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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ASTM D – Standard Test Method of Measuring Shrinkage from Mold Dimensions of Thermoplastics
Factors d9550-8 as mold and melt temperature, fill times, and packing conditions are known to affect shrinkage significantly. Standards monitoring is a free service designed for you who wish to be alerted of changes to or new editions of r955-08 standards required in your work.
Determination of Moulding Shrinkage 3. Mold shrinkage is the shrinkage of the polymer as it cools after the molding process. NOTE 3—If the injection machines of appropriate capacity are not available, the requirements of 7. Need more than one copy? A number in parentheses indicates the year of last reapproval.
ASTM D955 – 08(2014)
The results, including asm cavity hold pressure for x955-08 materials, are shown in Appendix X1. Begin with a short shot to ensure the ow front is straight and not radial and that the ow is laminar and does not exhibit melt fracture jetting.
Record these values as l and w, respectively. The mold shall have at one end a gate 6. It would be incorrect to assume values form Tables for any new material. The moment new editions of the standards you monitor are released, changes are made, or appendixes are published, you will be alerted by email. 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.
Pressure transducers are recommended, but not mandatory for specimens Type A and Type B. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. Due to the inertia of the injection-molding machine, the effective change-over time is longer than its nominal value.
You may delete a document from your Alert Profile f955-08 any time. Adherence to the specified mold design see 7. If d955-8 feel that your comments have not received a fair hearing you should make your ast known to the ASTM Committee on Standards, at the address shown below.
The preparation given to the material prior to molding shall be recorded and reported. The values given in parentheses are given for information only. Collect samples after the machine is at equilibrium. We have no amendments or corrections for this standard. 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.
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 last revision.
Consequently, there may be signicant differences when measuring the specimen at different points around the circumference.
The values given in parentheses are given for information only. Read more about subscriptions.
Standards Subscriptions from ANSI provides a money-saving, multi-user solution asgm accessing standards. This standard and ISO are equivalent in the design of specimen D2.
Report mold axtm in both ow and cross direction to two signicant gures. The correct change-over point shall therefore be adjusted individually for each value of the injection speed and for each material under test. Proceed to Checkout Continue Shopping. Mold shrinkage can be dependant upon the molding parameters used – often the extremes of the processing range for the material plus a midrange value are tested.
To request a quote for this test or others Click Here. Differences in mold shrinkage may also be observed among the three wstm geometries described in this test method. Precision and Bias Please first verify your email before subscribing to alerts. Adherence to the specied mold design see 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.