2011 June | Plastic Injection Molding Manufacturer

June 10, 2011

The Basic Facts Of Plastic Injection Molding Process

Filed under: Plastic Injection Molding — Tags: Basic, Facts, injection, molding, plastic, Process — @ 7:10 am

Article by Arya

Plastic injection molding process by definition may be the progression of injecting plastic-type right into a mold (or mould in European circles), cooling the plastic-type, ejecting it in the mold, and packing the completed item for sale on the consumer. This sounds easy and in it’s fundamental form it is, however the procedure required with generating all this take place is in fact very complex.

A range of components are produced using plastic injection molding process which varies in the smallest component to an whole body component of a vehicle.

Plastic-type components applied for the plastic injection molding process are thermoplastics or thermosetting plastics. Each the thermoplastic and thermosetting plastic molding are polymers. Some broadly utilised thermoplastics are nylon, polyethylene, and polystyrene while bakelite, vulcanized rubber are the extensively utilized thermosetting plastic. At times a polymer with a quite excessive elasticity is also utilised. This type of polymer is known as elastomer

The Basic Steps of Plastic Injection Molding Process can be Described in Six Steps. These include Heating, Plasticizing, Injecting, Packing , Cooling, and Ejecting are: Heating the plastic material resin for the required variety of the item getting used. Developing the shot size by way of use of a reciprocating screw which conveys the melted plastic-type for the front in the screw. Injecting the plastic-type to the mold beneath stress to fill the cavity of the mold. Packing the plastic-type to produce a total portion within the mold. Cooling the plastic in the mold by means of the usage of cooling channels most commonly with water. Ejecting the cooled component in the mold. Repeating the process more than and more than once more.

Troubleshooting on Plastic Injection Molding Process and How to Improve FlashingFlashing is the excess material at the ends of the part or on the side of the parting lineFlashing on plastic injection molding process caused by the injection speed is too high or excessive volume of material so that material into the gap cavity, clamping force or power the press mold is less so material into the gap parting line, or mold condition defects.Improve: decrease injection speed, review the position of a stroke and a holding position, raise the pressure mold clamping, check whether the mold is a problem.

 Silver-StrikeSilver-Strike is sign white / silver which appears in the direction of material flow injectionSilver-Strike on plastic injection molding process caused by resin material moisture is still high, the moisture content is transformed into a gas that is mixed with molten materials within the cylinderImprove: needed a good drying material with time and temperature sufficient to remove moisture.

 WrapWrap is product form bent / curvedWrap on plastic injection molding process caused by common lack of pressure distribution of the product or differences in depreciation.Improve: increase cooling time or decrease injection pressure, check for mold cooling system or correct the mold.

 Bubble-BlowholeBubble-Blowhole is hollow or air bubbles that occur in the product, but we can not see it unless the product is transparent or air bubbles that occur on the surface of the product.Bubble-Blowhole on plastic injection molding process caused by the gas mixed with molten materials within the cylinder.Improve: make sure materials have passed the drying process properly, raise the screw back pressure during the plasticizing process to force the gas out of the cylinder, improving gas ventilation systems in the mold so the gas is not trapped in the product, decrease injection speed to give time for the gas out through the ventilation systems.

 WhiteningWhitening is white marks / cracks / under cut on the product side of the tangent.Whitening on plastic injection molding process caused by the different pressure of the inequality area of a product, mold design that makes uneven cooling products between one side with the other side, or the product over pack in some places as the material coolsImprove: polish on the mold cavity is happening whitening product, lower injection pressure to prevent over-pack in the product

 BurnmarkBurnmark is scorch mark on a product in the last section filled with material.Burnmark on plastic injection molding process caused by the burning gas because the gas trapped, injection speed is too high, or a gas ventilation system in the mold is blockedImprove: add scerw back pressure to reduce the gas content in liquid material, lower injection velocity and widen or create a gas ventilation system

 Short shootShort shoot is some of the product is lost or not filled materials during the process of injectionShort shoot on plastic injection molding process caused by the injection speed is too low so that the material to harden before they reach the last section filled with material, mold temperature is too low so blocking the flow of material, the volume of material is less or unstable.Improve: increase injection speed and mold temperature, check the check-ring is worn or is normal to prevent backflow material from the front to the back, review the position of a stroke and a holding position.

