An Investigation and Design of a Set of Magnesium Luggage Citation King, Emmett Thomas (1947) An Investigation and Design of a Set of Magnesium Luggage. Master's thesis, California Institute of Technology. doi:10.7907/q2m6-b707. https://resolver.caltech.edu/CaltechTHESIS:05282025-202307566 Abstract No abstract. Item Type: Thesis (Master's thesis) Subject Keywords: (Industrial Design) Degree Grantor: California Institute of Technology Division: Engineering and Applied Science Major Option: Engineering Thesis Availability: Public (worldwide access) Research Advisor(s): Unknown, Unknown Thesis Committee: Unknown, Unknown Defense Date: 1 January 1947 Record Number: CaltechTHESIS:05282025-202307566 Persistent URL: https://resolver.caltech.edu/CaltechTHESIS:05282025-202307566 DOI: 10.7907/q2m6-b707 Default Usage Policy: No commercial reproduction, distribution, display or performance rights in this work are provided. ID Code: 17286 Collection: CaltechTHESIS Deposited By: Benjamin Perez Deposited On: 26 Jun 2025 18:29 Last Modified: 26 Jun 2025 18:38 Thesis Files PDF - Final Version See Usage Policy. 16MB Repository Staff Only: item control page

AN INVESTIGATION AND DESIGN OF A SET OF WJ.AGNESIUM LUGGAGE r Thesis by EMMETT KING In Partial Fulfillment of the Requirements for the Degree of Industrial Designer California Institute of Technology Pasadena, California 1947 TABLE OF CONTENTS Summary 1 Introduction 3 Market Survey 4 Consumer Research 15 Luggage in Use 20 Material Research 33 Design Solution 47 Fabrication 59 Design Summary 64 Appendix 66 SUMMARY The use of a metallic material for luggage permits a more simplified type of construction than does leather or fabric and in addition fabrication by high production methods is possible. Of the metallic materials available magnesium, with its low specific gravity, suggests itself to the designer as a luggage material worthy of investigation .. The magnesium alloy, Dow FS-la, is the most suitable and will be used as she et which will be drawn to form the case. The closure will be of the same alloy shaped by extrusion and will be spot welded to the case. A clear melamine-alkyd resin has been tested for abrasion and is suggested as the finish for the magnesium luggage. A market survey made to determine the number of units th&t might be sold in 1947 indicates a potential market for about 50,000 units. A consumer survey has been made to determine consumer preferences and a functional study of luggage in use made to determine the advantages and defects of present luggage .. The designed luggage depends for its appearance on the direct use of the material in a form dictated by the material and the functional aspects of luggage .. design is adapted to mass production methods without involving excessive tooling costs., The INTRODUCTION Luggage design is one of the lesser known fields of activity of the industrial designer but it is a field in which he can be of service to the consumer~ The purpose of this investigation is to design for the traveler, luggage that is more convenient, durable and attractive though available at moderate cost . New materials are developed and new methods of fabrication are devised which offer to the designer new possibilities for luggage. Magnesium, a material new to the luggage field, is investigated and a set of luggage is designed to take advantage of its pharacteristic properties. In order to make a complete design investigation, the subject is divided into Market Survey Consumer Research Luggage in Use Material Research Design Solution r In each phase of the investigation, the factors which influence the de sign of luggage are studied in order to incorporate them into the design solution. market survey which follows is the first step in the investigation . The MARKET SURVEY The size of the luggage market is of importance to the manufacturer and the designer because a knowleq.ge of the size of the market determines the production processes to be used and the amount of new tooling that might be e.conomically undertaken . A market survey was made in this study to determine the 1947 market demand for hand luggage. As a preliminary step in the market survey the industry as a whole will be considered in order to provide a background for more detailed considerations., The luggage trade was severely curtailed during the war years and 1946 operations, due to scancity of materials, do not reflect the normal conditions within the trade ., Information on the luggage business was sought from the national trade associations - The Luggage and Leather Goods :Manufacturers of America, National Luggage Dealers Association and the National Luggage Salesmen's Association but these have no available recent figures. The last available complete government information is the 1939 census and this will be used in this thesis as representative of the normal conditions of the industry. The complete census data pertaining to luggage is briefly summarized in Table I on the following page: 6. TABLE I 1939 Census Data on Luggage No .. of Manufacturers Reporting Total Sales 329 $36,826,000. Suitcases, Trunks, Briefcases, all other luggage Cost of materials used Value of Products Value added by Manufacture Suitcases and Travel Bags only Leather Non-Leather Leather Non-Leather $19,214,722 .. 36,591,482. 17,376,760 .. Number 1,596,814 5,178,490 Value $8,910,642. 12,893,290. %Number %Value 23 .. 6 76.,4 40.9 59.l %of Value of Total Production Suitcases and Travel Bags. Satchels, Briefcases, Trunks, Boston Bags, Hat Boxes, Radio Cases, Sample Cases, etc .. Channels of Distribution Manufacturers Sales: Direct to retailer Wholesalers and Jobbers ~holesale Branches Industrial Users Other 65.,5 34 .. 4 % 71 .. 0 16.-2 5 .. 6 5 .. 1 2.1 100.0 Retail Stores Department Sto.r es Luggage Stores Furniture Stores Jewelery Stores Variety Stores Sporting Goods Stores %Total Luggage Sales 39.,8 39 .. 3 11 .. 1 6.4 2 .. 1 1.3 100.0 7 .. These figures indicate that the luggage industry is not a large industry and that manufacturing costs represent about one half of the value of the goods produced . Suitcases and travel bags account for 65 percent of the value of tetal volume produced and tbat although 3½ times as many non-leather bags are produced, the value of leather bags represents 40 percent and non-leather 60 percent of the total value of bags produced .. The main channel of distribution in the luggage business is from manufacturer directly to retailer (71 percent) although there is some wholesaler and jobber distribution (16) percent ) in the trade., Department stores and luggage stores represent the major retail sales outlets and account for approximately 80 percent of the luggage sold., In an effort to predict the 1947 market for luggage, the following must be considered. "Prospects for 1947, are that production will not reach the demand, because continuing shortages of wood, leather, rayon for linings and even metal fittings, and locks still exist . " B~ Judelle, Research Director "Luggage & Leather Goods" Magazine "Industry members assert, when they are permitted to make leather luggage the backlog and current demand will be sufficient to allow them to produce at a high rate for at least three years ., " J.G . Schnitzer,Chief Leather Unit UoS. Department of Commerce "Here are the Department of Commerce estimates on 1947 supplies and production based on the best data available: Luggage will reach new post-war sales peaks .. " Regional Commerce Bulletin U.. S .. Department of Commerce Field Service, Los Angeles "Careful and intelligent forecasting of the future shows that our industry may look forward to a probable annual retail sale approximating $235,000,000. Further analysis shows the likelihood of some 20,000,000 new customers. "There is even the possibility that the unfair •Luxury" tax on luggage may be dropped with a consequent stimulant to the consumer purchasing. "It is indeed the better part of good judgement for all factors in our industry to give first consideration to the interests of the ultimate con sumer. "There is a general fear that if prices advance too much or unjustifiably, the resultant customer reaction will leave retailers with too much merchandise at prices the customer will refuse to pay." Aw J~ Mellin, Editor "Luggage & Leather Goods" December, 1946 Mr. Mellin's statement reflects the attitude of the luggage industry as a whole. Buyers and luggage store owners realize that there is a large potential market, but that prices keep the goods from moving as rapidly as desired. It has been stated that while the O.,.P.,A .. 