Monday, May 24, 2021

Biography of Walter A. Shewhart

Walter A. Shewhart 

The industrial era was approaching its second century when ​​a young engineer Walter A. Shewhart changed the course of industrial history by bringing together the disciplines of statistics, engineering, and economics. He referred to his greatest achievement, the invention of the process control chart, as "building a scientific basis for achieving economic control". The Shewhart control chart is now sometimes referred to as the process behavior chart. 

Walter A. Shewhart

Shewhart wanted statistical theory to meet the needs of the industry. He demonstrated a restlessness of the person in search of a better way. A science man who patiently developed his and others' ideas, he was an astute observer of the world of science and technology. Whereas the literature at the time discussed the stochastic nature of both biological and technical systems and spoke of the possibility of applying the statistical method to these systems. Shewhart showed how it was to be done. In this regard, a genuine pioneer in the field of quality control can be claimed. His book, Economic Control of the Quality of Manufactured Products, was published. The basic principles of quality control in 1931 are considered complete and complete. 

Often called an advisor, Shewhart served in the War Department, United Nations, Government of India, and others. He was active with the National Research Council and the International Statistical Institute. He was a fellow of many societies and in 1947 became the first honorary member of the American Society for Quality. Many believe that the Shewhart Medal, awarded for outstanding technical contributions to the quality profession, is the most prestigious award ever received by the American Society for Quality Offer. 

Saturday, May 22, 2021

History of Quality

History of Quality

The quality profession has a long history, which has greatly accelerated over the last eighty years. Joseph M. Juran (1988) has traced the practice of the quality profession back to the traditional Egyptians and the building of the pyramids. For centuries, quality was intrinsically linked with craftsmanship, and each craftsman controlled all aspects of the final product of his craft. This changed dramatically with the Industrial and economic Revolution. 

History of Quality

Modern quality practices began in two stages: large-scale inspections within the early 1900s and control charts around the 1930s. As a result of the scientific management of Frederick Taylor, mass inspection became common. Workers stopped checking the quality of their work and instead handed it over to specially trained inspectors. Although the inspection is an important element of quality, Walter Shewhart's invention of the process control chart introduced the quality profession. Alton Mayo's Hawthorne study for Western Electric resulted in an awareness of worker motivation and attitudes as quality contributors in the early 1930s.

 The next major push for quality came during World War II when suddenly poor quality products could destroy people's lives. At the same time, hundreds of American companies were called to manufacture goods for the most precise requirements. Many quality control techniques, such as acceptance sampling and process control charts, which were only encouraged before the war, became mandatory as part of the defense effort. Two of the leading practitioners of the quality profession - W. Edwards Deming and Joseph M. Juran established their professional credentials during this period. The two later traveled to Japan to teach statistical and management tools to the defeated nation. The two later traveled to Japan to teach statistical and management tools to the defeated nation. In the 1970s, it became clear that the Japanese had learned their lesson well: American, former masters, frequent trips to the Japanese, alumni to explore Japanese successes, and proven Japanese methods at home. 

The American Society for Quality Control, now known as the American Society for Quality (ASQ), was born soon after World War II, when Martin Brumbaugh observed that if he were to bring various local quality control societies into a national organization Can see if you can integrate then you will get a lot of benefits. Faced with this task, he recognized the superb skills of George Edwards, who was then head of inspection engineering at Bell Telephone Laboratories. Edwards became the first president of the society and helped establish the policies that guide its operation to date. 

The first three awards given by society to recognize these three pioneers of quality were the Brumbaugh Prize, the Shewhart Medal, and the Edwards Medal. Over time, society has created several other awards, each of which honors a specific hero of the profession and recognizes outstanding achievement in a particular area of ​​the profession. 

Wednesday, May 12, 2021

Plastic | Types of Plastic |


Hello friends, 
Today, We'll discuss Plastic & its types. Hopefully, you'll understand this topic.
First of all, thanks for visiting.
Now, below topics that we are covering today.


The plastic term is derived from the Greek word 'Plastikos' which means "Fit for molding". It is a polymer that is a carbon chain of many monomers. The monomer is a single element. 

Note: All plastic is the polymer and not all the polymers are plastic because other metal is also made up of polymer. For example Iron.



There are two types of Plastic.
  1. Thermoplastic
  2. Thermoset

1. Thermoplastic: 

That plastic is solid at normal temperature. But it becomes soft when heated. That is, when we heat it, it becomes soft and when cooled again, it takes solid form. 
Thermoplastic can be remelted and reused. It can be recycled easily.
For example- PS, PE, PP, PC, HDPE, ABS, etc.

2. Thermoset: 

That plastic that can't be melted again and reused. Once it melted in any form and again when trying to melt, degrade the material. Its physical strength is high. Due to high insulation, it is used to make electric appliances. It is adhesive therefore it is used for making fevicol and plastic paint.
For example- PF, Epoxy resin, Bakelite, Melamine, etc.


PE (Polyethylene): 

By a scientist named Singler, high-density polyethylene was identified by identifying the hazards found in the lime system and using a special catalyst to extract a new technique for preparing polyethylene from ethylene air at low pressure and temperature. The new plastic had more features than the previously made plastic. Research got a new direction due to this plastic. It was first produced in India in 1961.

Polyethylene is of two types:
  1. Heavy polyethylene
  2. Light polyethylene

Physical properties: 

  • Colour: It is white-colored & transparent.
  • Density: Its density is up to 0.915 to 0.930 gm/cc. Due to its density being less than water, it floats in water, Which means, there is no effect of water on it. 
  • On applying to heat: It becomes soft in boiling water. It remains flexible up to 70°C.
  • Light: There is a slight effect after some time.
  • Electricity: It is a very good electrical insulator.
  • Weather & Climate: There is no special effect. 

HDPE (High-Density Polyethylene):

HDPE (High-Density Polyethylene) materials have a linear structure in shape. Its density is lies between 0.95 to 0.97 gm/cc. These are high crystallinity and are 80% to 90%. The softening temperature point for this material is 135°C. HDPE materials are stiff and hard.

Linear structure
Linear chain

LDPE (Low-Density Polyethylene): 

LDPE (Low-Density Polyethylene) materials have branched structures in shape. Its density is lies between 0.91 to 0.925 gm/cc. These are low crystallinity and which is 50%. The softening temperature point for LDPE is 115°C. This material is tough and flexible.

Branched structure

Clamping force | How to calculate the clamping force in injection molding machine |

 CLAMPING FORCE:  Clamping force is an engineering term used in mechanical and manufacturing processes. The meaning of clamping force is to ...