The challenge of sustainable plastic manufacturing

Why is plastic manufacturing such a large target for sustainability initiatives? There are two major components to this: the amount of energy consumed in manufacturing processes and what happens to plastic products at the end of their lifetimes. Challenges with recycling plastic materials mean that the vast majority of U.S. plastic ends up in landfills (epa.gov) and can contribute to pollution.

Sustainability in plastic manufacturing often refers to the methods manufacturers take to reduce environmental harm, and this is a vital part of any sustainability initiative. But for us at SSI, another critical component of our sustainability model is starting with a plastic forming method — vacuum forming — that avoids many common pitfalls from the beginning.

Why thermoformed plastic and vacuum forming are better for the environment

Thermoforming, and specifically vacuum forming, can be a greener choice for manufacturing for two main reasons:

1. Common thermoplastics are often recyclable

PET and HDPE are some of the world’s most common thermoplastics, and both of these materials are highly recyclable. Products made from these are more likely to be reprocessed into new components at the end of their lifespans rather than sitting in a landfill. PETG, polypropylene, and TPO are also among the easier plastics to recycle.

2. Vacuum forming processes use less energy and produce less waste

Component design in thermoforming is precise, allowing manufacturers to use less material in production. Scrap material produced in trimming can be reused, and plastic is often a lighter, less costly material to transport and ship than other materials. Additionally, vacuum forming consumes less energy than other forming methods (e.g., injection molding).

If you have the choice between thermoformed plastic and another material, there’s a good chance your thermoplastic option is more eco-friendly (though, of course, this will also depend on how the component is used, for how long, and what happens to it at the end of its lifespan).

How other types of plastic forming stack up

You’ll encounter many other types of plastic forming methods besides vacuum forming. Here’s how your other options compare:

Injection molding

• Highly efficient material use
• Some waste and recyclables may be fit for reuse
• Creates durable products that have a relatively long potential lifespan
• Requires high energy to melt and pressurize materials

Blow molding

• Fairly efficient for its applications
• Products are often made from recyclable PET
• At large volumes, good ratio of energy used per unit manufactured
• Requires high energy to melt and form components under pressure
• Thin gauge of products limits their reusability and raise environmental risks

Rotational molding

• Recyclable materials may be used
• Produces highly durable parts with longer potential lifespans
• Less material efficient due to thicker gauge needed for components
• Requires high energy to heat materials for extended periods
• Generates more waste than other methods
• Higher ratio of energy used per unit manufactured

Your application and specific needs govern the type of manufacturing process you need to use, but when vacuum forming is an option, it could be your greenest choice.

Sustainable materials for vacuum forming

Not all thermoplastics are equally sustainable. Many are recyclable, but it can be difficult to find facilities and programs equipped to process them and material production can involve high energy consumption and substances like petroleum and styrene. 

However, there are thermoplastics that can be produced with relatively low environmental impact and have better-established recycling programs. These include:

1. HDPE
2. PET
3. Polypropylene
4. PETG 
5. TPO

Some other options that are moderately sustainable include HIPS and ABS, but HDPE is the gold standard for sustainability among thermoplastics.

Benefits of using sustainable plastics and forming methods

Why make sustainability a priority in your material and manufacturing choices? There are some practical reasons that can benefit your business. Reusing and recycling typically cut costs, and choosing less energy-intensive materials and processes can benefit your bottom line as well as the environment. Sustainability is increasingly valued by consumers, which has led many businesses to adopt corporate responsibility pledges. Offering products made with a sustainability strategy in mind can attract customers, both at the consumer and business levels.

Sustainable plastic manufacturing at SSI

Looking for a manufacturing partner who can support your sustainability goals? At SSI, our focus on vacuum forming lays a strong foundation for our own green initiatives:

80% recycled stock

80% of our stock product is recycled — this means the vast majority of our scrap is recycled and used in our new thermoplastic sheets. Our process is simple; after production, we collect the remaining material (or scrap) and ship it to our supplier to be recycled into new sheets. 

Each box of scrap is around 300 lbs, and our truck loads can carry 46–48 of these at once, around six times a year — resulting in 80,000+ lbs of material sent for recycling on an annual basis. By weight, we end up recycling over a third of the plastic material we order (with the rest going into our finished components).

85% reduction in propane consumption and emissions

Utilizing the industry’s most modern technology in thermoforming, we’ve replaced our gas ovens with electric ovens and quartz heaters to reduce our propane consumption and exhaust gasses by 85%. These quartz heaters are also energy efficient, requiring less electricity to operate.

Recyclable materials

When the project and application permits it, we have recyclable materials on hand for production (including HDPE, polypropylene, PETG, and TPO). For products such as air ducts, wireways, and hidden panels, we can typically use recycled material — and at a lower cost, as well.

Durable & long-lasting parts

Many of our components are used to replace fiberglass and metal alternatives. Thermoformed plastic parts tend to last longer, take less damage from environmental forces, and need less maintenance. We can produce plastic parts that are UV resistant, high impact, light, chemical resistant, and flame retardant. Our high-quality materials produce components that can last many years.