9 .. price controls were in effect new small luggage enterprises started and were granted a favorable price in excess of that in effect for established manufacturers. Some estimated that hundreds of new manufacturers entered the luggage business on reconversion from war work. As in other lines, the mortality of these new- comers is expected to be high when prices return to more normal levels and material~: become more available .. In an effort to obtain a correlation between the 1939 volume and 1947 volume of the luggage business, the following members of the luggage trade were asked how 1947 business would compare with the 1939 volume of business. Those asked and their replies are given below: Luggage Buyer of Large Los Angeles Department Store: "1946 was better than double 1939, in unit and dollar volume. 1947 is expected to increase over 1946, both in unit sales and dollar volume .. " Luggage Buyer of Large Los Angeles Department Store: "1947 is expected to be 2½ to 3½ times dollar volume of 1939." Luggage Buyer, west Coast Mail Order House: "In the industry as a whole, twice as many units sold in 1946 as in 1939, atfour times the dollar value." 10., A conservative estimate would , pJ_ace the 1947 demand at twice that of 1939, as will be seen in the market survey summary. Luggage Types Available on the Market: There is practically an infinite variety of luggage types on the market but the ~ajority fall into the following classifications: Leather and simulated leather Fabric Canvas Paper or fibre Metal. Leather The highest quality luggage is made of leather and is found chiefly in man's bags - soft sided and semi-formed .. The most popular leather is top grain cow hide aniline dyed. There is some pig skin shown although very little at present and some expensive bags are made of shell cordovan. In ladyts bags whi ch are formed over a bass wood or veneer box, a considerable number of better bags are of raw hide in natural or russet shades . Simulated Leather Simulated or artificial leather is used as a covering in manYs formed and semi-formed bags at a much lower price range than leather. Fabric The most common type of luggage is fabric known als o as "airplane linen" or "airplane canvas., 11 The fabric covering is applied over a bass wood or veneer frame and the edges are protected wit h leather or simulated leather. The fabric is usually cotton impregnated with plastic,cellulose nitrate being the most common but other plastics are in use also .. The weave varies from a simple crash through twills to complex weaves and the colors vary from grays to brilliant stripes. Canvas Canvas luggage, as distinct from "airplane canvas," is used as a material for soft man's bags such as the folding Val-a-pa.k type and in man's bags as a substitute for leather . bound with leather. The edges and corners are Canvas luggage sells for a lower price than leather or fabric types. Paper or fibre The cheaper grades of luggage are made of paper and fibre and encompass the complete range from cardboard 12., to paper filled plastic. This luggage is made down to a price and handled only in the low priced stores. Metal Metal luggage is of two types; one is very low priced suitcase of sheet steel that has not been made during the war, but is found in low priced luggage stores, as a cqpetitor of cardboard luggageo metal The other type of luggage is the Halliburton line of aluminum luggage which is in the present market. It is competitive with good quality fabric and medium price leather luggage. stores that handle it say it is quite popular$ The One store buyer who did not handle it said it had a place in the future luggage market. Luggage prices in many cases have been doubled and tripled over prewar prices .. Seventy-five dollars for good (qality man's leather bag is not unusual. One store v owner s&id that customers who did not question the price of a piece of luggage before the war, now, when told the price of the pi eces they are considering is $50 to $75, put off their buying . Hide prices have doubled over prewar levels, cotton has doubled and wages and other materials all have increased necessitating an increase in luggage prices. 13 .. The Federal Excise Tax adds 20 percent to all luggage in addition to state or local taxes. In the case of a $50.00 bag this becomes impressive: Price of bag $50.,00 Federal Tax (20%) lOcOO Sales Tax (2½%) Price including taxes 1.25 $61.,25 The effect of higher prices in luggage in view of discussion with buyers will find the consumer favoring the less expensive types and in some cases the consumer will not buy but will continue to use his present luggage. SU1\ifr..'1ARY In 1939 there was produced 6,775,304 suitcases and travel bags. The editor of 11 Luggage and Leather Goods" est imates 20,000,000 units will be sold in 1947 . The buyers of luggage for the local department stores and mail order houses expect 2½ times the 1939 sales or 16,000,000 units. The luggage manufacturer with a 1939 record of sales will base his 1947 production at twice his 1939 figure if he thinks his position in the market is the same as in 1939~ The manufacturer new to the luggage field or producing a ne w item, such as magnesium luggage, hasa 14. much different probleme As will be seen from the inform- ation supplied by the store buyers in the consumer research section about one percent of the luggage sold is metal. With a capable sales organization and good retail outlet coverage, the magnesium luggage manufacturer might expect to sell about one third of one percent of the total market or about 50,000 units. This figure is adequate to justify developing and tooling costs. Sales by the manufacturer will be directly to the retail outlet and department stores and luggage stores will account for 80 percent of the sales . The number of units sold will be dependent upon the price . The most favorable market will be for items in the $20 - $25 range and the size of the market will decrease rapidly with price increase . 15. CONSUMER RESEARCH In order to produce an acceptable design the designer must consider the conditions at the point of sale and the factors considered by the consumer in choosing luggage. In this study the consumer research is divided into two parts: Preferences. Buying Habits and Customer The consumer research for this thesis was done by a study of sales methods of various stores and by interviews with buyers or proprietors of the following stores: The May Company Bullock's, Downto wn Herbold's, Pasadena Gump's, Pasadena Sears Roebuck Company Broadway Luggage Shop, Pasadena This group handles all classes of luggage from the lowest to the highest price and serves all buying classes. As an illustration - one store handles a t 7w piece set of man's leather luggage priced at $323.00 while one of the other stores handles a two piece set of' luggage at $3 . 55e 16 .. The buyer or proprietor was interviewed and asked the following seriew of questions: Q: A: At what season is most luggage sold? Ali: During the summer vaca~ion season and at •• Christmas time for gifts. Q: Is luggage buying done equally by men and women? All: More by women. One buyer estimates eight out of ten buyers are women. The reasons suggested: women are better shoppers and do more of the family buying. Q: Does the man or the woman make the decision when buying luggage for the familye All: The woman A: A: Q: A: What does the man look for in luggage? All: Practicality. Q: A: What does the woman look for in luggage? All: Style and price. Q: What percentage is done for business trips? 25 to 40 percent. A: Q: A: What percentage is done by vacationists? 