Zwick HIT – A Striking Solution 

Pendulum impact testers for plastics testing—accurate, reliable and ergonomically designed

Together with tensile and flexure tests, Charpy impact tests are the most frequently performed mechanical tests in the polymer industry Zwick's HIT range of pendulum impact testers are available from 5 to 50 joule and offer a solution that combines high precision with cost- effectiveness. 

Key Advantages and Features

  • 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.

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Pendulum impact testing of plastics

Achieve reliable test results with standard-compliant testing to Charpy, Dynstad, Izod, and impact tensile methods A/B with the HIT series of pendulum impact testers

Product Features of HIT Pendulum Impact Testers

Reliable test results

The process of designing a pendulum impact tester for consistently low natural vibrations begins in the vicinity of the specimen, with the pendulums and fixtures.

Zwick uses high-performance carbon materials for its HIT pendulums. These 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.

Intelligent impact testing

Just as the mass of a calibrated weight is engraved on it, each Zwick 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 captured and returned to the starting position by a motor drive.

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 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

The HIT table – a solid foundation

Like a rock among the breakers, the HIT support table stands firm at every impact. Its welded frame guarantees maximum stiffness, while wide-based leveling feet ensure firm, stable support.

The support table’s positioning-stops allow perfect matching to the pendulum impact tester. The massive base section of the HIT pendulum impact testers is a vibration-damping metal casting. Three sturdy, lockable leveling feet provide secure footing and allow for horizontal alignment of the instrument.

All of this means that you can be sure of obtaining reliable test results regardless of local conditions.

Safety for every application

To protect operators from flying specimen fragments or prevent contact with a falling pendulum Zwick has a range of recommended 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. Two-handed operation is required to release the pendulum, eliminating the possibility of reaching into the pendulum impact tester during a test.

Plastics Impact Testing Applications

Pendulum impact testers allow varied loading of specimens. 

  • Charpy tests: ISO 179, ASTM D6110
  • Izod tests: ISO 180, ASTM D256, ASTM D4812
  • Impact tensile tests: ISO 8256 Methods A and B, ASTM D1822
  • Dynstat bending and impact tests: DIN 53435

Charpy

Charpy Tests

Charpy fixtures consist of a massive cast base. Test-specific items such as supports and anvils are selected according to the range of specimens.

Test results are significantly influenced by the roughness and radius of the anvils, which are fully precision CNC manufactured, with 100% measurement. Zwick does not supply single-part anvils, for which it is difficult to achieve dimensional accuracy. The location of the anvil relative to the tup is ensured via an optional jig during installation.

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.

Optionally available for the Charpy fixture are a pivoted safety shield and alignment units to enable correct positioning at the center of impact, using either the notch or the front edge of the specimen.

Advantages

  • Fast fixture changes
  • Precision manufacture of anvils, with documented 100% dimensional accuracy verification

Izod

Izod Tests

Two types of Izod fixture can be used. The manual fixture is equipped with a fine-threaded lead-screw, allowing precisely controlled gripping of soft, hard or clamping-sensitive specimens.

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 to ensure that the specimen is always positioned in the plane of the notch root.

Adjustment to suit specimen width in the impact direction is via quick-change inserts with lateral guides.

Advantages

  • Rapid specimen centering and gripping
  • Fine adjustment of gripping force
  • Fast testing with pneumatic fixture
  • Constant gripping force enables high reproducibility

Impact tensile test

Impact Tensile Tests

For impact tensile 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 impact tensile 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 shoulders at one end of the specimen. The other end of the specimen is gripped in the impact tensile 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 impact tensile fixture, while the pendulum plus specimen continues its travel.

An impact tensile fixture is available for each standard. Yokes are available from 15g to 120g.

Advantages

  • Rapid changeover to either test method
  • Precise specimen clamping and alignment

Dynstat

Dynstat Tests

HIT pendulum impact testers can also be equipped for Dynstat impact tests to DIN 53435. A Dynstat fixture and the five standardized pendulums cover the range of application.

Working Together with testXpert II Testing Software

Evaluations

Expand your options with testXpert II

Zwick testing software provides a clear overview of all recorded impact characteristics in a results table and graph, allowing you to produce comprehensive statistical evaluations.

Store your data simply and reliably:

  • in a report prepared in accordance with the standard
  • in a test series contained in Zwick testing software
  • automatically exported to your database.

How well do you know your material? Learn even more with instrumentation and Zwick testing software. The high data-acquisition rate and automatic identification of the type of failure enable accurate, repeatable, traceable test results.

Instrumentation

Use Zwick's HIT pendulum instrumentation to measure the complete force-deflection diagram during impact and obtain detailed information about your material.

Zwick testing software automatically identifies and records the type of break, speeding up your test sequence and eliminating operator influence.

Technical Overview

Pendulum impact testers are available from 5 to 50 joules.

Up to 5 J

Technical data for HIT5P basic unit

Type

HIT Plus PC version

HIT Pur (stand-alone version)

Item No.

1038012

1038013

Use

with PC

without PC

Potential energy

5

5

J

Dimensions

Overall height, approx.

658

685

mm

Overall width, approx.

680

680

mm

Overall depth, approx.

404

404

mm

Weight

Without fixtures, approx.

70

70

kg

With typical fixtures, approx.

