Plastic Mold Approval Checklist - Plastics Engineering general ...
mjh368 (Chemical) 13 Apr 06 14:00. HMMMnot sure where you are going with this. you will need more than a check sheet to approve a mold. but a good way to "learn" about the mold is look at is the way the designer did: 1.part design. 2. number of cavities *required machince-shot size, tonage. 3. type of mold.
Trying to mold plexiglass, lexan, or a clear plastic sheeting - Eng-Tips
Apr 20, 2003 · RE: Trying to mold plexiglass, lexan, or a clear plastic sheeting TomH (Automotive) 22 Apr 03 21:38 Acrylic IS best for light covers, but it absorbs a tiny amount of moisture and must be dried in an oven at 215 degrees for a while before raising the temp or …
How is a mold grained?? - Eng-Tips
Jan 5, 2003 · The texture exist as standard negatives (as in photo negatives), these are positioned onto the mould serface and the acid is aplied. Time determines the depth of etch. Obviously this is a very skilled and precise job, the peparation itself is very tedious and takes hours or days. Texture repair is also an art.
Drawing Reqs: Molded Parts - Drafting Standards, GD&T
Jan 9, 2007 · We have done basic molding before, but usually related to taking simple delrin machined parts (spacers, bushings, etc) and converting them over to injection molding for lower part costs. We have also done thermo forming or vacuum forming, and rotational modling for simple covers, drainage trays, and close-out panels.
Carbon Fiber mold - Plastics Engineering general discussion - Eng …
Aug 14, 2001 · You create a plastic bladder that will slide into the the initial 2 or 3 layers of the CF sleeving (prepregged before mold insertion of course) and you will inflate this bladder so it pushes the sleeving against the inside walls of the pvc piping. Hold until it sets up, and remove it from the 2 part tubing mold. Bake for an hour at about 200 ...
Over-molding plastic on metal air leakage problem - Eng-Tips
Jul 16, 2021 · Hello, We are working on an over-molding part in which Brass over mold with Nylon 6 30% GF. A design like the cylindrical brass part with knurling or some grooves from over-molding face and plastic covered with open one end like cap design.
Metallic Color on Plastic Injection Molded Parts - Eng-Tips
Aug 5, 2007 · RE: Metallic Color on Plastic Injection Molded Parts Pud (Mechanical) 5 Aug 07 15:22 If the finish you want can be painted then it will probably be cheaper to add pigments.
Sealing a metal pin in plastic - insert molding ... - Eng-Tips
Mar 5, 2017 · Option 1: insert molded straight pin - may leak as plastic shrinks, and insert mold tool more money plus more time (possible danger of damage to mold). But it's quite simple. Option 2: insert molded with labyrinth features on pin - better as more surface area and longer fluid path so more resistance to leaking.
SPI tolerancing standards for drawings - Eng-Tips
Mar 6, 2013 · RE: SPI tolerancing standards for drawings. mcgyvr (Mechanical)7 Mar 13 08:18. There is really nothing wrong with unequal drafts as long as the part can be molded AND release easily from the mold. The unequal drafts could be part of the design too and need to be that way to allow it to fit somewhere or whatever.
Heat from plastic injection machines - HVAC/R engineering - Eng …
Feb 25, 2010 · Be very careful with humidity control. BronYrAur (Mechanical)26 Feb 10 14:26. The "cheat sheet" used by AEC for chiller sizing is as follows: Injection Molding 30#/Hr HD Polyethylene = 1 ton 35#/Hr LD Polyethylene = 1 ton 35#/Hr LD Polypropylene = 1 ton 50#/Hr Polystyrene = 1 ton 75#/Hr P.V.C. = 1 ton 45 #/Hr P.E.T. = 1 ton Extrusion and blow ...