60 to 75 percent. Q: A: Do guarantees and warantees influence the buyer? All: Secondary. Confidence in store is primaryo Q: Has the war changed buying habits? All: No .. A: In the interviews discussed in the preceeding section, the following questions ~ere asked to determine customer preferences in luggage: 17., Q: A: Q: A: Q: A: Q: A: What factors influence the customer's choice of luggage? Brand Appearance Price Name Weight Other Gump's May Company Bullock's Broadway Lug gage shop Herbold's 1(85%) 2 Sears Roebuck l 2 l 1 3 2 2 2 1 1 3 3 3 Impor- Important tant only in choosing between types 2 What percent (in units) of luggage sales in 1947 do you expec,t to be Gumpts May Company Broadway Luggage Shop Herbold's Sears Roebuck Leather Fabric Metal 30-40 35 60- 70 60 1-5 35 65 20 80 50 15 Paper l½ 5-10 15-20 What sizes of hand luggage are most popular? All: Lady's Man's 24 11 Two- suiter 21" Overnighter 21" Wardrobe What types of lining are most popular? All: Lady's Man's Linen or Crash Rayon Q: A: What colors in linings are preferred byrm.en? All: Tans to oyster gray., Q: A: What colors in linings are preferred by women? All: Browns, tanj blues; least popular: red, yellow and green . 18., Q: A: Q: A: What was the best selling item of luggage in your experience? Man's Lady's Two-suiter 21" Wardr obe Gump's May Company 21 11 Overnighter Val-a-pak 21 11 Wardrobe Two- suiter Bullock's Broadway Luggage Shop 29 11 Fortnighter 21 11 Overnighter Gladstone Herbold's before war and Wardrobe Sears Roebuck 21 11 Overnighter What, in your opinion, will luggage be like in five years? Gump's: Leather, soft sided instead of veneer formed. May Company: More men to canvas for better wear. Bullock's: No comment. Broadway Luggage Shop: Leather, fabric, aluminum also; sizes same as nowv Herbold's: Leather and fabric as now. Sears Roebuck: Same as 1939. SUM}l[J.ARY Most of the luggage buying is done by women and the most important considerations in their selections are appearance and price. The male customer considers the practical aspects of luggage. Ap proximately 65 percent of the luggage sold will be fabric luggage and 30 percent will be leather, the remainder will be paper and metal. Th e most popular sizes are the lady's 21 inch overnight bag and 21 inch wardrobe; the most popular man's item is the 24 inch t wo-suiter. As a result of this research the designer will make every effort to design luggage of attractive appearance for the lady's sizes and with practical features in the man's line. The trade and consumers are quite well satisfied with conventional types and anticipate no revolutionary changes~ This indicates to the designer that too radical departures may meet with sales resistance and require extensive advertising and sales promotion efforts. 20., LUGGAGE IN USE A study of luggage in use was made to determine a) the method of handling luggage in travel in order to design luggage of greater convenience, b) the weight of the various size bags when filled in order to design bags of sufficient strength, c) the weak points of present luggage and the causes of failure in use in order to design luggage without these shortcomings. a) Luggage handling methods: Automobile travel - Hand luggage is well adapted to automobile travel since all but the largest pieces can be stowed conveniently in the rear seat, available enroute and free of damage because of the upholstered surfaces of the car interiore Hand luggage when carried in the trunk is liable to damage from tires, tools, grease and sand., Bus travel - Modern busses have convenient facilities for both short haul and long distance travelers., Ample compartments, well lighted, are located under the seats at floor level. They are 21 . 17½ inches high and designed to protect the luggage. Overhead racks are constructed of polished rods or stainless steel sheet to prevent damage to luggage. They measure 8½ in. high and extend 16½ in. from the side wall. Enlarged dust proof and watertight exterior compartments will accomodate pieces up to 24 in. x 24 in. x 45 in. Railroad travel - Railroad car builders are incorporating many features to aid in handling and stowing baggage in the newer cars. The Pullman seat has a space 9 in. x 16 in. x 28 in. beneath it sufficient to handle most hand luggage and in the coaches and chair cars, in addition to the overhead racks, provision is being made for stowing luggage at the end of the coach in a compartment capable of handling the larger piecese Bedrooms, roomettes as well as drawing rooms on the nev; sleeping cars are equipped with ample overhead space for all luggage. There is a trend toward mechanizing the handling of checkable luggage by the installation of conveyor belts and mechanical lifts. In order to become more familiar with luggage handling by railroads the facilities of the Los Angeles Union Depot were studied and the General Baggage Agent, Mr. M. P., Livingstone, was consulted on baggage handling problems. The traveler with only non-checking luggage either carries it to the car himself or gives it to a red cap who delivers it to the car on a steel luggage cart. The car porter places the luggage at the passenger's seat or in the luggage compartment. It is carefully handled through this method and is seldom damaged . The checkable luggage is presented at the baggage counter and the train indicated on the tag .. It is handled mechanically as much as possible and is liable to damage since it is stowed in the baggage car and loaded and unloaded as rapidly as possible. The general baggage agent was asked the following questions: Q: A: How many pieces of luggage does the average train traveler have? Two pieces .. A: Is the tendency of travelers to have more or less luggage than formerly? Less larger pieces and more smaller pieces. Q: A: Is the tendency to check through more or less? Checking through less. Q: The luggage space in the passenger car is designed to hold how many pieces for each passenger? Two or three pieces for each passenger. Q: A: Air travel - The most phenomenal growth of travel is exhibited by the air lines. "Air passenger traffic jumped 70 percent reaching eight times the 1939 rate. Air passenger miles were about 40 percent as great as Pullman traffic." U*S *Department of Commerce Field Service, Los Angeles April 1, 1947, Volel, No16. 23. To study air line luggage handling problems two and a half days vrnre spent at the Los Angeles Municipal Air port in the baggage rooms of the United Air Lines and T.,W., A., Air line baggage is presented at the dovmtovm ticket office and brought to the field in bus s es or presented at the field to be weighed and stowed in the baggage compartment of the plane. Plane baggage facilities vary with the plane as do handling methods. The two engine planes have the baggage sections aft of the pilots compartment below the floor level ., The compartments are loaded and un- loaded by handc The new Douglas DC-6 airliners have eight preloaded cargo containers - dural baskets 34 in~ wide by 26 in. deep and 72 in~ long which go into two compartments located fore and aft within the fuselage .. An overhead monorail system is designed for handling the baskets and mechanical loading devices permit loading and unloading without interference with other service activities. Lockheed has designed a supplementary cargo carrying unit which can be attached to the underside of the Constellation in 30 secondso It will handle any type of baggage and become6 immediat~y available for loading and unloading of baggage when the plane lands~ With its use it is claimed the baggage can be delivered to the deplaning passenger within five minutes. In unloading the two engine transport a metal chute is used on which the baggage slides dovm from the baggage space to ground level. This chute unless carefully maintained in smooth condition can cause damage to luggage by scratching or cutting the side. Occasionally a piece of luggage will drop from the chute to the ground - a distance of up to 15 feet. Steamer travel - No limitation on the weight or size of hand luggage is imposed by shipboard travel and the luggage is carefully handled and stowed in the passenger's stateroom. 