Testing and Quality Control: With the advent of Science and Technology, the concept of testing is an integral part of research and development, product design and manufacturing.
Why we need testing?
• To prove design concepts
• To prove a basis for reliability
• Safety
• Protection against product liability suits
• Quality Control
• To meet Standards and Specifications To meet Standards and Specifications
• To verify the manufacturing process
• To evaluate competitors products
• To establish a history for new materials
Fundamental Aspects of Testing:
Test Method
AA definitive definitive procedure procedure for for the the identification identification, measurement measurement and and evaluation evaluation of one or more qualities, characteristics or properties of a material, product, system or service that produces a test result.
Test Data Helps
• To determine the suitability of plastics for a particular application, for quality control purposes or to obtain a better understanding of there behavior under various conditions
• The physical property data obtained by testing is required to design the product development and failure analysis.
• The testing data are required for to promote the use of plastics.
• Testing feed back helps to aid improved design or quality control procedures.
Quality Control Test:
Quality control datas are useful for finding suitability of a material design, and product quality. It carries out the actual test, make use of test planning and test data processing. The data processing helps In checking reproducibility and accuracy of the test result.
Standard Method of Test:
Standard methods of tests are required for evaluation
• Basic plastics molecule from laboratory level to the resin & the Product.
• It helps product reliability.
• Liability registration
REASONS FOR TESTING
1. To ensure
• Incoming raw material are acceptable and consistent quality.
• Product of intermediate stages of manufacture are of an acceptable and consistent quality.
• End product of the overallll process is of consitent and acceptable quality.
2. To evaluate
• New or competitive materials or modifications to a process.
• The fitness for purpose of a material, process or product.
3. To obtain
• Early evidence of changes taking place in a process.
4. To prove
• Design aspects.
• Quality control and Safety
Types of Tests:
The following are the major types of test:‐
1. Analytical Test.
2. Material Characterization Test.
3. Material property test.
4. Product test.
Analytical tests are important for :
Quality control
Development of new materials.
Product designing.
Process Optimization.
Major analytical tests are :
Density and specific gravity test.
Water absorption test.
Moisture analysis.
Sieve Analysis Sieve Analysis.
Material Characterization Test
Material characterization tests are used for:
• To identify the material
• To determine chemical composition To determine chemical composition
• To determine Structure
• To determine Flow Behavior
Major Characterization Tests are:
• Melt Flow Test
• Viscosity Test Viscosity Test
• Molecular Weight and Molecular Wt Distribution
• Thermal Properties (TGA, DSC, TMA)
• Spectroscopy
• Microscopy
1. The property datas of the material are the major resource for selection of material,, pprocess opptimization and product and
mould design.
2. The various properties of plastics materials are determined by
standard standard test test methods methods, such such asas ASTM ASTM, ISOISO etc etc.,
• The most common material property tests are:
• Mechanical properties.
• Thermal Properties.
• Electrical Properties.
• Optical Properties.
• Weathering Properties
• Chemical Properties
3. Testing of plastics product is important for predicting product performance.
4. This test can be carried out from test specimen prepared
by machining the products or the whole product.
5. Non Destructive Test
• Preferable where the product is very expensive and which
cannot be destruct.
• Ultrasonic Ultrasonic and and Radiography Radiography methods methods are are Advanced Advanced NDT
Standard and Specification:
Standard and specification helps to develop common language for developers, designers, fabricators, purchasers and suppliers, End
users.
Standard:- A technical document based on consolidated results of science, technology and experience approved by a standardizing body for the benefits of the people.
Standardization Standardization:- It is the activity giving solutions for repetitive applications to problems, essentially in the sphere of science, technology and economics aimed at the achievement of the optimum
degree of order in a given contest.
Technical specification:- A document which lays down characteristics of a product or a service such as levels of quality performance, safety or dimensions.
Types of Standards:
•Basic standard:- It contains general provisions for one particular field.
•Terminology standard:- It is concerned with terms, definitions, explanatory explanatory notes, notes, illustrations, illustrations, examples, examples, etc etc..
•Testing standards:- A standard concerned exclusively with test methods supplemented with other provisions related to testing such as sampling, statistical methods and sequence of testing.
•Product standard:- A standard specifying some or all the requirements to be met by a product.
•Safety standard:- A standard aimed at the the safety of the people and goods.
Bodies or Organization – Formulating Standards
INTERNATIONAL ORGANIZATION:-
1. International Organization for Standardization (ISO):- In plastics field the principle body producing standard is ISO.
2. International Electrochemical Commission (IEC):- In electrical field IEC producing
standards.
NATIONAL ORGANIZATION:-
1. British Standard Institution (BSI):- BSI was formed in 1901, producing standards in all
fields.
2. American National Standard Institute (ANSI): ANSI is the premier standardization body
in USA.
3. American Society for Testing & Materials (ASTM): ASTM is a Scientific & Technical
Organization formed for the development of standards on characteristics and performance of materials, products, systems and services and promotion of related knowledge.
4. Deutsche Institute Fur Normung (DIN):- The German standard organization was formed
in 1917 producing standards in all the fields in German language which published in English, French French and and Spanish Spanish also.
5. Bureau of Indian Standards (BIS):- BIS is engaged in developing national standards and
their revision/review from time to time.
Aims of Standardization:
Aims of standardization in general :-
• To achieve maximum overall economy in terms of Cost.
• To ensure maximum convenience in use – simplification, rationalization, interchangeability of parts, increased
productivity, elimination of unnecessary waste and shortening of inventories.
• To adopt the best possible solution to recurring problems by use of scientific knowledge and technological developments.
• Standardization of sampling procedures, test methods, grading schemes and quality specification.
Quality & Standardization:
•Quality is “ the totality of features & characteristics of a product or service that bear on its ability to satisfy a given need in an economical manner.”
• The objective of standardization is to ensure maximum convenience in use by simplification, rationalization and
interchangeability of parts, increased increased productivity, elimination of waste, shortening of inventories, etc.
Specimen Preparation:
Manufacturing process: Orientation of the molecule chains, as they are created
in, e.g. an injection operation or during stretching (films, deep drawing), has
significant effect on the various characteristics. Other things which effect the
characteristics of the specimen are;
1. cooling speeds
2. Tool temperatures
3. injection speeds
4. curing temperatures
5. and times.
The manufacturing process of a test specimen can be standardized only for molding materials. Tests on finished components allways Show the status of the material at the location the specimen.
Mechanical Properties:
Fundamental to the understanding of a material’s performance is a knowledge of how the material will respond to any load.
The important mechanical properties are
1. Tensile tests
2. Flexural properties
3. Compressive properties
4. Creep properties
5. Stress relaxation
6. Impact properties
7. Shear strength
8. Abrasion
9. Hardness tests
