The purpose of the Math Skills for Injection Molding booklet is to develop certain essential math skills for use in manufacturing. There is a major emphasis on units and unit cancellation; identifying knowns and unknowns; and hints for determining the order and structure of equations when solving for unknowns. The book should serve useful to train operators, technicians and inspectors as well as the supervisors, engineers and managers who work in manufacturing.
There are also numerous examples done using spreadsheet software to demonstrate and train such spreadsheet software approaches.
This booklet will have discussion and detailed solutions for the following calculations:
• basic algebra - basic math rules and principles; order of math operations
• conversion factors to change units;
• correlation analysis - direct and indirect relationships;
• cycle and cooling time; heat load and water flow requirements;
• hydraulic cylinder speeds (extend & retract time);
• intensification ratios, mechanical advantage, clamp tonnage, injection speed, fill time;
• interpolation - how to determine precise data values from incremental data;
• part molding costs and pricing, molding utilization values;
• percentages, efficiency & basis for change; percent change;
• process capability (Cp & Cpks + Pp & Ppks); standards deviations and means;
• projected area in a mold;
• proportions and ratios - cross multiplication to solve for unknowns;
• residence time in barrel and dryer;
• thermal expansion and coefficients
• trigonometry - calculating size changes with tapers, resultant forces acting thru tapers; solving for unknown tapers; lengths and/or size changes using basic trigonometry
