Car interior and exterior trim mould making

Provides a complete line of plastic mold and molding components for cars and truck regarding air induction systems, fluid management systems, fuel systems, car exterior and interior trim moulds systems, including instrument panels,bumper,car door mould,fenders,grilles,tail  light and spoilers for the global automotive industry. Processes include blow molding, injection molding, thermoforming,  interior/exterior painting, and metal stampings .

Automotive tail light mould:

• plastic mold:Automotive light
• mold cavity:1+1
• Hotrunner:4 drops with “HOTSET”  heating coils,separted temperaturer controller
• mold cavity steel:DIN 1.2738
• mold core steel:DIN 1.2312
• mold slider insert:DIN 1.2738 with Nitriding
• Core insert activation:4 Hydraulic Cylinders
• Plastic material:ABS
• Cycle time:40 Secs
• Delivery time:50 days.

truck grille mould features:

• truck grille mouldcavity:1
• Hotrunner:4 drops with yudo hotrunner system with time sequence control
• truck grille mould steel:DIN 1.2312
• truck grille mould core steel:DIN 1.2312
• mold slider insert:DIN 1.2738 with Nitriding
• Plastic material:ABS
• Cycle time:50 Secs
• Delivery time:45 days

The main steps of car exterior and interior trim moulds trial

In order to avoid production time waste, it is necessary to adjust and control various processing conditions before mass production to find out the best temperature and pressure conditions, for future daily operation.

• keep the continuous products measurements and record the important dimensions (sample should be cooled to room temperature for measurement).Compare the samples size, pay attention to:
• the optimization running operation should keep for at least 30 minutes until stable, then at least have a dozen of moulded samples, the make notation indicating the date , number and cavity , in order to test the its operation stability and the reasonable tolerance .
• reasonable adjustments to reduce the overall cycle time.
• screw forward time should be longer than the plastic gate freezing time; otherwise, the weight of the product can be reduced. And when the mould is heated, the screw forward time also need extend for compaction products.
• wait until the machine and mould conditions to be stabilized, even for a medium-sized machine it may have to wait more than 30 minutes. Use this time to check the products possible problems.
• adjust the pressure and injection volume to produce a product with satisfactory appearance. The flash should be avoided completely, especially for some moulded products not yet fully solidified. Little change in the filling rate may cause a great change in the filling.
• clean the feeding system thoroughly prevents degradation compound or foreign material into the mould. Because they would be harmful for the mould operation. Check the material temperature and the mould temperature if suitable for the processing.
• checks the barrel for the correct plastic material, and the correct drying (different raw materials for trial and mass production may lead to different results).

1.  If the size of product is stable;
2.  if some certain sizes have increase or decrease trend, and display machine processing conditions still changing, such as poor temperature control or oil pressure control;
3.  The size change is within tolerance.

• if the product size does not change also the normal processing conditions are stale, to observe whether each cavity moulded sample weight acceptable, the size should be within allowable tolerances. The consecutive unstable weight should be kept, in order to check the mould cavity size.

How to estimate car exterior and interior trim moulds cost

In car exterior and interior trim moulds making shops the quotations are generally determined with the help of prognosis procedures. From the literature two general basic methods for predicting costs are known:

• cost function and
• costs similarity.

The first method, the cost function starts with the assumption that there is a dependency between the costs of car exterior and interior trim moulds and its characteristics. This dependency is expressed in a mathematical function. The characteristics are the independent variables or affecting quantities, which determine the costs.

The second method is the costs similarity. Starting with an injection mold to be calculated and its characteristics, another existing car exterior and interior trim moulds with similar characteristics is looked for in the shop- The costs for this mold are generally known and can now be used for the new object. In doing so one can fall back on existing data such as the system of classification.

Both methods have their advantages and disadvantages. The cost function provides accurate results only if the affecting quantities have nearly the same effect on costs. This is rarely the case with the variety of injection molds today .

With the similarity method one can only fall back on molds which are designed in the same way and, thus, have similar cost-effective quantities. To make use of the specific benefits of both methods a combination of them presents itself, this can be achieved by grouping similar injection molds or structural components of the same kind together and determining a cost function within each group.

There is a proposal,therefore,to divide the total calculation into four cost groups related to their corresponding functions.

Costs are determined for each cost group and added to the total costs.The systematic work on the individual groups and the additive structure reduces the risk of a miscalculation and its effect on the total costs.

In the following the individual groups for estimating car exterior and interior trim moulds cost are presented in detail

Cost Group I: Cavity

With cost group I the costs for making the cavity are computed.

They are essentially dependent on the contour of the part, the required precision and the desired surface finish. The costs are determined by the time consumption for making the cavity and the respective hourly wages.

Time Factor for Parting Line

Steps in the parting line are considered by the time factor:

Time Factor for Surface Quality

The quality of the surface is as important for the appearance of the molding as for its troublefree release. The surface quality factor is affected by the roughness height, which can be achieved with certain machining procedures. It can be taken from Table below.

Machining Time for Fixed Cores

The machining and fitting of cores in both cavity halves is covered by the time factor C_c. This work becomes more difficult with increasing deviation of the fitting area from a circular shape. The contour factor is multiplied by the number of cores with equal fitting area.

 Cost Group III: Basic Functional Components

Runner，heat-exchange and ejection systems are basic functional components and therefore by necessity part of every injection mold. If individual elements are related to these basic components, their costs, including additional expenses, can be determined in a more general way. Thus, listing them is all that is needed for the calculation, since their dimensions have only a modest effect.

Sprue and Runner System

The type of runner system h determined by economic requirements, part geometry and quality demands.The costs for sprue gates, disk gates, tunnel gates, and edge gates can be calculated with some experience.

Other Cost Calculation Methods

Apart from the methods presented here, there are a number of other ways of calculating the costs of injection molds. Important here are primarily those methods which are based on the similarity of molded parts and molds:

Costs Based on Similarity Considerations

Similarity car exterior and interior trim moulds making cost(instrument panels,bumper,car door,fenders,auto grilles,tail  light and spoilers) is based on the principle that similar molds or similar molded parts cause similar costs. This is a systematic approach to what is actually standard practice. It requires a database containing molds that have already been costed and which are used for performing the new costing.

It must be borne in mind that car exterior and interior trim moulds of similar construction are not necessarily used for making similar molded parts. Equally, it is possible for similar molded parts to be made by means of different and thus less similar molds.