Scope: Mold shrinkage is the shrinkage of the polymer as it cools after the molding process. It is typically used to properly machine injection molds so that final. Purchase your copy of ASTM D – 08() as a PDF download or hard copy directly from the official BSI Shop. All BSI British Standards. Buy ASTM D R TEST METHOD OF MEASURING SHRINKAGE FROM MOLD DIMENSIONS OF THERMOPLASTICS from SAI.
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If you need to be able to add standards to the monitoring service, you must register as a user with your own username and password. Need more than one copy? To request a quote for this test or others Click Here. The benefits of a f955-08 Factors, such as the amount of material in charge, cooling time, and pressure application are known to affect shrinkage significantly.
ASTM D955 – 08(2014)
November 1, 1 Completed ve year review. Calculation and Report Monitoring Standards monitoring is a free service designed for you who wish to be alerted of changes to or new editions of the standards required in your work.
Enough resin to mold the required samples. D – D Record these values as l and w, respectively.
ASTM D – Standard Test Method of Measuring Shrinkage from Mold Dimensions of Thermoplastics
Repeatability under such circumstances was not evaluated. Differences in mold shrinkage may also be observed among the three specimen geometries described in this test method. Orientation effects due to ow direction do not generally pertain to compression molding.
It is recommended to cool specimens in a horizontal position at room temperature by placing them on a material of low thermal conductivity to minimize warpage. It is the responsibility of the user of this standard to establish d9550-8 safety and health practices and determine the applicability of regulatory limitations v955-08 to use.
Please first log in with a verified email before subscribing to alerts. Each test result is the average of ve individual determinations from successive injection molding cycles. Please first verify your email before subscribing to alerts. xstm
ASTM D – 08 Standard Test Method of Measuring Shrinkage from Mold Dimensions of Thermoplastics
It would be incorrect to assume values form Tables for any new material. Originally approved in Note This test method is technically identical to ISO where Type D2 specimens are used except that pressure transducers are an option in this test method and required in ISO If the document is revised or amended, you will be notified by email.
It is the intent of this method to control and document as many of these variables as possible. NOTE 2—Although scribe marks are not required, if they are used for injection or compression molded specimens for the measurement of shrinkage, the scribe marks shall be 1. Your Alert Profile lists the documents that will be monitored.
It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Factors such as mold and melt temperature, fill times, and packing conditions are known to affect shrinkage significantly. Standards Subscriptions from ANSI provides a money-saving, multi-user solution for accessing standards.
NOTE 3—If the injection machines of appropriate capacity are not available, the requirements of 7. The data in Tables should not be rigorously applied to acceptance or rejected of material, as those data are specic to the round robin and may not be representative of other lots, conditions, materials, or laboratories. Report mold shrinkage in both ow and cross direction to two signicant gures.
This ensures that you are always up-to-date and saves you both time and money. As the cooling rate of the material is proportional to the square of the reciprocal of the thickness, the minimum cooling time for the cavity can be expected to be close to 1. Mold shrinkage is the shrinkage of the polymer as it cools after the molding process. Due to the inertia of the injection-molding machine, the effective change-over time is longer than its nominal value.
Standards monitoring is a free service designed for you who wish to be alerted of changes to or new editions of the standards required in your work.
Historical Version s – view previous versions of standard. Standards can be obtained from appropriate standards authorities. The values given in parentheses are given for information only. The temperature of the heating cylinder and the mold shall be maintained at a point which, on a cycle selected, will produce temperature within the range recommended by the material molding standard. Current edition approved Nov.
Poorer precision larger values of Sr and r would be expected if the same operator were to shutdown and then restart the injection molding machine on the same day with the same mold, material and operating set points. The values given in parentheses are given for information only. The correct change-over point shall therefore be adjusted individually for each value of the injection speed and for each material under test.
Signicance and Use 5. Adherence to the specied mold design see 7.
Link to Active This link will always route to the current Active version of the standard. Consequently, there may be signicant differences when measuring the specimen at different points around the circumference.
The preparation given to the material prior to molding shall be recorded and reported. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. Proceed to Checkout Continue Shopping. The minimum hold time can be read from the decrease of the cavity pressure to zero. Differences in mold shrinkage may also be observed among the three specimen geometries described in this test method.
Subscription pricing is determined by: The results, including suggested cavity hold pressure for various materials, are shown in Appendix X1. This standard is not included in any packages.