25., TYPES OF LUGGAGE USED BY AIR TRAVELERS The weight of various types of luggage in actual use is of importance to the designer and the air lines present the only convenient means of determining the weight of the bags as used in actual travel. In order to obtain data on a large number of bags, a study was made at the United Air Lines and the T.W.A. baggage rooms at the Los Angeles Municipal Airport. The air line identification tag attached to the baggage gives the weight of the bag. From this the size and type of bag plus the weight was readily recorded. The data obtained is presented in Tables II and III on the following pages. An examination from the point of view of materials used for luggage reveals a surpDisingly close correlation between the bags in actual use and the sales reported by the store buyers in the consumer research. Luggage sales Luggage in use J& Fabric %Leather 65 53 34 35 If leatherette and canvas are added to fabric, we ha1Te fabric 62 and leather 34 percent .. 26 TABLE II TYPES OF LUGGAGE USED Br AIR TRAVELERS Number of Units % % 32 43 11 1 21 8 LeatherLadys Total Leather Paper Metal Total Units Units Fabric ette Lad;y' s 21"0vernighter 18"0vernighter 16"0vernighter 2l"Wardrobe 24TrWardrobe 26"Wardrobe 29"JK Wardrobe Hat & Shoe Box Round Hat Box Total Lady's 27 7 1 4 l 1 15 1 14 1 7 20 5 1 10 5 7 5 3 3 4 2 1 2 2 3 1 1 74 100 48 1 66 Man's 21" Overnighter 18" Overnighter 24 11 Two- suiter 5 26" Two- suiter 9 28" Wardrobe 1 Gl&,dstone Canvas Val-a-pak Suitcases Club Bags Brief Cases 1 5 3 3 4 1 6 7 9 5 3 3 4 15 20 11 1 15 4 8 7 25 14 1 19 10 2 13 2 1 8 Man's 12 1 1 2r.·,.' 1 4 4 3 3 Total Man's 15 8 4 48 2 2 79 Grand Total 81 8 7 52 3 2 152 Lady's Bags 89 0 4 5 1 0 Man' sBags 19 10 5 61 2 2 All Bags 53 4 34 2 l %Units 5 10 7 7 1 10 4 5 5 2 2 100 52 9 5 100 27 . TABLE III WEIGHT OF LUGGAGE USED BY AIR TRAVELERS .. . Average Weight . pounds 1.n ., Fabric LeatherAverage ette Leather Paper Metal W~ight LADY'S 21 11 0 vernight 18 11 Overnight 16 11 Overnight 21" Wardrobe 17 14 14* 17 14 16 8 11* 25 24 11 Wardrobe 26 11 Wardrobe 29" Wardrobe 25 20 43** Hat & Shoe Box Round Hat Box 8* 21* 25 25 20 26* MAN'S 21 11 Overnight 16 11 Overnight 24 11 Two-suiter 26 11 Two- suiter 28 11 Wardrobe 31 31 (Can vas 20 12 25* 20* 32 29 20 12 Al.25* 27 only) 31 31 3Q-¾; ' Gl&,dstone Val-a- pak 24* 2q 27 26 Suitcases 28 28 Club Bags 16 16 Briefcases 20 20 * Insufficient data for average- single weight reported ** Believed to be used as a sample case - not representative 28 ., In the case of lady's bags, fabric definitely dominates and since the leather bags reported were raw hide there is a negligible amount of leather (as we think of it in man's luggage) in lady's use. Man's luggage in use shows a predominance (61 percent) of leather types and only one third as much fabric luggage., Luggage Sizes Of the 153 pieces of luggage included in this study, a fact worthy of especial notice is the almost equal division of pieces of man's and lady's luggage 79 and 74 respectively. Of the 17 sizes of luggage reported, three sizes account for 51 percent of the total. These same three sizes were reported by the store buyers as the most popular. They are: lo Lady's 21 in. overnighter 2. Lady's 21 in. wardrobe 3. Man's two-suiter. Gladstone bags and suitcases, considered obsolescent items, represent 15 percent of the total bags and 28 percent of the man's bags. Their obsolescence results from the fact that they do not keep the contents wrinkle-free as does a two-suiter or wardrobe. 29., Weight The study summarized in Table III on the factor of weight gives average figures for the most common types of bags when used for air travel .. There may be a slightly lower average weight for air travel as against automobile or train but the difference is probably very slight. Some average weights of use in design may be summarized Lady's 21 inw overnighter Lady's 21 in. wardrobe Man's 21 in. overnighter Man's two-suiter Average Weight (pounds) of bag filled .. 17 25 20 31 New top quality bags representative of two sizes and three types of materials were weighed empty and the results are as follows: Lady's 21 in. wardrobe Aluminum Fabric 10 pounds 9 pounds Man's Two-suiter Aluminum Fabric Leather (Ven . frame) Leather (soft sided) 12 pounds 12 pounds 13 pounds 10 pounds It can be seen that there is very little difference in the weight of the finished bag regardless of the material used. Defects in Present Designs In order to find the deficiencies in present luggage, the store buyers and the baggage agent at the Los Angeles Union Depot were asked specific questions concerning the weak points of present luggage in service. The questions asked and the answers are as follows: Q: A: What parts of luggage fail most often in service? Sears Roebuck Locks Gump's Hinges,locks, hand loops Bullock's Handles and locks Herbolds Locks Broadway Luggage Shop Handles, loops, locks, catches May Company Locks, post type handle holders and bag corners. Questions asked the general baggage agent, Los Angeles Union Depot: Q: A: Q: A: Q: A: Q: A: Q: A: Which type of luggage, in your opinion,. resists wear best? Wood frame fabric covered. What, in your opinion, are the most common shortcomin~s in luggage from the baggag"e agents point of vi ew? 1~ Breaking plastic handles, 2. Spot welds on locks . W hat part of luggage is the chief point of failure in use? 1. Handle 2~ Locks Material when not wooden construction throughout. What is the chief cause of most failures: Overpacking? Weak material? Weak hardware? Abuse? Accidents? Overpacking. Flat irons being heavy and pointed often cause damage when not secured properly . What type of accident in handling most frequently causes damage to luggage? Dropping on corner~ 31 .. Q: A: Q. .• A: What percent of luggage is delayed due to loss of baggage tag? Five percent of luggage . Of the baggage delayed, 75 percent has no identification on it . Would delay or loss best be prevented by ll Name and address plate built into luggag e? 2 Name and a ddress tag attached to luggage? 3 Initials or name stamped on luggage? 4 Other? lj Name and address plate built into luggage. 2 Name and address tag attached to luggage. 3 Initials or name stamped on lug gage. Q: What, in your opinion, will luggage be like in five years? A: There will be a great improvement, in materials and construction . Alu..rninum luggage has a future - it is light and suitable for train and plane . The baggage handlers at the Los Angeles Airport were asked which part of luggage failed most in service and their ans wer was handles., They also expressed the opinion that luggage with rounded edges and c orners was less susce pt i ble to damage t han tha t vd th sharp edges and corners. Asked about aluminum luggage, they said it was new and they were seeing more pieces as time goes on . They liked it because of its rounded corners. SUMI\ilARY As a result of the study of luggage in use the following conclusi on of design importance were made: Luggage f a cilities in trains, buss es and aircraft and the hand ling equipment at depots and terminals are designed for present luggage sizes . Users of luggage 32 .. find the present sizes adequate to their use. The design of new l uggage should not depart too far from present sizes., . , A limited line of three pieces would consist of a lady's 21 in .. overnighter and 21 in. wardrobe and a man's t wo-suiter.