Plastics processing and moulding · Manufacturing
Price every moulded part on the resin and machine time it really uses
A plastics processor buys polymer at this week's price and sells parts at last quarter's. We cost each part from shot weight, regrind, cycle time and machine tonnage. We also track how much of every resin price movement has actually been passed on.
In one paragraph
Injection-moulding, blow-moulding, extrusion and thermoforming units live on the spread between polymer prices and part prices. Most turn over ₹10–300 crore and supply appliance, automotive, FMCG, pharmaceutical and building-products customers. Resin dominates cost and moves with petrochemical prices. Conversion cost depends on the machine, the mould and the cycle time of each part. The owner or managing director usually leads the work.
Owner or managing director
The economics
How the money moves in this trade
Polymer is usually the largest single cost. Its price follows feedstock and supplier price lists that change frequently. Customer prices are typically revised on a lag, sometimes on a formula and sometimes by negotiation, so margin swings with every move in the polymer market. Masterbatch, additives and the share of regrind allowed in the part all change the material cost. Runners, start-up scrap and purge material add weight that is never sold.
Conversion cost depends on machine tonnage, cycle time, the number of working cavities and power. Moulds may belong to the customer or to the processor, and their maintenance, cavity blocking and replacement decide output. A processor that makes plastic packaging, or intermediate material for it, counts as a producer under the plastic waste management rules. Its extended producer responsibility obligations have to be tracked and costed alongside production.
The problem
Where the numbers usually break down
Resin pass-through is never reconciled
Price revisions are agreed with customers, but nobody compares them with the actual resin cost movement over the same period.
Regrind and purge are not costed
Runners, start-up scrap and purge are reground or sold without a record, so material yield per part is unknown.
One machine-hour rate for all tonnages
A small and a large press carry the same conversion rate, so large parts are under-priced and small ones over-priced.
Cavity blocking cuts output unseen
Moulds run with blocked cavities after damage, halving output per shot while the part is still priced on full cavitation.
Customer-owned moulds are not tracked
Moulds held on behalf of customers are not registered, insured or reconciled, and their maintenance cost is absorbed.
What we do
The work, and the result each part produces
Part costing from shot weight and cycle time
Material per part from shot weight, runner weight and regrind ratio, and conversion from cycle time and the actual press used.
Each part's cost reflects its own process.
Machine-hour rates by tonnage class
Separate rates for each band of press tonnage, built from depreciation, power, maintenance, labour and utilisation.
Large and small parts are priced on their own machines.
Resin pass-through tracker
Resin purchase prices compared with customer price revisions by grade and customer, with the gap quantified each month.
Unrecovered resin cost is visible and claimable.
Material yield and regrind reconciliation
Resin issued, parts produced, regrind generated and reused, and scrap sold reconciled by weight.
Material loss is traced to a part or a press.
Mould register and maintenance costing
Every mould recorded with its owner, cavitation, working cavities, shot count and maintenance cost.
Mould condition is treated as a cost driver.
EPR obligation tracking
Quantities of plastic packaging placed on the market recorded in the form the obligation requires, with the cost of meeting it accrued.
EPR is a known cost rather than a year-end surprise.
Where we start
The first steps of an engagement
Resin purchases and mould records
We ask for resin purchase invoices by grade, the customer price-revision history, part-wise shot weight and cycle time, the press list by tonnage and the mould register if one exists.
Resin cost against price recovered
For the main customers and grades, resin cost movement over recent quarters is set against the price revisions actually agreed.
Rates by press tonnage
Machine-hour rates are split by tonnage class, and regrind, purge and start-up scrap start being recorded by part and press.
A resin pass-through report
The first report shows resin cost movement against price recovered by customer and grade, with part costs restated on the new machine rates.
How it is measured
The reports the work is judged on
Each is recorded as a baseline before the work starts, so later reports have an honest comparison.
- Resin cost movement against price recovered, by customer
- Material yield and regrind ratio, by part
- Machine utilisation by tonnage class
- Working cavities against designed cavities
- Contribution per machine hour, by part
- EPR obligation accrued against met
Who it suits
Written for, and not the right fit for
- You need EPR registration, returns or certificates filed with the regulator on your behalf — that filing is your own responsibility, and we prepare the data for it.
- You make printed flexible packaging rather than moulded or extruded products — our packaging page is the closer fit.
- Injection-moulding, blow-moulding, extrusion and thermoforming processors.
- Processors supplying appliance, automotive, FMCG or pharmaceutical customers.
- Units whose margins swing with polymer prices without a clear explanation.
Services
Services this work draws on
Costing and profitability
What each product, line and customer really contributes.
Explore service ↗MIS and financial planning
Reporting built around the questions you actually need answered.
Explore service ↗Outsourced accounting
Your books kept current and reconciled, closed to a published calendar.
Explore service ↗ESG and sustainability advisory
Sustainability data you can evidence before you commit to a target.
Explore service ↗Every other service, also available in this trade
Common questions
Questions owners in this trade ask
How do we recover resin price increases without a formula?
Even without a formula, a monthly record of resin cost against what's been recovered gives you a factual basis for each price conversation. It's harder to refuse a revision when the gap is quantified by grade.
Does EPR apply to plastic moulders?
It can. Makers of plastic packaging, and of the intermediate material it is made from, are treated as producers under the plastic waste rules. Whether that covers your products is a regulatory question for you and your adviser; we help you hold the quantity data the obligation needs and cost it properly.
Is it worth tracking cycle time by part?
Usually, yes. Cycle times tend to drift from the figure used in the quotation, and a few seconds on a high-volume part changes its cost noticeably.
5th Quadrant performs costing, accounting and reporting. Registration, returns and certificates under extended producer responsibility rules are the client's own responsibility with the regulator; we prepare the underlying data and support. Statutory audit and prescribed certifications are signed by an independently engaged licensed professional. Full detail is on our Professional Scope page.
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