Blow molding is a manufacturing process in which air is used to inflate soft plastic into a mold cavity. It is a two part manufacturing process. First a parison or starting tube of molten plastic is made and then the tube is inflated into the desired shape. The parison is made either by extrusion or injection molding. The parison is placed in a mold cavity and inflated to take the shape of the mold. Blow molding is used to make hollow plastic containers such as bottles, … Read more
The use of carbon fibers in plastic materials has a long history. As early as 1879, Thomas Edison was experimenting with carbon fibers made from cotton threads and bamboo slivers. In fact, the first incandescent light bulb heated by electricity contained carbon fibers. In the 1960’s, Dr. Akio Shindo at the Agency of Industrial Science and Technology in Japan developed a carbon fiber based on polyacrylonitrile (PAN). The resulting fiber contained 55% carbon. … Read more
Have you ever been reading a material data sheet and wondered what ASTM means? Well, you’re not alone. “ASTM” followed by numbers or letters is used on data sheets to indicate the test used to develop the data. These tests are standardized so that they can be reproduced by labs around the world. Here’s a brief rundown on ASTM International’s history and operations.
ASTM is an international standards and testing organization with headquarters in West Conshohocken, … Read more
When evaluating a material for use in a particular application, engineers usually look first at the material properties data sheet or material data sheet for short. These are available on-line for most plastic materials. This sheet will give typical values for a variety of properties. Usually it will include values for physical properties and mechanical properties as well as thermal and electrical properties. Typically, the material properties data sheet will include what ASTM, … Read more
As we discussed in our last post, reinforcing fibers are added to plastic resins to increase the tensile strength and flexural modulus of the composite as well as the heat deflection temperature of the plastic. In this blog post, we will take a closer look at glass fibers.
Glass fibers are used as a reinforcing agent for many plastic composites. Called GRP’s or glass reinforced plastics, these materials are made up of many fine fibers of glass combined with a plastic matrix. … Read more