I have been using various types of rubber and flexible vinyl floor mats in my cars for more than 20 years and presently have clear vinyl mats in one of my cars. Some dealers often supply cheap black rubber ones with new cars, but they smell too much and the smell persists for months. Paper or thin PE ones are sometimes used by service stations to avoid dirtying the customer’s mats during servicing. Assuming we are talking about regular mats to be bought by car owners, there are many choices available in shops stocking automotive accessories and most seem to be rubber or flexible vinyl, which may be clear or pigmented.
We have received a lot of inquiries from start-up companies, some of them have a budget limit at the product development stage. Many of our existed customers started to cooperate with us when they were a startup company, ACO Mold is happy to be supportive to help customers develop new product. We can try to lower down the mold cost as much as possible via 4 ways.
Because inserts are manually placed by an operator before the injection cycle you blow the tool surface with cold air, increase the residence time (furthermore not the same amount from one shot to another!) and bring potential pollution through the inserts and manual operation (even though operators usually wear gloves in this case). This makes a good number of possible root causes. I'd see the "over-shearing" as an interesting one to investigate (after moisture content of course) for 2 reasons: the PA12 you use has a high viscosity / low fluidity (it is hard to inject) + it first flows around an insert, that is made of metal. Trying to pre-heat these inserts (at least on 30 consecutive shots), this should ease the material flow near the sprue.
A book of "Mold Standards" is a detailed description of what is required to match the mold with the molding factory, their equipment, machines, clamping systems, water hook ups, hydraulics for cylinders, air hook ups and cylinders, brand and type of steels/materials that are required, Hot Runner brand, electrical hook up and wiring requirements, brand and type of components (DME, Hasco), etc. This should never come from the mold maker, he'll build you what is cheapest for him.
Most organic pigment manufacturers uses their own test method and most of them are molding a chip in a homogeny thickness with a certain length and width (longer length) and then measures the shrinkage in length vs transverse direction to provide what could be called a warping index. The uniso-tropical shrinkage is a sign of warping and an iso-tropical index of 1 is of course the best (= same shrinkage in length as well as in transverse direction).
All pigments act as nucleators and will influence shrinkage and warping in semi crystalline resins. Some organic pigment chemistries are really powerful nucleators and will provide a high degree of warping (e.g. Phtalocyanine pigments). Besides general aspect as part- and mold design and a careful selection of pigments, nucleating agents may be added to overcome warping effects.
Rib is a frequently used feature in plastic injection molded parts design for the purpose to enhance the strength of the plastic parts, typical rib design see below figure.
The thickness and location is essential of the rib design. Usually, ribs should be designed with a thickness of 1/2 of the wall thickness to avoid a thick section at the base of the wall, which would cause sink marks on the part surface. Ribs are usually spaced at a distance at least twice the wall thickness to allow enough steel between the ribs for adequate cooling.
A appearance issue on a rear lamp part for automotive due to first use of a PMMA material. This is a blue opaque colored plastic including metallic particles in order to get a shiny aspect. There is important visual defect such as flow mark due to poor aggregation of particles with material.
This sounds more like the melt front losing injection pressure allowing the metallic particles to separate out or a knit line, which will be very difficult to solve. The melt fronts collide and then the particles fail to align in the same direction, creating a different look. Melt and mold temperatures will help, and valve gate changes as well, if used in the injection mold.
Proper location of the gate point will be directly affect the quality of the injection molded parts gate location selection should follow the following principles:
- Gate location should be chosen in parting surface, so that it would be easier for machining and maintenance.
- The runner should be designed even, mold flow distance and sectional size in balance can achieved stable molding quality.
- Gating location should be on the thick-wall area so it ensure the cavity can be filled completed.
- The mold flow should not be right on the inserts or lifter, high pushing pressure of melt flow would probably deform the inserts.
- Try to avoid weld marks or weld lines created in the critical surface, changing location of gating and try to make the weld line on uncritical surface.
- Consider the venting when design the gating, make sure the end of the mold flow have good venting.
- Gates should be easily removed and gate mark should not affect the appearance of the molded parts.