Vacuum forming is a manufacturing process in which a sheet of plastic is heated to a pliable forming temperature, formed to a specific shape in a mold, and trimmed to create a finished product. There are several common standards and specifications that are used in the vacuum forming process, including:
ASTM D4703-17: Standard Guide for Testing Flat-Plate Photovoltaic (PV) Modules and Panels Using a Solar Simulator
ASTM D648-14: Standard Test Method for Deflection Temperature of Plastics Under Flexural Load in the Edgewise Position
ASTM D790-17: Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials
ASTM D955-12(2017): Standard Test Method for Warpage of Extruded Plastic Shapes
ASTM D946-19: Standard Test Method for Impact Resistance of Plastic Film by the Free-Falling Dart Method
ASTM D1598-15: Standard Test Method for Time-to-Failure of Plastic Pipe Under Constant Internal Pressure
ASTM D5947-18: Standard Guide for Vacuum Forming Plastics
ISO 9073-1:2010 Plastics — Methods of test for moulding and extrusion — Part 1: General requirements
ASTM D638-14: Standard Test Method for Tensile Properties of Plastics
ASTM D256-17: Standard Test Methods for Determining the Izod Pendulum Impact Resistance of Plastics
ASTM D1822-18: Standard Test Method for Tensile Properties of Plastics by Use of Microtensile Specimens
ISO 294-4:2011 Plastics — Determination of tensile properties — Part 4: Test conditions for mouldings and extrusions
These standards and specifications provide guidelines for testing and evaluating the dimensional tolerances, surface finish, and material properties of vacuum formed parts. It is important for manufacturers to adhere to these standards in order to ensure that the parts produced meet the required specifications and can function as intended in their intended applications.
ASTM D4703-17, Standard Guide for Testing Flat-Plate Photovoltaic (PV) Modules and Panels Using a Solar Simulator, is an industry standard developed by the American Society for Testing and Materials (ASTM) that specifies guidelines for testing the performance of flat-plate photovoltaic (PV) modules and panels using a solar simulator. This standard is applicable to all types of flat-plate PV modules and panels, including crystalline silicon, thin-film, and concentrator PV.
The standard covers procedures for measuring the spectral response, electrical performance, and thermal characteristics of PV modules and panels, as well as guidelines for reporting the test results. It also provides specifications for the solar simulator itself, such as the spectral irradiance distribution and the size and position of the test area.
One of the key aspect of this standard is the requirement of uniform illumination over the entire test area, and proper conditioning and stabilization of the modules or panels prior to testing to prevent variations in measurement results. The standard also provides guidelines for the measurement of performance parameters such as the short-circuit current, open-circuit voltage, and power output.
This standard provides a useful tool for manufacturers and researchers to evaluate the performance of their PV modules and panels and to make comparisons between different products. It also allows for consistency in testing procedures, so that performance results can be compared between different laboratories and manufacturers.
It is worth noting that this standard is not limited to vacuum forming, it provide guidelines for testing PV modules and panels using solar simulator, vacuum forming is a manufacturing process that is commonly used in the production of PV modules and panels, and the dimensional tolerance, surface finish and material properties are crucial for the performance of PV modules and panels.
ASTM D648-14, Standard Test Method for Deflection Temperature of Plastics Under Flexural Load in the Edgewise Position, is an industry standard developed by the American Society for Testing and Materials (ASTM) that specifies a procedure for determining the deflection temperature of plastics under flexural load. The deflection temperature is the temperature at which a specified deflection occurs under a specific load.
This standard applies to plastics in the form of molded test specimens, and it is intended to provide a measure of the heat distortion resistance of the material. This test method is suitable for plastics that soften and flow when heated, such as thermoplastics, and it is not suitable for thermosetting plastics or reinforced plastics.
The test procedure involves heating a test specimen, which is supported on two supports, and applying a load at the center of the specimen. The load and the temperature are both increased until the specified deflection is reached. The temperature at which the deflection occurs is recorded as the deflection temperature.
This standard is widely used in the vacuum forming industry, especially when working with thermoplastics. It is useful for determining the heat resistance of the material, which is an important characteristic in vacuum forming because the plastic sheet is heated to a high temperature in order to be formed into a specific shape. A material with a high deflection temperature can withstand the high temperatures better, and will have less distortion and warpage, which is important for achieving tight tolerance and good surface finish. This information can also be used by manufacturers to determine the suitability of different materials for different applications and to make comparisons between different products.
In addition to its use in vacuum forming, this standard is also commonly used in other industries such as automotive, electrical and electronic, packaging, and more. It provides a consistent way to measure the heat distortion resistance of plastics, which can be used to determine material selection, evaluate the quality of the finished product, and ensure the product meet the requirement.
ASTM D790-17, Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials, is an industry standard developed by the American Society for Testing and Materials (ASTM) that specifies procedures for determining the flexural properties of plastics and electrical insulating materials. Flexural properties refer to the ability of a material to bend or flex without breaking under a specific load. These properties are important in the vacuum forming industry because the plastic sheet is bent or flexed to conform to the shape of the mold during the forming process.
