desing of mould tool & cooling channel optimization of industrial helmet

191

International Journal of Research and Innovation (IJRI)

International Journal of Research and Innovation (IJRI)DESING OF MOULD TOOL & COOLING CHANNEL OPTIMIZATION OF

INDUSTRIAL HELMET

Bhonagiri Sudhir kumar1, Kandathil Abraham Mathew2,

1 Research Scholar, Department of Mechanical Engineering, Hyderabad Institute of Technology And Management, Hyderabad, India.2 Professor, Department of Mechanical Engineering, Hyderabad Institute of Technology And Management, Hyderabad, India.

*Corresponding Author:

Bhonagiri Sudhir kumar, Research Scholar, Department of Mechanical Engineering, Hyderabad Institute of TechnologyAnd Management,Hyderabad,India.

Published: October 29, 2015Review Type: peer reviewedVolume: II, Issue : VI

Citation: Bhonagiri Sudhir kumar, Research Scholar (2015) DESING OF MOULD TOOL & COOLING CHANNEL OPTIMIZA-TION OF INDUSTRIAL HELMET.

INTRODUCTION TO HELMET

A helmet is a form of protective gear worn on the head to protect it from injuries.

Ceremonial or symbolic helmets (e.g., English policeman's helmet) without protective function are sometimes used. The oldest known use of helmets was by Assyrian soldiers in 900BC, who wore thick leather or bronze helmets to protect the head from blunt object and sword blows and arrow strikes in combat. Soldiers still wear helmets, now often made from lightweight plastic materials.

In civilian life, helmets are used for recreational activi-ties and sports (e.g., jockeys in horse racing, American football, ice hockey, cricket, and rock climbing); danger-ous work activities (e.g., construction, mining, riot police); and transportation .

Materials

Types of synthetic fiber used to make some helmets:

• Aramid• Twaron

In former times lightweight non-metallic protective mate-rials and strong transparent materials for visors were not available. In Greece in ancient times helmets were some-times strengthened by covering the surface with boars' tusks (= their canine teeth) laid flat.

INJECTION MOLD COOLING DESIGN

The design of the injection mold cooling system is very important. The cooling time takes up 70% to 80% of in-jection molding cycle, a well-designed cooling system can shorten the molding time and improve the productivity magnificently.

Poor design of cooling system will extend molding time, increase production cost, and the injection mold tempera-ture has great influence to the mold shrinkage, dimen-sional stability, deformation, internal stress and surface quality.

Abstract

A Plastic Material Is Any of A Wide Range of Synthetic Or Semi-Synthetic Organic Solids That Are Moldable. Plastics Are Typically Organic Polymers Of High Molecular Mass, But They Often Contain Other Substances. They Are Usually Synthetic, Most Commonly Derived From Petrochemicals, But Many Are Partially Natural.

Molding Is The Process of Manufacturing By Shaping Liquid Or Pliable Raw Material Using A Rigid Frame Called A Mold Or Matrix. This It May Have Been Made Using A Pattern Or Model of The Final Object.

Cooling channels are used in mold tool to reduce the temperature of the object to help molten material to solidify quickly before the ejection. It is quite useful to increase the production rate.

The aim of this project work is to design mold structure and optimize cooling channel system to reduce effect of war page of industrial helmet.

Literature survey and data collection will be done to understand working process of cooling channels, effects of war page on plastic part’s, mold optimization.3D model of industrial helmet will be prepared by reverse engineering process Assembly of complete mold will be prepared for further process.

Analysis will be carried out on mold cooling channel’s for evaluation and Analysis will be done on different model’s to obtain optimum structure and cooling channel system.

Conclusion will be mode according to the obtained results

1401-1402

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So what are the factors that matter to the cooling effec-tive?

Plastic wall-thickness

Part with thicker wall would need longer cooling time. Generally, the cooling time is approximately proportional to the square and the thickness of plastic parts. If pos-sible, propose to the part designer to minimum the wall thickness.

Cooling system design rules:

• Ensure cooling efficiency, achieve shortest the cooling line meanwhile get quality parts.• Ensure uniform cooling to avoid deformation.• Ease of manufacturing.

Some examples of injection mold cooling design, If pos-sible, the number of cooling channels should be as many as possible, diameter of the cooling channel should be design as large as possible, cooling speed of A is faster than B as figure below. Diameter of cooling channel usu-ally are 6-12mm.

Cooling channels layout must be reasonable. When the wall thickness of part is uniform, the distance of each channel to the surface of parts should be even, which means the layout of channels should follow the actual geometry of the part, see figure A. When the thickness of the part is un-uniform, then thicker wall area need more cooling, see figure B, the injection mold cooling channel can be closer to the part to enhance the cooling effect.

Usually temperature of the sprue gate area are highest, so the cooling start from there would achieve the best cool-ing effective, see figure below.

WARPAGE INTRODUCTION

Part warpage, either soon after molding or at some time in-service, is a problem frequently experienced by injec-tion molders and, at times, also by extruders. Similar to mold shrinkage, the causes and control of warpage are closely related to inherent material characteristics and the laws of heat transfer. In this Technical Tip, we explain the causes and general guidelines to minimize warpage. It should be noted that warpage, like mold shrinkage, is a very complex mechanism and many factors, other than those mentioned here, have an effect on warpage. In some cases, a specific variable may have a different effect de-pending on other factors present.

