DaShangHui 大商汇 market, off QianXingLu 前兴路, off GuangFuLu 广福路
From DianChiLu end, take GuangFuLu, go past Aegean, past the overpass, turn left onto QianXingLu. (If you get to the new Metro on the right of GuangFulLu you have gone a little too far.)
On QianXingLu, after about 300m turn right onto ShangHuiLu, and you are in the DaShangHui fabric market area. Look out for the bus stop (end of the line for the 181), cross the canal, then turn left onto HuiShangLu, following the canal on your left. After about 200m you've gone as far as you can go on this road. Turn right onto a slightly larger road, HuiYunLu. You will see the foam shop about 50m on your left.
Foam of all thicknesses and densities. Owner is friendly and helpful and will deliver.
If the following link works for you, I would say it is directly opposite DingLi Business Department: