ASTM D1709

What Is ASTM D1709?

ASTM D1709, Standard Test Methods for Impact Resistance of Plastic Film by the Free-Falling Dart Method, specifies procedures for determining the impact resistance of plastic films and sheets.

The test measures the energy required to cause failure of a specimen when struck by a hemispherical dart dropped from a specified height. Results are typically reported as the dart mass or impact energy corresponding to a statistically determined 50% failure rate.

O dart impact test standard is commonly applied to:

• Polyethylene (PE) films
• Linear low-density polyethylene (LLDPE) films
• Low-density polyethylene (LDPE) films
• High-density polyethylene (HDPE) films
• Multilayer barrier films
• Stretch films
• Shrink films
• Agricultural films
• Medical packaging films
• Pharmaceutical packaging materials
• Industrial protective films

Understanding the ASTM D1709 Test Methods

The standard includes two primary testing methods.

Test Method A

Method A uses:

Parâmetro	Requirement
Dart Head Diameter	38.1 mm
Drop Height	660 mm
Typical Test Range	Approximately 50 g to 6 kg

Method A is commonly used for thinner and lower-impact-resistance films.

Test Method B

Parâmetro	Requirement
Dart Head Diameter	50.8 mm
Drop Height	1520 mm
Typical Test Range	Approximately 300 g to 6 kg

Method B is generally selected for stronger films requiring higher impact energies.

Results obtained from Method A and Method B should not be directly compared because the test conditions differ significantly.

How Does the Dart Drop Test Method Work?

O dart drop test method evaluates the ability of a plastic film specimen to resist failure from a controlled impact.

The basic principle involves:

1. Clamping a specimen securely in a circular fixture.
2. Selecting an appropriate dart weight.
3. Positioning the dart at the specified height.
4. Releasing the dart vertically.
5. Observing whether the specimen fails.
6. Adjusting dart weight according to the testing procedure.
7. Determining the impact failure weight corresponding to a 50% failure probability.

The test simulates real-world impact conditions encountered by packaging materials during handling and distribution.

Staircase Testing Technique

The staircase method is the primary procedure specified in ASTM D1709.

In this approach:

• One specimen is tested at a time.
• The dart weight is increased after a non-failure result.
• The dart weight is decreased after a failure result.
• A constant weight increment is used throughout testing.

This method efficiently identifies the impact level at which approximately half of the specimens fail.

Typical Staircase Sequence

Test Number	Dart Weight	Result
1	300 g	Pass
2	330 g	Pass
3	360 g	Fail
4	330 g	Pass
5	360 g	Fail

The sequence continues until the required number of failures and non-failures is achieved.

Alternative Group Testing Technique

The alternative procedure tests specimens in groups of ten.

For each group:

• One dart weight is selected.
• The percentage of failures is recorded.
• Dart weight is adjusted between groups.

Testing continues until sufficient data points are generated to establish the 50% failure level.

This method is often used in research and material characterization programs.

Equipment Required for ASTM D1709 Testing

A compliant dart drop impact tester should include:

ASTM D1709 Dart Drop Impact Tester from Cell Instruments

Cell Instruments offers a professional dart drop impact tester designed for ASTM D1709 dart impact test for plastic film applications.

Key Features

Especificações técnicas

Item	Especificação
Método de ensaio	ASTM D1709 Method A / Method B (Optional)
Intervalo de teste	Method A: 50–2000 g
	Method B: 300–2000 g
Diâmetro do dardo	Method A: 38 ± 1 mm
	Method B: 50 ± 1 mm
Altura do impacto	660 mm / 1500 mm
Exatidão	0.1 g (0.1 J)
Tipo de braçadeira	Braçadeira pneumática
Fornecimento de gás	0,6 MPa
Tamanho do espécime	>150 mm × 150 mm
Fonte de alimentação	AC 110–220 V, 50 Hz

Related Impact Testing Standards

Organizations often use ASTM D1709 alongside other packaging and film testing standards.

Padrão	Descrição
ASTM D3420	Pendulum impact resistance of plastic film
ASTM D882	Tensile properties of thin plastic sheeting
ASTM D1922	Elmendorf tear resistance
ISO 7765-1	Free-falling dart impact test, staircase method

Choosing the Right Dart Impact Testing Solution

When selecting equipment for ASTM D1709 compliance, laboratories should evaluate:

• Method A and Method B capability
• Automation level
• Result calculation functions
• Data management requirements
• Repeatability and accuracy
• Safety design
• Future testing needs

A properly designed dart drop impact tester enables reliable impact resistance evaluation, supports quality assurance programs, and helps manufacturers develop stronger, more durable plastic film products.