- The sizes of a complete nine piece line is given under the Design Solution. The average weights of present bags are Lady's 21 in. overnighter Lady's 21 in. wardrobe Man's 21 in. overnighter Man's two-suiter Empty (pounds) Filled (pounds) 8 17 9-10 25 9 20 31 10-13 This indicates to the designer the range within which the weight must be to be competitive., The average weight filled serves as a starting point to determine the load which the bag mu.st carry. The common points of failure are handles and locks. The chief cause is overpacking about which the designer can do very little except to make the hinges and catches as strong as possible. The most common accident is dropping the bag on the corner. Luggage with rounded edges and corners is less liable to damage from this source* Delay in recovery of a lost bag can be best prevented by a name plate built into the luggage~ 33. MATERIAL RESEARCH Present luggage materials - leather and fabric have many inherent advantages; leather possesses a flexi- bil ity and toughness that particularly suit it for luggage use., Fabric, vYhen coated with plastic, demonstrates a durability adequate to use as a luggage material. Simu- lated leathers are the subject of intense research and new improved types are being produced every year. These new leathers have not only very good resistance to wear but it is hard to distinguish the better types from real leatherc A new luggage material was sought not because of the properties of fa bric, real or simulated leather but because of disadvantages of construction of luggage when using these materia.ls. •Soft-sided leather luggage is essentially sevm together and lacks rigidity. This lack of rigidity prevents tight dust proof and moisture proof closure and subjects hinges and catches to misaligrunentc The veneer box luggage covered with fabric, leather or artificial leather likewise lacks rigidity though not to so great an extent. The corners of this type of bag are the critical points for wear and the vulnerable spots when the luggage is dropped. 34 .. A metallic material, it was thought, would have advantages over these types .. These advantages are 1. It would permit a more simplified construction, 2. It would be adapted to high production methods. The materials considered were steel, aluminum and magnesium. Steel sheet, while possessing high strength properties and ease of fabrication, would have weight disadvantages if used in thicknesses sufficient to prevent denting .. Aluminum has been successfully adapted to luggage use and magnesium had not been so adapted so it was decided to investigate the possibilities of magnesium as a luggage material .. The weight-stiff- ness ratio of magnesium permits fabrication in magnesium with thicker sections for the same or lighter weight. The obvious form in which to use magnesiwn for luggage is in sheet. The sheet may be formed and the edges welded by helium arc or riveted .. This method is used on a set of magnesium luggage which has gone into production recently. to cast corner postse The sheet edges are riveted 35 .. PROPERTIES OF MAGNESIUM ALLOY DOW FS-la Composition of Magnesium Alloy Dow FS-la: Aluminum Manganese (Min) Zinc Silicon (Max) Copper (Max) Nickel (Max) Iron (Max) Other Impurities Magnesium 2.5 to 3 .. 5 0 .. 20 0.7 to 1.3 0~30 0.05 0.,005 0.005 0.3 Remainder Tension: Ultimate Strength Typical Spec., Min. 37,000 psi 32,000 psi Yield Strength* Typical 22,000 psi Elongation in 2 inches Typical Spec. Min .. 21% 12% Compression Yield Strength* 16,000 psi Shear Ultimate Strength 21,000 psi Hardness Brinell 500 kg Load 10 mm Ball Rockwell E 56 67 Endurance Limit 500 x 10 6 Cycle s 12,000 ps i Specific Gravity lo77 1/Veight - pounds per cu ., in., 0.064 Melting Point 1160° F * The stress at which the stress- strain curve deviates Oe2% from the modulus line., 36 .. Another method of utilizing sheet is to obtain the form desired by dravdng,, Magnesium alloy sheet, when heated, permits dravving to luggage depths in a single draw. This offers to the designer the inducement of low handling costs and though die costs may be hign they would be absorbed in a large run without adding an excessive amount to each piece. Finishes for Magnesium There are various types of finishes available to the designer for use on magnesium alloys each well suited to a particular purpose - they are Mechanical Chemical Electro-chemical Electroplated Painted., Of the mechanical finishes, polishing and buffing can be used to produce an attractive bright metallic luster on magnesium .. If protected with a clear lacquer, this type of application finds a field in decorative finishes., Sand and shot blasting, scratch brushing and similar finishes may also be used for special effects., 37 . Electro-chemical or chemical treatment of magnesium will not produce coatings of hardness comparable with anodized aluminum. They do produce protective coat- ings in neutral shades that may be colored by organic dyese Some electroplating has been done but it is still in the process of development., Chromium plating of magnesium is not commercially availa ble at the present time although some work is being done on it by Dow., Painted finishes offer a wide range of possibilities on magnesirun . The ap pearanc e and sales appeal of magnesium alloy articles can often b'e · enhanced through the use of novelty finishes by means of which many ' interesting effects are obtainable. Although the term "novelty" might imply a lack of' durability, many of these finishes have a permanent place in the field of metal finishing and provide good protection as well as appearance., These materials very often reduce finish- ing costs since their natural roughness obviates the necessity for surf.s.cing and sanding operations so often re quired in gloss enamel finishes. Many novelty finishes are self-performing and yield crystallized, cracked, checkered, mother-of-pearl, leather, hammered metal or wrinkled effects wi thout further treatment . 38. Baked Japan and color coats are used for various kinds of product finishing. The materials are available in different lusters varying from flat to high gloss. Rapid finishing, excellent adhesion and good wear resistance are some of the advantages of baked finishes and a clear finish applied to the luggage designed would enhance the sales appeal of the luggage and aid in conveying the factor of lightness to the consumer. A study was made of va1~ious coatings ap plicable and the most promising seemed to be a melamine formaldehyde alkyd resin type. Melamine resin adds durability to alkyd coatings as well as other desirable features of shorter baking schedules, harder films, better wear and chemical resistance. Melamine resins are unique in this respect; they are the only hard resins which actually improve the durability of the alkyds. No published data of melamine coatings on magnesium vvere available so a study was made of a melamine-alkyd resin. The study follows: 39 .. Test of Melamine Baking Finish A melamine baking finish (SV 142 Leon Finch Co.) composed of 25 percent melamine resin and 75 percent alkyd resin in Butanol was studied on magnesium. In a preliminary test magnesium sheet samples were alkaline cleaned in a solution whose composition was Trisodium Phosphate 4 Sodium Carbonate 4 oz ., Soap Water oz. .. 1 oz .. to make a gallon. The bath was maintained at 180-210° F and the samples were immersed 5 to 10 minutes. After the alkaline cleaning the samples were rinsed and immersed in a bright pickle solution whose composition was Chromic Acid 1.5 pounds Magnesium Nitrate 4.,0 ounces Calcium Fluoride 0.,75 ounces Water to make a gallon . The samples were i mmersed from 2 to 5 minutes in the solution then thoroughly r i nsed and dried. After painting with the melamine finish, the samples were air dried for 4 5 minutes and baked at 250-275° F. for ohe hour . 1'1°J io l\]r:. 2'2 These pr eliminary samples /\were used in order to develop a technique in acid treating, spraying and baking .. The treatment given each of the twenty-one samples is given in the appendix. The chemically treated samples produced 1:llsuitable finishes and it was decided to use mechanical cleaning and surface preparation., Samples 4 in., x 4 in. of .072 in., sheet were prepared with a ¼ in., hole drilled in the center., Ill!:ill scale and surface imperfections were removed by the use of emery paper followed by a b~right buffing on a cloth wheel. A satin brushed finish was then applied with fine emery paper. The buffing compeund and surface dirt was r~moved by cleaning twice in acetone followed by rubbing with a clean dry cloth., The samples were then spray painted with the mel2.mine resin, follovving which they were air dried for 45 minutes, then baked at 250-275° F for 60 minutes .. The samples were then weighed on a laboratory precision balance and run for 1,000 cycle s on the Taber .Abraser with a 1,000 gram weight on each CS-10 Viheel., At the completion of the test the samples were again weighed and the loss in weight is sho~n in Table IV and summarized below: Sample No:J.. 25 26 27 28 29 Loss in weight per 1,000 cycles 15 .. 