Tengwei insists on the quality control from the source, and selectsthe high-quality source materials from well-known domesticand foreign brands.

灰分含量:此要求可防止减损海绵性能的填充。

Ash content：this requirement preventsloss of sponge fill performance

It is required that the ash content should be less than 4% ofthe weight under the 700 degrees Celsius.(International Standard)

Tengwei insists on using the material ofmeeting the international environmental standard.

All products will not add calcium carbonate, ensure thatash content lower than 0.5%.

Bayer company is one of the mostwell-known 500 companies in the world . The company’s headquarters is in Leverkusen, Germany,There are 750 production plants in 200 sites on 6continents, It has 120,000 employees and350 branches, almost all over the world, The high molecule, medical care,chemical industry and agriculture are the four pillar industries of thecompany. The company has over 10,000 productsand is the largest industrial group in Germany.

Royal Dutch/ ShellGroup of Companies, called “Shell”, at present, It is the largest oil company in the world,Meanwhile it’s also the largest retailer of automotive fuel and lubricants on aglobal scale. Business scope all over the world. businessin 140 countries around the world, and there are 90000employee, Oil and gas production account for 3% and 3.5% of world outputrespectively. As the largest industrialcompany in the Netherlands,In the 2012 “FORTUNE”magazine, it ranked first among the top 500 companies in the world.

Air Products Chemicals INC is major supplier ofindustrial gases, relatedequipment and services and chemicals. Company business scope all over theworld, and there are factoriesacross the United States,Canada, Puerto Rico, SouthAmerica, Europe and China.Momentive Performance Materials Inc, In December 2006, Apollo investmentcorporation completed the acquisition of GE high-tech materials group andestablished it. It’s the world's second largest producer of organic siliconproducts and its associated products.

Founded in November 1981, gaoqiao petrochemical corporationis a subsidiary of Chinapetrochemical corporation. It is the firstmulti-industry and cross-sectoral economic complex in China. It has a refining capacityof 11.3 million tons/year, and the production capacityof chemical products is 1 million tons/year, and the power plant has ainstalled capacity of 195,000 kw. DCP is the world's largest producer with morethan 50% of global market. The Polyether is thelargest production base in China.Phenol Acetone, rubber device is one of the best in China.