PT Blog

Managing warpage is a complicated task, given the number of factors involved and how each one can affect the others. Simulation software can make this work easier by allowing engineers to address the problem earlier in the product design cycle.

Using simulation tools, such as Autodesk Moldflow, allows engineers to set up and run analyses to visualize how much shrinkage and warpage to expect, given the current part’s material, design, and expected processing conditions. Through the visualization tools, results can be scaled and anchored for easier interpretation and comparison to other simulations.

In late 2017, I reported on Braskem forming a technological partnership with Danish-based Haldor Topsoe, that would put the company on the road to developing ‘Green’ PET, to add to its portfolio of biobased PE and EVA. The collaboration called for Braskem and Haldor Topsoe, a global leader in catalysts and technology for the chemical and refining industries, to explore a pioneering route for the production of monoethylene glycol (MEG) from sugar at a single industrial unit, which reduces the initial investment in production and consequently makes the process more competitive. MEG is one of two key components used to make PET, and has a current global market estimated at around  $25 billion.

The partners have now announced the startup of a pilot plant in Lyngby, Denmark, and say it marks a decisive step in confirming the technical  and economic feasibility of producing renewable MEG on an industrial scale. Built in Denmark, the unit has annual production capacity of hundreds of tons of glycolaldehyde, a substance that is converted into MEG. The goal is for the plant to convert various raw materials, such as sucrose, dextrose and second-generation sugars, into MEG. Currently, the compound is made from fossil-based feedstocks, such as naphtha, gas or coal. Starting in 2020, clients will receive samples to test in their products.

Rikutec Group of Germany, a specialist in blow molding large parts—both a processor and machine builder—has introduced what it says is the packaging industry’s first all-plastic drum that meets the highly stringent demands of Packaging Group 1 regulations specified by the ADR European agency for safe storage and transport of highly aggressive chemicals. The blow molded “tank in a tank” requires no secondary container and also meets U.S. Dept. of Transportation regulations. “Rikutec has developed the highest rated dual-containment drum in the industry,” says Andreas Amberg, president of Rikutec America.

Wittmann Battenfeld has made several enhancements to its liquid silicone rubber injection molding equipment. The most important changes are a revised screw design and integration of the LSR dosing pump into the machine’s control system via OPC-UA communication, the emerging standard for Industry 4.0. Any commonly available LSR dosing and pumping system can now be connected to a Wittmann Battenfeld press controller via an OPC-UA interface, the company says.

The revised injection screw has an optimized shaft seal at the end of the shaft in front of the screw coupling to reduce the risk of silicone leaking out toward the screw drive. Another improvement is to the check valve, combining a larger flow cross-section with a faster and more precise closing mechanism. This has led to a significant improvement in shot-weight precision compared with the predecessor version, the company reports.

A number of injection molding machine builders are betting that the answer is Yes. If you’re looking for evidence to answer that question for yourself, consider this demonstration at last month’s Plástico Brasil 2019 show in São Paulo. A 160-metric-ton all-electric Engel e-motion press molded thin-wall PP ice-cream cups in four cavities with IML in 2.2 sec. Total shot weight was 14.8 g. The machine boasts injection speeds up to 500 mm/sec. Credit for the extremely fast cycles also goes to Beck Automation of Switzerland, which provided the IML automation.

Though it’s not easy to find an apples-to-apples comparison with a hydraulic machine, Arburg demonstrated four-cavity molding of PP tubs with IML in 1.95 sec at NPE2018. The shot size was quite similar (each tub weighed 3.4 g). The press was an Allrounder 570 H (200 m.t.) with an electric clamp unit and hydraulic accumulator injection unit. IML automation came from Brink B.V. of the Netherlands.