WHAT CAUSES WARPAGE?

Warpage of thermoplastic parts can be caused by two mechanisms: the contraction of the polymer during cool-ing and the tendency of high-molecular-weight molecules to "relax' if they are under stress. The first is easy to un-derstand, as it is a common property of all solids. The second may be compared to stretching a rubber band. As the stress is reduced, the band returns to its original size at a speed related to the rate of stress reduction. However, if the band is “frozen” while stretched, it retains its shape until the temperature increases sufficiently to allow it to “relax” and return to its normal state.

CONTROL OF WARPAGE

As noted, there are certain polymer material character-istics such as high molecular weight, low heat transfer coefficients, crystallinity, contraction during cooling, etc., which are inherent and cannot be changed. The primary keys to achieving low or minimal warpage are in the de-sign of the part and mold. A thorough review of the fac-tors that cause warpage, conducted at the design stage, can circumvent many problems after the mold has been constructed.

INTRODUCTION TO CAD

Computer-aided design (CAD), also known as comput-er-aided design and drafting (CADD), is the use of com-puter technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer. CADD software, or environments, provide the user with input-tools for the purpose of streamlining design processes; drafting, docu-

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International Journal of Research and Innovation (IJRI) mentation, and manufacturing processes. CADD output is often in the form of electronic files for print or machin-ing operations. The development of CADD-based soft-ware is in direct correlation with the processes it seeks to economize; industry-based software (construction, manu-facturing, etc.) typically uses vector-based (linear) envi-ronments whereas graphic-based software utilizes raster-based (pixilated) environments.

MODEL OF INDUSTRIAL HELMET

The above image shows sketcher

The above image shows adding ribs

The above image shows final model of industrial helmet

MOULD FLOW ANALYSIS

Mould flow, 3D solids-based plastics flow simulation that allows plastics part designers to determine the manu-facturability of their parts during the preliminary design stages and avoid potential downstream problems, which can lead to delays and cost overruns. Following are the benefits:

• Optimize the part wall thickness to achieve uniform fill-ing patterns, minimum cycle time and lowest part cost Identify and eliminate cosmetic issues such as sink marks, weld lines and air traps.

• Determine the best injection locations for a given part design

Mould flow analysis gives you the ability to maintain the integrity of your product designs. It provides you the tools to quickly optimize part designs and check the impact of critical design decisions on the manufacturability and quality of the product early in the design process.

PLASTIC FLOW ANALYSIS OF INDUSTRIAL HELMET USING MATERIAL POLYPROPYLENE (PP)

Plastic flow analysis

The Flow Analysis summary page gives an overview of the model's analysis, including information about actual in-jection time and pressure and whether weld lines and air traps are present. In addition, the dialog uses the Confi-dence of Fill result to assess the mould ability of the part.

The above image shows Plastic flow analysis

Fill Time

This result shows the flow path of the plastic through the part by plotting contours which join regions filling at the same time. These contours are displayed in a range of colors from red, to indicate the first region to fill, through to blue to indicate the last region to fill. A short shot is a part of the model that did not fill, and will be displayed as translucent. By plotting these contours in time sequence, the impression is given of plastic actually flowing into the mould.

The above image shows Fill time

Confidence of Fill

The confidence of fill result displays the probability of a region within the cavity filling with plastic at conventional injection molding conditions. This result is derived from the pressure and temperature results.

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The above image shows Confidence of fill

The above image shows Fill time

The above image shows Confidence of fill

The above image shows cooling quality

PLASTIC FLOW ANALYSIS OF INDUSTRIAL HELMET USING MATERIAL HIGH-DENSITY POLYETHYLENE (HDPE)

The above image shows Flow front temperature

The above image shows Quality indication

PP ABS HDPE

Injection Time:

2.73 sec 3.18 sec 4.05 sec

Injection Pressure:

61.91 MPa 98.57 MPa 106.90 MPa

Surface Temperature Variance Range

-14.45 deg.C to 19.34 deg.C

-21.44 deg.C to 21.29 deg.C

-21.44 deg.C to 21.29 deg.C

Freeze Time Variance Range

-2.38 sec to 4.33 sec

-2.41 sec to 4.53 sec

-2.41 sec to 4.53 sec

Cycle Time: 18.34 sec 21.65 sec 15.58 sec

MOULD EXTRACTION

The above image shows parting surface

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The above image shows core

The above image shows cavity

INTRODUCTION TO ANSYS

ANSYS is general-purpose finite element analysis (FEA) software package. Finite Element Analysis is a numeri-cal method of deconstructing a complex system into very small pieces (of user-designated size) called elements. The software implements equations that govern the be-haviour of these elements and solves them all; creating a comprehensive explanation of how the system acts as a whole. These results then can be presented in tabulated, or graphical forms. This type of analysis is typically used for the design and optimization of a system far too com-plex to analyze by hand. Systems that may fit into this category are too complex due to their geometry, scale, or governing equations.

