Pendulum impact testers for tests on plastics – SCS INSTRUMENTS
Industries
- Predominantly plastics
Max. energy
- 50 joules
Type of test
- Charpy
- Izod
- Dynstat
- Tensile impact test
Pendulum impact testers for plastics testing – accurate, reliable and operator-friendly
In addition to tensile and flexure tests, Charpy impact tests are the most frequently performed mechanical tests in the polymer industry. ZwickRoell’s HIT series pendulum impact testers offer a high-precision, cost effective solution.
Advantages and features
Advantages
HIT pendulum impact testers automatically identify the pendulum in use, ensuring that measured values are always determined in the correct range and in accordance with the standard in use.
A world first is the use of carbon double rods for the pendulum. This provides a high level of stiffness in the impact direction and a strong concentration of masses at the point of impact.
Each pendulum is equipped with a quick-change device. Pendulums can be changed quickly and without the need for tools.
The optional pendulum disc brake is virtually wear-free.
Operator convenience is a prominent feature of the HIT pendulum impact testing systems. Easy-to-reach controls, on the same level wherever possible, help avoid user fatigue.
The electronics contain a high-resolution digital encoder for accurate measurement of the impact angle. An RS232 interface is available for connection to laboratory data-management systems. A PC can be connected via a USB plug-and-play interface.
Intuitive and workflow-based touch operation
All test-related settings are grouped logically and are separated from higher-level system settings. The operator is guided through the test configuration step by step. The saved test configuration can be easily exported and transferred to other instruments.
Quick familiarization with user management also applies to stand alone
Integrated user management reduces the number of operator input options to a minimum. Users see only what is important to them so they can focus on the task at hand right from the start.
The new standardized operating philosophy allows the operator to move easily between the instrument and the PC.
Reliable test results
The consistent design of a pendulum impact tester for low natural vibrations starts near the specimen with the pendulums and fixtures.ZwickRoell uses high-performance carbon materials for our HIT pendulums. They offer the following advantages:
Significantly greater pendulum stiffness
Ideal distribution of mass
Repeatable, reproducible test results.
You can test in a measurement range up to 80% of potential energy. This is made possible by the very high ratio of instrument mass to pendulum mass.
Changing between the various HIT fixtures is quick, while precision guides guarantee a continuous positive-fit to the baseplate.
Ergonomic design throughout
Operator convenience is a prominent feature of the HIT pendulum impact testing systems. Everything is within an arm's reach and operational controls are at a uniform height.
To change the fixture, simply slacken the retaining bolts slightly. The fixture can then be withdrawn from the guides and another slid into its place. Limit stops ensure reliable positioning.
The pendulum is easily changed by means of a quick release lock, No additional tools are required, simplifying the operation and saving time.
Specimen disposal is via the integrated collecting tray.
The electronics feature a simple, easy-to-operate keyboard. During series tests the results can simply be read off from the large, clear display
Massive support frame and stable base
The welded table frame guarantees maximum stiffness, while wide-based leveling feet ensure firm, stable support. The support table’s positioning stops line up perfectly with the pendulum impact tester's frame. The HIT pendulum impact tester base plate is constructed with vibration-damping metal casting, and the ratio of its mass to the pendulum mass complies with standard requirements. Three sturdy, lockable leveling-feet provide secure footing and enable horizontal alignment of the instrument. This means that you can be sure of obtaining reliable test results regardless of local conditions.
Intelligent impact testing
Just as the mass of a calibrated weight is engraved on it, each ZwickRoell pendulum carries its data with it in the form of electronically readable pendulum coding.
The pendulum identifies itself to the electronics through standard, type of test, energy capacity, starting angle and other physical data. Also stored in the instrument are data on air and bearing friction. Erroneous measurements are thus eliminated.
Freely selectable starting angles enable optimum test parameters, for example impact speed and energy loss at impact. After the test, the pendulum is automatically caught and returned to its initial position by a motor.
Safety for every application
To protect operators from flying specimen fragments or prevent contact with a falling pendulum ZwickRoell recommends a range of solutions:
During Charpy tests the safety guard on the Charpy fixture ensures that specimen remains stay within the pendulum impact tester.
The swiveling safety housing enables optimum access, for example during Izod tests.
The electrically interlocked safety device eliminates air supply during a test and provides maximum protection from shattering specimens. The pendulum is released by two-handed operation - it is no longer possible to reach into the pendulum impact tester during a test.
testXpert III and instrumentation
ZwickRoell testing software provides a clear visual presentation of all impact characteristics recorded in a results table and graph, allowing you to produce comprehensive statistical evaluations.
