Drop Weight Impact Tester

What Does the Test Evaluate?
A falling weight applies a sudden, concentrated impact to the film. The operator records whether the specimen fails under the selected conditions. A series of tests using defined mass adjustments can then establish the impact failure weight required by the applicable method. For ASTM D1709, the result represents the dart mass associated with an estimated 50% specimen failure rate at the specified test conditions. This provides a practical basis for comparing film impact resistance when specimen preparation and testing conditions remain consistent.

The result is specific to the method used. It does not independently establish tensile strength, seal strength or the performance of a complete filled package.

How the Drop Weight Impact Tester Works
A film specimen is positioned across the clamping opening and secured without wrinkles or unintended stretching. The selected dart assembly is held above the specimen at the required height. Releasing the dart allows gravity to drive the impact. After each drop, the operator examines the specimen and records failure or non-failure according to the test method. Further specimens are tested using the prescribed sequence and mass adjustments. The drop counter records trials; it should not be confused with an impact-force or absorbed-energy measurement system. Direct measurement of those quantities requires suitable instrumentation.

Applications in Film Manufacturing and Conversion
The instrument can support quality evaluation of suitable flexible films, including polyethylene packaging films, polypropylene films and multilayer structures where the selected method applies.

Typical uses include:

• Comparing production batches made to the same film specification.
• Investigating changes following resin or formulation adjustments.
• Evaluating the effect of process changes on impact performance.
• Comparing incoming film supplies under an agreed procedure.
• Supporting development trials involving alternative film structures.
• Assessing whether a material meets a customer’s specified impact requirement.

Material suitability depends on specimen behaviour, thickness, fixture compatibility and the chosen test method. Rigid sheets, pipes and complete cartons require separate evaluation of the appropriate equipment.

ASTM D1709: Selecting the Correct Test Method
ASTM D1709 includes Methods A and B, which use different dart-head dimensions and drop heights. The method should be selected from the material specification or customer requirement. Results from different methods should not be treated as directly interchangeable. Comparisons also require attention to film thickness, conditioning, dart geometry and other prescribed test conditions. When requesting a quotation, identify the method you need rather than specifying only the standard number. This allows the supplied dart, weights and height arrangement to be checked against the intended procedure.

Recommended Testing Workflow

1. Identify the requirement: Select the standard, method and acceptance criteria.
2. Prepare specimens: Follow the sampling and conditioning requirements, keeping specimen identification clear.
3. Record thickness: Document thickness so that differences between samples can be assessed.
4. Check the setup: Verify dart condition, mass, height, alignment and clamping.
5. Perform the impact: Release the dart and inspect the specimen using the method’s failure criteria.
6. Continue the test series: Use fresh specimens and the prescribed mass-adjustment sequence.
7. Calculate and report: Determine the required result and retain the individual observations.

This workflow is an overview. Operators should follow the applicable standard and the supplied operating instructions for the complete procedure.

Understanding and Comparing Results
Under equivalent test conditions, a higher impact failure weight generally indicates greater resistance to the specified falling-dart impact. Meaningful comparisons depend on controlling the variables that influence the result.

A useful test record should include:

• Material identification, batch and film structure.
• Specimen thickness and conditioning details.
• Standard and test method.
• Dart configuration, drop height and mass increments.
• Individual failure and non-failure observations.
• Calculated result, test date and operator.

Unexpected variation should prompt checks of specimen uniformity, clamping, dart condition and setup before conclusions are drawn about the material.

Drop Weight Impact Tester Price and Configuration
The quotation depends on the selected method, supplied dart assemblies, weight set, accessories and documentation requirements. To obtain a suitable offer, share the material type, film thickness, required standard, test method and expected impact range. Also confirm electrical and compressed-air requirements, whether a compressor is included, and which accessories are supplied as standard.

Pacorr can review your application and discuss the appropriate configuration before finalising the quotation.

Frequently Asked Questions

Is a drop weight impact tester the same as a dart impact tester?
For flexible-film testing, a falling dart is one form of drop-weight impact testing. However, the broader term also covers machines designed for other specimen types. Select equipment by its method, fixture and specimen compatibility.

Does the machine display impact strength automatically?
The published configuration includes a trial counter. Calculation, automatic result reporting and software functions should be confirmed separately for the model being supplied.

Can this instrument test PVC pipes or rigid components?
Compatibility should not be assumed. Pipe and rigid-component testing can require different supports, strikers, impact capacities and methods. Share the specimen and standard for technical assessment.

Why can two films of the same thickness give different results?
Resin composition, processing conditions, film orientation, layer structure and local defects can affect impact behaviour. Thickness alone does not determine the result.

Does a higher result guarantee better packaging?
It indicates better resistance under the selected impact conditions. Packaging selection may also require seal, tensile, puncture, friction and complete-package testing.

How should an acceptable result be decided?
Use the approved material specification, customer requirement or validated internal acceptance limit. One universal passing value is not suitable for every film.

What information is needed for a quotation?
Provide the material, thickness range, required standard and method, expected testing range, accessory requirements and installation location.

Discuss Your Film-Testing Requirement
Contact Pacorr to review specimen suitability, configuration and pricing.

Phone: +91-8882149230
Email: info@pacorr.com
Website: www.pacorr.com