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Home  >>  Products  >>  Abrasion  >>  Wahability/Linear Test Equipment

Washability / Linear Test Equipment

Twenty Two versatile models testing wear, scrubbability, washability, breakaway & Kinetic frictions. 

With hundreds of millions of strokes to our credit the Gardco washability machine has been proven as the industry standard for testing wear, scrubbability, washability breakaway and kinetic friction. This work horse is designed, built and manufactured in the USA, Gardco Washability machines are used in all the major laboratories around the globe, with an emphasis on reliability and durability it is the solid choice for your testing needs.

All testing with this type of equipment involves moving one surface with respect to another under controlled conditions and determining any resulting change or interaction between the surfaces.

Washability Machine
The line of Gardco LINEAR MOTION TEST EQUIPMENT spans the range from the simplest washability machine to the most sophisticated equipment providing force recording of test motion resistance. Such force measurement has the potential of eliminating subjective operator evaluations by quantifying many types. Model D10 pictured right.


Characteristics Common to All Electric Models


Dimensions / Weight: The base of all models is 0.25 inch thick aluminum plate. It is 16" deep for all models, 16" long for all D10 Models and 22" long for all other models. One-half of the depth of the machine supports all functional mechanisms and their housing. The front half of the base provides the working surface or area for product testing. The base is supported on one-half inch high feet to provide clearance for clamping test products at both ends and along the entire front edge of the base. Net Weight: (Approx. 40-50 pounds)

All functional elements are mounted above the normal level for product testing and therefore are not subject to damage by accidental liquid spills.

Heavy gage brushed aluminum houses all functional components with only the drive fork bracket extending forward to carry the drive fork over the test area. Access to the component area is by removal of only two screws from the lid of the housing. All controls and indicators are mounted on the front surface of this housing. The housing is eight inches high on fixed speed models and ten inches high on variable speed models.

The drive fork is fabricated from 1/16" stainless steel. It is held in place by a bracket of the same material which is secured to linear bearings carried on accurately spaced parallel bars. Reciprocation of the drive fork assembly on the parallel bars is by a unique double chain and sprocket arrangement. Up to 25 lbs ( 11kg) load can be applied to the drive fork at one time. There are no belts, cables, springs or other such mechanisms in the drive chain requiring service or maintenance.

Absolute linearity is obtained with unique drive system. Acceleration and deceleration is sinusoidal providing for the smoothest possible change in direction at the end of each stroke.

The drive fork is adjustable vertically with respect to its drive bracket. In its lowermost position it is less than one-half inch above the test surface with the tray and glass plate in place. This relative low position minimizes the tendency of the carried surface to tilt in the direction of travel. The fork can be raised in half inch steps, inverted and further raised to accommodate test specimens up to two and a half inches thick without losing close proximity to the test surface.

Design of the drive fork cradles accessories used in the test and permits them to simply be lifted free. There are, therefore, no rotational or other unbalancing forces imposed on such auxiliaries. They are "Free Floating" and self-leveling.

There are three equally spaced holes in each of the tines of the drive fork. A test auxiliary can be placed in either of the three pairs of holes to accommodate positioning of the test specimen. The spacing also permits simultaneous cradling of three brush boxes, two abrasion boats or two sponge boxes for multiple specimen testing.

Electric drives used in fixed speed models are right angle gearhead motors are totally enclosed, non-ventilated permanent split capacitor type.These ball bearing motors are rated for 115 volts, 60/50 Hz, continuous duty with a temperature rise of 40°C (104°F). (Machine cycle rate is based on 60 Hz operation.) The gear case is zinc alloy, grease filled, hardened steel worm with phenolic output gear and ball bearing output shaft. Electric drives used in variable speed models are right handle gearhead motors of totally enclosed non-ventilated 90 volt permanent magnet type. These ball bearing motors are rated for continuous duty with a maximum temperature rise of 40°C (104°F). The 115 volt motor speed controller is solid state, with constant torque speed regulation and a motor speed range of 10/1. The motor gear case is die cast aluminum, oil filled with hardened steel worm and bronze output gear.

The digital cycle counter is electrical and is energized through a switch from the drive linkage. The desired number of cycles is set by hand simply by pressing the Up/Down key to the desired increment for each digit, a maximum setting of 9,999 can be achieved. On start of operation, the  dial counts  to the preset value and turns off the machine. The counter then may be manually reset to run the same count or the count may be changed.

All electrical components of single rate model are fused for 2 amps while all variable rate model are fused for 3 amps. The fuse holder is located on the right side of the housing. An electrical diagram is located under the lid of each machine.

