Orders combining into one product
When combining orders to the same delivery address, Packing Partner has settings that control how the items from each order are combined. These are found in Tools>Options>Collect>Sales to same buyer.
In general you should set Combining to Title unless you have defined a specific product code for all of your products.
Title should be used for most cases where you don't have individual either Code, SKU or Location defined for your products.
Code, Location and SKU are used if you want to use your product codes to determine which are the same products.