Margaret Knight, Inventor of Paper Grocery Bag

paper bag machine

 Received first patent in 1868; obtained at least 25 more patents over her lifetime

 Invented a machine that could create the square-bottomed grocery bag that is still used today

 Margaret Knight was born in York, Maine in 1838 (1838-1914). Her family moved to Manchester, New Hampshire, where she and her siblings grew up. She loved devising different types of toys for herself and her brothers to play with, and the boys constantly had new requests for her.

Her father died when she was 12, and she went to work in a cotton mill to help the family. She was joined their by her brothers as they became old enough. 

One day at work, a snagged thread caused a shuttle to fly off its moorings along the processing line. A worker was injured.  Knight witnessed the accident, so she made suggestions to management about how to prevent another accident. She also worked out a way to create a covered shuttle which was protective. At the time, Knight didn’t know about patents. Though companies went on to use her idea, she never profited from that particular one.

Worked in a Paper Bag Factory

 In 1868 Margaret Knight worked in the Columbia Paper Bag Company in Springfield, Massachusetts.  At the time, paper bags were created as flat paper containers with envelope-like openings. Knight thought a square-bottomed bag would be more useful. She also realized that the system would need to be automated or no company would be interested in producing them.

She studied the bag-making machine where she currently worked to figure out how a machine might be altered to accomplish the task. She eventually put together a wooden model she could use to test her plan. She saw that it worked but knew that to apply for a patent, she needed a working model made of iron.  She took the project to a machine shop in Boston and explained what she wanted them to build.

One of the workers there—Charles Annan—understood the value of what she created. He copied her idea and applied for a patent. 

Knight got word of what happened and filed a lawsuit against Annan. She had complete documentation of her work She showed drawings of early models of her invention and even presented diary entries that proved how long she had worked on this machine. In 1871 she received the patent.

Manufacturing Bags

In 1870, Margaret Knight and a business partner set up a company to make the bags herself.  As the manufacturing process got started, Knight encountered some resistance to her as a woman, but as she proved her complete understanding of manufacturing and the machinery, she won the workers’s respect. The Eastern Paper Bag Company was ready to go.

Knight went on to invent many other useful products, almost all of which had to do with manufacturing. She moved to Framingham, Massachusetts, but she retned space on High Street in Boston where she could run her experiments. She spent many long hours there.  

Most of her patents had to do with various ways to improve manufacturing. One was a machine for boring holes, another was for a numbering machine, and yet another pertained to making windows and sashes.  In the mid-1890s she dedicated herself to creating a better machine for making shoes. 

Final Inventions

Though she was in her sixties when automobiles were coming into their own, she was fascinated by them. She patented a series of improvements to the rotary engine. Her gasoline-powered engine was known as the Knight Silent Motor. She also developed “non-skiddable” tires.

Knight never had a family, and she died in 1914.

At her death, she held patents for 22 inventions and had assigned patents for an estimated 60 more to her employers or financial backers.

Share with Others!

2 thoughts on “Margaret Knight, Inventor of Paper Grocery Bag”

  1. Pingback: Stephanie L. Kwolek (1923-2014), Inventor of Kevlar - America Comes Alive

Leave a Comment

Your email address will not be published.

Translate »
Scroll to Top