This standard applies to both unreinforced and reinforced plastics and electrical insulating materials in the form of test specimens, including but not limited to, sheets, plates, rods, tubes and molded shapes. The standard provides two test methods for measuring flexural properties: the three-point bending test and the four-point bending test. The three-point bending test is typically used for thin materials and the four-point bending test is typically used for thicker materials. Both methods involve applying a load to the center of the specimen while it is supported at two points, and measuring the deflection of the specimen at the center of the load.
The flexural properties determined by this test method includes flexural modulus, flexural strength, and flexural strain at maximum load. Flexural modulus is a measure of the stiffness of the material and flexural strength is a measure of the material’s ability to withstand bending or flexing without breaking. Flexural strain at maximum load is the amount of deformation of the material at the point where it fails.
This standard is commonly used in the vacuum forming industry to determine the suitability of different materials for different applications. Materials with a high flexural modulus and strength will generally be more suitable for vacuum forming because they will retain their shape better during the forming process and will be less likely to warp or crack. The information obtained from this standard can also be used to compare different materials and to evaluate the quality of the finished product.
It is worth noting that vacuum forming is a manufacturing process which needs the combination of multiple properties from a material, such as the heat resistance, impact resistance, tensile strength, and so on. The result from this standard is just one part of the data that can be used to evaluate the suitability of a material for vacuum forming, manufacturers should always consider multiple aspects when choosing materials for a specific application.
ASTM D955-12(2017), Standard Test Method for Warpage of Extruded Plastic Shapes, is an industry standard developed by the American Society for Testing and Materials (ASTM) that specifies a procedure for measuring the warpage of extruded plastic shapes. Warpage is the deviation of a surface or a cross-section of a plastic part from its expected position, due to the inherent anisotropy of the plastic material, and it is an important characteristic in vacuum forming process.
This standard applies to plastic shapes such as sheets, plates, rods, tubes and profiles, that are extruded or co-extruded and then cooled, and it uses a rectangular test piece with parallel planes cut out of it to measure warpage. The standard describes the method for measuring the warpage of the rectangular test piece by measuring the distance between the centers of gravity of the four quadrants of the test piece, in both the longitudinal and transverse directions. It also provides information on the size and shape of the test piece and the conditions of measurement.
Warpage can be caused by many factors such as uneven cooling, crystallization, and shrinkage, and it can affect the dimensional stability of the plastic part, affecting the tightness of the tolerance, and the overall performance of the part. This standard can be used to measure the warpage of plastic parts, before and after the vacuum forming process, and to evaluate the effect of the different parameters of the vacuum forming process on the warpage of the parts.
It is important for manufacturers to measure the warpage of their plastic parts and to take the necessary steps to minimize it. This may involve adjusting the cooling rate, using specific types of resins, or other process adjustments. In addition, measuring the warpage of the plastic part before and after the vacuum forming process, it can also help manufacturers to evaluate the quality of the vacuum forming process, and to make any necessary adjustments.
It’s worth noting that ASTM D955 is not specific for vacuum forming and apply for all extruded plastic shapes, but it is common to use this test on vacuum-formed parts, specially when the part has to be flat and have a high dimensional stability. This standard is widely used in the vacuum forming industry and other industry to ensure the quality of the finished product and ensure that it meets the desired specifications.
ASTM D946-19, Standard Test Method for Impact Resistance of Plastic Film by the Free-Falling Dart Method, is an industry standard developed by the American Society for Testing and Materials (ASTM) that specifies a procedure for measuring the impact resistance of plastic films. Impact resistance is a measure of a material’s ability to withstand impact or sudden force without breaking or puncturing. This is an important characteristic in vacuum forming, as the plastic film needs to be able to withstand the forming process and any other handling or transportation that may occur after the forming process.
This standard describes the procedure for measuring the impact resistance of plastic film using a free-falling dart. The test involves dropping a dart from a specified height onto the film and measuring the energy absorbed by the film. The impact resistance is reported in terms of the puncture resistance of the film, and the energy absorbed by the film. The standard also specifies the requirements for the dart, the test conditions, and the minimum number of test specimens to be tested.
The impact resistance is a crucial property for plastic films that are used for vacuum forming, as it ensures that the plastic film will not be damaged or punctured during the forming process, and the part produced will have the desired properties after being formed. This test method is also useful to evaluate the quality of the finished product and determine if it meets the requirements of the application. Impact resistance is especially important for applications where the parts will be exposed to impact or other mechanical loads, such as packaging or transportation.
It’s worth noting that the results of this test method are specific to the free-falling dart method, and the results may not be the same as those obtained by other impact testing methods, or in real-world conditions. There are other standard tests that can be used to evaluate the impact resistance of plastic films such as ASTM D256-17 (Izod Impact Test) and ASTM D4812 (Charpy Impact Test). It is good for manufacturers to use multiple methods to evaluate the impact resistance and evaluate the suitability of the material for the intended application.
In summary, ASTM D946-19 is widely used in the vacuum forming industry as a test method to evaluate the impact resistance of plastic films. This standard provides a consistent and reliable way to measure the impact resistance of plastic films, and can be used to determine the material selection, evaluate the quality of the finished product, and ensure the product meets the requirements.
In the beginning, I proposed twelve standards of vacuum forming, please allow me to describe the first five standards in today’s article, and the remaining seven points will be explained in the next article. The title of the article is Vacuum forming – some standard test methods
Now please allow me to do a brief introduction about our vacuum forming factory:
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