How can I loop through all different Product Types in Craft Commerce?
Hoping this is what you are looking to do?

{% for productType in craft.commerce.productTypes %}

  {{ productType.name }}&lt;br&gt;

{% for product in craft.commerce.products.type(productType.handle).find() %}

  {{ product.title }}&lt;br&gt;

{% endfor %}

{% endfor %}