ISO 845 Cellular Plastics & Rubber Apparent Density Testing | UnitedTest Density Balance Manufacturer

Information on the most widely used ASTM standards within the materials testing industry

Descriptions of the most prominent lSO standards within the materials testing industry

Standards including EN, DIN, JlS, and more

Mechanical testing of polymer materials in the automotive industry is directly related to the safety of components and the reliability of the entire vehicle. UnitedTest can cover mechanical performance testing for automotive interior and exterior parts, as well as functional components, adapting to automaker standards and providing comprehensive testing solutions including tensile, impact, and fatigue tests.

Mechanical testing in the battery industry determines the tensile and puncture resistance of core components such as separators and electrodes, directly affecting battery safety and cycle life. UnitedTest can cover full-dimensional mechanical testing of battery materials, compatible with national and international standards, and provide customized testing solutions.

Mechanical testing in the consumer goods industry determines product durability and safety, such as impact resistance for toys and fatigue resistance for home appliances, making it core to compliance and quality. UnitedTest can cover mechanical tests for all categories of consumer goods, including tensile, impact, and hardness tests, compatible with national and international standards, and offers customized testing solutions.

In the field of medical and biomedical sciences, mechanical testing determines the safety and compatibility of implanted devices and biomaterials, making it a core part of regulatory approval. UnitedTest can cover a full range of tests including tensile, fatigue, and wear tests, compatible with national and international standards, and provides customized biomechanical testing solutions.

Material strength is a course that most engineering fields are required to study in university education. This interesting course is very practical and makes use of testing equipment in the materials laboratory.

Mechanical testing of industrial products and components is essential to ensure their load-bearing, fatigue resistance, and impact resistance, directly preventing production accidents and ensuring stable operation of equipment. UnitedTest can cover a full range of tests including tensile, hardness, and fatigue, complying with national and international standards, and provides customized industrial mechanical testing solutions.

Mechanical testing in the plastic pipe industry determines ring stiffness, impact resistance, and tensile performance, directly preventing pipe bursts and deformation risks. UnitedTest can cover full-dimensional mechanical testing of pipes, complies with ISO,ASTM,EN et.c, international standards, and provides customized testing solutions.

In the construction engineering and building materials industry, mechanical testing determines the compressive and tensile properties of materials such as concrete and steel, which is core to ensuring the safety and durability of buildings. UnitedTest can cover the full range of building material mechanical tests, complies with ISO, ASTM international standards, and provides customized testing solutions for compressive, tensile, and other properties.

Mechanical testing in the food and beverage industry involves the compressive and tensile performance of packaging and the safety of food texture, directly ensuring storage, transportation safety, and the eating experience. UnitedTest can cover all-dimensional mechanical testing for packaging and food texture, comply with national and international standards, and provide customized testing solutions.

Mechanical testing in the packaging industry determines the packaging's resistance to compression, impact, and tension, directly ensuring the safety of contents during storage and transportation. UnitedTest can cover comprehensive mechanical testing for packaging, complying with ISO, ASTM Standards, and provides customized testing solutions for compression, drop, tear, and more.

Mechanical testing in the transportation industry concerns the load-bearing and fatigue resistance performance of core components such as vehicles, tracks, and containers, directly ensuring transport safety and equipment durability. UnitedTest can cover mechanical testing for all types of transportation materials, complying with national and international standards, and provides customized testing solutions including tensile, fatigue, and impact tests.

Metallurgical testing examines the properties of metallic materials to determine if a particular metal is appropriate for its intended use.

Testing of polymer materials covers mechanical, thermal, and chemical properties, verifying strength, heat resistance, composition, and ensuring product quality and compliance.

UnitedTest offer world-class testing solution in testing for polymeric materials, including elastomers, thermoplastics, composites, coatings, and structural adhesives in a variety of industries.

Testing of rubber and elastomers is used to assess the various properties and performance of materials under different conditions. This is crucial for ensuring the safety, functionality, and quality of rubber and elastomer products used in industries such as automotive, construction, consumer goods, and aerospace.

Conduct adhesive testing using various testing methods to determine their performance and characteristics in applications across multiple industries such as aerospace, automotive, construction, packaging, industrial, medical, and energy, thereby supporting application development and quality assurance.

UnitedTest supply machine and testing solution for tension, compression, fracture toughness, direct shear, triaxial and ultrasonic velocity are common concrete and rock testing applications.

