Frequently asked questions about film technology.

For packaging films (e.g. blister packs for pharmaceuticals and food), construction and technical films (roofing membranes, floor coverings, furniture films), credit cards, printing and advertising films. The process delivers very uniform thicknesses at high throughput and is the dominant process for rigid and flexible PVC.

Roll gap, roll temperatures, roll speeds and friction, roll bending (compensation of roll deflection) and roll crossing (skewing) of the rolls. Added to this are the rheology and temperature of the compound and the size of the bank (rolling bank) in the nip. From these, our model calculates the mean film thickness, calendered width, throughput and the optimal roll bending and roll crossing values for minimum thickness tolerance.

Process analysis on your line, optimization of changeover times and thickness profile, selection and integration of measurement technology (thickness, gloss, color, surface, shrinkage) as well as training of calender operators – on request with the VR headset for calender technology, without occupying the production line.

Thickness variations in the cross and machine direction (die lip, melt pulsation, chill roll run-out), gel and speck formation, surface defects, color deviations with liquid color dosing, as well as shrinkage and warpage during further processing. Many of these causes can be assigned directly to the line using inline measurement technology.

Instead of masterbatch granules, liquid color is dosed directly into the extruder. Advantages: fast color changes, lower inventory, finer color gradation. We have developed dosing and measurement concepts that monitor the color value inline and keep the dosing stable.

The basic equations (mass balance, momentum equation, heat balance, rheological equation of state) are the same. Separate models exist for the cooling process, film shrinkage and thermoforming, which we adapt to your line.

Thickness profile around the circumference, shrinkage in the machine and cross direction, optical properties (haze, gloss), tear strength, sealability and winding quality. The thickness distribution is particularly demanding to measure because of the rotation of the die or haul-off.

Offline via shrinkage and shrink force measurement on sample strips at a defined temperature; inline via web tension and width measurement. We offer both approaches and link the results with the line parameters.

Yes. Our 30 years of industry experience cover calendering, extrusion and blown film – from process analysis through measurement technology to complaint reduction.

Through offline tests such as residual stability (thermal load capacity of the polymer), rheology, moisture and color value. Our residual stability measurement tests up to five samples simultaneously in the heating cabinet and evaluates the degradation using a color camera – ideal for optimizing stabilizer contents.

Thickness variations in the machine direction reveal run-out errors and emerging bearing damage on individual rolls. Using Fourier analysis, we assign the variation to rotational speed and roll diameter – the basis for preventive maintenance instead of unplanned downtime.

Because properties such as shrinkage, residual stability, thickness tolerance or surface tension only become visible under temperature, tension or pressure. End-to-end data linking of manufacturing and converting (batch, line parameters, measured values) makes causes traceable.

Yes. Our models for the cooling and thermoforming process calculate wall thickness distribution and warpage from film and process parameters – for the design of formats and for evaluating material alternatives before tooling is built.

Using sol-gel technology and spray application with IR drying, surfaces are created that are antimicrobial, conductive, scratch-resistant or specifically more or less printable – properties that the film alone does not provide. Developed in collaboration with Klöckner Pentaplast.

With an anti-counterfeiting system that introduces unique, machine-verifiable features into the film or packaging and reads them out. Developed jointly with the Technical University of St. Petersburg.

Inline via gloss and color value measurement directly on the web, offline in the laboratory on samples. Both values are linked with the process parameters in order to assign deviations to their cause.

Thickness profile (cross and machine direction), gloss, color value, surface inspection (gels, scratches, holes), bank level evaluation in the nip or rolling bank, web width, shrinkage via web tension as well as bearing monitoring on rolls and drives. Details on the Inline measurement technology page.

Via standard interfaces (OPC UA, fieldbus, database/REST). We link measurement data with the machine's control data, quality data from the laboratory and order data from the ERP – see Industry 4.0.

Usually yes: even a single measured parameter (e.g. longitudinal thickness or bearing condition) noticeably reduces scrap and complaints. Together with you, we check which parameter offers the greatest leverage before any investment is made.

Evaluation of plastic raw materials, longitudinal thickness profile, residual stability, scratch resistance, dimensional measurement of formats as well as shrinkage and shrink force measurement. Details on the Offline measurement technology page.

Each sample is assigned to batch, roll and line condition. This allows laboratory results to be correlated with process parameters and the causes of complaints to be reliably demonstrated.

Stable process parameters, fewer complaints, preventive maintenance, traceable quality per roll and batch as well as faster changeovers. The data are usually already available – they just are not linked.

No. We build on existing control and measuring systems and add interfaces and evaluation step by step. Getting started works with one line and one measured parameter.

The data stay in your network. Solutions such as WARDEN run in the local network and are accessible via web browser; internet access is optional.

A tool for predicting plant failures and identifying possible causes: three alarm levels, WLAN communication between the devices, data view online and from the archive – on any device with a web browser.

Through bearing monitoring (vibration, temperature) and through the longitudinal thickness profile of the film: periodic thickness variations that match the rotational speed and diameter of a roll indicate run-out errors or incipient bearing damage.

Mean calendered film thickness, calendered width per roll, expected throughput, film shrinkage in the machine and cross direction as well as the optimal values for roll bending and roll crossing at minimum thickness tolerance.

Images of your own calender line are loaded into the VR headset; data are entered directly in the VR environment, and the model shows the calendering result. New calender operators practice changeovers and optimizations without using the production line. Project description as PDF.

Yes, the line is represented as a 3D model – for visualizing measuring points, film path and changeovers, and as the basis for the VR application.

1. Short discussion of the task. 2. On-site analysis on your line (process parameters, measuring points, quality and complaint data). 3. Concept with levers, measurement technology and effort. 4. Development, modeling and testing. 5. Implementation, training of machine operators and anchoring in your systems.

For manufacturers, converters and finishers of plastic films as well as for machinery and measurement technology builders – from mid-sized companies to corporate groups, in German-speaking countries and internationally (German, English, Russian).

Long-standing research partnership with the Technical University of St. Petersburg (Prof. Dr. T. B. Chistyakova), industrial projects with Klöckner Pentaplast and MFS, technical books published by Hanser. More under References and Publications.

On a time-and-materials basis (daily rates) or as a project flat rate with defined deliverables. The basis is our Terms of Sale, Delivery and Payment. The first meeting is without obligation.

By phone at +49 170 9188587, by email to info@kohlert-consulting.de or via the contact form.