GLM Posted July 14, 2007 Share #1 Posted July 14, 2007 Shown here are the matching EM "Plastic Economy" Service Collar Emblems. I believe this pattern was adopted or authorized for wear sometime in 1943, or shortly after the war time strategic metals bans on bronze and brass went into effect. As with the plastic cover or hat emblems, the only differences observed in the collar emblems are colors, ranging from medium chocolate brown to very dark brown (almost black). The rollers found on these plastic economy collar emblems are completely different from any other EGA rollers found from before, during or after WWII. They are unique in the fact that they are circular in shape, with serrated or grooved edges and are not the "flower" shapes of other WWII era zinc rollers. These rollers are made of stamped zinc, which will corrode over time, so it's very important that they be kept as clean as possible so they don't corrode and weld to the aluminum screw posts of the emblems. >>>---> Gary Link to comment Share on other sites More sharing options...
GLM Posted July 14, 2007 Author Share #2 Posted July 14, 2007 Also found on the collar emblems are embossed production run numbers. So far, I have found numbers 2, 3, 4, 6, 7 and 12. If anyone has numbers other than those, please let me know, so I can add them to my records. >>>---> Gary Link to comment Share on other sites More sharing options...
GLM Posted August 5, 2007 Author Share #3 Posted August 5, 2007 I have 4 "Plastic Economy" Service Collar Emblems, 2 are stamped with a "4", one is stamped with a 10 and one is stamped with a 11. I'm sorry for the poor quality of the one stamped 10 GICOP, Thanks for the additional lot numbers. I've added them to my records. Are your two # 4's a matching collar set or are they for the same side? Gary Link to comment Share on other sites More sharing options...
Mark M Posted August 5, 2007 Share #4 Posted August 5, 2007 Gary Here is a "5" you can add to your list. Mark Link to comment Share on other sites More sharing options...
Old Marine Posted April 4, 2008 Share #5 Posted April 4, 2008 Hi all, Here are my 3 Plastic EGAs. I have had these in collection for a few years now. They are all in pretty good shape, and to me they look like they all match. I'd like to hear you opinions and comments. The top one is numbered 6 or 9 The bottom right one is also numbered 6 or 9 The bottom left one is numbered 10 Thanks Dennis Link to comment Share on other sites More sharing options...
Brig Posted April 4, 2008 Share #6 Posted April 4, 2008 we've been trying to figure out the numbers for some years. We've gathered that emblems exist in every number 1-12. here's a thread on the latest theory http://www.usmilitariaforum.com/forums/ind...showtopic=17947 Link to comment Share on other sites More sharing options...
jeremiahcable Posted April 4, 2008 Share #7 Posted April 4, 2008 Nice little trio of birds there. One of the theories is that Kodak made a lot of these and that the triangle is their mark. Looks like they have the correct aluminum rollers as well, good find. Link to comment Share on other sites More sharing options...
teufelhunde.ret Posted April 4, 2008 Share #8 Posted April 4, 2008 Nice little trio of birds there. One of the theories is that Kodak made a lot of these and that the triangle is their mark. Looks like they have the correct aluminum rollers as well, good find. Actually Kodak did make some (?) of these emblems, with a Tenite product. I do believe the idea which recently surfaced that these number represent "mold numbers", is actually what this is all about? s/f Darrell Link to comment Share on other sites More sharing options...
Plant#4 Posted April 4, 2008 Share #9 Posted April 4, 2008 If you look at the number 10, the triangle is to the left. With this logic the top one will be a number 6 and the bottom right will be a number 6 , the numbers may represent a date code of mold manufactor, or a date code of item produced, or producer of the mold, ect. Production information is often lost to the later generations. Many tool and die makers (companies) produced items for several manufactures of products. Production codes are hard and fast....but only when you have the key that defines the codes. Even inhouse producers of molds will have more than one master and may or (may not!) make a "few" sutble variations, due to whom wanted what, how many and how fast. just a thought, Dave Link to comment Share on other sites More sharing options...
Brig Posted July 27, 2008 Share #10 Posted July 27, 2008 I know we've hit this pretty hard, that the numbers were just mold numbers, but I was wondering about your matched pairs. What combinations have to guys stumbled upon on known matched pairs. I'd like to see what plates were being used together. And, by chance, has anyone stumbled upon a pair where both had the same mold number?? The only matched pair that came together that I have has the numbers 5 for the right collar, and 11 for the left. So far, we know of the plates running together as follows left/right (as worn) 11/5 Link to comment Share on other sites More sharing options...
