MOLDING UNDRIED PET
Despite PET's well-known sensitivity to minuscule amounts of moisture, Aoki Technical Laboratory Inc. of Japan demonstrated molding of flat detergent bottles without any predrying. According to Aoki officials, the only "secret" is use of a two-stage screw and vented barrel. This technique reportedly maintains 93% of original resin I.V. in the finished bottle. Acetaldehyde in the resin can also be reduced through venting.
Nor is eliminating drying the whole story here. The undried, amorphous resin used was not typical of "solid-stated" bottle resin, which has a typical I.V. of 0.73. Instead, this was "precursor" material of 0.65 I.V., as is typical before solid-stating. After molding, the resin's I.V. reportedly decreased to around 0.60, similar to fiber-grade PET. Aoki officials say this suggests the possibility of using lower-cost PET resins, since solid-stating, drying, and crystallizing reportedly account for 15-25% of resin cost. Aoki machines are represented in this country by Formex, Inc., Dayton, Ohio.
Also new at the show was the first injection-stretch-blow machine from Jomar Corp., Pleasantville, N.J. Few details were available for the pre-show report on the ISB-II, which is aimed at relatively low-volume production of custom PET bottles in sizes up to 250 ml. This rotary two-station machine ejects bottles out the bottom of the blowing station. It's designed particularly for ease of maintenance and mold change. The machine has a 90-g shot capacity, 10-ton preform clamp, and 4-ton blowing clamp. There are no tiebars, hence no bushing wear. It has an Allen-Bradley 503 controller with color terminal. At the show, the machine molded 4-oz stock bottles with 20-mm neck finish in six cavities on a 12.8-13 sec cycle (10 million bottles/yr). Machine price is around $300,000.
NEW ACCUMULATOR LINE
Later this year, Graham Engineering Corp., York, Pa., plans to enter the accumulator-head machine market. Graham will build the machines. Design and sales assistance are provided by Robert Slawska and Charles Magnani, both formerly of APV Sterling (now Sterling Davis-Standard), who have formed a new consulting firm called Proven Technology, Inc. The new machines will have single or dual heads from 1 lb to 35 lb and up, press sizes from 36 x 26 in. to 74 x 60 in., and clamps from 50 to 100 tons.
Placo of Japan has signed a licensing and cooperation agreement with Bekum America Corp., Williamston, Mich., for joint marketing of Placo's "3-D" blow molding machines for low-scrap production of complex parts such as automotive ducts. Those accumulator-head machines are also being marketed in North America by Hobson Brothers Aluminum Foundry & Mould Works, Inc., Shell Rock, Iowa. (Hobson also represents Placo's deep-draw blow molders.)
According to a Hobson spokesman, Placo has developed a less expensive version of its 3-D machine for the U.S. market. It has the mold platens fixed at a 45 [degrees] angle in place of a variable-tilt mechanism. That helps bring the price down from about $1 million to $550,000 for a monolayer machine. Multilayer is also available.
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|Title Annotation:||Top of the News from NPE '94; developments in molding technology and equipment|
|Author:||Naitove, Matthew H.|
|Date:||Jul 1, 1994|