 Sink-markSink-mark is concave or hole on the surface of a productSink-mark on plastic injection molding process caused by the differences in viscosity between the material with normal temperature and materials that require a longer cooling time and gathered in one side.Improve: in principle, very difficult to find solutions to this mold design, add a holding pressure or holding pressure time to maintain stable material pressure within the mold, extend the cooling time to reduce the depreciation rate, change the form of mold to reduce the level of viscosity differences (for example, by adding dummy-pin.)

 Flow MarkFlow Mark is signs or wave lines on the surface of product.Flow Mark on plastic injection molding process caused by too low injection speed, mold temperature is too low, or mold gate hole is blocked so that the material can not flow normally.Improve, increase injection speed, mold temperature and check for mold gate holes

 Jetting lineJetting line is line burst on the surface of the product, starting from the gate pointJetting line on plastic injection molding process caused by the mold temperature is too low and the injection speed is too high that will occur in bursts mark on the surface of the product Improve: raise the mold temperature and injection speed down.

About the Author

I am Arya, profesional injection molding plastic. Visit http://plastic-molding.org/plastic-molding/plastic-injection-molding-process/ for more my article

Comments (0)

June 2, 2011

Analysis: auto body repair fiberglass plastic parts (Figure) – automotive, plastics, glass, steel –

Filed under: Plastic Injection Molding — Tags: Analysis, auto, automotive, body, fiberglass, Figure, glass, parts, plastic, plastics, repair, steel, — @ 4:11 pm

Article by hi joiney

Auto Body Plastic Pieces of material for the general PVC, PU, PE, FRP or SMC. The site is generally used bumper, fender, hood, grille, trunk lid, the car pedals and skirt rub board, etc.. Have all Plastic Body, such as the Chevrolet bullet body is SMC (sheet molding compound), some antique classic cars and wedding cars are all plastic body, most of the material is FRP (glass fiber reinforced plastics) is. Damaged plastic parts, repair is difficult to replace most of the main assembly, where describes a glass fiber reinforced plastic (FRP) repair method of plastic parts for pilot reference. 1 materials and tools ready 1.1 required material: unsaturated Polyester Resin (196 # or 191 #), has been heir ring peroxide (initiator H), cobalt naphthenate (accelerator E), medium-alkali glass fiber woven fabrics were, dry and free of impurities Talcum powder (425 head or more). 1.2 Main tools: scissors, a angle grinder, cutting grinding wheel (100 × 16 × 3) number, 1L plastic basin of about two, flat paint brush (50mm) 2-3 to, putty knife. 2 parts preparatory work before repairing2.1 parts of a small crack can be the first folder with angle grinder grinding wheel will crack open in front at 90 ° bevel, bevel to open in the end, and then emery cloth (80 #) to groove around and groove on the back to remove old paint and sanding Other Dirt. Grinding range Figure 1. Figure 1 2.2 has cracks and pores of the parts, should be first with the angle grinder to cut defects in all, do not have to bevel the edge labeled, but Xu Yong abrasive cloth to polish around the back area to the actual damage grinding Scope and paste the size of fiber decision, refer to Figure 2. Figure 2 3 repair the tear 3.1 According to defects in the size of the cut glass fiber cloth. Repair Service general than the first one around the big 20-30mm, later than the former one for each block surrounding a large 20-25mm. Repair the site of 1-2mm thick glass fiber cloth can be two; 2-4mm thick parts, can be used 4 layers; some of the parts requiring high strength, can be 6 or 8 layers layer. 3.2 proper amount of resin according to actual needs (the amount is usually 2.3 times the fiber weight) will lead agent – has been heir peroxide and accelerator ring – ring burning acid ratio of cobalt in turn joined by 100:4:4, and immediately stir. 3.3 flat brush dipped in tune with the need to repair Office, good resin layer of resin on the back of brush, then fiber from small to big stack in the need to repair Office paste. Fabric must be saturated with resin, can not have bubbles, sandwich, etc.. Wait until after curing, with the angle grinder to remove burrs flash. 3.4 2 way and then adjusted against the small number of resin, adding talc and have laid a good glass fiber yarn, transferred into a fiber resin putty, putty knife in the face with a V-groove and the holes filled. Scratch can not afford the time to polish the range of good. After curing can angle grinder to smooth finishing, sanding sandpaper with water formation. If a below standard, add some time, and strive to repair the whole match Putty and parts, preferably 0.5-lmm paste the system slightly, up tired ways to refer to Figure 3. Figure 3 3.5 If there is breakage of the inserts can be directly inserts paste in the middle of the glass fiber, shown in Figure 4, Figure 5.

About the Author

I am Frbiz Site writer, reports some information about bugaboo car seat adapter, recaro baby seats.