UnitedTest has helped a number of companies involved in the wood, paper, cardboard, and corrugated industry with their testing needs. Our materials testing systems are capable of testing raw materials, components, and finished products.

UnitedTest testing system is trusted by leading medical device manufacturers, universities, and medical research laboratories worldwide. Whether testing tissues or bioresorbable materials, stents, or sutures, UnitedTest offers a variety of single-actuator and dual-actuator systems to meet your biomedical testing needs.

Mechanical testing in the textile fabric industry determines core properties such as fabric tensile strength, tear resistance, and wear resistance, directly affecting product durability and safety. UnitedTest can cover comprehensive mechanical tests for textiles, complying with national standards / ISO standards, and provides customized testing solutions including tensile, tear, and puncture tests.

The mechanical testing of industrial components directly determines the load-bearing, fatigue resistance, and wear resistance of the parts, helping to avoid equipment failure risks. UnitedTest can cover a full range of tests including tensile, hardness, and fatigue, is compatible with ISO/ASTM/GB standards, and provides customized mechanical testing solutions for industrial components.

Mechanical testing in the glass-ceramics industry determines core properties such as flexural strength, hardness, and fracture toughness, directly helping to avoid brittleness and failure risks. UnitedTest can cover comprehensive testing for flexural strength, hardness, and fracture toughness, compatible with national and ISO/ASTM standards, and provides customized testing solutions.

Tensile test evaluates material resistance to stretching, measuring strength/elongation critical for quality control. UnitedTest offers universal tensile testers (10-600KN) compliant with ASTM/ISO standards, providing tailored solutions for metals, polymers, medical & industrial materials.

Compression test assesses material resistance to compressive loads, measuring strength/deformation critical for quality validation. UnitedTest offers compression testing machines compliant with ASTM/ISO standards, providing tailored solutions for concrete, plastics, metals and industrial components.

Flexural & Bend tests evaluate material resistance to bending forces, measuring strength, stiffness and ductility for quality assurance. UnitedTest provides flexural testing machines (3-point/4-point bend) compliant with ASTM/ISO standards, offering tailored solutions for composites, plastics, metals and construction materials.

Torsion Test evaluates material resistance to rotational forces, measuring torsional strength/ductility critical for fasteners, insulators, shafts. UnitedTest offers torsion testers compliant with ASTM A938/ISO 16047, providing tailored solutions for automotive, aerospace, fastener industries.

Fatigue Test assesses material durability under cyclic loading, critical for predicting service life of industrial components. UnitedTest offers fatigue testing systems (axial/bending/torsion) compliant with ASTM E466/ISO 12106, providing tailored solutions for automotive, aerospace and manufacturing sectors.

Peel Test measures material adhesion strength by evaluating resistance to peeling forces, critical for adhesives, films, packaging. UnitedTest offers peel testers compliant with ASTM D903/ISO 8510, covering 90°/180° peel tests, and tailored solutions for packaging, automotive, textile industries.

Impact Test evaluates material resistance to sudden shock loads, critical for assessing toughness and fracture risk. UnitedTest offers impact testers (Charpy/Izod/fall weight) compliant with ASTM E23/ISO 148, providing tailored solutions for metals, plastics, glass and industrial components.

Tear & Shear Test evaluates material resistance to tearing and shearing forces, measuring critical strength parameters for quality control. Tear tests (Elmendorf/trouser/trapezoidal) assess resistance to crack propagation in films/fabrics, while shear tests measure resistance to parallel forces in joints/bolts. UnitedTest provides universal testing machines (10KN-600KN) with specialized fixtures for both tests, compliant with ASTM D624/D3164 and ISO standards, serving automotive, packaging and construction industries.

Hardness test measures material's resistance to permanent indentation, critical for quality control. UnitedTest offers universal hardness testers (Rockwell/Brinell/Vickers) compliant with ASTM/ISO standards, plus tailored hardness testing solutions for diverse industrial needs.

Biaxial/triaxial tests evaluate material performance under multi-axis loads, critical for biomaterials, metals and composites. UnitedTest provides compliant testing machines (ASTM/ISO) for planar biaxial, static/fatigue triaxial tests, with tailored solutions for industrial & biomedical needs.

