For full functionality of this publication it is necessary to enable Javascript.

Self-Cleaning Molds

U.S. Patent 9,227,350 (January 5, 2016), “Molding System Having a Residue Cleaning Feature and an Adjustable Mold Shut Height,” Jean-Christophe Witz, Sven Kmoch, and Ralf Walter Fisch (Husky Injection Molding Systems Ltd., Bolton, Ontario, Canada).

Mold cleaniness of certain parts is critical in blow molding with preforms for a continuous, efficient molding process with a minimum of defects. Witz, Kmoch, and Fisch developed a method for periodic cleaning of a sensitive part of the mold, such as a preform neck, without mold disassembly, using a special cleaning component. This device blocks the melt and forces a cleaning fluid through the mold and out the vents after cleaning. This system is designed to operate after a predetermined number of molding cycles.

Thermally Conductive Polymers

U.S. Patent 9,238,879 (January 19, 2016), “Method of Fabricating Thermal Conductive Polymer,” Yongrak Moon and Kangmin Jung (SK Innovation Co., Ltd., Seoul, South Korea).

In some applications, the low thermal conductivity of thermoplastics leads to heating problems and limits their applications. Thermally conductive fillers can help, but highly filled plastics are difficult to process. 

Moon and Jung fabricated a thermally conductive polymer fiber by spinning an ultra-high molecular weight polyolefin (UHMWPO) gel, stretching the gel filament, drying, and repeating the process. This results in a filament with 80 to 95% crystallinity and a dichroic ratio of 1 to 10. The UHMWPO has a weight-average molecular weight of 3,500,000 to 10,500,000 g/mol and an absolute viscosity of 5 to 45 dL/g.

Very Strong Laminates

U.S. Patent 9,238,347 (January 19, 2016), “Structural Member Formed from a Solid Lineal Profile,” Sherri M. Nelson, David W. Eastep, Timothy A. Regan, Michael L. Wesley, and Richard Stiehm (Ticona LLC, Florence, Kentucky, USA).

Reinforced structures can be formed by pultrusion. Unfortunately, very high tensile-strength materials are limited by processing difficulties. 

Nelson et al. produced a high-strength material by laminating several reinforced ribbons with aligned continuous fibers embedded within a thermoplastic polymer. The continuous-fiber ribbons are fused together by pultrusion to form a solid profile with very high tensile strength.

These ribbons contain 40 to 90 wt% fibers in a thermoplastic matrix of any of the engineering thermoplastics (polybutylene terephthalate is especially suitable). The ribbons are heated above the softening temperature of the thermoplastic matrix and pultruded through two dies. The first die laminates the ribbons, and the second die shapes the laminate.

Hot Filling Plastic Bottles

U.S. Patent 9,238,341 (January 19, 2016), “Preform Neck Crystallization Method,” Yoichi Tsuchiya (Nissei ASB Machine Co., Ltd., Nagano, Japan).

Hot filling blow-molded plastic containers, especially polyethylene terephthalate (PET) wide-neck containers, can be a problem because of sagging during filling. Resistance to this filling can be developed by crystallization of the plastic.

Tsuchiya developed a neck crystallization method by inserting a core into the neck and heating the neck while rotating the preform on its axis and cooling. The heating of the neck is done in two stages, a rapid heat step and a slow heating step. The first heating quickly starts the crystallization, and the second heating enables precise control.

A Better Body Armor

U.S. Patent 9,238,332 (January 19, 2016), “Protective Material Arrangement,” Michael Dunleavy, Sajad Haq, and Caroline Joleen Morley (BAE Systems plc., London, UK).

Body armor provides protection against a variety of “impact events”—especially gunfire. Typical body armor consists of several layers of a polyaramid (Kevlar) fabric, but these fabrics tend to be heavy and hot. Attempts to improve body armor by impregnating the fabric with a shear-thickening fluid have failed; impregnating actually degrades anti-ballistic properties. 

Dunleavy, Haq, and Morley instead encased layers of antiballistic fabric in an armor fabric impregnated with a polymeric material. This polymer is an ionomer such as an ethylene-methacrylic acid copolymer with a mixture of neutral repeat units and 15% or less ionized units. This material even shows self-healing after an impact event. Other high-strength fibers may be used such as graphite, nylon, glass fibers, nanofibers, and high-strength polyethylene fibers.

Injection Molding Motors

U.S. Patent 9,238,318 (January 19, 2016), “Method for Manufacturing a Motor,” Chao-Wen Lu and Chih-Wei Chan (Delta Electronics, Inc., Taoyuan Hsien, Taiwan).

In motorized applications such as motor-driven fans, durability is limited by vibrations. Lu and Chan reduced this problem by injection molding a cushioning material between a bushing and the motor. The motor consists of a substrate, a bearing, a shaft, and a stator. The rotating shaft of the fan is connected to the motor through an opening in the motor and separated from the substrate by a bushing. This bushing is shielded from the motor by a cushioning material such as rubber, a damping material, or other elastic, moldable material which is injection molded into the structure during assembly.

Precision Molding

U.S. Patent 9,233,496 (January 12, 2016), “Adjustment Mechanism of Mold System Having Electrically Adjusting and Positioning Functions,” Cheng-Hsien Wu, Cheng-Hao Chiu, Chieh-Ju Wu, and Kai-En Chang (National Kaohsiung University of Applied Sciences, Kaohsiung, Taiwan).

In many molding operations, a precise and frequent adjustment of a mold system is essential for reliable and reproducible molding operations. But methods for very fine adjustments during molding are lacking.

Wu et al. developed a mold system including a carrier platform with at least two adjustment mechanisms. Each of the adjustment units includes a positioning member and a pivotally electrically driven adjustment device.

Controlling Radiation

U.S. Patent 9,227,383 (January 5, 2016), “Highly Flexible Near-Infrared Metamaterials,” Kok Wai Cheah and Guixin Li (Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong, China).

Metamaterials are composites of many different materials, including metals, ceramics, and plastics. Their properties are determined by geometry and structure as well as by the properties of the individual materials. These smart materials are capable of manipulating electromagnetic waves or radiation in ways not possible by conventional materials.

Cheah and Li developed a multilayer flexible metamaterial that can manipulate near infrared radiation on transparent PET substrates using flip chip transfer (FCT) techniques. This device can be transformed into various shapes by bending the PET substrate. This device is tunable via manipulation of its flexible substrate without changing the material’s composition. These materials enable novel tunable sensors and emitters.