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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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. D — 08 Standard Test Method of Measuring Shrinkage from Mold Dimensions of Thermoplastics1 This standard is issued under the xed designation D ; the number immediately following the designation indicates the year of original adoption ashm, in the case of revision, the year of last revision. For example, thermoplastics, which absorb moisture must be dried before molding.
ASTM D – Standard Test Method of Measuring Shrinkage from Mold Dimensions of Thermoplastics
Record these values as l and w, respectively. Read more about subscriptions. Each test result is the average of ve individual determinations from successive injection molding cycles. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every ve years and if not revised, either reapproved or withdrawn.
Calculation and Report We have no amendments or corrections for this standard. 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. Signicance and Use 5. The length or diameter of the cavity is d9550-8 depending on shape of mold.
Link to Active This link will always route to the current Active version of the standard. This service is not available if you are a URL user where you do d955-088 log in with an email address.
Your comments are invited either for revision of this standard or for additional standards and should be addressed to D55-08 International Headquarters. Enough resin to mold the required samples. 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 ASTM D ISO
Mold shrinkage is calculated as inches per inch or percent or mm per mm for the specified dimensions and conditions. Subscription pricing is determined by: Differences in mold shrinkage may also be observed among the three specimen geometries described in this test method.
Users of this test method should apply the principles outlined in Practice E to generate data specic to their laboratory and materials, or between specic laboratories. The benefits of a subscription: Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm.
Each laboratory obtained one test result for each material. The results, including suggested cavity hold pressure for various materials, are shown in Appendix X1.
Three percent warp is dened as 3 mm depth deection, positive or negative, per mm in length. 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. The preparation given to the material prior to molding shall be recorded and reported.
Due to copyright restrictions, we are not able to provide copies of standards. The method also accommodates shrinkage at 24 and 48 h, which may be critical for some materials. A web subscription provides an axtm and secure access to standards, and you are guaranteed to always have the latest edition.
This ensures that you are always up-to-date and saves you both time and money. Poorer precision larger values of Sr and r would aatm 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. At point R, the value of the cav ity pressure at hold is recorded. If the document is revised or amended, you will be notified by email.