75

75

kg

Test results, numerical

impact energy [%], impact energy [J], impact strength [kJ/m2][1]

impact energy [%], impact energy [J]

Units

SI, metric, Anglo-American

J, ft lbf, %

Control functions

friction and friction correction, vertical pendulum setting, oscillation period

friction and friction correction, vertical pendulum setting, oscillation period

Correction functions

air and bearing friction, kinetic yoke energy (impact tensile test)

air and bearing friction, kinetic yoke energy (impact tensile test)

Interfaces

RS 232, USB

none

Pulse resolution

0,018

0,018

°

Electrical supply

100 ... 240, 50/60, 70

100 ... 240, 50/60, 70

V, Hz, W

  1. Test result impact strength can be called up provided a PC with Zwick testing software is connected. The specimen dimensions are input on the PC or, for example, imported via calipers and Zwick testing software.

Up to 5.5 J

Technical data for HIT5.5P basic instrument

Type

HIT Plus (PC version)

HIT Pur (stand-alone version)

Item No.

1038015

1038014

Use

with PC

without PC

Potential energy

5.5 (4.06 ft Ibf)

5.5 (4.06 ft Ibf)

J

Dimensions

Overall height, approx.

920

920

mm

Overall width, approx.

870

870

mm

Overall depth, approx.

500

500

mm

Weight

Without fixtures, approx.

136

136

kg

With typical fixtures, approx.

150

150

kg

Test results, numerical

impact energy [%], impact energy [J], impact strength [kJ/m2][1]

impact energy [%], impact energy [J]

Units

SI, metric, Anglo-American

J, ft lbf, %

Control functions

friction correction, pendulum vertical position, oscillation period, device data display

friction correction, pendulum vertical position, oscillation period, device data display

Pulse resolution

0,018

0,018

°

Interfaces

RS 232, USB device

none

Electrical supply

100 ... 240, 50/60, 70

100 ... 240, 50/60, 70

V, Hz, W

Compressed air

6, dry, oil-free (required only for accessories operated by compressed air)

6, dry, oil free (required only for accessories operated by compressed air)

bar

  1. If PC with testXpert testing software is connected. The specimen dimensions are input via the PC or, for example, imported via calipers and Zwick testing software.

Up to 25 J

Technical data for HIT25P basic instrument

Type

HIT Plus

HIT Pur

HIT Plus with pendulum lift

Item No.

1038019

1038020

1038018

Use

with PC

without PC

with PC

Potential energy

25 (18.45 ft Ibf)

25 (18.45 ft Ibf)

25 (18.45 ft Ibf)

J

Dimensions:

Overall height, approx.

1170

1170

1170

mm

Overall width, approx.

1180

1180

1180

mm

Overall depth, approx.

500

500

500

mm

Weight

Without test fixtures, approx.

215

215

225

kg

With typical test fixtures, approx.

235

235

255

kg

Test results, numerical

impact energy [%], impact energy [J], impact strength [kJ/m2][1]

Impact energy [%], impact energy [J]

impact energy [%], impact energy [J], impact strength [kJ/m2][1]

Units

SI, metric, Anglo-American

J, ft lbf, %

SI, metric, Anglo-American

Control functions

friction correction, pendulum vertical position, oscillation period, device data display

friction correction, pendulum vertical position, oscillation period, device data display

friction correction, pendulum vertical position, oscillation period, device data display

Pulse resolution

0,018

0,018

0,018

°

Safety device

safety housing left and right

safety housing left and right

Safety housing, electrically interlocked

Interfaces

RS 232, USB

none

RS 232, USB

Electrical supply

100 ... 240, 50/60, 70

100 ... 240, 50/60, 70

100 ... 240, 50/60, 150

V, Hz, W

  1. If a PC with testXpert II testing software is connected, the impact strength test result can be called up. The specimen dimensions are input on the PC or, for example, imported via calipers and testXpert II.

Up to 50 J

Technical data for HIT 50P basic instrument

Type

HIT Plus

HIT Pur

HIT Plus with pendulum lift

Item No.

1038021

1038022

1038017

Use

with PC

without PC

with PC

Potential energy

50 (36.90 ft Ibf)

50 (36.90 ft Ibf)

50 (36.90 ft Ibf)

J

Dimensions:

Overall height, approx.

1170

1170

1170

mm

Overall height, approx.

1180

1180

1180

mm

Overall height, approx.

500

500

500

mm

Weight

Without test fixtures, approx.

215[1]

215[1]

215[2]

kg

With typical test fixtures, approx.

235[1]

235[1]

235[2]

kg

Test results, numerical

impact energy [%], impact energy [J], impact strength [kJ/m2][3]

impact energy [%], impact energy [J]

impact energy [%], impact energy [J], impact strength [kJ/m2][3]

Units

SI, metric, Anglo-American

J, ft lbf, %

SI, metric, Anglo-American

Control functions

friction correction, pendulum vertical position, oscillation period, device data display

friction correction, pendulum vertical position, oscillation period, device data display

friction correction, pendulum vertical position, oscillation period, device data display

Pulse resolution

0,018

0,018

0,018

°

Safety device

safety housing left and right

safety housing left and right

safety housing, electrically interlocked

Interfaces

RS 232, USB

none

RS 232, USB

Electrical supply

100 ... 240, 50/60, 70

100 ... 240, 50/60, 70

100 ... 240, 50/60, 150

V, Hz, W

  1. The testing system possesses the weight required by the standard if bolted to a table permitted for this type (HIT 50) or if attached to a concrete base/base weighing at least 200 kg by means of heavy-duty anchor bolts/screws.
  1. The testing system only possesses the weight required by the standard if bolted to a table permitted for this type (HIT 50) or if attached to a concrete base/base weighing at least 200 kg by means of heavy-duty anchor bolts/screws.
  1. If a PC with testXpert II testing software is connected, the impact strength test result can be called up. The specimen dimensions are input on the PC or, for example, imported via calipers and testXpert II.

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