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Recent content by Elastomatt

  1. Elastomatt

    Cryogenic Deflashing

    All, I have received parts back and have a mixed result - the trimming is generally good (once optimum process established). However some parts have got remnants of the flash that was removed stuck to the surface. Is there a standard method to remove the post trim flash, the sub-contractor we...
  2. Elastomatt

    Cryogenic Deflashing

    I am having some parts cryogenically deflashed by a sub-contractor. Are there any issues to be aware of (cracking, reduction of seal 'life'). The parts are small o-rings for a snap on type fitting and should last 30 years+. appreciate any input to add to my Google search!! Thanks
  3. Elastomatt

    CR4 and EN 43 A... how different are they?

    Thanks Guys, that has clarified things a bit for me.....guess I need to have words with my supplier!! Elastomatt
  4. Elastomatt

    CR4 and EN 43 A... how different are they?

    Hi, I am seeking a bit of advice regarding steel (and the different names/references that are used). I have a supplier offering me a component in CR4, but my customer wants EN 43 A..... are these materials the same? I have had a Google-hunt but didn't help make the picture any clearer for...
  5. Elastomatt

    potable water EPDM

    Thanks Metten, I received a copy of that report last week that was issued in 1999, so it will be interesting to see what is different!
  6. Elastomatt

    potable water EPDM

    Hi Metten, If you could ask your contact at DSM about the paper I would be grateful. I have been in contact with Bayer and I am awaitng their reply. Many Thanks Elastomatt
  7. Elastomatt

    potable water EPDM

    Graham, Useful reply as usual and more info. to go on then I had from an hour of searching on the net!! Sounds like it is going to be a fun project.....I now understand why they gave it to me!! My gut feel on the molasses was that it gives the microbes something to thrive on, but the other...
  8. Elastomatt

    potable water EPDM

    Guys, I am on here seeking some advice, I have just got a project to source/develop an EPDM compound to pass BS6920 (odour/flavour and MDOD in particular).The part we are looking at developing will come into contact with drinking water before and potentially after the stopcock and apparently we...
  9. Elastomatt

    Stamped part tolerances (dimensions)

    Thanks Graham, We always work to ISO3302-1 (typically M2). The stamping process has left a curvature on the profile, this was explained to the customer (who didn't want to spend on tooling!). I'm thinking he will need a simple 2 plate compression tool if he can't accept the stamped profile...
  10. Elastomatt

    Stamped part tolerances (dimensions)

    Guys, Help needed to identify a dimensional standard for punching parts from rubber sheets (10mm thick 70A EPDM in this instance). Our customer has referred to ISO2768, but this is for parts cut from sheet metal (or when metal is cut away). If I should have posted this elsewhere then let me...
  11. Elastomatt

    Post-mix dwell time

    Thanks guys, when I worked in a compound development lab (many moons ago) we waited 24hours from mixing to moulding/extrusion (all moulding was compression). In production they used material after 48hours, once the material has completely cooled I couldn't think of a good reason for waiting...
  12. Elastomatt

    Post-mix dwell time

    What is the preferred dwell time from mixing to processing? As a rule my current company leave material for 72hours before processing (NR, EPDM and NBR polymers). Is this excessive? I have previously worked in a company that kept to 48hrs. What is the general opinion; pros and cons etc. Thanks
  13. Elastomatt

    Joining mixed material extrusion

    Hi All, Back seeking some advice regarding joining a mixed material extrusion. The profile is basically a boot/door seal design with a sponge bulb on a plastic (so our lab tells me) covered metal carrier. We have had some issue with the joining of this process, the customer has requested the...
  14. Elastomatt

    Rubber to Metal bonding

    BTB, We resolved the issue by moving the metal preparation to a sub-contractor. We set out sepcific instructions relating to the primer thickensss and monitoring of. I found that our process was applying inconsitent thickness of primer. We have worked with Lord who checked some samples for us...
  15. Elastomatt

    Curing conditions - EPDM

    Hi All, Is there a limit to the temperature EPDM should be cured at? Would the max temp change depending on the method of manufacture (compression, injection or extrusion (hot air and microwave))? Is the max temperature more related to the breakdown of any sulphur cross links rather than the...

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