Performing Department
Food Science & Human Nutrition
Non Technical Summary
A substantial safety issue affects the production, handling and storage of newer packages such as pouches and trays for shelf-stable foods. These types of packages are replacing market share traditionally held by cans and jars. Unfortunately, unlike cans and jars that are a mature technology with well-established quality control procedures, these less-robustpouches, trays and other thin-material structures lack a comprehensive method for integrity inspection and are at risk for food contamination, product loss and quality/nutrient degradation.Because of this lack of reliable methods and equipment, production facilities, many of them located in Illinois, have a much higher defect rate than with cans and jars, and rely on manual visual inspection or "hold and reject" systems, both of which are unreliable and potentially problematic. The proposed project will provide an improved method for ensuring the security and safety of food packaged and stored in these newer types of structures.Manual inspection, as might be expected, is unpredictable and variable, and many operations do not provide the proper diffuse lighting and operator rotation to ensure reliability. "Hold and reject", while not often discussed, relies on "blown" packages (bloated from microbial gas formation) to indicate which are defective. These are then discarded and the rest are sent on for consumption. Given the range of non-gas-forming pathogens, this is a significant safety hazard.Additionally, we have been made aware of similar problems in many types of operations ranging from PCR/gel-array kits to medical diagnostic systems and even intravenous (IV) solution bags that face similar types of defects and detection difficulties. As the pace of microbial rapid detection and identification systems evolves, and as newer and lighter medical device systems are designed, similar sorts of fabrication challenges will be faced by several other industries. This provides an opportunity for the development of simple, robust inspection methods as a safety check in the fabrication processes of food packaging as well as medical and other devices. The UIUC Packaging Lab has a long history of examining methodologies to this end.
Animal Health Component
0%
Research Effort Categories
Basic
35%
Applied
35%
Developmental
30%
Goals / Objectives
Hypothesis:That dynamic infrared imaging can provide a relatively simple, robust means of ensuring seal, bond and weld integrity in a range of materials and applications and that this can provide a means for improving food system safety in packaging, distribution and storage.Specific Objectives:1. To develop a faster and more accurate imaging/data collection system. Since the current imaging systems use highly adapted handheld equipment originally intended for classroom demonstrations, reliability and data accuracy continues to be problematic beyond basic proof of concept work. What is needed is direct thermographic videography with data output. A University of Illinois Campus Research Board Grant has been submitted to fund the "next generation" camera system (FLIR Model A655sc FLIR Uncooled Fixed Mount Camera and necessary lenses and cabling) for the laboratory.2. Using better equipment (if possible) to develop and quantify the factors involved (temperature, material properties such as thermal conductivity and thickness, and time factors) in developing an IR/thermography-based device for the real-time imaging of defective materials, seals and fused polymer and metallic joins. With speeds already at 5 frame/second from preliminary trials, commercial use is already feasible in limited situations. The boundaries of utility for the method need to be defined in order to understand in which situationsthe methods accuracy will roll off as well as those that offer optimum utility. We will be using samples of "real world" materials and structures that have been supplied to the lab by industry, and will be developing the relationships that determine what the speed, resolution and utility limitations on the method are, and to provide general design guidelines for practical device design and utilization.3. To develop, refine and evaluate the algorithms used to rapidly detect and quantify defects based on thermographic images. The preliminary work that has been done with MATLAB will be continued, because of its ubiquity and ease of use. We also have an interest in determining practical parameters (frame rate, resolution, bolometer parameters) that may make the systems faster and simpler.4. To understand the scaling implications of the technology, in terms of scan speed, material thickness and thermal properties and related factors such as noise and accuracy and their impact on the safety of packaged food, in order to work with interested parties in the several industries in Illinois that have already expressed interest (packaging, medical device consumables, plastic molding) as well as others as previously described.5. To begin initial work on phase-lock and standing wave thermography to provide tomographic information on these materials and structures and advance the understanding of the techniques used in both large scale and microthermographic materials and life sciences applications. This advanced work will be the result of understanding of the basic parameters and limitations developed in steps 1 - 3, and working with interested parties.
Project Methods
Work will be conducted in the UIUC Packaging Laboratory (293 AESB) with support from the ABE machine shop facilities. The current scanning equipment consists of an adapted handheld FLIR I-7 (FLIR Inc., Boston MA) thermal camera combined with a single-axis digital drive sample transport system (fabricated in-lab) and videography Samsung HMX Q10BN digital video camera. Still frames are processed using MATLAB (MathWorks, Natick, MA) to determine if simple image-processing algorithms can be used to detect gaps or anomalies in the materials in streaming video and the computational time and overhead. This equipment has served well to prove the concept and can reliably define defects up to the imaging resolution of the equipment, but work needs to progress to provide better accuracy, precision and scalability. Improvement of the imaging equipment, if possible, will use the FLIR A655sc camera which has a 50 fps imaging rate at 640 x 480 pixels (and 200 fps at 640 x 120 pixels, which is adequate for our use) will allow much higher resolution at high speeds, direct video file feed to the analyzing computers and thus a "real time" demonstration of the method's utility. Barring that, the existing 5 FPS, 140 x 140 pixel cameras may be used to extend the estimation of the method's utility, application and limitations. Image analysis will be continued using MATLAB, for reasons of simplicity and flexibility. Dedicated applications may be produced in C or Python for singular applications if needed, though compiled MATLAB applications seem more than capable at this point.The proposed work would continue the current physical scanning system but adapt several variations to explore the system in other modes of usage. 2D transmission scanning will be accomplished by using inexpensive 3D printer drivers to position and image the material with a fixed IR laser and camera. Transmission scanning of non-planar materials will be explored on blowmolded plastic items using a variable power fiber-optic IR laser to access the inside of the material and provide the thermal input for imaging using the same 3D driver or a rotational stage.