5 mg 14.0 mg 18.,0 mg 16.,0 mg 18 .. 0 mg 4.1 .. MAGNESIUM SAMPLES ON RACKS PREPA..qATORY TO SPRAYING 111"..AGNESIUM SAL'\ITLES ON RACKS FOR BAKING FIG., l 42._ TABER ABRASER IN OPERATION SAMPLES SHOWING ABRADED RINGS FIG . 2 43 .. These values show a loss of approximately one-half that of a baked enamel (Sample D, .Appendix F) and one half that of uncoated magnesium .. In order to determine approximately what thickness of the coating is worn off in 1,000 cycles .. The middle of the path over which the abrading wheels would travel w.s measured and marked on the back of the sample. Four marks were made on this path 90° apart and by means of micrometer calipers the thickness of sheet and coating before abrasion was measured at each point., After abrasion the total thickness at each point was again measured$ From these measurements,as shovm in Table V, an approximate decrease in coating thickness in 1,000 abrasion cycles was obtained. An average decrease would be a bout 0.-0007 in~ but the large decrease in sample Now 27 cannot be explained. Samples of thin sheets to which the resin had been applied have been bent through 90° and returned to their original shape with no tendency to chip or flake off indicating good adhesion to the metal. The study of va.rious alkyd-mel2.mine combinations to find the one possessing, in the highest degree, all the required properties must be left to another study .. This type of resin combination appears to be TABLE IV LOSS IN WEIGHT DUE TO ABRASION Weight After* Abrading (grams) Loss in Sample Number Weight Before* Abrading (grams) 25 35.3355 26 Weight Loss(mg) (grams) 1,000 cy .. 35.,3200 .0155 15.,5 35.3635 35.3495 .0140 14 .. 0 27 35.5825 35.5645 .,0180 1a .. o 28 36.0210 36.0050 .,0160 16.0 29 36.0165 35.9985 .0180 18 .. 0 * Weights shown include weight of copper hook (o.5585 gms) by which samples were held in balance. 45 TABLE V DECREASE IN COATING THICKNESS IN INCHES FOR 1,000 ABRASION CYCLES Sample Point of Measurement* No.25 No.26 No.27 No.28 No .. 29 .,0007 .0007 .. 0011 .,0007 .,0004 180° .,0004 .,0006 .,0011 .. 0013 .,0007 270° .,0006 .0007 .0007 .,0006 .,0005 360° .0007 .,0008 .0011 -0005 .0009 90 0 * o0 and 360° line was arbitrarily chosen as the line between the center hole and small hole at t he top of the sample ., The angles are measured clockwise from this line ,on the back of the plate . 46. well suited for use on magnesium luggage because it not only protects the magnesium from corrosion but possesses the additional characteristics of adhesion, resistance to abrasion, color retention and resistance to water spotting and chemicalsv 47 . DESIGN SOLUTION In the solution of the luggage problem, the designer has the Market and Consumer Surveys and the Material Research and must from these and from rational considerations produce an effective and pleasing design. From market survey and consu.n1er survey, the designer concludes what the trade and consumer like and dislike about present luggage., The materials research determines the advantages and limitations of his materialse In the rational considerations of functional, psychological and aesthetic factors, the designer opens the way to new ideas. Rational Considerations in Luggage Design a., Functional Factors: A piece of hand luggage must have: 1 .. Capacity Sufficient to carry the clothes and articles for which it was made. 2. Protection For the contents from the elements and dirt. 3. Convenience In carrying; to fill and empty; to open and close; to stow in carriers, cars, luggage racks, etc. 48 .. 4., Strength To resist damage to contents; to case itself;in handles and fittings. 5., Durability To resist wear .. b. Psychological Factors: Its appearance should suggest: 6., Its function By showing the factors listed under a. It must appear to be a piece of luggage., 7., Lightness To as great a degree as possible without compromising its appearance of strength and durability., 8., Convenience Inuse - functional convenience alone is not enough, it must seem convenient also,. 9., Security It must seem strong., 10 ., Suitability For use by men and women in a single line it should appeal to both men and women., c~ Aesthetic Factors: In appearance it should be: 11., Pleasing in appearance - Of good taste in materials and color appealing to pride of ownership ., 12., Simple straightforward use of materials devoid of applied ornamentation., Design of Basic Shape 1. Luggage is essentially a container to hold clothes and accessories used in travel and at destination., 20 Containers suitable for clothes are bags or boxes ., 3 o Containers suitable for other articles are boxes. 4., The bag has resilience but when subjected to prolonged pressure garments will wrinkle . 5., The box will resist crushing but is weak at the flat sides and corners. 6. Both of these considerations can be minimized by a box with rounded edges ab) sides may be arched ) the corners roundedc 7., As an alternative to the above , the structure may be made of thicker section and the corners reinforced f:r•om within and protected vd th outside corner pieces (as in trunks and leather luggage~) 8 .. Internal bracing de.ereases capacity and may add to weight .. 9. External bracing, unless carefully faired in to main structure , presents opportunity for broken up appearance and production difficulties., 10. Rounded sides seem preferable from structural point of view. 11., Rounded corners and edges decrease the volume of the case., 12 e The loss in capacity is not directly proportional to the loss in volume as would be the case if sharp cornered objects were to be packed in the case since clothes and accessories will conform to the rounded corners., 130 The basic shape then is an arched box with rounded edges and corners. 50 .. MATERIALS 1~ Metallic materials like magnesilllil sheet are suitable for luggage when a) formed b) drawn 2. Drawing possesses the following advantages: 1 .. Fewer production steps involved, 2. Closer finished tolerances possible, 3 .. More unified structure, 4. Welding and riveting avoided with improved finished appearance .. 3. The basic shape derived from rational considerations is well adapted to production by drawing. We have derived a basic shape as a starting point and drawing of sheet as a means of fabrication. The size of existing luggage by test and by consU1I1er preference in adequate to its function so the basic sizes should not depart too far from this. The tendency to make the luggage narrower to stay close to the body seriously limits capacity and efforts to offset this by increasing height or width makes the bag less convenient to control while walking., A consideration of the functional uses and advantages and shortcomings of present sizes determine the sizes for the luggage designed and a nine piece set will Qe in the following sizes: 51., Length Height Width 1 .. Lady's 21" Overnighter 2., Lady's 18 11 Overnighter 3., Lady's 21" Wardrobe 4., Lady's Traincase 5. Lady's Hat & Shoe Box 6 .. Pullman Case 7 .. Man's Two-suiter 8., Man's 21" Overnighter 9. 29 11 Wardrobe 21 18 21 13 18 26 24 21 29 13½ 13 17 7½ 18 16 18½ 14 16 7 6½ 9 9 11 8½ 8 7 9 HANDLE The handle of a piece of luggage is possibly the most important single factor in its design because it is Functionally - Aesthetically - the longest sustained point of contact with the user~ it is the focal point of attention in observing a bag. It is necessary that the designer consider all of the factors in handle design such as lo Comfort of grip: l a) Is cross section adequate to 1 2 3 Conform to hand under load, Suit long and short fingers, To enable fingers to close proper degree - long finger nails of women. b) Is the length correct ll To fit a large hand, 2 To center hand in handle 3 For use with gloves., c) Are there ridges or seams to rub or cause discom.fort~ 52., d) Is the material of handle best suited for tactile qualities. e) Is material suitable in warm or cold climates. f) Does it have the required degree of rigidity or resilience. 