ANSYS is the standard FEA teaching tool within the Me-chanical Engineering Department at many colleges. AN-SYS is also used in Civil and Electrical Engineering, as well as the Physics and Chemistry departments.

THERMAL ANALYSIS ON INDUSTRIAL HELMET WITH STRAIGHT COOLING CHANNELS WITH WATER AS COOLANT

The above image shows imported model

The above image shows meshed model

The above image shows load applied

The above image shows temperature

The above image shows total heat flux

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International Journal of Research and Innovation (IJRI) THERMAL ANALYSIS ON INDUSTRIAL HELMET WITH ZIGZAG COOLING CHANNELS WITH WATER AS COOL-ANT



THERMAL ANALYSIS ON INDUSTRIAL HELMET WITH SPIRAL COOLING CHANNELS WITH WATER AS COOL-ANT



water glycol

Straight Zigzag spiral Straight Zigzag Spiral

tempera-ture

200 200 200 200 200 200

total heat flux

5.9198e-14

6.8771e-15

4.7871e-14

1.3172e-14

6.8771e-15

6.9655e-15

Direc-tional heat flux in X

5.0854e-14

4.9278e-15

4.6474e-14

7.3145e-15

4.9278e-15

5.8607e-15

Direc-tional heat flux in Y

8.2583e-15

3.9391e-15

4.6989e-14

3.0377e-15

3.9391e-15

5.1032e-15

Direc-tional heat flux in Z

2.9329e-14

4.2854e-15

2.0568e-14

3.5655e-15

4.2854e-15

5.0786e-15

GRAPHS FOR ANALYSIS RESULTS

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CONCLUSION

• In this project, we have designed an Industrial Helmet as per the parameters.

• Core and Cavity is extracted for the Helmet.

• Die design is prepared for the same.

• The modeling, core-cavity extraction and die design is done in PRO/ENGINEER.

• Mould Flow Analysis is done on Helmet, We are using mould flow analysis for finding the material filling, pres-sure distribution during injection molding process.

• Mould Flow Analysis is done using “Plastic Advisor” which is a module in Pro/Engineer.

• By simulating the plastic-filling process for injection-molded parts, Pro/ENGINEER Plastic Advisor enables engineers to design for manufacturability, uncover prob-lems, and propose remedies, reducing development time and expense.

• ASPER THE ANALYSIS GLYCOL SPIRAL WILL PROVIDE GOOD THERMAL TRANSPORTATION WHICH REDUCES WARPAGE TO THE COMPONENT WHILE DOING MANU-FACTURING.

• ASPER THE MOULD FLOW ANALYSIS RESULTS PP MA-TERIAL IS BETTER WHILE CONSIDERING MANUFAC-TURING PARAMETERS LIKE PRESSURE, FLOW QUAL-ITY AND FILL TIME.

• By using this process manufacture of Helmet can be done without any failures….

REFERENCES

1)Improving thermal properties of industrial safety hel-mets Yeh-Liang Hsu*, Chi-Yu Tai, Ting-Chin ChenDepartment of Mechanical Engineering, Yuan Ze Univer-sity, Chung Li 320, Taoyuan, Taiwan, ROC

2) Design and Analysis of Industrial Helmet 1Anil Kumar. K, 2Y. Suresh babu M.Tech 1,2Depart-ment of Mechanical Engineering, Rajiv Gandhi Memo-rial College of Engineering & Technology, Affiliated to J.N.T.University Anantapur, Nandyal,

3)Design and Analysis of Industrial Safety Helmet using Natural FibersRajasekar.K PG Student, Department of Mechanical En-gineering, Narayanan.L Assistant Professor, Department of Mechanical Engineering

4)The Damping of Off-Central Impact for Selected Indus-trial Safety Helmets Used in PolandRyszard Korycki, Department of Technical Mechanics, Technical University of £o´dz´, Poland

5)INTERNATIONAL JOURNAL OF OCCUPATIONAL SAFE-TY AND ERGONOMICS

6) Improving Thermal Comfort in Industrial Safety Helmet using Phase Change Material

7) GOWTHAM VIGNESWARAN1, L. ARULMURUGAN2 K.S.Rangasamy College of Technology,8)Design and Analysis of Multi-Funtional Helmet for the IndustriesA.V. PRADEEP *, R. SURYA KIRAN ** *(Department of Mechanical Engineering, Sankethika Vidya Parishad, Vi-sakhapatnam-45,India)

9)Fabrication of Industrial Safety Helmet by using Hybrid Composite MaterialsB.Murali, D.Chandramohan, S.K.Nagoor Vali and B.Mohan,Department of Mechanical Engineering,Veltech,Avadi,Chennai, India

Author

Bhonagiri Sudhir kumar,Research Scholar, Department of Mechanical Engineering,Hyderabad Institute of Technology And Management,Hyderabad,India.

Kandathil Abraham Mathew, Professor , Department of Mechanical Engineering, Hyderabad Institute of Technology And Management,Hyderabad,India.

desing of mould tool & cooling channel optimization of industrial helmet

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