(f) If more than one security interest attaches to the product or mass under (c) of this section, the following rules determine priority:
- (1) a security interest that is perfected under (d) of this section has priority over a security interest that is unperfected at the time the collateral becomes commingled goods;
- (2) if more than one security interest is perfected under (d) of this section, the security interests rank equally in proportion to the value of the collateral at the time it became commingled goods.