2. Handle Strength: a) Does it have required strength to carry the load .. b) Is it capable of withstanding hard usage. 3e Handle Suspension: a) Does it facilitate control of the bag in use., b) Is it designed to carry load and stand wear. c) Does it permit handle to lay flat on be.g. d) Is it in the way when ba.g is being filled or emptied~ e) Is its mape such that it will damage other bags that may be rubbed against it .. Psychological Factors 1. Does it look like a handle. 2. Does it look comfortable. 3 .. Does it look strong. Handles of existing luggage were tri ed and handles made and teted on a heavily loaded bag. As a result of this handle study one size handle for man's lugg&ge and onesize for lady's luggage wer e designed 53 .. which conform to the factors discussed above. An opaque thermoplastic resin was chosen as the handle material because of its light weight, resistance to shock, ease of cleaning, feeling of cleanliness, low cost and ease of fabrication. Reinforced with a metal strip in which the handle pin bushings are set, the plastic will have the load spread over a larger area and will not be distorted. Handles and loops are one of the greatest points of failure in use. The maximum of protection to handle and loops With the maximum comfort in handle can best be achieved by insetting a hand-fitting ~andle •. This is easiest done in metal luggage - difficult in wooden luggage and impossible in leather type construction. It was decided then to use this type of handle inset, made as a second draw after the case is drawn. The designed inset has been kept to a minimum to maintain bag capacity and facilitate the second draw. CLOSURE: The majority of present bags have unsatis factory systems of closure. Leather bags close by simply overlapping the edges and box frame bags usually have a stepped edge. A tongue and groove type 54. of closure is superior to the above types in that it 1. Adds rigidity to the structure which makes bag less liable to damage, 2. Maintains catches and locks in alignment, 3. Excludes moisture and dust more effect- ively .. In the magnesium luggage designed, this closure is composed of two magnesium alloy extrusions and is spot welded to the case with a one in.spot s pacing. HARDWARE: Hinges: A piano type hinge is used for rigidity and strength .. Catches: The catehes and locks are of the conventional type spaced so that the fingers are not struck when the catch is opened? The catches and locks are designed to be harmonious with the case and be of adequate strength .. Locks and catches of conventional design, if made of good material, will last the life of the luggage. Locks and catch troubles arise from poor materials and spot welding the lugs on the catches. Overpacking and misalignment due to a non-rigid case weaken locks and catches. LINING: The linings in the man's cases will be of good quality cotton crash in a pale tan tint. The linings of the women's cases vdll be of heavy rayon in ·vvarm brown colors .. 55 . NAlvIE PLATE: One of the shortcomings of luggage is the lack of adequate means of identification . Loss of bags and delays in delivery are due in part to the absence of the ovvner 's name and address. In the designed bag, a name plate will be located in the handle inset. The plate will be covered with a cap upon which the initials of the owner may be placed. FINISH The case will have a scratch brush finish and a clear melamine-alkyd baked coating. This resin combination gives a hard mar-proof surface with adequate protection to the magnesium alloy. To prevent excessive scuffing and abrasion on the sides, a bead is raised so that if the case should slide along a rack or chute the wear will be taken by the bead rather than the whole surface. It also serves to strengthen the case and relieve the austerity of the lines. The possibilities of using magnesium alloy sheet for the box and covering the surface with fabric, artificial leather or spun glass cloth were investigated and it was decided that the cost of finishing the magnesium would be less than the cost of the added coveringe Also the additional weight to the luggage was considered undesirable. The complete possibilities of covered magnesium luggage might be worthy of exploration by some other designer. Z ;;5 .• , Cle · i - :::J . I er, vl .. I ~ ~ 0 . UJ 0 C -.-- - -.::( - · l'.) ~ - l'.) ~::: ~ <! __, -~- ~ .....J :S = I _j_ rm -. ( ( I I J I I i - -- ----- ' (F ---- \ ~ ~ I r 1, ~ - :I I s I w g - ~ I !~ ' N 1-' I ··-1·-·-· -- FIG-. 3 - -· - > f- z :> I I ' _l_ - - r LL i ~ 11 e- ~Y~- - .: ,, / -- .?Y.i; ~~ - ~ ~ ' --=t - --- - - ~ -- "4-- - -- -- ~~ 9Y,/ ~ ,c • 11vif(r .:::e- ~ ·:<,1-- - 7"8- - -~ ::r- . d= I I I I S E.C. A A 44"'< . - ::i a··~ 1e"R - -- - -.~'-./'re.,,~ - -- - - ~-l (S ec DRA"·1NG 1 s o" '.., cc , ,c ,., s ) = I .J_ vV I I '!. 24% SEC. BB ~ = = = = = =L = = = = = = = = -~ 4'1 ·,,,..,1 ~ I 1 ' I .. 1 -,t 1 I :! -.,,,:tI --tf,,,.~·--.:_ 2~,~- ,q • 1 f 3;,,;_ - · ·- 12. %" l l ' 18 ¾" l,{E, -x i - ·' I -~ *·T l ~.,.,. T[ 3l4 - -- ,,; -_j i J~ · ¾; DESIGN TWO SUITER MA Y 194 7 SEC. CC _..J__ DRAWING I l tMMtTT KING '~ i' ··- ..:•c _ LUGGAGE , • ._ :i. ,/i , : 7 DD i--V/-----1--v.-.i DETAI l . ~ l l / 1/l/i'llllll3 • ~?Vi~·.:., 11/U'N.•11!(,·~= ~ - - - -- - l -'ff.- t }(, DETAI L DD FABRICATION OF THE DESIGNED LUGGAGE The fabrication of the designed luggage is better suited to a metal product manufacturer than a leather goods or luggage maker as they are tooled at present., Hydraulic presses can be readily adapted for magnesium use by the application of gas heat or electric heat to the dies . The other conventional metal working equipment is readily adapted to use on magnesiwn., The literature on the fabrication of magnesium is quite extensive as can be seen from the bibliograp4yw No purpose would be served in going into the field of magnesium fabrication in this thesis. Only the steps involved in making the designed luggage will be considered. Each side of the designed case will be dra~n ,, in a hydraulic press from .064Dow FS-la magnesium alloy at 600° F. using the same dies for both sides. The handle inset would be shallow drawn in a heated die before the piece cooled from the first draw. The edge closure will be two extrusions in Dow FS-1 alloy formed hot and spot welded with one inch spacing to the case. The total weight of the magnesium alloy used in a 21 in. x 13½ in. x 7 in .. case of .,064 sheet would be vv STE P.S I -J ,_,., D .0' ·,,,/\"\ \,II./• I ~ I MAG N ESIU/"/l I ( : ~. L UGG A GE / _ _ _ _. . ,:I; KING- .. M/\Y 1947 FIG. 5 61. less than six pounds. The brush finish will be applied after all fabrication is completed . The melamine coating will be sprayed and the case baked by means of infra red lamps. The lining will be inserted after the handle and hardware have been installede Design Calculations: In order to determine the thickness of the sheet to be used in the case, the follo vving assumptions are made: That points of local strain such as the handle supports can be reinforced by small backing plates leaving the large areas of the sides as the weak point. severe or unusual strains such as dropping from a 15 foot height or impact against a sharp object are not cons idered as normal loads and must be neglected. The stacking of other bags on the designed bag is normal however and in use as many as five bags may be stacked upon a single bag. The weakest point for this . type of load is the sides of the bag and the deflection of the center of this' area will determine the thickness of the sheet to be used . 