Friction and wear tests assess material resistance to friction, abrasion and wear, critical for industrial material performance validation. UnitedTest offers tribometers compliant with ASTM G99/ISO standards, covering pin-on-disk, four-ball tests, and tailored friction & wear testing solutions for diverse industries.

Pressure test evaluates material/component resistance to static/dynamic pressure, critical for sealing, strength and safety validation. UnitedTest offers pressure testing machines compliant with ASTM/ISO standards, covering burst, hold-pressure tests, and tailored solutions for industrial, automotive & medical sectors.

Fire test assesses material flammability, heat resistance and fire-retardant performance, critical for safety compliance across industries. UnitedTest offers fire testing equipment compliant with ASTM/ISO/UL standards, providing tailored fire test solutions for building materials, plastics and industrial components.

Non-destructive Test (NDT) evaluates material/component integrity without damage, critical for safety & quality across industries. UnitedTest offers ultrasonic/X-ray/magnetic particle NDT equipment compliant with ASTM/ISO standards, plus tailored NDT solutions for aerospace, automotive & manufacturing sectors.

ISO 845 Cellular Plastics & Rubbers Apparent Density Tester | UnitedTest

ISO 845 defines laboratory test methods to measure apparent overall density and apparent core density for cellular plastics and foamed rubbers, distinguishing skin-included and skin-free core density values. UnitedTest manufactures ISO 8455 compliant density testing machines for foam and cellular material quality control.

ISO 845 is an international standard dedicated to cellular plastics and rubber materials, outlining uniform laboratory procedures for determining apparent overall density and apparent core density of foamed polymer and rubber products. The standard clearly differentiates two key density parameters: apparent overall density, which accounts for mould-formed surface skins on foam specimens, and apparent core density, tested after full removal of all mould-generated surface layers.

For skinless cellular materials with no mould-formed surface structure, the overall density classification is not applicable, ensuring accurate and standardized density evaluation for all types of foamed plastics and rubbers. This testing method is widely used in foam material manufacturing, packaging production, automotive foam component inspection, construction cellular material certification and polymer material R&D, ensuring consistent material porosity, structural uniformity and product quality.

UnitedTest designs and manufactures high-precision ISO 845 cellular material density testing machines. Our professional testing equipment delivers accurate, repeatable apparent density and core density test results, fully complying with ISO 845 standard requirements for industrial quality inspection and laboratory material qualification.

Test Principle

The test follows the fundamental density definition: density = mass / volume.

1. Measure specimen mass by weighing.

2. Calculate specimen volume from its geometric dimensions.

3. Compute apparent density with formula:

ISO 845 Cellular Plastics

Test Specimen Requirements

Specimen geometry shall allow easy volume calculation (regular block‑shaped preferred). Cutting must not distort the original cellular microstructure.

Minimum total specimen volume: 100 cm³. Specimen should be as large as feasible given sample and instrument limits.

For rigid foams with surface skins: the skin‑area‑to‑volume ratio of test specimens must match that of the original bulk sample when testing apparent overall density.

Quantity: Minimum five valid specimens for each test series. A finished manufactured article may serve as the test sample if its total mass and volume can be precisely measured.

Equipment required for ISO 845 Cellular Plastics & Rubber Apparent Density Testing

Balance

capable of weighing specimen mass with accuracy of 0.1 %; weighing reading accuracy for specimen is 0.5 % during practical test operation

ISO 845 Cellular Plastics

Dimension‑measuring instruments

complying with ISO 1923 for linear‑dimension measurement of cellular materials

Auxiliary items

cutting tools (without deforming cell structure), desiccator for dry‑condition conditioning, standard‑atmosphere environmental chamber for specimen conditioning

Key Test Parameters & Stipulations

Specimen minimal volume: 100cm^3;

minimum specimen count: 5 pcs

Balance accuracy requirement: mass resolution 0.1 % capacity accuracy; practical weighing tolerance 0.5 % of reading.

Reporting rule: mean density rounded to nearest 0.1kg/m^3; standard deviation expressed to two significant figures.

