ASTM C167 Standard Test Methods for Thickness and Density of Blanket or Blanket Thermal Insulation

The standard “ASTM C167 Standard Test Methods for Thickness and Density of Blankets or Blanket Thermal Insulation” published by the American Society for Testing and Materials (ASTM) describes test methods for determining the thickness and density of flexible, felt or woven thermal insulation blankets, rolls or quilts composed of fibrous materials, with or without surface coating or reinforcement.

Accurately measuring the thickness and density of blanket or blanket insulation is crucial for determining its thermal insulation properties. For a given blanket or blanket product, thickness and density are often directly related to its thermal insulation value. These testing methods are crucial for manufacturing quality control to ensure that products maintain their claimed insulation values.

Equipment used in the tests includes:

• Depth gauge: The disc should be made of a suitable, transparent plastic material so the operator can see when it contacts the insulation. The disc should always be perpendicular to the pin and should have a friction device that will grip the pin unless it is intentionally moved. The pin should be of sufficient length for the material being measured.
• Steel ruler graduated in 1 mm intervals.
• Balances with sufficient capacity and precision to weigh the test sample with an accuracy of plus/minus 0,5 percent.

A test sample should consist of a representative roll or bundle of insulation. For bundles containing 20 or more layers of insulation, five layers of insulation should be selected. Otherwise, a three-layer insulation or five-layer insulation selection technique can be used. Doubled insulation layers count as two layers of insulation for the purposes of the selection and selection method. In the three-layer insulation method, the middle insulation and the second insulation are selected from each end of the bundle. In the five-layer insulation method, the bundle is divided into five blanket groups of as equal a number as possible. The first blanket is selected from each group. Only one blanket should be selected from the two end blankets within the bundle. Blankets up to 122 cm plus/minus 0,63 cm are cut.

When sampling from cut rolls, five blankets are cut to a roll width of 122 cm plus/minus 0,63 cm long. One blanket is cut from the center of the roll, two blankets are cut from the ends of the roll, and a fourth and fifth blankets are cut at quarter-points along the length. For blankets wider than 61 cm, each of the five blankets is cut to a roll width of 61 cm plus/minus 0,63 cm and a length of 122 cm plus/minus 0,63 cm.

Before unwrapping the material, the entire roll is weighed to the nearest 0,11 kg. Two methods can be used to obtain the exact roll weight. The first method removes the insulation product from its packaging before weighing. The material expands and may expand slightly; care must be taken to ensure the entire roll is weighed accurately. The second method weighs the packaged insulation product, then weighs only the packaging material. The packaging material weight is subtracted from the packaged product weight to obtain the net material weight.

ASTM C167 is a widely accepted standard. It includes test methods for determining the thickness and density of blanket or quilt-type thermal insulation materials, such as fiberglass or mineral wool. These materials are widely used in residential, commercial, and industrial buildings to improve energy efficiency and thermal comfort. The primary objective of this standard is to provide a consistent and accurate methodology for measuring two key physical properties of thermal insulation:

• Thickness: The dimension perpendicular to the surface of the insulation.
• Density: The mass of the insulation per unit volume (usually in kilograms per cubic metre).

These features are important in terms of:

• Ensuring insulation performance meets design specifications.
• Supporting energy efficiency certificates and building code compliance.
• Comparing products from different manufacturers

ASTM C167 applies specifically to flexible fibrous insulation materials supplied as blankets or quilts. It is not intended for use with rigid board insulation or loose-fill products. This standard is divided into two main test methods:

• Method A: Thickness by compression of specimens: This method is used when compression is expected during assembly. The specimen is placed under a standard weight, and the thickness is measured after compression. This reflects the in-service thickness, which affects thermal resistance.
• Method B: Thickness without compression: This method is used when the material is installed without compression. Thickness is measured under very light loading to prevent material deformation and ensure the natural fullness of the insulation.

According to this standard, density is calculated using the formula: density = mass / volume. Here, mass is determined using a precision balance. Volume is the product of the measured thickness and the surface area of ​​the test specimen.

Common applications of this standard include:

• Residential wall and attic insulation
• Commercial heating, ventilation and air conditioning (HVAC) system duct wrapping
• Industrial pipe or equipment insulation

This standard is important for the following reasons:

• Ensures consistent product quality: This standard provides standardized test methods for thickness and density, allowing manufacturers and quality control laboratories to consistently measure insulation properties. This prevents batch-to-batch variation and ensures products meet specifications.
• Supports accurate thermal performance ratings: Thickness and density directly affect the thermal resistance of insulation materials. The resistance value determines how well the insulation resists heat flow and is important for reducing energy loss in buildings. This standard ensures these physical measurements are accurate, ensuring values ​​are not over- or under-specified.
• Compliance with building codes and energy regulations: Most building codes and energy efficiency standards require materials to meet specific performance criteria. This standard helps verify insulation products' compliance with these standards by providing reliable measurements. It also supports certification programs that require third-party testing or verification.
• Fair comparison between products and manufacturers: Standardized testing allows architects, engineers, and contractors to objectively compare different insulation products. It also allows buyers to make informed decisions based on performance metrics, not marketing claims.
• Optimizes installation and design: Knowing the actual thickness and density of duvet or blanket insulation allows:
  • Avoiding excessive compression which may reduce thermal efficiency.
  • Ensuring insulation fits snugly in wall cavities, ceilings or HVAC systems.
• Improves safety and performance: Density can affect not only thermal performance but also fire resistance, sound control, and moisture absorption. This standard provides baseline data that can be used to evaluate other critical performance areas.
• Reduces the risk of construction defects or energy loss: If insulation is sized incorrectly or the density is incorrectly specified, air gaps or thermal bridges can occur. This can also lead to energy waste.

As a result, ASTM C167 is a fundamental standard in the construction and insulation industry, ensuring blanket insulation is accurately measured for thickness and density. These values ​​are critical in determining how well a product performs in real-world conditions and help maintain consistent quality across insulation materials.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, has a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with ASTM C167 Standard Test Methods for Thickness and Density of Blanket or Thermal Insulation.