Product Overview

LLW pressure measurement film is a low-pressure type film designed for 0.5–2.5 MPa contact pressure testing and pressure distribution evaluation. It is used to visualize contact conditions and identify pressure variations across mating surfaces in industrial applications.

Product Information

  • Model: LLW
  • Type: Two-sheet pressure measurement film
  • Pressure Range: 0.5–2.5 MPa
  • Size: 270 mm × 6 m
  • Shelf Life: 2 years

Function

LLW pressure measurement film is used to:

  • visualize pressure distribution across contact surfaces
  • evaluate contact uniformity and interface condition
  • identify high-pressure concentration and low-pressure zones
  • support pressure estimation using density reference curves

Features

  • produces visible red color under pressure for direct evaluation
  • color density corresponds to applied pressure level
  • suitable for low-pressure contact testing
  • enables both qualitative and semi-quantitative analysis

Structure and Working Principle

The film consists of two layers:

  • L sheet (microcapsule layer)
  • K sheet (developer layer)

When pressure is applied:

  • microcapsules rupture in proportion to pressure
  • released dye reacts with the developer
  • a red color image is formed on the K sheet
  • higher pressure results in darker color density

Standard Pressurization Conditions

Two typical pressurization methods can be used:

Continuous pressurization

  • pressure increase time: approximately 5 seconds
  • holding time: approximately 2 minutes

Instantaneous pressurization

  • pressure increase time: approximately 5 seconds
  • holding time: approximately 5 seconds

Measurement Method

After pressurization:

  • observe the color distribution on the film
  • darker areas indicate higher pressure
  • lighter areas indicate lower pressure
  • blank areas indicate no effective contact

For more accurate evaluation, compare the color density with the corresponding reference chart under matched environmental and loading conditions.

Precautions

  • do not apply pressure to the film before use
  • avoid touching or rubbing the active surface
  • use gloves when handling if necessary
  • ensure contact surfaces are clean and dry
  • do not reuse the film after testing
  • evaluate results after 30–60 minutes for stable color development

Storage Conditions

  • store in original packaging
  • keep away from direct sunlight and heat
  • avoid exposure to water, oil, or solvents
  • prevent contact with plasticizers and chemical contaminants