Data is easily and safely stored:
- In a report prepared in accordance with the standard
- In a test series contained in testXpert III
- Automatically exported to your database
Instrumented impact testing allows additional information on material characteristic values and properties to be obtained, and fracture mechanics investigations and automated fracture evaluations to be performed. Instrumented pendulums and expanded electronics are available for high-accuracy recording of the high-speed processes involved in breaking through a specimen.
Quick testing at low temperatures
Impact strength is a critical characteristic of the material used at low temperatures. ZwickRoell offers a temperature-conditioning box and magazine for cooling specimens. For testing at low temperatures the specimens are first conditioned in a cooling box. The magazine with the specimens is then attached to the specimen feeder, which is fastened to the HIT pendulum impact tester. This way the specimens can be quickly and conveniently removed and tested.
Plastics Impact Testing Applications
General
Specimens can be loaded in variety of ways by pendulum impact testers.
Charpy tests: ISO 179, ASTM D6110
Izod tests: ISO 180, ASTM D256, ASTM D4812
Tensile impact tests: ISO 8256 Methods A and B, ASTM D1822
Dynstat bending impact tests: DIN 53435
Charpy
Charpy fixtures consist of a heavy cast base. Test-specific accessories, such as supports and anvils, are selected according to the specimen range.
The anvils used, which have a surface finish and radius that can significantly affect the accuracy of the test results, are precision CNC machined and are 100% dimensionally accurate. ZwickRoell does not supply single-part anvils, for which it is difficult to achieve dimensional accuracy. During installation, the location of the anvil relative to the upper anvil is ensured via an optional jig.
As anvils are subject to greater wear than supports, cost-effective replacement of two-part anvils independently of other accessories is available. Quick-change adapter plates ensure that the impact point is matched to the specimen width in the impact direction, while the specimen thickness (vertical direction) is accommodated via suitably dimensioned supports with alignment pins to ensure accurate insertion.
An optional swiveling protective shield can be used with the fixture, and a positioning aid helps to locate the specimen correctly, using either the notch or the front edge of the specimen.
Advantages:
- Quick changing of Charpy fixture
- Precision manufacturing and documented 100% dimensional accuracy control of the bearings
Izod
Two types of impact fixtures can be used: The manual fixture clamps the specimen via a fine-threaded lead screw, This allows clamp-sensitive, soft and hard samples to be clamped sensitively.
The pneumatic fixture is ideal where high throughput is required or temperature-conditioned specimens are to be tested. It also enables excellent reproducibility when clamping-sensitive materials are being tested.
Quick clamping via a switch on the fixture itself minimizes the time from removal of the specimen from the temperature-controlled area to actual testing.
Both fixtures are equipped with a centering unit, which ensures that the specimen is always positioned at notch root level.
Adjustment to suit specimen width in the impact direction is via quick-change inserts with lateral guides.
Advantages:
- Quick specimen centering and gripping
- Fine adjustment of the specimen gripping force
- Quick testing using the pneumatic fixture
- High reproducibility due to the constant gripping force
Tensile impact test
For tensile impact tests the specimen and yoke are aligned in a jig and clamped together.
Depending on the test method in use, the specimen plus yoke are clamped in either the pendulum or the tensile impact fixture.
The appropriate templates are used to set up for the various ISO and ASTM specimen types.
For tests to ISO 8256, Method A, a yoke is attached to the shoulder at one end of the specimen. The other end of the specimen is gripped in the tensile impact fixture. The free end of the specimen plus the yoke is struck off by the pendulum hammer. Yokes are available with masses from 15g to 120g.
For tests to ISO 8256 Method B and ASTM D1822 one end of the specimen is clamped in a specially designed pendulum hammer; a yoke is attached to the other end, which hangs free. In the test the yoke is stopped by the tensile impact fixture, while the pendulum plus specimen continues its travel.
A tensile impact fixture is available for each standard. Yokes are available from 15g to 120 g.
Advantages:
- Quick configuration changes between the two different test methods
- Precise specimen alignment and gripping
Dynstat
HIT pendulum impact testers can also be equipped for Dynstat impact tests according to DIN 53435. A Dynstat fixture and the five standardized pendulums cover the range of applications.
Pendulum impact test on plastics
Standard-compliant testing according to Charpy, Dynstat, and Izod and tensile impact tests, Method A/B with the HIT series of pendulum impact testers—be sure to hit your target with ZwickRoell!
Technical overview
