We are the best in our field PAPER INDUSTRY

CCC EEETTTRRR Center for Tribology, Inc.LEADERS IN TRIBOLOGY TEST INSTRUMENTATION AND SERVICES

PAPER FRICTION TESTING SYSTEM

CETR Background

Center for Tribology, Inc. (CETR) is a privately held h i g h - t e c h n o l o g y engineering firm located in the city of Mountain View, in the heart of California’s famous Silicon Valley.

CETR was founded by Dr. Norm V. Gitis in 1993 to perform failure analysis, qualification and ongoing reliability testing of critical moving interfaces to assist industries such as paper, pe t ro leum, coat ings , ceramics, computers, automotive, aircraft and aerospace.

Dr. Gitis has dedicated h i s 2 5 y e a r c a r e e r exclusively to the field of tribology and industrial tribological applications. After a dist inguished career at the Soviet Academy of Sciences, where he authored three books and numerous papers on tribology, Dr. Gitis came to the United States where he first joined I B M i n 1 9 8 9 a s a distinguished researcher.

Since its founding, C E T R h a s b e e n a phenomenal success. It has developed a strong customer base in North America, South-East Asia and Japan. CETR has grown from a single-person consulting firm to a s t a f f o f a l m o s t 4 0 engineers and technicians within the past seven years.

Advanced Paper TribometerModels: APT-2MT, APT-2M, APT-2HT, APT-2H

CCC EEETTTRRR

Features

Description

It is well known within the paper industry that the The micro-tribometer can provide any rotational understanding and control of friction is a key or linear motion, in both vertical and horizontal parameter that is critical to measure in paper directions, and thus fully simulate all the development, manufacturing and quality assurance dynamics involved in moving paper interfaces. testing. The science of friction, wear and lubrication Sliding velocity can be as low as 0.5 microns per is called tribology. The methodology of precision second to over 40 meters per second. Loading repeatable and reproducible measurements of is produced using a computer controlled close-friction and wear is called t ribometro logy. lo op servomechanism for stability and accuracy Developed and produced by CETR's 40-people- (far superior to a dead weight mechanism) for strong team of technical staff and tribologists, the constant or linearly increasing loads from 1 mN Advanced Paper Tribometer is the most advanced (0.1 g) to as high as 200 N (20Kg). Options to instrument available today to study paper in moving control temperature, humidity and atmospheric interfaces. pressure at the interface are also available.

Friction force (Fx), normal load (Fz), friction The Advanced Paper Tribometer is a highly torque (FT) wear depth (WD) and acoustic precise instrument and can accommodate both em is si on (A E) ar e me as ur ed us in g a ideal friction pairs per industry standards or other sophisticated A/D conversion system for real-time non-standard interfaces that may be required by viewing and logged into the computer system for researchers either studying the fundamentals of post-test analysis. Electric contact resistance paper friction or wishing to simulate exact real- (ECR), electric capacitance (EC) and a near-field world conditions. focus digital camera are also readily available.

Studies the fundamentals of paper friction, macro and micro-mechanical properties

Precise measurements of friction force, coefficient of kinetic friction, static friction, stick-slip motion, adhesion, tear resistance, rupture resistance, paper wear and paper fatigue

Accurately performs repeatable and reproducible paper-on-paper sliding, paper-on-roller sliding,pen on paper sliding, eraser on paper sliding, tensile strength testing and indentation testing,

Forces and loads from 0.1g to 20kg, Velocities from 1 micron/sec to 2500 meters/min

Typical ApplicationsComputer controlled experiments. Repeatable and reproducible data.

The envelope of Coefficient of Friction (COF) performance can be quickly characterized for paper sliding on paper at various normal loads. In this experiment load (Fz) was decreased from 500 mN (50 grams) to 50 mN (5 grams). Measurements were conducted during unidirectional linear sliding at a speed of 1 mm/s for a total of 60 seconds at each load. The lower paper specimen was held stationary on the flat surface of the lower stage. The moving upper paper specimen was mounted on a self-leveling flat surface to keep the upper paper exactly parallel to the lower paper surface while in motion. It is quickly evident that COF increases with decreasing normal force, indicating involvement of both elastic and plastic deformation at the paper interface as well as a creeping mechanism.

Friction Coefficient of Paper Sliding on Paper as a Function of Load

This experiment is designed to evaluate paper's ability to resist damage that may be caused by strong normal loads onto a point contact (simulating harsh pen-on-paper writing conditions). Normal force was linearly increased from 0 to 200 mN onto a pin during slow rotation of the paper. Friction force is displayed on the graph in green, acoustic emission (indicative of Stick-Slip encountered immediately preceding tearing and during paper tearing) is displayed in blue and normal load is displayed in red. At the time of 10 seconds, corresponding to a normal force of about 50 mN, start of tearing was evident by a sudden increase in acoustic emission and simultaneous change in the slope of the friction force plot. The normal force during start of tearing can be defined as the critical load. Needless to say, the higher the critical load measured for a given paper, the better the resistance of the paper to tearing.