Furnished with each machine is an instruction manual covering operation and maintenance. Included is an electrical diagram and for variable cycle rate machines a graph for the setting of cycle rate dial and instructions for changing the minimum and maximum rate settings for variable rate machines.

Velocity of the drive fork is a function of stroke length as well as cycle rate. The following graph relating rate dial setting to cycles per minute and drive fork velocity in inches per second is representative of Models D10V, D10VF and D10VFI. The relationship for other models is similar except for the cycle rate - velocity ratio.

The motor speed control unit installed in all variable cycle rate models has a rated range of 10:1. Factory setting of both high and low limits are shown under "Characteristics" for each model. Internal adjustments permit changing these limits. There is interaction between these adjustments. Changing one will affect the other. The procedure for this rate limit change is furnished with operating instructions for each variable cycle rate unit.

There are two basic reasons for measuring friction. The first is to determine the “slipperiness” of a surface. The other may be of much greater importance. It is quantifying a change in a surface as it is subjected to cleaning or wear testing. A simplified classical definition of friction is: Whenever an object moves upon another, resistance offered to the motion is called FRICTION. Characteristics of friction between such object surfaces are:
  • It varies with respect to the nature of the surfaces.
  • It varies directly with pressure between the surfaces.
  • It is independent, within limits, of surface contact area.
  • It is independent, within limits, of rate of motion.
  • Static (starting or break-away) friction is always greater than kinetic (sliding or motion) friction.
  • Coefficient of friction is defined as the force required to move one surface over another divided by the weight on the surface. The coefficient of friction has a wide range. For example: greased metallic surfaces may be as low as 0.05, wet leather on metal 0.36 and dry leather on metal 0.56.

In order to measure friction between any two surfaces, one surface must be moved with respect to the other. The pressure or loading between the surfaces must be fixed and known. The force required to start the motion and to retain it in steady state must be determined.

Gardco linear motion test equipment with force measurement capabilities are ideally suited for measuring friction. Models with cut-out bases are designed for making measurements not only on prepared samples but also directly on the surface supporting the machine. The variable rate features of these models permit operating at a sufficiently low velocity so that kinetic energy and momentum factors may be neglected. A velocity of three to five inches per second is suggested when working with most surfaces. The force recorder is highly recommended for use in this measurement even though there is force indication on the machine panel. The recorder provides greater sensitivity and a high response record of force resistance throughout the machine cycle and for repeat cycles.

In order to provide a wide range of different surfaces and the loading on these surfaces, Gardco has produced an auxiliary weight for the abrasion boat and a modified sponge box to carry a much heavier weight. Both of these items are directly cradled by either the standard fork or extended machine drive fork.


Twenty-Two Models - Basic Model Characteristics - See Price List
WA-2151 D10 (D1)* 10" No 8" x 18" 37 No No No
WA-2153 D10V (DV1)* 10" No 8" x 18" 6-60 Yes No No
WA-2653 D10VP 10" No 8" x 18" 15-45 Yes No No
WA-2155 D10VF (DVF)* 10" No 8" x 18" 6-60 Yes Yes No
WA-2157 D10VFI 10" No 8" x 18" 6-60 Yes Yes Yes
WA-2163 D12V 12" No 8" x 24" 5-50 Yes No No
WA-2164 D12V 12" Yes 8" x 24" 5-50 Yes No No
WA-2166 D12VF 12" Yes 8" x 24" 5-50 Yes Yes No
WA-2168 D12VFI 12" Yes 8" x 24 5-50 Yes Yes Yes
WA-2171 D16 (DL1)* 16" No 8" x 24" 37 No No No
WA-2173 D16V (DLV1)* 16" No 8" x 24" 4.5 - 45 Yes No No
WA-2175 D16VF(DLVF1)* 16" No 8" x 24" 4.5 - 45 Yes Yes No
WA-2177 D16VFI 16" No 8" x 24" 4.5 - 45 Yes Yes Yes

Note: V = Variable Speed    F = Force Sensing   I = Built in Interface
  1. D12 Models, when fitted with extended drive fork, permit testing on test surface such as floors, ship decks and other large surfaces.
  2. Cycle Rate Range of variable speed machines may be shifted. (See "Characteristics of Variable Speed Models").
  3. Force sensing machines may be equipped with an interface with plug in outlets to drive an external recorder

  *   Replaced Models

The information contained in this product leaflet is believed by the Paul N. Gardner Company to be accurate and is furnished for the education and ultimate benefit of the buyer. Rights are reserved to change any herein contained information, without prior notice, if warranted by new product data. There is no warranty, expressed or implied, regarding the accuracy of this presentation or results obtained from the use of the described equipment. The described products and related information herein contained are furnished upon the condition that the person receiving or using it shall determine to his own satisfaction the suitability thereof for his particular purpose.


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