Thermoforming Quarterly is a journal published quarterly by the Thermoforming Division of the Society of Plastics Engineers. The magazine is a great way to keep up with industry trends and developments. SPE Thermoforming Division members receive the magazine by mail four times a year. Non-members can access old issues here via PDF file. If you are not an SPE member this is a great reason to join! Become a member today to start receiving this valuable information in your mailbox.
We welcome objective, technical and related articles that provide valuable information to our community of thermoformers, toolmakers, material suppliers and OEMs. Articles are typically 1500-2000 words. We recommend viewing past articles for further guidance. All submissions should be in MS Word, 12-pt Times New Roman.
Artwork, illustrations, photos and graphics should be 300 dpi. We prefer .eps .jpeg and .pdf files
Deadlines for copy and artwork– 1st Quarter: February 15; 2nd Quarter: May 15; 3rd Quarter: August 1; 4th Quarter: November 15
All submissions can be sent to Conor Carlin, Editor, at email@example.com
Thermoforming Quarterly Sponsorship Sales Contact: Lesley Kyle, +1 914-671-9524 or firstname.lastname@example.org
Fourth Quarter 2016
PET Thermoform Recycling: A Case Study in Packaging Recyclability Claims and Realities
by Resa Dimino, National Association for PET Container Resources (NAPCOR)
Earlier this year, the Sustainable Packaging Coalition’s Centralized Study on the Availability of Recycling found that a substantial majority of Americans have recycling programs available to them that accept all PET packaging. Included in this designation were not only bottles and jugs, but also non-bottle PET packages: the clamshells, cups, tubs, lids, boxes, trays, egg cartons and similar rigid, non-bottle packaging made of PET (#1) plastic resin that are increasingly common on retailer shelves.
The growing prevalence of PET thermoforms in curbside PET bottle bales is unmistakable (see Figure 1). As such, reclaimers have had to adapt to a stream containing these materials, but as the reclaiming industry struggles with increased contamination and yield loss, this comes at a difficult time.
Along with increasing thermoforms, reclaimers are faced with the impact of lighter weight containers, full wrap shrink labels, metal components, and other design elements that impede recyclability and negatively impact PET yield. At the same time, they are facing tight operating margins that result from competition with extremely low virgin materials prices. The result: reclaimers need to buy more bales to produce the same amount of salable rPET flake, and often sell that flake for less. It doesn’t take an MBA to see that this is a tough business.
Additive Manufacturing for Thermoforming Molds
By Patrick Price, Additive Manufacturing Research Engineer, Stratasys
Traditionally, thermoforming tooling has been made from wood, RenShape board or machined metals. Although these legacy techniques are still relevant today, quality and cost concerns associated with these methods are driving thermoform part manufacturers to look for new tooling solutions for low- to moderate-quantity production runs. The market need for a solution led the engineers at Stratasys® to investigate the feasibility of additively manufacturing thermoform tooling using FDM® (fused deposition modeling) to reduce tooling cost, material waste and lead time. Figure 1 shows a part being formed over an FDM tool.
FDM thermoforming tool design is similar to how tools are designed in conventional manufacturing methods for most features including draft angles, corner radii and draw ratios. The coefficient of thermal expansion (CTE), thermal conductivity and inherent porosity of the FDM tool must be considered during the design process as they differ from traditional materials and tooling methodology. The CTE of FDM materials is typically much higher than traditional tooling materials such as aluminum. This CTE value must be taken into account when designing the tool so that the expansion of the mold meets the desired part tolerance when the tool reaches an elevated, steady-state temperature during the forming process. Thermal conductivity is reduced compared to that of aluminum and will also need to be considered. Longer cycle times or additional cooling fans may be required to ensure the mold does not overheat. The inherent porosity of FDM tooling is typically an advantage but for some geometries, sidewalls or elevated flat surfaces may need to be sealed with a high-temperature epoxy to prevent vacuum from being drawn through these regions to promote sheet flow.
Full articles appears in print magazine mailed to members.