T.sub.m of the oriented polyethylene in the polyethylene based film structure and a second sealing bar of the conductive heat sealing device operates at a second operating temperature of at least 15° C. higher than the operating temperature of the first sealing bar. The seal formed with the polyethylene based film structure retains at least 99 percent of its original surface area prior to forming the seal.

The present disclosure is concerned with a method of forming a seal with a polyethylene based film structure. The polyethylene based film structure has at least one layer formed with an oriented polyethylene having a predetermined melting temperature (T.sub.m). A conductive heat sealing device provides heat to form the seal, where a first sealing bar of the conductive heat sealing device operates at a first operating temperature of at least 10 degrees Celsius (° C.) below the T.sub.m of the oriented polyethylene in the polyethylene based film structure and a second sealing bar of the conductive heat sealing device operates at a second operating temperature of at least 15° C. higher than the operating temperature of the first sealing bar. The seal formed with the polyethylene based film structure retains at least 99 percent of its original surface area prior to forming the seal.

A method for producing a heat-shrinkable product is provided. First, a polymer composition containing a polymer, a crosslinking agent and a micro-encapsulated foaming agent uniformly dispensed therein is melt mixed. The foaming agent has a peak activation temperature which is higher than a temperature of the melt mixing. Next, the polymer composition is injection molded into a molded product. This carried out at the peak activation temperature to activate the foaming agent. Then, the molded product is crosslinked within the mold.