According to the city of Portland's website plastics particularly are recycled incorrectly. Size and shape are what is important. There are are lots of plastics it recommends not recycling, at least not in your home mixed recycling. These items include small things like plastic coffee cups, plastic cutlery, plastic lids, plastic to-go containers. The reason being that the size of many of these products makes them hard to sort out from all the other recyclables. The website also mentions that some items, like to-go containers, are very recyclable because they are often made of materials that are not profitable for companies to recycle. Biodegradable and compostable plastics are not meant to be recycled either because they are meant to breakdown quickly, and can contaminate other plastics in the recycling process which reduces quality of goods being produced by the recycled plastics.
The only plastics the site recommends to recycle at home, or work, are plastic bottles, jugs, buckets, and tubs over 6oz. You can however save these extra plastics and bring them to one of several places around town. Portland Metro has a website to help find them, https://www.oregonmetro.gov/tools-living/garbage-and-recycling/find-a-recycler, or you can contact them at 503-234-3000. Unfortunately, since the recent changes in international recycling some of these businesses have had to stop collecting these smaller plastics, or are limiting what they can take. Another solution is to reduce personal use of these small plastics. Replace plastic cups by bringing your own ceramic or metal one. Use a reusable water bottle instead of plastic ones. Try to avoid plastic take out containers, straws, and cutlery.
I focused on recycling rules about plastic for the city of Portland specifically for this blog, but here also is a link to Portland's comprehensive recycling site. These are incredibly easy to find. Most major cities have one. Here a few examples New York, Chicago, and Nebraska.