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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Each material was supplied in granular form to each of the testing laboratories by a single supplier. Start Webshop Product catalog Product presentation. Summary of Test Method 4. November 1, 1 Completed ve year review. Subscription pricing is determined by: Signicance and Use 5. Mold shrinkage is calculated as inches per inch or percent or mm per mm for the specified dimensions and conditions.
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 or, in the case of revision, the year of s955-08 revision. Due to the inertia of the injection-molding machine, the effective change-over time is longer e955-08 its nominal value. NOTE 4—Although this specimen may be used to determine mold shrinkage in both the ow and cross ow directions, the lling pattern does not produce uniform ow lengths and orientation.
Differences in asfm shrinkage may also be observed between the three specimen geometries described in this test method. 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.
Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. 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.
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ASTM D – 08 Standard Test Method of Measuring Shrinkage from Mold Dimensions of Thermoplastics
Factors, such as the amount of material in charge, cooling time, and pressure application are known to affect shrinkage significantly. You need to log in before adding standards to the monitoring service. Test specimens are molded under specified conditions. Values would not be expected to be in agreement with those obtained using the specimens described in 8.
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A superscript epsilon indicates an editorial change since the last revision or reapproval. Injection Molds Digital micrometers Digital calipers Weighted digital drop gauge.
ASTM D – Standard Test Method of Measuring Shrinkage from Mold Dimensions of Thermoplastics
Proceed to Checkout Continue Shopping. The values given in parentheses are given for information only. Standards Subsctiption may be the perfect solution. The parts aastm and after 48 hours, the molded parts are measured and the shrinkage is calculated. Thus the mass of material injected into the cavity is not clearly dened and the orientation of the material near the gate will be perturbed. Adherence to the specied mold design see 7.
This standard is not included in any packages. Three percent warp is dened as 3 mm depth deection, positive or negative, per mm in length. Factors such as mold and melt temperature, fill times, and packing conditions d955-008 known to affect shrinkage significantly. This standard is also available to be included in Standards Subscriptions.
Enough resin to mold the required samples. As the cooling rate of the satm 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. Differences in mold shrinkage may also be observed among the three specimen geometries described in this test method. A number in parentheses indicates the year of last reapproval.
If the document is revised or amended, you will be notified by email. Record these values as l and w, respectively. Orientation effects due to ow direction do not generally pertain to compression molding.
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. It is the intent of this method to control and document as many of these variables as possible. The results, including suggested cavity hold pressure for various materials, are shown in Appendix X1. At point R, the value of the cav ity pressure at hold is recorded. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
ASTM D955 – 08(2014)
You may delete a document from your Alert Profile at any time. There are no recognized standards by which to estimate the bias of xstm test method. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. The mold shall have at one end a gate 6. Differences in mold shrinkage may also be observed among the three specimen geometries described in this test method. Mold shrinkage is the shrinkage of the polymer as it cools after the molding process.
Users of asm standard are expressly advised that astn of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. 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