A novel solution for non-contact thickness measurement of non-PET containers

Agr International has introduced a novel, breakthrough method to measure thickness distribution in HDPE, PP, PE and similar containers. With this method, an entire segment of containers is now able to be measured for thickness distribution with light-based technology. Prior to this development, many HDPE, PP, PE and similar containers that were highly colored and had limited transparency, were not able to be measured using non-contact, light-based measurement techniques.

In the development of its new Gawis 4D dimensional and thickness measurement system, Agr engineers were challenged to include the ability to measure thickness on a broader range of bottles including those constructed of HDPE and non-PET materials. To address this, a novel “Integrated Method for Thickness Measurement” was developed and implemented into this system. This patent pending method incorporates a proprietary programmable spectrometer and utilizes the integrated- method to analyze the signal level of multiple absorption bands within the entire NIR band width. Using this new technique, bottles that are highly colored and have a transparency to IR light as low as 5% can now be measured for thickness.

The benefits of non-contact, IR-based thickness measurement, such as the fast, reliable and accurate measurement that PET bottle producers have taken advantage of for years, has not been available to the manufacturers of HDPE and similar non-PET bottles. In the past, light-based IR thickness measurements have been limited to materials with high levels of light transmission. PET bottles are ideal for this technology since the majority are transparent and have IR light transmission and absorption levels that are very high and predictable. On the other hand, HDPE, as with many other non-PET materials, is generally translucent, meaning some IR can pass through, but detailed shapes cannot be seen in the IR spectrum. The amount of colorant used in the bottle, especially solid colors, further limits IR light transmission and absorption. Consequently, because of weak IR light transmission and absorption, light-based thickness measurements of HDPE and non-PET bottles has been difficult and not very practical.

This breakthrough overcomes many of the measurement challenges presented by non-PET materials and offers a new measurement alternative for HDPE and non-PET bottles used in the food, cosmetic, personal care and related industries. The Integrated Method for Thickness Measurement technology is now standard on Agr’s Gawis 4D Measurement System. With this capability, in addition to all types of PET products, the Gawis 4D can measure containers manufactured from a wide range of polyolefins, including highly colored materials, making the device ideal for testing labs that process a wide variety of containers and products. With the growing pressure to reduce carbon footprints through container lightweighting and source reduction, the ability to measure material distribution on non-PET bottles with high accuracy and repeatability is increasingly important.

Agr’s Gawis 4D is the latest offering in a long line of automated laboratory measurement systems for plastic bottles and containers. The Gawis 4D is designed to provide highly accurate and repeatable dimensional gauging as well as high precision, non-contact thickness measurement over the entire bottle or preform, with a throughput of less than twenty seconds per sample. In addition to the Integrated Method for Thickness measurement, this system offers a number of key features designed for simple and fast operation. These include Agr’s patent pending AutoJob™ automated job setup for dimensional measurements, a library of standard industry finish templates, easy-to-operate multi-function touch and go UI, Industry 4.0 compatibility and a wealth of data transfer methods.