Nip Measurement

Ensuring uniform nip pressure across the entire surface area of those rolls is crucial to producing a reliably consistent product, maintaining productivity, minimizing machine down time, reducing waste, and more.
Obtain a uniform nip impression for roll setup, maintenance, consistency, and longevity
Taking routine nip impressions can help identify:

  • Nip pressure and uniformity
  • Roller alignment
  • Proper machine setup
  • Crowning (under- or over-crowning)
  • Diameter variations
  • Deflections
  • Blanket & surface wear

Nip Pressure Measurement Option

There is no “one-product-fits-all” approach but depending on your application needs Tekscan offers three solutions:
Fujifilm Prescale Film

single-use nip impression paper

Primary Use: Maintenance Tool

Also known as nip impression paper or a Fuji impression, Prescale film is used to measure pressure between nip rolls and calender rolls.

  • Snapshot pressure measurements
  • Visual pattern of peak pressure
  • One-time use
I-Scan

multi-use nip pressure measurement system

Primary Use: Instrumentation Setup

A powerful, versatile tool that accurately measures and analyzes dynamic contact pressure between rolls.

  • Used to understand full surface area of the nip
  • Over 200 sensors to choose from in different shapes and pressure ranges
  • Real-time display of pressure sensor data
NPAT

advanced nip pressure alignment tool

Primary Use: Maintenance & Setup Tool

The NPAT™ captures nip footprints and relative pressure distribution between nip rolls.

  • Used to measure pressure distribtion, nip width, and cross width across rolls
  • Clear visual representation of rolls using static snapshots
  • Ideal for large nip roller areas

Comparison of Nip Impression Systems


FujiFilm Prescale (“Nip Impression Paper” / “Fuji Impression”)

Nip impression paper is used to measure contact pressures and is as easy as passing the film through the nip rollers. The film structure consists of micro-encapsulated color forming and developing material. When pressure is applied to the film, a red color impression is formed in varying density according to the amount of pressure and pressure distribution.
Main features

  • Film is available in rolls and can be cut to size
  • 7 available pressure ranges up to 30,000+ psi
  • Peak pressure snapshot
  • Optional digital analysis software
Example pressure profile from nip impression paper
I-Scan™

I-Scan is a versatile solution for optimizing a process or manufacturing parameters. The I-Scan nip impression sensor is placed in the nip for real-time roller pressure measurement. With a wide range of sensor form factors and data analysis tools in the software, I-Scan is a powerful tool for a research and development team to improve yield.
Main features

  • Ideal for engineering team analysis
  • Recording & playback of dynamic pressure images
  • Fast (100 Hz) sensor scanning
  • Supports high temp sensors
Data returned from a square I-Scan sensor
Nip Pressure Alignment Tool™ (NPAT)

NPAT is an advanced, easy-to-use tool used to capture nip footprints and relative pressure distribution between nip rollers. The system utilizes a sensor made up of an array of thin and flexible pressure sensitive bands, which can be configured to match the size of an application.
Main features

  • Helps prevent equipment and product damage
  • Provides quantifiable and credible data
  • Easily maintained in-field
  • Allows for proper machine set-up, machine comparison, and preventative maintenance
Sample software output from Tekscan's NPAT

Compare Solutions with this Chart

Nip Impression PaperI-ScanNPAT
Primary UseMaintenance toolInstrumentation setup. Used by R&D engineers to optimize processes.Maintenance & setup tool
Data CapturedStatic display of pressure that captures peak load only; No timing dataReal-time, dynamic display of contact area of the nipRelative nip uniformity and pressure distribution
Ideal Nip Roll SizeCut to size> 450 mm (18 in)450 mm (18 in) to 10,973 mm (432 in)
Analysis CapabilitiesDigital scanner; software only displays degree of pressureFeatured packed, robust software with in-depth analysis tools and featuresRobust software with analysis tools and features
Efficiency & ProductivitySingle-use product with a cumbersome setup processReusable, mix and match sensors capturing in-depth analysis of nip contact areaReusable sensors that capture changes in pressure distribution in real-time