Guest dc9 Posted August 10, 2008 Share #11 Posted August 10, 2008 Hello Everyone, This is my first post in this Forum, and having been a plastics design engineer for a number of years and in the business for a decade (or so), I think I can add some more information for consideration. More than likely these individual #s are "cavity" numbers in a particular mold. The plastics molder, for cost reasons, is going to construct a mold with many cavities to produce 4, 8, 12 maybe even 24 individual pieces every time they "shoot the plastic into the mold." Typically, there are going to be a symmetric number of cavities to balance the (high) forces experienced during injection molding. By constructing molds in this manner, versus molding just one piece every shot, they are going to be able to amoritize the cost of the mold across the total number of pieces produced before they have to build another mold (the metal does wear out). Depending on the type of plastic used, and a host of other considerations, the molder may get up to 1 million cycles out of 1 mold. Multiplying the number of cavities per mold will determine how many total pieces would be produced per mold. The molder can then take the cost of the mold + the cost of material + overhead + profit and bid the job for the government. Realistically, given the total # of pieces that could be produced in this manner and the number of Marines requiring the pieces, I would bet that there was only 1 maker of these pieces, with possibly 1 backup manufacturer or alternate to avoid "single sourcing" the parts. Each maker might have 2 molds either running simultaneously or using 1 in production and 1 as backup. (These next comments are a lot less likely, but, can also be considered). In regards to the "shapes" surrounding or next to the numbers; depending on the sophistication of the molder and cost considerations, they may have designed the mold to have replaceable cavities, inserts or moving pieces for each of the cavities. The molder may designate different versions of the replaced mold components by using a different shape, for instance. The government (or customer) may have specified that each different supplier use a shape as a designated maker's mark. Depending on the orientation of the shape, it may have something to do with directional instructions or information. Today, if you notice on plastics parts, there are all types of markings that may designate calendar day, time, version, maker's marks, type of plastic, cycle of the mold, etc. - these all drive toward traceability and quality concerns around the manufacture of the part. It would be interesting to determine what the greatest/highest # is among the population of pieces out there to take an educated guess as to the number of total cavities in the mold (for a part the size of the Cover EGA my guess would be 4, with the Collar EGAs probably numbering 12). It would also be interesting to note the variety of shapes. If there are different shapes, one should be able to note if there are subtle differences in the features on the surface of the parts (with the same numbers) in an attempt to identify replaced mold components or different makers. Back then, mold manufacturing was more art, then today's automated CNC production, yielding noticeable differences in the styles across makers or versions. I hope this rambling is helpful and adds some insight. I am curious to hear how these comments compare to the features on your pieces and will monitor this posting for response. Regards, Erich Link to comment Share on other sites More sharing options...
teufelhunde.ret Posted August 10, 2008 Share #12 Posted August 10, 2008 WOW, thats a mouthful! Let me see if I can get my hands around this... two molds w/ 12 cavities (one mold ea for left and right emblems)? To get back to Brig's question, this would explain why we see them in pairs with differing molds (or cavity numbers), as they would have been mixed during the process of inserting the screwback into the body of the emblem? BTW, these were made from Bakelite & Tenite. Link to comment Share on other sites More sharing options...
Guest dc9 Posted August 17, 2008 Share #13 Posted August 17, 2008 A couple more clarifications. Bakelite is a "thermoset" plastic, which basically means once it "sets," it will not "reflow" again. Thus, thermosets are not recyclable (versus most of today's plastics which are classified as "thermoplastics.") Thermosets harden through heat and a chemical reaction and while they can stand very high temperatures, and are resistant to most chemicals, etc.; they are brittle. More than likely the screw inserts were "molded in" to the EGA during the manufacturing, since post processing techniques would be more costly and result in breakages with all the extra handling. To the point about left and right hand molded pieces - there could have been separate molds, or in a say, 24-cavity mold, there could be 12 cavities for a left hand piece and 12 for right. Erich P.S. Your fine forum inspired me this past weekend to pick up my first 2 collar EGAs (what I believe are 1937 versions) at a swap meet - 1 sterling PB, the other an EM screwback. I will post pictures in the appropriate forums for feedback. Link to comment Share on other sites More sharing options...
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