by Chad Jones, Sherry Laboratories
A quick glance at one’s surroundings and one can find a widening variety of plastic products in both consumer and industrial applications. This increase in the use of plastic materials is partly enabled by advances in material science and technology, and partly enabled by the continuing need for cost and weight reduction. New applications, and in some cases new materials, can benefit from the evaluations and analysis offered through commercial laboratories.
Innovations in plastic materials and additives are allowing for new and exciting applications. Take, for instance, the work being done to introduce nanotechnology into the field of plastics manufacturing. These materials are being engineered so they can be processed using the same steps as typical formulations, but include some unique and improved material properties. Scientists have found ways to use nanoscale fillers and reinforcements to increase such properties as transparency, strength, thermal conductivity and electrical conductivity. Another area of growth is in the use of engineering thermoplastics plastics. Engineering thermoplastics are used for applications that demand higher performance such as higher strength, heat resistance, chemical resistance or fire resistance. Materials in this category include polyamides, polyimides, polycarbonates, polyesters, polyacetal and others. The aerospace, automotive and petroleum industries are heavy users of these advanced materials and new applications continue to be developed.
New materials and new applications require thorough R&D and engineering review in order to support long-term success of the products. Some of these newer materials are for highly engineered and critical applications. Once in the marketplace, additional inspection and evaluation of the product is usually required. Significant effort is involved to make sure existing and new products will last, that they are safe and that they can be trusted. Ineffective quality and engineering efforts can result in products that may disappoint or endanger. Consumer disappointment results in a tarnished image of the product, the manufacturer or distributor. If safety has been compromised, then the rebuilding of consumer confidence will require a long term effort and carries the potential of costly litigation consequences.
Injection molders and other plastic processors dealing with new materials or processes can use outside laboratories for routine quality control testing. Many organizations require testing to determine conformance to material specifications. More complicated projects can involve contamination testing and failure analysis. In many situations, obtaining test results from a third-party laboratory is often a necessity, especially when testing for safety.
Testing for routine quality control can involve a range of standardized tests. Many molders benefit from receiving inspection tests designed to confirm material before it is processed. These tests can be physical or mechanical in nature (e.g., density, tensile strength, impact strength). In the absence of internal specifications, parameters listed on the supplier’s lot certification can be checked to confirm the properties. It also can be worthwhile to prepare infrared spectra “chemical fingerprints” of materials to document consistency and establish baselines.
Examining material for contamination and determining root cause of failures are important and valuable services offered by commercial laboratories. Contaminations issues that have plagued materials and processes often can be resolved rather easily when the investigative tools of a laboratory are applied. A thorough documentation of an investigation into a failure will help support solutions to preventing further occurrences.
The use of external testing laboratories is an excellent way to evaluate the efforts of product development and manufacturing activities. Often an in-house laboratory is geared to accomplish a few tasks using methods or protocols developed sometimes decades earlier. However, a commercial testing and engineering laboratory can offer an extensive array of resources and capabilities for the evaluation of many types of materials and products using the most recent technology and procedures. Obtaining information about the important performance properties helps to ensure the plastic components and assemblies will be safe, function well and last for many years.
Testing for safety may not simply be ensuring adherence to internal standards, but also determine conformance to a variety of regulations. Multiple government agencies, federal and state, evaluate and monitor plastic products for compounds determined to be harmful. Careful attention to current and developing regulations is important for molders, distributors and suppliers of plastic resin and products.
It is imperative that products containing regulated components have those compounds at levels below permissible limits allowed by the regulations. Some of these regulations result in big headlines, and consumer awareness can be high. A few years ago, the Consumer Product Safety Improvement Act of 2008 was put in place to provide more stringent toy safety requirements, most notably for content of lead and phthalates. In fact, part of the regulation is being phased in this August with the enforcement of the 100ppm limit on lead in childrens products.
Safety is not only important for the consumer, but also is a concern for the molder. A recent report by the National Toxicology Program (NTP) highlighted two compounds familiar to the plastics industry. The NTP, through the Department of Health and Human Services, released the 12th Report on Carcinogens (RoC). The report included the addition of six substances to the list. Of the 240 compounds, it now lists formaldehyde and styrene as known or potential carcinogenic compounds.
The addition of styrene to the RoC list has caused significant concern due to its prevalence in the plastic industry, mostly as utilized with thermoset plastics. The report highlights the risk for workers in the reinforced-plastics and styrene-butadiene rubber industries. Molders of thermoplastics should know that styrene is the precursor to polystyrene and the two should not be confused. No claims have been made that polystyrene is unsafe for consumers, where it finds significant use in the food packaging industries. Government regulations for styrene exist from the DOT, Coast Guard, EPA, FDA and OSHA.
Formaldehyde is another compound familiar to the plastics industry. It is used in the production of urea-formaldehyde, melamine-formaldehyde (melamine), phenol-formaldehyde (phenolic) and polyacetal. It also is commonly used as a chemical intermediate. Formaldehyde-based products are commonly used as adhesives and binders for wood products. Government regulations are plentiful for formaldehyde and include those issued by CPSC, USDA, HUD, DOT, EPA, FDA, OSHA and the MSHA.
Being aware of regulations and reports regarding the safety of products and molding materials is important for molders. Taking action to ensure compliance to regulations is an important and preventative measure to negate financial risks down the road. Commercial testing laboratories play vital roles in providing data in this regard.
The technical services offered from commercial laboratories can greatly assist plastic molding companies and suppliers in efforts to introduce and keep high quality products in the marketplace. Whether it is for routine quality tests, compliance testing, contamination analysis, failure analysis or testing for safety, these services are well worth the time and resources required to complete.
Chad Jones is the manager of nonmetallic testing for Sherry Laboratories, Broken Arrow, OK. He can be reached at 918.258.6066 or chadj@sherrylabs.com. Visit Sherry Laboratories at www.sherrylabs.com.