Paper Tear-Strength Resistance Test

COCoefficient of Friction (COF) was measured as a function of time at a constant normal load of 10 grams and nominal speed of 10 mm/s. Stick-Slip phenomena were observed, indicating the speed dependence of COF is a decreasing function for the speed range involved in the motion. For details, please see the dynamic analysis for stick-slip motion by Gao et al., Wear, V173, 1994, pp.1-12 (Contact CETR for a reprint). Stick-Slip motion is generally unwelcome, since it can increase wear and possibly cause a paper tear at the interface due to oscillating and fatigue. It also deteriorates motion stability and smoothness of the interface. Methods for stick-slip prevention can be found in the given reference.

Paper Sliding on Rotating Rubber Roller (Stick-Slip Motion)

Here we show an example of a real-world paper wear test for pencil eraser reciprocating against paper in a simulation of eraser action. Coefficient of friction (COF) was measured under a normal load of 10 grams, with the eraser reciprocating at a 10mm stroke with a velocity of 5 mm/s. COF continually increased with time as the eraser moved against the paper surface. This behavior suggests that the contact area between the eraser and the paper increased significantly during the test as paper and eraser material worn off so that the two surfaces (the eraser and the paper) became more confirming. Using this method, the Advanced Paper Tribometer proves to be very capable of distinguishing performance and durability of paper in an eraser-paper moving interface.

Linearly Reciprocating Pencil Eraser On Paper Test (Micro-Wear)

The Advanced Paper Tribometer is an extremely flexible instrument capable of performing a variety of micro-mechanical experiments. In this example, deformation of paper during Micro-Tensile testing was observed and measured as a function of pull-force from 0 to 60 N then back to 0 N. As evident in the load-displacement plot, the displacement during the relaxation phase of the experiment is smaller than during the tension phase of the experiment. This behavior suggests that plastic deformation and creep deformation (visco-plastic) occurred in the paper sample under tension. This observation is also in agreement with a previous observation of COF as a function of normal force for this paper. For soft papers, the displacement will be larger at a given pull-force. One can also study the creep deformation at various increasing and decreasing rates of the pull-force.

Paper Micro-Tensile Strength and Creep Test

Sales Offices and Distributors

Our sales engineers and sc ien t i s t s a re a lways available to answer any questions and to provide customized solutions to your testing requirements.

To schedule a demonstration of the Advanced Paper Tribometer or to receive any addi t ional in format ion, please contact us at the numbers below.

We are certain you will be pleased with our products and services.

_____________

Center For Tribology, Inc. 1711 Dell Avenue, Campbell, CA 95008

408/376-4040408/376-4050

http://www.cetr.comEmail:

Japan Distributor:

CETR Sales Agents are located throughout North and South America,Europe and Asia. Please contact us for the agent nearest you.

, USA Phone: Fax:

sales@cetr.com

Mediken, Inc.2-19-4 Nishishinbashi, Minato-kuTokyo 105-0003Japan Phone: 81-3-5470-9801Fax: 81-3-5470-9377http://www.mediken.co.jp Email:mediken@mediken.co.jp

Advanced Paper Tribometer Features

HARDWARE

Upper Specimen

Lower Specimen

Y Z Translation X Y Translation

Horizontal & Vertical Rotation

Reciprocation

Thermal Control

SOFTWARE

Data Acquisition

Data MonitorRecording

Motion Control

8 channels

20 kHz Data Rate

Data Summary, Charts

Data Format Converting

Data Average, Smoothing

Data Analysis

FrictionForce

NormalLoad

FrictionTorque

Wear DepthDisplacement

X, Y, Q Position

AcousticEmission

ElectricResistance

Electric Capacitance

Digital Video

ARAMETERS MEASURED & RECORDEDP

ScratchResistance

MicroHardness

ElasticityCreep

Adhesion Delamination Durability

FUNCTIONAL TESTING

Environment Control

FrictionWear

ElectricContacts

Center for Tribology offers nearly immediate CETR offers several payment options, including delivery for the Advanced Paper Tribometer. lease-to-buy terms, making the Advanced Paper Upon shipment, our installation engineer will Tribometer extremely affordable even for smaller travel to your laboratory and spend two days laboratories. setting up the instrument, training your personnel Please call 1-408-376-4040 for pricing and assisting you in developing test methods quotations and for information about a CETR specific to your research. distributor or agent nearest you.

The Advanced Paper Tribometer is covered by a full one-year warranty on manufacturer’s defects, both parts and labor. An extended warranty is available to ensure uninterrupted service for years to come. henever you have a technical question or want

to request modifications to your existing hardware or software, our engineers will always be ready to support you.

modifications. The Advanced Paper Tribometer is designed around a modular concept and new options to expand test capability can be added anytime without requiring factory installation.

Our technical support department is Wproud of continuously maintaining a 24-hour response time to user calls and 48-hour response time to requests for parts and quotes for

We are proud to have an unusually strong Numerous new options are constantly being added engineer ing team that is always happy to to the Advanced Paper Tribometer by request of customize the to your scientists in universities, commercial research labs exact specifications. CETR can also assist you in and by industry organizations. Customizations supplying easy-to-operate ruggedized paper are easily accommodated and very reasonably testers for high volume quality control and for priced. If you have a unique request, please do production control in your paper mills. not hesitate to contact us.

Advanced Paper Tribometer

Customization

Delivery and Prices

Warranty and Technical Support

CCC EEETTTRRR