Frequently Asked Questions (F.A.Q.)
Do you accept credit cards?
Can you help me to select what testing will meet my needs?
Can you identify a small particle of contamination?
Can you identify an unknown plastic?
Can you identify an unknown metal?
Can you send me a copy of a specification?
Can you determine the amount of regrind in a plastic?
How does moisture change the properties of polyamide (Nylon)?
Yes, we are happy to accept Visa, Mastercard, & American Express.
Definitely. Our customer service people are trained scientists who also operate the equipment in the laboratory. We are not interested in selling testing which will not further your business needs. When we ask "Why are you doing testing?" it is because we want to make sure that our tests will answer the questions that you have instead of just giving you a test result.
Yes, we can identify most contaminants using SEM/EDS Analysis and FTIR Analysis (ASTM E1252). The SEM/EDS allows us to magnify up to 100,000X and then identify what elements are present in an individual particle one micrometer (39 micro-inches) or smaller in diameter. If the primary elements in the particle are carbon and oxygen then we know that the particle is probably organic and can use our FTIR microscope to identify how the elements are bonded together. The FTIR microscope cannot magnify as high as the SEM/EDS but can easily analyze most particles visible to the human eye.
Yes, we commonly identify the major components of plastic using FTIR Analysis (ASTM E1252) to identify the major polymer type, SEM/EDS Analysis to identify the major inorganic filler, and TGA Analysis (ASTM E1131) to quantify the total inorganic fillers. This combination of tests can be done for under $500 using only one gram of material.
Although the tests listed above will identify the major components of a plastic, the exact grade and trace elements of the material will not be identified. Additional testing can be done to further characterize the material but often it is more cost effective to perform mechanical testing to quantify the performance of a material than to do a complete deformulation. Deformulation is testing to attempt to identify and quantify every component in a material even those present in trace quantities.
Yes we routinely do chemical analysis of metals using Glow Discharge Spectrometry (GDS), X-Ray Fluorescence (XRF), and/or SEM/EDS. We are able to provide a quantitative analysis of the important elements in a metal and match it to existing industry standards including the Unified Number System (UNS).
Unfortunately a majority of the specifications and test methods we work with are copyrighted and we cannot distribute copies. Copies of most test methods can be purchased from sources such as www.global.ihs.com, www.astm.org, www.sae.org, www.ansi.org, www.asme.org, and www.iso.org.
Unfortunately we cannot directly measure the amount of regrind in a plastic but we can indirectly measure the amount of degradation caused by all factors including regrind, moisture, and/or improper molding. Regrind is material that has been molded into parts, ground up, and then mixed back in with the raw material to be re-used for molding. If the molding process is very gentle and the material is not significantly degraded during molding then it is theoretically possible to use 100% regrind with no reduction in the quality of molded parts. On the other hand, if the molding process heavily degrades the material during molding then only a very small amount of regrind can cause a significant reduction in the quality of parts.
When plastic material is degraded it results in the molecular chains of the polymer getting cut into smaller lengths. This reduction in chain length can happen due to several processing issues such as too much regrind, too high a molding temperature, or excessive moisture in the raw material. By measuring the degradation level of the material we can determine if there is a problem with processing but not if it was caused by regrind or another processing issue.
If you think about plastic as a plate of spaghetti then you can imagine how the spaghetti will flow more easily as the individual pieces get cut into smaller lengths. Therefore we can indirectly measure degradation by comparing the viscosity of the original resin with that of the molded parts. If the original resin is not available then it is sometimes possible to compare the viscosity to that of a data sheet value for the material. This measurement is typically done by testing for Melt Flow Rate (ASTM D1238) or Viscosity Number (ISO 307).
Moisture can change the properties of polyamide in two ways. The first is that moisture in the raw material (resin) during molding can cause a permanent reduction in the chain length of the material resulting in brittle parts. The second is that moisture can be absorbed into a polyamide part and make it temporarily more flexible until the part dries out again.
Moisture reacts with polyamide if it is raised above the melting point of the plastic. The water hydrolyzes the molecular chains in the polyamide and makes the material permanently more brittle. This brittleness can be quite insidious because there may be no visible indication of molding problems. After molding it is no longer possible to test for the moisture because it has reacted with the plastic and then boiled away leaving a completely dry part. It is very important to make sure that polyamide material is completely dry before molding. The moisture content of the resin before molding can be measured by Karl Fischer Titration (ASTM D6869). After molding, permanent degradation can be measured by comparing the Viscosity Number (ISO 307) of the part to that of the original raw material.
Once a polyamide part is molded it can absorb moisture resulting in reduced strength and improved impact resistance. The difference is that the plastic was not melted and therefore the moisture cannot react with the material and create a permanent reduction in chain length. The material is like a kitchen sponge which softens when wet but hardens again every time it dries. It is common for manufacturers to soak a polyamide part in water prior to assembling snap together parts to make sure they don’t break during assembly.
A part that has been degraded by moisture during molding will always be brittle but can be made temporarily less brittle by soaking in water. Unfortunately a degraded part in the wet condition is likely to be less impact resistant than a good part in the dry condition.