--- title: "Mechanical Engineering Expert Not Allowed to Opine on Zippers" meta: "og:description": "The mechanical engineering expert was barred from opining on whether the zipper material actually used to produce the Tru Fru pouches was defective" "og:title": "Mechanical Engineering Expert Not Allowed to Opine on Zippers" author: "Expert Witness Profiler" description: "The mechanical engineering expert was barred from opining on whether the zipper material actually used to produce the Tru Fru pouches was defective" --- # Mechanical Engineering Expert Not Allowed to Opine on Zippers Posted on June 8, 2026 by Expert Witness Profiler Plaintiff Amcor Flexibles North America, Inc. (Amcor) brought this action against Defendant Reynolds Packaging, LLC (Reynolds), asserting claims for negligence, indemnification, and breach of warranty arising out of Amcor’s purchase from Reynolds of allegedly defective zippered, food-storage pouches. Reynolds sued the Third-Party Defendant Reynolds Presto Products, Inc. (Presto), the manufacturer of the zipper component used in the pouches, for breach of implied warranty. Reynolds offered the opinion of [Matthew Furrer](https://expertwitnessprofiler.com/expert-witness/Matthew-Furrer/1575952) in support of its contention that Presto’s zippers were defective. ## **Mechanical Engineering Expert Witness** [Matthew J. Furrer](https://expertwitnessprofiler.com/expert-witness/Matthew-Furrer/1575952) is the owner and a primary consulting engineer at Krenz Engineering. He holds a bachelor’s degree and master’s degree from the Mechanical Engineering department at the University of Wisconsin – Madison. [Discover more cases with Matthew Furrer as an expert witness by ordering his comprehensive Expert Witness Profile report](https://expertwitnessprofiler.com/order/add?eId=1575952&pId=3). ## **Discussion by the Court** Amcor manufactures flexible packaging materials, many of which are used to package food products. Tru Fru, one of Amcor’s customers, ordered zippered, food-storage pouches for its chocolate-covered frozen and/or freeze-dried fruit products. Amcor subcontracted with Reynolds to produce the pouches from the film Amcor provided, and Reynolds purchased the plastic zippers that made the pouches resealable from Presto. Reynolds incorporated the zippers into the pouches and then shipped the finished product to co-packers to be filled with Tru Fru product. During the packaging process, a fuzz-like plastic contaminant known as “angel hair” was found in some of the packages. Furrer, a mechanical engineer, did not dispute the finding of the joint investigation that the zipper guide originally on the Hudson-Sharp machine was a cause of the angel hair in the finished Tru Fru product. In fact, Furrer did not analyze the zipper guide and made no attempt to determine whether the machine caused the problem. Nor did Furrer dispute that once the Hudson-Sharp zipper guide was modified, no further angel hair contamination was noted. Instead, Furrer’s opinion was that there could have been another cause of the angel hair contamination, namely, that the zippers provided by Presto were defective in that they had angel hair accumulations at the time the zipper material was delivered to Reynolds and before it was incorporated into the pouches. ### **_Analysis_** Regardless of whether Furrer is qualified by his education, training, or experience, the Court is satisfied that Reynolds has failed to establish by a preponderance of the evidence that his methodology is reliable or that the proffered testimony is relevant. To begin with, Furrer’s methodology involved conducting a test that had little resemblance to the actual operation of the machines used to produce the pouches, and the test was conducted on zipper material that had previously been rejected by Reynolds as nonconforming because of the presence of strings. It is undisputed that this rejected material was not used to produce the pouches that were delivered to Tru Fru’s co-packagers and were later found to contain the angel hair contaminant. This is not a test that could produce a reliable answer to the question of whether the zipper material actually used to produce the Tru Fru pouches was defective. ## **Held** The Court granted Presto’s motion to exclude the expert opinion of Matthew Furrer. ## **Key Takeaway** Furrer is unable to offer more than speculation as to whether the zipper material actually utilized in the Tru Fru pouches was defective. In other words, his opinion that it could have been defective is insufficient to assist the factfinder. It is therefore irrelevant and thus inadmissible. ## **Case Details:** --- ## **You Might Also Like** ![Political Science Expert Allowed to Opine on Election Ballot Secrecy](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/06/blog-pic-640X480-2026-06-12T202339.329.jpg) [**Political Science Expert Allowed to Opine on Election Ballot Secrecy**](https://expertwitnessprofiler.com/mechanical-engineering-expert-not-allowed-to-opine-on-zippers/political-science-expert-allowed-to-opine-on-election-ballot-secrecy)![Law And Legal Expert Not Allowed to Opine on Forfeiture](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/06/blog-pic-640X480-2026-06-12T192154.573.jpg) [**Law And Legal Expert Not Allowed to Opine on Forfeiture**](https://expertwitnessprofiler.com/mechanical-engineering-expert-not-allowed-to-opine-on-zippers/law-and-legal-expert-not-allowed-to-opine-on-forfeiture)![Cardiology Expert Allowed to Opine on the Need for Additional Treatment](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/06/blog-pic-640X480-2026-06-12T162818.175.jpg) [**Cardiology Expert Allowed to Opine on the Need for Additional Treatment**](https://expertwitnessprofiler.com/mechanical-engineering-expert-not-allowed-to-opine-on-zippers/cardiology-expert-allowed-to-opine-on-the-need-for-additional-treatment)![Employee Benefits Expert Allowed to Opine on Benchmarks](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/06/blog-pic-640X480-2.jpg) [**Employee Benefits Expert Allowed to Opine on Benchmarks**](https://expertwitnessprofiler.com/mechanical-engineering-expert-not-allowed-to-opine-on-zippers/employee-benefits-expert-allowed-to-opine-on-benchmarks)![Law Enforcement Expert Not Allowed to Opine on Training And Supervision](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/06/blog-pic-640X480-2026-06-10T185337.163.jpg) [**Law Enforcement Expert Not Allowed to Opine on Training And Supervision**](https://expertwitnessprofiler.com/mechanical-engineering-expert-not-allowed-to-opine-on-zippers/law-enforcement-expert-not-allowed-to-opine-on-training-and-supervision)