Details Test Procedures

Dimension measurement: Measure each dimension in millimetres according to ISO 1923. Take at least three independent readings per dimension; for rigid board‑type cellular materials, take minimum five readings across central regions. Compute dimension averages and calculate specimen volume from mean dimensions.
Weighing: Weigh each conditioned specimen, record mass in grams with 0.5 % accuracy requirement.
Density calculation: Compute density for every specimen using the given formula. Calculate the arithmetic mean density of all specimens and round mean result to nearest 0.1kg/m^3. Apply buoyancy correction for very‑low‑density foams when necessary.
Statistical computation: Calculate estimated standard deviation s of the dataset and report to two significant figures using stipulated formula.
Test report compilation: record all mandatory items specified in clause 9 of ISO 845:2006, including standard reference, material identification, conditioning climate, skin status, specimen defects, individual results, mean density, standard deviation, buoyancy correction status and any deviations from test protocol.

Industrial Application Fields

ISO 845 applies broadly to rigid, semi‑rigid and flexible cellular plastics and cellular rubbers (foamed polymers). Typical industries include:

1. Building & construction: thermal‑insulation foams (extruded polystyrene, polyurethane foam boards).

2. Automotive industry: lightweight cellular rubber and plastic components, acoustic‑absorption foams.

3. Packaging industry: protective cushioning foams.

4. Household goods: foam padding, cellular rubber products.

5. Aerospace: lightweight cellular structural foams.

Note: for complex irregular‑shaped finished parts, buoyancy‑based alternative measurement is suggested instead of ISO 845 geometric‑volume method.

Related standard:

ISO 845	Cellular plastics and rubbers - Determination of apparent density
GB/T 6343	Cellular plastics and rubbers - Determination of apparent density
ASTM D1622	Standard Test Method for Apparent Density of Rigid Cellular Plastics
ISO 1183-2	Plastics. Methods for determining the density of non-cellular plastics-Density gradient column method
JIS K 7112	Plastics -- Methods of determining the density and relative density of non-cellular plastics
ASTM D3574	flexible cellular urethane foams, includes density among broader foam properties.

Importance of the ISO 845 Apparent‑Density Test

Apparent density is one of the most fundamental performance indicators for cellular polymer materials:

1. Density strongly correlates with critical functional performances of foams: thermal insulation capacity, mechanical strength (compression, tensile property), resilience, acoustic damping and water‑absorption behaviour. Lower‑density foams normally deliver better thermal insulation yet reduced mechanical strength; higher‑density foams provide enhanced structural robustness at higher material cost and weight.

2. Distinguishing between apparent overall density (with skin) and apparent core density (skin‑removed) eliminates bias caused by hard dense surface skins generated in moulding/extrusion, enabling fair comparison of intrinsic core‑foam properties among different batches or suppliers.

3. Provides unified global laboratory test protocol, ensuring repeatability within‑lab and reproducibility between‑labs for quality‑control, incoming‑material inspection, product specification verification and research‑development of cellular plastics and rubbers.

4. Supports material formulation optimisation and manufacturing‑process tuning, helping manufacturers stabilise foam quality and meet end‑product specification requirements in construction, automotive, packaging and other sectors.

Keywords: ISO 845 cellular plastics density tester,foamed rubber apparent density test machine,cellular material core density test rig,mould skin foam density testing equipment,polymer foam overall density analyzer,industrial foam material quality control tester,packaging foam density verification apparatus,automotive cellular component density tester,construction foam polymer material test system,skin-free foam core density measurement instrument,foamed rubber physical property tester,cellular polymer laboratory qualification machine

Analytical density balance is a precise measuring instrument that uses Archimedes' principle. It's mainly used to measure the density of solids, liquids, floating objects, or irregularly shaped items and is applied in fields like electronics, rubber, chemical industry, and research.

Electricity hot blast drying oven is mainly used to measure the dimension change of plastic material after heating, suitable for plastic pipe, plastic sheet etc. ,

Constant temperature and humidity test chamber Equipment for testing the performance of materials in various environments and testing various materials heat-resistant, cold-resistant, dry-resistant, moisture resistance.

Q1: What is ISO 845 test used for?

A1: ISO 845:2006 measures apparent overall density and apparent core density for cellular (foamed) plastics and rubbers. Apparent overall density includes mould‑formed surface skin; apparent core density excludes skin by trimming all outer skin layers off specimens. It applies to rigid, semi‑rigid and flexible foam materials used in construction, automotive, packaging and other sectors.

Q2: Why is ISO 845 apparent density test important for cellular materials?

