As China's car industry continues to grow, the country's concerns about air quality are growing alongside the number of drivers. And it's not just the air outside the car that is gaining attention.
At the end of this year, China's regulators are expected to come out with standards for the amount of volatile organic chemicals in the air inside of new vehicles. The new regulations on VOCs will have an impact on material makers from paint and polish to the polypropylene products used in a car.
``Out of all the plastics in a car, 40 percent are polypropylene'' in China, according to Chen Guang Qiang, chief engineer at Kingfa Science and Technology Co. Ltd. ``It's used in instrument panels, console panels, door panels, seat parts, glove boxes and air conditioning systems. PP covers a large share of indoor space and constitutes a source of pollution inside the car.''
Chen spoke on his own company's strategies for addressing the new regulations at the 4th Asia/China PP Markets and Tech conference, held April 21-22 in Shanghai. The event was organized by Singapore's Centre for Management Technology.
To fulfill the new VOC requirements, molders will have to ensure the quality of raw materials that they use, keeping an eye out for impurities in additives and mistakes in molding processes.
``Most raw materials cannot meet the requirement of automotive manufacturers,'' Chen said. ``The solvents used during polymerization can also pose a problem.''
To ensure that the raw materials used at Kingfa are admissible, the company uses a high-performance liquid chromatography test to separate all the components of the raw material that they use. The company tests for formaldehyde content as well as acetones and acetaldehyde.
During molding, Chen advises to maintain a heat exposure period of two to five minutes, helping to decompose the raw material and rid it of possible VOCs. Before the molding process, the company also dries the raw material. ``This gets rid of moisture, so we can ensure good surface quality and reduce VOCs,'' he said.
In addition, Kingfa makes sure to keep molds clean and adds VOC absorbers into the mix.
``We suggest leaving the parts in a ventilated environment for a certain period of time before assembly,'' he said.
The company's last line of defense, Chen said, is the human nose. ``For those who work all day with plastics, the odor might not seem much of a problem,'' he said. ``We ask professionals to do a smell test and grade the parts.''
Kingfa providse training for odor testers, to make sure they are sensitive enough. ``We have to calibrate our noses,'' Chen said.