62 No formula has been found to exactly suit the designed shape., The formula given by Timoshenko ➔~ for a flat plate with fixed edges and uniformly loaded is the closest approximation., The area considered is that within the bead on the largest case (a = 15 in. b = 17 in.) The load applied is assumed as 150 pounds or that caused by the weight of five thirty pound cases. Timoshenko's formula is 4 (w) = 0.,0164 "1t:I)< .9.L Eh ~ for materials whose Poissonr:s ratio .,/ =- 0.3 and whose ratio of sides b/a = 1.1 where (w) = maximum deflection at center of plate(in.,) a = length of smaller side (in.) = 15 q = load intensity on plate (psi) = 150/255 E = modulus of elasticity for Mg (psi) = 6.5 x 10 ' h = thickness of plate (in.) = .,064 (w) max l 5 0 X 50 620 0.0164 X 255 ' 6.5 X 10 " X~0~64 'JI 0.,288 in. The maximum bending stress is well within the elastic limit as shown by the following: * "Theory of Plates and Shells" Chapter VI, pg. 229 63. The equation for the maximum bending moment as given by Timoshenko is M == .,0581 qa' from v-v-hich ga% - S .: 0 .. 187 h:z - Maximum unit stress 150 8 = 0.-187 X 255 which is within the elastic limit. X 255 = 6030 psi The .064 in. sheet will weigh 25 percent more than Oe051 ine sheet but will shovv only half as much deflection. Before investing in dies a shape as close as possible to the designed bag should be made of 0.064 inc sheet and tested under load to find the ~ctual resistance not only in bending but to impact also. DESIGN SUMMARY The designed luggage will be made from .v064 in .. magnesium alloy sheet dravm to form the case and will be finished in a clear melamine resin . A man's 24 in . x 18 in. x 8 in., two-suit er has been fully developed as a model for the complete set .. •rhe salient features of the designed luggage may be enumerated as follows: 1~ It is designed for mass production . 2 .. .An attractive appearance is achieved in the clean direct use of the ma terial and a feeling of lightness suggested in the form of the case w 3 .. It is designed for durability. 4 .. The inset handle protects a most vulnerable point in the luggage., 5., The edge closure gives the case rigidity and protects the contents .. 6 .. The handle is designed for ease in carry- ing and control of the bag. 7. It is suitable for use by men and women. 8. The incorporated name plate assures return to the owner when misdirected. The designer has made an attempt to use magnesium for a purpose to which it is suited by its unique physical properties and to fabricate it in a manner to best take advantage of these properties in luggage use . The often repeated "Form Follows Function" finds an illustration in this design which depends 65 , for its appearance on its form and the metallic quality of the material . A piece of luggage lasts about eight years in service and an effort has been made to avoid faddish or transient styiing, and to design a bag that is distinctive and useful .. APPENDIX Table of Contents of Appendix A Bibliography B Interviews C Correspondence D Treatment of Preliminary Samples F B BIBLIOGRAPHY MARKET RESEARCH "The Technique of Marketing Research" "A Company Gui de to Marketing Research" "Modern Market Research Procedures" "Annual Statistical Review" "Introduction of New Consumer Products" 11 Trade & Professional Societies of U.S . 11 "U.S.Census, 1939 11 "Census of Business,1939" "Census of Manufacturers, 1939" "Trade Practice Rules for the Luggage & Related Products Industry" American Marketi ng Ass 1 n McGraw Hill,NY,.937 American Management Assn AMA Research Dept . No . 5 R .. D .. Crisp Amer,.Mgn' t Ass 'n Market Series No.6 , J an . 46 U~S .. Dept.af Comrnerce,1946 u .. s .. Dept . of Commerce,1935 u .. s.Dept . of Commerce U. S .. Dept . of Commerce u. s.Dept . of Commerce u.s.Dept . of Commerce u. s .Federal Trade Cornm . 41 MAGNESIUM FABRICATION "Magnesium by the Ton 11 The Dow Series "Designing with Magnesium" "ASurvey of Wrought Magne sium Alloys" "Spot Welding Magnesium Alloys" "Fundemental Alloying Nature of Magnesium" ''Processing of Magnesium Alloys" "Aircraft Oil Tanks of Mg. Alloy" 11 Deep Drawing Mg Alloy Sheets "A Protective Finish for Mg Alloys" "Painting Mg Alloys" "Mg Processing Tecbniquesn "Deep Drawing Mg Domes" tTDrawing Magnesium" "Hot Forming M_g Alloy Sheet" "Mg Sheet Easily Formed" "Production Principles for Deep Drawing Mg Parts" "Organic Finishes for Mg. 11 "Protective Treatments for Mg Al loys" Fortune,pg.156,March , 1944 Dpw Chemical Company American Magnesium Company Winkler , Trans .. ASM~Oct~44 Dorcas&Simpson, Iron Age Apr .. 26,1945 Carapella, Metal Progress, August, 45 Simpson,"Al & Mg Dec.1945 West , "Al & Mg Aug .. 1945 Weber&Berg,IronAge, Mayl0 , 45 Mason,Iron Age , Mar.21,46 Wray,Ind & Eng Chem,July41 Simpson "Elec . Mfging,Apr46 Fulliksen,Metals & alloys April,1945 Allen,Prod . Eng & Mgmt, May45 west,Iron.Age , Aug.16,1945 West,Amer . Mach, May 25,44 Gillespie,Mat . &Methods March, 1946 C lose, Metals & Alloys, June,45 Bleiweis& Fusco,Metal s & Alloys , Feb . 1945 DESIGN TtTheory of Plates & Shells" Timoshenko,Eng .. Soc. Monogra phs C INTERVIEWS The following have generously supplied information used in this thesis: J., v., Winkler Dow Chemical Company Los Angeles J., G. McGowan American Magnesium Company Los Angeles Charles Miller Northrup Aircraft Corp. Hawthorne, California Orville Shantz Gump's, Pasadena c., D. Dickson Sears Roebuck & Company Los Angeles J., L .. Harris Bullock's, Los Angeles Re D .. Herbold Herbold's, Pasadena Leo Garfield Broadway Luggage Shops Pasadena G. A., Casto The May Company,Los Angeles M.. p., Livingstone General Baggage Agent Los Angeles Union Depot J., N. Stone American Cyanamid Company Azusa, California L., Cota Leon Finch Company Los Angeles E., D•. Witaman J.P. Fuller Company Los Angeles w. c . Rogers United Air Lines Los Angeles Municipal Airport .. D• CORRESPONDENCE J. G. Schnitzer Acting Chief Textile & Leather Industry Section,Office of Domestic Commerce, U~ s .. Department of Commerce Beatrice Judelle Research Director, ''Luggage & Leather Goodsy 1170 Broadway,New York City A. B., Sheldon Exec.,Secty .. ,National Luggage Dealers Ass'n, 241 Genesee St .. , Utica,2,N.,Yw Eo B. Soebbing Secty.,Amer. Ass'n of Baggage Traffic Mgrs.,,1405 Railway Exchange Bldg<P st. Louis, Mo., Samuel Singer Secty.,Luggage & Leather Goods Salesmen's Ass'n.,358 5th Ave.,New York City Maurice Levitan Exec.,~ecty.,,Luggage & Leather Goods Mfgrs., Ass'n,220 5th Avee,New York City MANUFACTURERS Hartman Company Racine, Wisconsin Oshkosh Trunk & Luggage Co .. Oshkosh, Wisconsin vVheary Company Racine, Wisconsin Independent Trunk Petersburg, Virginia & Bag Company U.. S.,Luggage & Leather Products 29 West 3'-±thSt .. ,New York City Schwayder Bros., 4270 High st .. ,Encorse Sta .. ,Detroit,Mich .. HARDWARE The Excelsior Hardware Co. Stamford, Conn. Horn Luggage Div.,RiceStixCo. st. Louis, Mo., Milwaukee Stamping Co. . 816 So .. 72nd Street Milvvaukee, Wisconsin National Brass Cov Grand Rapids, Mich., Yale & Tmme 1\/If g., Co. Stamford, Conn American Hardware Corp. New Britain, Conno Brainerd Mfg.,Co., East Rochester, N.Y. North & Judd Mfg. Co~ New Britain, Conn. Eagle Lock Co. Terryville, Conn. E PLASTIC MATERIALS Carbide & Carbon Chemical Corp .. New York City,N~Y~ Firestone Rubber & Lastex Co~ Fall River, Mass. Hercules Powder Co. vVilmington, Del. E.I.DuPont deNemours & Co. Arlington, N.,J~ B. F. Goodrich Co. Akron, Ohio Monsanto Chemical Co. Springfield, Mass. Bakelite Corporation 30 East 42nd st. New York City F FREPAR.ATION OF PRELIIviENA,.-qy SAMPLES Sample Pre paration Abrasion Test Los s Alk. Pickled Baked275° Wt.Loss - mgf No. Buffed Brushed Clean Time (Min) Time (Min) Wig Cycles lbOocy. Sample 1. 2 ., 3. X X X X 4,. 5. 6. 7. 8. 9 .,, 10. 11 . 12. 13. 14. 15. 16. 17 . 18. 19. 2 2 2 2 X X X 2 25 1400 600 60 60 40 60 40 60 12 10 13 10 800 500 60 11 400 27 60 40 60 60 60 40 60 60 100 60 80 60 60 16 31 10 26 15 25 16 17 700 1600 19 300 33 1600 1000 1000 300 1100 600 700 1900 16 15 25 53 15 20 300 300 18 33 40 33 16 20 Rejected X Rejected X 3 X X 2 X X X X X 2 X 2 X X X 20 ., x 21. X Rej ected 22 .. Steel D Mag. (Back of #4 buffed only) All samples air dried 45 minutes before baking. Melamine Resin, SV142, Leon Finch Company 25% Melamine 75% Semioxidizing Alkyd Resin Butanol Solvent. Abrasion test on Taber Abraser (Research model) 1000 gram weight on each CS-10 wheel. 12 15 52 22 44 1700 600 1000 23 17 8 31 37 44