Illinois Tool Works Inc.

Gary L Vadnais

Manuel C Enriquez

James P Nelson

Karl G Adams

William Donald Robinson

Donald L Van Erden

Bobby L Goin

Patrick T Rigney

Jesse G McLawhorn

Donald Van Erden

Polyester strapping made from polyester and less than 3% by weight of a polyolefin additive exhibits improved resistance to longitudinal splitting when the strapping is later placed under tension in packaging reinforcement applications. The polyolefin improves the longitudinal split resistance of the strapping without facilitating unwanted longitudinal stretch of the polyester strapping when under tension. The polyolefin additive may be combined with other conventional additives, or may be used alone in order to minimize costs.

High integrity polyester strapping

A process for preparing a PET flake mixture for use in connection with the fabrication of high-performance plastic strapping comprises the steps of initially collecting post-consumer and non-post-consumer PET materials having an initially wide range of relatively low intrinsic viscosity (IV) values with a relatively low average intrinsic viscosity (IV) value, and processing the same through solid state polymerization (SSP) so as to obtain a wide range of relatively high intrinsic viscosity (IV) values with a relatively high average intrinsic viscosity (IV) value. The initially collected materials are chopped into flakes and chunks, and the chunks are removed by a suitable destoner so as to render the remaining mixture comprised substantially entirely of flake materials or segments. This is advantageous because the flake segments, as opposed to the chunk segments, are able to be substantially increased in intrinsic viscosity (IV) values and within a relatively short period of time, and in addition, the flake segments are essentially crystalline while the chunk segments are essentially non-crystalline which would otherwise undergo rapid crystallization and generate a substantial amount of heat of crystallization. Such heat of crystallization undesirably raises the temperature of the polymerization process whereby the materials tend to become sticky and agglomerate thereby impeding the flow of the materials being processed as well as tending to clog components of the processing apparatus.

Inline solid state polymerization of PET flakes for manufacturing plastic strap by removing non-crystalline materials from recycled PET

A process for preparing a PET flake mixture for use in connection with the fabrication of high-performance plastic strapping comprises the steps of initially collecting post-consumer and non-post-consumer PET materials having an initially wide range of relatively low intrinsic viscosity (IV) values with a relatively low average intrinsic viscosity (IV) value, and processing the same through solid state polymerization (SSP) so as to obtain a wide range of relatively high intrinsic viscosity (IV) values with a relatively high average intrinsic viscosity (IV) value. The initially collected materials are chopped into flakes and chunks, and the chunks are flattened so as to render the remaining mixture comprised substantially entirely of flake materials or segments. This is advantageous because the flake segments, as opposed to the chunk segments, are able to be substantially increased in intrinsic viscosity (IV) values and within a relatively short period of time. The initially collected materials have intrinsic viscosity (IV) values which are within the range of 0.60-0.80 dl/g, and as high as 0.90 dl/g, and the diversity of such materials is underscored or emphasized by the fact that the difference in such intrinsic viscosity (IV) values of the initial or starting materials is at least, or greater than, 0.05 dl/g, is probably at least 0.10 dl/g, and can be within the range of 0.10-0.30 dl/g.

Inline solid state polymerization of pet flakes for manufacturing plastic strap

The present invention describes a process of making strap using both post consumer and non-post consumer PET of wide distribution intrinsic viscosity (IV) through direct solid state polymerization in a flaked state to produce PET with increased, heterogenous IV suitable for high performance strap extrusion. The process increases the IV of post-consumer resins, consisting principally of polyethylene terephthalate (PET), by chopping the post-consumer plastic into flakes and chunks, rolling the flakes and chunks, preheating the flakes, and further heating the flakes and chunks in an atmosphere of hot nitrogen gas, thereby increasing the intrinsic viscosity. PET polymers having increased viscosities according to the present invention provide a polymer useful in manufacturing high performance strap.

Growing community of inventors

Grayslake, IL, United States of America

Gary L Vadnais