A2: Density is a fundamental indicator closely linked to thermal insulation, compression strength, cushioning performance, acoustic absorption and material cost of foams. Lower‑density foam usually brings better thermal insulation but lower mechanical strength; higher‑density foam gives stronger mechanical properties with higher weight and material cost. The test enables consistent quality control, incoming‑material inspection, R&D formulation tuning and cross‑lab comparable data worldwide. Distinguishing overall vs core density removes bias caused by dense mould skin.

Q3: What is the difference between apparent overall density and apparent core density in ISO 845?

A3:

Apparent overall density: density of specimen including mould‑generated surface skin. When cutting specimens from rigid foam blocks, skin‑area‑to‑volume ratio of specimen shall match original product sample.
Apparent core density: density measured after fully removing all mould‑formed skin layers, reflecting intrinsic property of inner foam matrix. If the material has no mould‑formed skin, “apparent overall density” term is not applicable.

Q4: How many specimens are required for ISO 845 test? What is specimen volume requirement?

A4: Minimum 5 test specimens per test group. Each specimen’s total volume shall be at least 100 cm³. Specimen shall be regular‑shaped for easy volume calculation, cutting shall not deform original cell structure. Manufactured finished articles can serve as test samples if mass and volume can be accurately measured.

Q5: When do I need buoyancy correction for ISO 845 testing?

A5: Buoyancy correction is required for low‑density closed‑cell foams below 15 kg/m³. Air buoyancy will make measured mass lighter than real mass and bring negative error. You need add mass of displaced air into calculation, and record temperature‑pressure‑humidity in test report.

Q6: Can ISO 845 be used for complex irregular‑shaped foam parts?

A6: ISO 845 geometric‑volume method is best suited for regular‑geometry specimens. For complex‑shape finished articles, standard suggests using alternative buoyancy / immersion volume‑measurement method instead of ISO 845 direct‑dimension‑calculation procedure.

Q7: What common errors cause bad ISO 845 test results?

A7:

Specimen cutting deforms foam cell structure.
Specimen volume less than 100 cm³ or insufficient number of specimens (<5).
Incomplete / wrong conditioning (too‑short waiting time after manufacturing, wrong temperature‑humidity).
Skin‑to‑volume ratio mismatched for overall‑density testing of rigid foam.
Neglect buoyancy correction for ultra‑low‑density closed‑cell foam (<15 kg/m³).
Too‑few dimension readings (ISO 845 requires ≥3 readings per dimension; ≥5 readings for rigid board‑form foam central area).

Q8: Why choose ISO 845 Foam Density Tester | Cellular Plastics & Rubber Apparent Density Machine from UnitedTest?

A8: UnitedTest is professional manufacturer of ISO 845 apparent density test equipment for cellular plastics and rubbers. Our foam density testing systems comply with ISO 845:2006, ISO 1923 and ISO 291 standards for lab quality‑control, R&D and third‑party inspection of rigid, semi‑rigid and flexible foams.

UnitedTest designs and manufactures complete testing solutions for ISO 845:2006 Cellular plastics and rubbers — Determination of apparent density. Our integrated foam apparent‑density test systems help material laboratories, foam producers, building‑insulation factories, automotive‑component suppliers and packaging manufacturers perform reliable apparent‑overall‑density and apparent‑core‑density measurement for foamed plastics and cellular rubbers.

Built to satisfy ISO 845 requirements, our test set‑ups combine high‑precision analytical balance, standardized dimensional‑measuring modules, specimen‑processing accessories and configurable data‑reporting software. The system supports core‑density (skin‑removed) and overall‑density testing, includes built‑in buoyancy‑correction calculation for ultra‑low‑density closed‑cell foams below 15 kg/m³, and auto‑generates test‑report templates matching ISO 845 test‑report requirements.

All our ISO 845 test instruments follow normative references ISO 1923 (linear‑dimension measurement) and ISO 291 (conditioning atmospheres). They are widely deployed for polyurethane foam, EPS/XPS insulation board, EVA cellular rubber, packaging cushion foam and lightweight automotive foam component quality verification.

As an experienced material‑testing‑equipment manufacturer, UnitedTest supplies standard ISO 845 density‑testing kits and provides custom‑configuration services according to customer laboratory conditions, sample‑size range and reporting needs. We deliver full‑set after‑sales service including installation guidance, operation training, instrument calibration support and long‑term technical assistance for global customers.

We offer customization to meet your specific needs. Our expert team will collaborate with you to develop the perfect product for you