steven's blog for plastic mold and plastic molding

Injection molding is the largest segment of plastics processing. Today the plastic mold maker have to use moulds with better coating that lasts longer and further understand preventive maintenance, as they are increasingly processing polymers or composites that are more aggressive to the surface of the moulds. Aggressive conditions of out gassing and moisture acidity often accompany abrasive wear as potential damage to expensive tooling. Further, the use of glass filler and wood fiber, etc creates more challenges. The growing tool complexity involves tinier, more intricate flow passages and more frequent use of moving cores and slides. All these factors have prompted development of a wider variety of mould coatings that can keep moulds operating longer between repair. Typically hard chrome plating with Rockwell hardness of about 72 is found to be quite good. Newer coatings with better performance are now available. A major drawback is chrome's environmental impact, since chromium...

If your company uses complex precision metal components, metal injection molding (MIM) can offer significant cost savings and eliminate design restrictions inherent in other metalworking technologies. Metal injection molding is a young technology, having only been practiced commercially since the mid 1980s. North American industry sales are reported to be near $60 million, and growing at over 30 percent per year. The process is essentially a marriage of the thermoplastic injection molding and conventional powder metallurgy processes. It offers the same level of design freedom for highly configured metal components as is available for plastic parts in the plastic molding process. The technology produces very high-density parts with mechanical properties superior to powder metallurgy, and comparable to wrought materials. It is successfully serving a variety of industries such as medical and dental tools, business machines, power hand tools, industrial equipment, electronics, medical an...

Blow plastic molding plastic containers with handle are very difficult to produce, and generally extrusion blow molding is used to manufacture such containers. The first important aspect of processing such containers is the design of the container. This requires an understanding of how the parison falls and how it is captured by the plastic mold and pinched and blown out into the final container shape. In a typical handle ware container, the aspect ratio of the handle is the ratio of the major axis (width of the handle perpendicular to the parting line) to the minor axis (width of the handle parallel to the parting line). An aspect ratio of 1:1 is optimum; at most, a 2:1 ratio can be blown. Higher aspect ratios are certain to create narrow or impossible processing windows. An optimum processing window requires a draft angle of 5° to 8° in the handle area so the part can be easily released from the mould. Textured parts will require more draft angle than polished parts. Handle webbin...

Peelable Pouches Appearances matter, even in the medical industry. So when operating room doctors at an Austin, Tex. hospital expressed their desire for a new style of peelable chevron header pouch — used to seal three-dimensional objects intended for use during surgery — flexible packager Rollprint Packaging responded with its new Duet product. The Duet pouch is manufactured by heat sealing a strip of DuPonts Tyvek high-density polyethylene film to a polyester/ extrusion-coated sealant to create the first side of the structure. The next step is to three-side, heat-seal the Tyvek/film combination to a layer of polyester/poly. At the bottom, the polyester/extrusion-coated layer extends slightly beyond the polyester/poly film side, creating access tabs at both corners where a dual chevron-opening feature has been created. According to Rollprint Packaging, the dual chevron at the outer edge makes it easier for operating room personnel — used to having only one opening option — to open and...